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Sample records for venous blood oxygen

  1. Calculating acid-base and oxygenation status during COPD exacerbation using mathematically arterialised venous blood

    DEFF Research Database (Denmark)

    Rees, Stephen Edward; Rychwicka-Kielek, Beate A; Andersen, Bjarne F

    2012-01-01

    for exacerbation of chronic obstructive pulmonary disease (COPD). Methods: Simultaneous arterial and peripheral venous blood was analysed. Venous values were used to calculate arterial pH, PCO2 and PO2, with these compared to measured values using Bland-Altman analysis and scatter plots. Calculated values of PO2......Abstract Background: Repeated arterial puncture is painful. A mathematical method exists for transforming peripheral venous pH, PCO2 and PO2 to arterial eliminating the need for arterial sampling. This study evaluates this method to monitor acid-base and oxygenation during admission...... be calculated from peripheral venous values so as to characterise changes seen during exacerbation. Application of the method has potential to reduce arterial sampling, decrease discomfort and enable venous sampling as routine practice....

  2. Cerebral venous blood oxygenation monitoring during hyperventilation in healthy volunteers with a novel optoacoustic system

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    Petrov, Andrey; Prough, Donald S.; Petrov, Irene Y.; Petrov, Yuriy; Deyo, Donald J.; Henkel, Sheryl N.; Seeton, Roger; Esenaliev, Rinat O.

    2013-03-01

    Monitoring of cerebral venous oxygenation is useful to facilitate management of patients with severe or moderate traumatic brain injury (TBI). Prompt recognition of low cerebral venous oxygenation is a key to avoiding secondary brain injury associated with brain hypoxia. In specialized clinical research centers, jugular venous bulb catheters have been used for cerebral venous oxygenation monitoring and have demonstrated that oxygen saturation hyperventilation, which induced changes in SSS oxygenation. Simultaneously, we measured exhaled carbon dioxide concentration (EtCO2) using capnography. Good temporal correlation between decreases in optoacoustically measured SSS oxygenation and decreases in EtCO2 was obtained. Decreases in EtCO2 from normal values (35-45 mmHg) to 20-25 mmHg resulted in SSS oxygenation decreases by 3-10%. Intersubject variability of the responses may relate to nonspecific brain activation associated with voluntary hyperventilation. The obtained data demonstrate the capability of the optoacoustic system to detect in real time minor changes in the SSS blood oxygenation.

  3. Monitoring tissue blood oxygen saturation in the internal jugular venous area using near infrared spectroscopy.

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    Ruan, Z S; Li, T; Ren, R R; Zhao, Y; Li, K; Mao, Y F; Shen, G; Jiang, L

    2015-03-31

    Central venous blood oxygen saturation (ScvO2) is an important monitoring index of fluid resuscitation. However, monitoring of ScvO2 is not continuous and invasive. Near infrared spectroscopy (NIRS) is an optical technology for the noninvasive detection of hemodynamic changes, with advantages of being real-time, continuous, low-cost, and portable. The present study aimed to determine whether a correlation exists between the tissue blood oxygen saturation in the internal jugular venous area (StO2) data obtained with NIRS and the ScvO2 and whether these two quantities are equivalent. Data were collected from 13 patients. We used ultrasound to locate the placement site for the NIRS light source outside the internal jugular vein. Meanwhile, a sample for blood gas analysis was obtained through the central venous catheter. A correlation analysis between the StO2 and ScvO2 of 13 samples was performed (Pearson correlation coefficient), suggesting a high correlation between them (r = 0.906, StO2 =1.0018 ScvO2 +2.8524). Bland-Altman analysis was also performed between the StO2 and ScvO2. Results were as follows: 100% of monitored points fell within the range of the mean ± 1.96 SD of the difference between the StO2 and ScvO2; range of the mean ± 1.96 SD of the difference between the StO2 and ScvO2 was 3 ± 10.2; confidence interval of the difference between the StO2 and ScvO2 was -7.2 to 13.2%. The StO2 monitored with NIRS correlated highly with the ScvO2 measured in the internal jugular vein. Therefore, the StO2 can be used for directing clinical treatment with further research.

  4. Venous oxygen saturation.

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    Hartog, Christiane; Bloos, Frank

    2014-12-01

    Early detection and rapid treatment of tissue hypoxia are important goals. Venous oxygen saturation is an indirect index of global oxygen supply-to-demand ratio. Central venous oxygen saturation (ScvO2) measurement has become a surrogate for mixed venous oxygen saturation (SvO2). ScvO2 is measured by a catheter placed in the superior vena cava. After results from a single-center study suggested that maintaining ScvO2 values >70% might improve survival rates in septic patients, international practice guidelines included this target in a bundle strategy to treat early sepsis. However, a recent multicenter study with >1500 patients found that the use of central hemodynamic and ScvO2 monitoring did not improve long-term survival when compared to the clinical assessment of the adequacy of circulation. It seems that if sepsis is recognized early, a rapid initiation of antibiotics and adequate fluid resuscitation are more important than measuring venous oxygen saturation. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. High flow rates during modified ultrafiltration decrease cerebral blood flow velocity and venous oxygen saturation in infants.

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    Rodriguez, Rosendo A; Ruel, Marc; Broecker, Lothar; Cornel, Garry

    2005-07-01

    The intracranial hemodynamic effects of modified ultrafiltration in children are unknown. We investigated the effects of different blood flow rates during modified ultrafiltration on the cerebral hemodynamics of children with weights above and below 10 kg. Thirty-one children (weights: 10 kg, n = 10) undergoing cardiopulmonary bypass were studied. Middle-cerebral artery blood flow velocities and cerebral mixed venous oxygen saturations were measured before, five minutes from the beginning, and at the end of ultrafiltration. Patients were classified according to their blood flow rates during ultrafiltration in three groups: high (> or = 20 mL/kg/min), moderate (10-19 mL/kg/min), and low flow rates (flow rates of ultrafiltration and the decline in mean cerebral blood flow velocity (r = - 0.48; p = 0.005) and cerebral oxygen saturation (r = - 0.49; p = 0.005) or hematocrit increase (r = 0.59; p = 0.001). Infants exposed to high flow rates had greater reduction of cerebral blood flow velocity and regional mixed venous saturation and higher hematocrit at the end of ultrafiltration compared with those subjected to moderate and low flow rates (p flow rates through the ultrafilter during modified ultrafiltration transiently decrease the cerebral circulation in young infants compared with lower blood flow rates. These effects may be related to an increased diastolic runoff from the aorta into the ultrafiltration circuit that leads to a "stealing" effect from the intracranial circulation, which may be important in infants with dysfunctional cerebral autoregulation.

  6. Creating a Controlled Arterio-Venous Shunt by Reversing the Extracorporeal Membrane Oxygenation Blood Flow: A Strategy for Weaning Patients Off Veno-Arterial Extracorporeal Membrane Oxygenation.

    Science.gov (United States)

    Mattke, Christian Adrian; Haisz, Emma; Pandya, Nischal; Black, Anthony; Venugopal, Prem

    2017-10-01

    To assess whether reversing the veno-arterial extracorporeal membrane oxygenation blood flow (thereby creating a controlled arterio-venous shunt) can be used to wean children off extracorporeal membrane oxygenation. The standard practice for weaning patients off VA extracorporeal membrane oxygenation is to gradually reduce the blood flows delivered through the extracorporeal membrane oxygenation pump to a minimum level followed by either insertion of an "arterio-venous bridge" and clamping of the blood flow to the patient or direct decannulation. "Pump controlled retrograde flow trial off" is a technique where the revolutions in the centrifugal pump are reduced to the point where the patient will drive the blood retrograde through the extracorporeal membrane oxygenation circuit, effectively turning the circuit into a controlled arterio-venous shunt. The revolutions per minute control the amount of shunt flow. This eliminates any cardiorespiratory support the extracorporeal membrane oxygenation circuit may provide to the patient. Feasibility study. Pediatric intensive care. Extracorporeal membrane oxygenation-dependent pediatric patients, who were ready for weaning, and possible separation from extracorporeal membrane oxygenation entered the trial. Pump controlled retrograde flow trial off. During 2016, pump controlled retrograde flow trial off was used in 17 patients, for a total of 23 episodes. One episode was unsuccessful in a patient with a body weight of 2.2 kg, where cardiac output was insufficient to provide blood flow to both body and extracorporeal membrane oxygenation circuit, though from 2.8 kg body weight upward, the technique was tolerated. The duration of pump controlled retrograde flow trial off was 15 minutes to 2.5 hours. Five cases led to a continuation of the extracorporeal membrane oxygenation run, as they were not ready to be decannulated. Fifteen patients were decannulated after the pump controlled retrograde flow trial off. No patient

  7. Effects of blood transfusion on oxygen extraction ratio and central venous saturation in children after cardiac surgery.

    Science.gov (United States)

    Nasser, Bana; Tageldein, Mohmad; AlMesned, Abdulrahman; Kabbani, Mohammad

    2017-01-01

    Red blood cell transfusion is common in critically ill children after cardiac surgery. Since the threshold for hemoglobin (Hb) transfusion need is not well defined, the threshold Hb level at which dependent critical oxygen uptake-to-delivery (VO2-DO2) status compensation is uncertain. To assess the effects of blood transfusion on the oxygen extraction ratio (O2ER) and central venous oxygen saturation (ScvO2) to identify a critical O2ER value that could help us determine the critical need for blood transfusion. Prospective, observational cohort study. Cardiac Surgical Intensive Care Unit at Prince Sultan Cardiac Center in Qassim, Saudi Arabia. Between January 2013 and December 2015, we included all children with cardiac disease who underwent surgery and needed a blood transfusion. Demographic and laboratory data with physiological parameters before and 1 and 6 hours after transfusion were recorded and O2ER before and 6 hours after transfusion was computed. Cases were divided into two groups based on O2ER: Patients with increased O2ER (O2ER > 40%) and normal patients without increased O2ER (O2ER transfusion. Changes in O2ER and ScvO2 following blood transfusion. Of 103 patients who had blood transfusion, 75 cases had normal O2ER before transfusion while 28 cases had increased O2ER before transfusion. Following blood transfusion, O2ER and ScvO2 improved in the group that had increased O2ER before transfusion, but not in the group that had normal O2ER before transfusion. The clinical and hemodynamic indicators O2ER and ScvO2 may be considered as markers that can indicate a need for blood transfusion. The limitation of this study is the small number of patients that had increased O2ER before transfusion. There were few available variables to assess oxygen consumption.

  8. Femoral venous oxygen saturation and central venous oxygen saturation in critically ill patients.

    Science.gov (United States)

    Zhang, Xiaohong; Wang, Jiandong; Dong, Yun; Chen, Youdai

    2015-08-01

    To investigate the relationship between central venous oxygen saturation (ScvO(2)) and femoral venous oxygen saturation (SfvO(2)) in a large group of critically ill patients. Observational study. A group of unselected critically ill patients with central line placed into superior vena cava were included. A 26-bed intensive care unit in a tertiary referral hospital. None. Venous blood samples of superior vena cava and femoral vein were collected within an interval of 5 to 15 minutes and analyzed with blood gas/electrolyte analyzer immediately. Although SfvO(2) was significantly correlated with ScvO(2) (r = 0.493, P 731 pairs of blood samples collected from 357 patients. The fit line of scatter diagram ScvO(2) vs SfvO(2) had a large intercept (48.68%) and a low slope (0.2978); ScvO(2) was still around 50% while SfvO(2) was nearing 0%. The distribution of blood flow, measured with Doppler ultrasound, had a similar trend in 237 patients and 412 measurements. The ratio of femoral artery flow over common carotid artery flow varied widely (from 0 to 7.13). Blood flow was not distributed in a fixed ratio to the superior vena cava-drained organs and tissues. Central venous oxygen saturation was not representative of the whole systemic circulation in critically ill patients. Central venous oxygen saturation alone might be misleading in goal-directed therapy. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Changes of blood flow, oxygen tension, action potential and vascular permeability induced by arterial ischemia or venous congestion on the spinal cord in canine model.

    Science.gov (United States)

    Kobayashi, Shigeru; Yoshizawa, Hidezo; Shimada, Seiichiro; Guerrero, Alexander Rodríguez; Miyachi, Masaya

    2013-01-01

    It is generally considered that the genesis of myelopathy associated with the degenerative conditions of the spine may result from both mechanical compression and circulatory disturbance. Many references about spinal cord tissue ischemic damage can be found in the literature, but not detailed studies about spinal cord microvasculature damage related to congestion or blood permeability. This study investigates the effect of ischemia and congestion on the spinal cord using an in vivo model. The aorta was clamped as an ischemia model of the spinal cord and the inferior vena cava was clamped as a congestion model at the 6th costal level for 30 min using forceps transpleurally. Measurements of blood flow, partial oxygen pressure, and conduction velocity in the spinal cord were repeated over a period of 1 h after release of clamping. Finally, we examined the status of blood-spinal cord barrier under fluorescence and transmission electron microscope. Immediately after clamping of the inferior vena cava, the central venous pressure increased by about four times. Blood flow, oxygen tension and action potential were more severely affected by the aorta clamping; but this ischemic model did not show any changes of blood permeability in the spinal cord. The intramedullar edema was more easily produced by venous congestion than by arterial ischemia. In conclusions, venous congestion may be a preceding and essential factor of circulatory disturbance in the compressed spinal cord inducing myelopathy. Copyright © 2012 Orthopaedic Research Society.

  10. Blood oxygenation measurements by multichannel reflectometry on the venous and arterial structures of the retina.

    Science.gov (United States)

    Vucea, Valentina; Bernard, Pierre-Jean; Sauvageau, Patrick; Diaconu, Vasile

    2011-09-10

    The aim of the present study was to propose a model and a method to derive the oxyhemoglobin blood content in the retinal veins and arteries by full spectrum reflectometry measurements in the spectral zone from 430 to 680 nm. We proposed a mathematical equation expressed as a linear combination of two terms S(OHb)(λ) and S(Hb)(λ) representing the normalized spectral absorption functions of the hemoglobin and the oxyhemoglobin, one term λ(-n) representing the ocular media absorption with scattering, and a family of multi-Gaussian functions, which usefully compensate for the noncompatibility of the model and the experimental data in the red spectral zone. The present paper suggests that the spectral reflection function in the area from 520 to 580 nm is optimal in calculating the oxyhemoglobin concentration of the blood contained in the endothelial structures of retinal vessels. The model calculation needs a function (1/λ)(-n) that corrects for the ocular media absorption and light scattering on the vessels' structures. For the spectral area of lights with wavelength larger than 580 nm, the reflected light represents mainly the light scattering on the red blood cells.

  11. Central venous oxygen saturation during hypovolaemic shock in humans

    DEFF Research Database (Denmark)

    Madsen, P; Iversen, H; Secher, N H

    1993-01-01

    We compared central venous oxygen saturation and central venous pressure (CVP) as indices of the effective blood volume during 50 degrees head-up tilt (anti-Trendelenburg's position) induced hypovolaemic shock in eight healthy subjects. Head-up tilt increased thoracic electrical impedance from 31...

  12. [Monitoring of jugular venous oxygen saturation].

    Science.gov (United States)

    Nakamura, Shunsuke

    2011-04-01

    The continuous monitoring of jugular venous oxygen saturation(SjO2) has become a practical method for monitoring global cerebral oxygenation and metabolism. SjO2 reflects the balance between the cerebral blood flow and the cerebral metabolic rate for oxygen (CMRO2), if arterial oxyhemoglobin saturation, hemoglobin concentration remain constant. Normal SjO2 values range between 55% and 75%. Low SjO2 indicates cerebral hypoperfusion or ischemia. Conversely, an increased SjO2 indicates either cerebral hyperemia or a disorder that decreases CMRO2. In minimizing secondary brain damage following resuscitation from cardiopulmonary arrest, SjO2 monitoring is thus considered to be an integral part of multimodality monitoring and can provide important information for the management of patients in neurointensive care.

  13. Central venous oxygen saturation does not correlate with the venous oxygen saturation at the surgical site during abdominal surgery.

    Science.gov (United States)

    Weinrich, Malte; Scheingraber, Stefan; Stephan, Bernhard; Weiss, Christel; Kayser, Anna; Kopp, Berit; Schilling, Martin K

    2008-01-01

    Measurement of central venous oxygen saturation has become a surrogate parameter for fluid administration, blood transfusions and treatment with catecholamines in (early) goal directed therapy in the treatment of acute septic patients. These strategies are not easily transferred to the postoperative management of abdominal surgery due to the different conditions in surgical patients. A study population of 15 patients (8 females/7 males) underwent elective major abdominal surgery: 6 gastrectomies, 5 major liver resections and 4 lower anterior rectum resections. Surgery was performed for primary or secondary malignancy. The patients' age was 65.4+/-12.7 (mean+/-standard deviation, range 44-84, median 62) years. Blood samples were taken intraoperatively from indwelling central venous lines as well as from draining veins at the surgical site. Blood gas analyses to determine the oxygen saturations were performed immediately. All patients were operated in standardized general anesthesia including epidural analgesia and in a balanced volume status. Central venous oxygen saturations and oxygen saturations in blood from the draining veins of the surgical site showed a wide range with high intra- and interindividual differences intraoperatively. Overall, at most time points no correlation between the two oxygen saturations could be detected in three operation types. A significant correlation was only observed at one time point during liver resections. Our results show a lack of correlation between central venous oxygen saturations and oxygen saturations in the draining veins of the surgical site during major abdominal surgery. Measurement of central venous oxygen saturations does not seem to be a good surrogate for the local oxygen supply in the field of interest in major abdominal surgery even under standardized conditions.

  14. Femoral venous oxygen saturation is no surrogate for central venous oxygen saturation

    NARCIS (Netherlands)

    van Beest, Paul A.; van der Schors, Alice; Liefers, Henriette; Coenen, Ludo G. J.; Braam, Richard L.; Habib, Najib; Braber, Annemarije; Scheeren, Thomas W. L.; Kuiper, Michael A.; Spronk, Peter E.

    2012-01-01

    Objective:  The purpose of our study was to determine if central venous oxygen saturation and femoral venous oxygen saturation can be used interchangeably during surgery and in critically ill patients. Design:  Prospective observational controlled study. Setting:  Nonacademic university-affiliated

  15. Arterio-venous shunts or low oxygen utilization?

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    Rozin, Alexander P

    2010-02-01

    An idea of arteriovenous shunts (AVS) was proposed for explanation of dynamic regulation of oxygenation and venous hyperoxia. A formula enabling calculation of AVS and real CO2 production has recently been derived by comparing data of arterial and venous blood gases. Regarding venous hyperoxia, there is a need to differentiate capillary to tissue transport defect (low oxygen utilisation-LOU) from AVS, which may exist simultaneously. The AVS may be associated with normal or relatively high oxygen utilization from the capillary vessels and increased CO2 production. AVS is proposed to carry protective and 'stealing' properties including renal, cardiac, and pulmonary hemodynamic. Calculations of the AVS may be important for dynamic assessment of vascular and metabolic status and in emergency medicine.

  16. [Central venous blood gas analysis].

    Science.gov (United States)

    Marano, Marco; D'Amato, Anna; Guiotto, Giovanna; Schiraldi, Fernando

    2015-01-01

    The hemodialysis might interfere with patients hemodynamic, as the technique allows a sophisticated game with extra and intravascular fluids. As the cardiocirculatory response could sometimes be unpredictable, it is interesting to collect valuable information by reaching a deep understanding of the tissue metabolism which is mirrored by the blood gas analysis of variations in arterial and central venous blood samples. Particularly interesting are the time course variations of the central venous hemoglobin saturation (ScvO2), which are directly related to the patient with O2-demand as well as to the O2-Delivery (DO2). The ScvO2 is determined by four parameters (cardiac output, Hb concentration, arterial Hb saturation and O2 consumption): If the fluids subtraction during dialysis was about to determine an occult hypoperfusion, the ScvO2 reduction would be a timely warning sign to be considered. Moreover, while the normal veno-arterial PCO2 difference is 2-4 mmHg, whenever a mismatch between O2-demand and DO2arise, a larger v-aPCO2 difference should be observed.

  17. The monitoring of venous saturations of oxygen in children with congenitally malformed hearts.

    Science.gov (United States)

    Martin, Jeff; Shekerdemian, Lara S

    2009-02-01

    Mixed venous saturation of oxygen has for some time been used as a tool to assess the adequacy of systemic delivery of oxygen in intensive care. In the post-operative child with cardiac disease, it is increasingly being used to assess adequacy of cardiac output. In many of these patients, true sampling of mixed venous saturation of oxygen is not possible due to the infrequent use of pulmonary arterial catheters, or the presence of intra-cardiac left to right shunting leading to mixing of systemic and pulmonary venous blood. The use of saturation of oxygen in the central venous blood as a surrogate for mixed venous saturation of oxygen has been widely investigated in adults, but its use remains controversial. In this review, we discuss the theory behind the use of mixed venous saturation of oxygen in evaluating cardiac output, the problems pertinent to those patients with congenitally malformed hearts, and explore the evidence for central venous saturation of oxygen as a surrogate for mixed venous saturation of oxygen, and its use as a therapeutic target to improve outcomes in this population of patients.

  18. Venous saturation and blood flow behavior during laser-induced photodissociation of oxyhemoglobin

    Science.gov (United States)

    Mamilov, S. A.; Yesman, S. S.; Asimov, M. M.; Gisbrecht, A. I.

    2013-03-01

    The value of relative oxyhemoglobin concentration (saturation) in arterial (SаO2) and venous blood (SvO2) plays a significant role in the oxygen exchange in tissue and is used as criterion of delivery of oxygen adequate to the needs of tissue cells. Reduction of the volume of blood flows as well as reduction of oxygen concentration in arterial blood causes hypoxia - deficit of oxygen in tissue. One of the main mechanisms of elimination of hypoxia is based on compensation of the oxygen deficit by increasing the oxygen extraction from arterial blood, which leads to reduction of oxygen in the venous blood 1. In this report two optical techniques for measurement of venous blood saturation are presented. The first one is based on the pulseoximetry with artificial mechanical modulation of the tissue volume and the second one on the spectrophotometry of human respiratory rhythm. Good correlation between the results obtained with both techniques is observed.

  19. L-lysine escinat, thiotriazolin, gordox and mydocalm influence on oxygen tension in the intestinal wall and acid-base balance and limited proteolysis in intestinal venous blood in terms of intraabdominal hypertension modeling

    Directory of Open Access Journals (Sweden)

    Sapegin V.I.

    2014-11-01

    Full Text Available In acute experiments on rabbits there were studied changes in oxygen tension in the intestinal wall tissues, acid-base balance and limited proteolysis and its inhibitors in intestinal venous blood, protective action of L-lysine escinat (0,15 mg/kg / single dose, thiotriazolin (25 mg/kg / single dose, aprotinin (gordox (10,000 units/kg / single dose in sequential modeling of standard levels increasing of intra-abdominal hypertension (IAH — 50, 100, 150, 200, 250, 300, 350 m H2O, and also of tolperison (mydocalm (5 mg/kg / single dose on modeling of stable 3-hour IAH 200 m H2O. The IAH modeling was performed by means of stand of our construction. Under the influence of IAH the compensated metabolic acidosis in intestinal venous blood with a compensative hyperpnoe develops, decline of oxygen tension in tissues and activating of a limited proteolysis as well as decline of its inhibitors activity in intestinal venous blood occur. By the degree of metabolic acidosis prevention investigational preparations were distributed as follows gordox > thiotriazolin = L-lysine escinat = mydocalm, and by prevention of decline of oxygen tension in tissues — thiotriazolin > L-lysine escinat > mydocalm > gordox, it is is connected with different rate of methabolic products excretion into the blood, due to the influence on blood circulation and transcapilary exchange. By the degree of prevention of proteolytic activity and inhibitory potential changes, investigational preparations were distributed as follows: gordox > mydocalm > thiotriazolin > L-lysine escinat, this is connected with inhibition of proteolysis in gordox, and in other ones – with reduction of ischemic damage of tissues. Owing to different mechanism of action thiotriazolin, L-lysine escinat and mydocalm may be simultaneously recommended for a conservative treatment of patients with intraabdominal hypertension syndrome.

  20. Spatial distribution of flow and oxygenation in the cerebral venous drainage system.

    Science.gov (United States)

    De Vis, Jill B; Lu, Hanzhang; Ravi, Harshan; Hendrikse, Jeroen; Liu, Peiying

    2017-08-09

    To investigate the venous oxygenation and flow in the brain, and determine how they might change under challenged states. Eight healthy human subjects (24-37 years) were studied. T2 -relaxation under spin tagging (TRUST) magnetic resonance imaging (MRI) and phase-contrast MRI were performed to measure venous oxygenation and venous blood flow, respectively, in the superior sagittal sinus (SSS), the straight sinus (SS), and the internal jugular veins (IJVs). Venous oxygenation was assessed at room air (0.03%CO2 , 21%O2 ) and under hyperoxia (O%CO2 , 95%O2 , and 5%N2 ) conditions. Venous blood flow was assessed at room air and under hypercapnia (5%CO2 , 21%O2 , and 74%N2 ) conditions. Whole-brain blood flow was also measured at the four feeding arteries of the brain using phase-contrast MRI. The changes in venous oxygenation and blood flow from room air to hyperoxia or hypercapnia conditions were tested using paired t-tests. Venous oxygenation in the SSS, the SS, and the IJVs was 61 ± 4%, 64 ± 4%, and 62 ± 4%, respectively, at room air, and increased to 70 ± 3% (P distribution did not change under hypercapnic condition (P > 0.5). The results found in this study provide insight into the venous oxygenation and venous flow distribution and its heterogeneity among different venous structures. 1 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2017. © 2017 International Society for Magnetic Resonance in Medicine.

  1. Central venous oxygen saturation monitoring: role in adult donor care?

    Science.gov (United States)

    Powner, David J; Doshi, Pratik B

    2010-12-01

    Monitoring oxygen saturation of blood drawn from a catheter placed within the superior vena cava (Scvo2) has recently been promoted as a substitute for evaluating oxygen saturation of mixed venous blood drawn from the pulmonary artery (Svo2). The Svo2 reflects the balance between oxygen delivery and oxygen consumption throughout the body and, among critically ill patients, may be helpful for assessing resuscitation, cardiac function, or oxygen homeostasis end points. Use of Scvo2 instead has been promoted because of its easier access and recent use during resuscitation of patients with severe infections. Although data from healthy subjects and critically ill patients are available, no study has been done among organ donors to evaluate customary values for either Scvo2 or Svo2 or how well the values correspond. After loss of oxygen consumption in the brain following brain death, the customary values for these variables may be different from values in other groups of patients. Therefore, until donor-specific normative values for these important parameters are identified, we do not recommend that Scvo2 be used to evaluate the balance between donor oxygen consumption and delivery or as a variable to guide treatment.

  2. Comparison of Minimally and More Invasive Methods of Determining Mixed Venous Oxygen Saturation.

    Science.gov (United States)

    Smit, Marli; Levin, Andrew I; Coetzee, Johan F

    2016-04-01

    To investigate the accuracy of a minimally invasive, 2-step, lookup method for determining mixed venous oxygen saturation compared with conventional techniques. Single-center, prospective, nonrandomized, pilot study. Tertiary care hospital, university setting. Thirteen elective cardiac and vascular surgery patients. All participants received intra-arterial and pulmonary artery catheters. Minimally invasive oxygen consumption and cardiac output were measured using a metabolic module and lithium-calibrated arterial waveform analysis (LiDCO; LiDCO, London), respectively. For the minimally invasive method, Step 1 involved these minimally invasive measurements, and arterial oxygen content was entered into the Fick equation to calculate mixed venous oxygen content. Step 2 used an oxyhemoglobin curve spreadsheet to look up mixed venous oxygen saturation from the calculated mixed venous oxygen content. The conventional "invasive" technique used pulmonary artery intermittent thermodilution cardiac output, direct sampling of mixed venous and arterial blood, and the "reverse-Fick" method of calculating oxygen consumption. LiDCO overestimated thermodilution cardiac output by 26%. Pulmonary artery catheter-derived oxygen consumption underestimated metabolic module measurements by 27%. Mixed venous oxygen saturation differed between techniques; the calculated values underestimated the direct measurements by between 12% to 26.3%, this difference being statistically significant. The magnitude of the differences between the minimally invasive and invasive techniques was too great for the former to act as a surrogate of the latter and could adversely affect clinical decision making. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Central venous blood gas and acid-base status in conscious dogs and cats.

    Science.gov (United States)

    Tamura, Jun; Itami, Takaharu; Ishizuka, Tomohito; Fukui, Sho; Miyoshi, Kenjirou; Sano, Tadashi; Yamashita, Kazuto

    2015-07-01

    To determine the reference level of central venous oxygen saturation (ScvO2) and clinical efficacy of central venous blood gas analysis, partial pressures of oxygen and carbon dioxide, pH, oxygen saturation, base excess (B.E.) and HCO3 concentration were compared between simultaneously obtained central venous and arterial blood samples from conscious healthy 6 dogs and 5 cats. Comparisons between arteriovenous samples were performed by a paired t-test and Bland-Altman analysis. Between arteriovenous samples, B.E. showed good agreement, but there were significant differences in other parameters in the dogs, and no good agreement was detected in cats. The ScvO2 in dogs and cats were 82.3 ± 3.5 and 62.4 ± 13.5%, respectively. Central venous blood gas analysis is indispensable, especially in cats.

  4. Changes of blood flow, oxygen tension, action potential and vascular permeability induced by arterial ischemia or venous congestion on the spinal cord in canine model

    National Research Council Canada - National Science Library

    Kobayashi, Shigeru; Yoshizawa, Hidezo; Shimada, Seiichiro; Guerrero, Alexander Rodríguez; Miyachi, Masaya

    2013-01-01

    ... disturbance induced by venous congestion is not fully understood. Since Kadyi's first description of the venous system of the spinal cord, there have been few other studies on the subject. 3 Regarding the intramedullary vascular system, the central part of the spinal cord is supplied unilaterally by branches from the central artery enteri...

  5. Analysis of Arterial and Venous Blood Gases in Healthy Gyr Falcons ( Falco rusticolus ) Under Anesthesia.

    Science.gov (United States)

    Raghav, Raj; Middleton, Rachael; BSc, Rinshiya Ahamed; Arjunan, Raji; Caliendo, Valentina

    2015-12-01

    Arterial and venous blood gas analysis is useful in the assessment of tissue oxygenation and ventilation and in diagnosis of metabolic and respiratory derangements. It can be performed with a relatively small volume of blood in avian patients under emergency situations. Arterial and venous blood gas analysis was performed in 30 healthy gyr falcons ( Falco rusticolus ) under anaesthesia to establish temperature-corrected reference intervals for arterial blood gas values and to compare them to temperature-corrected venous blood gas values with a portable point-of-care blood gas analyzer (i-STAT 1, Abbott Laboratories, Abbott Park, IL, USA). Statistically significant differences were observed between the temperature-corrected values of pH, partial pressure of carbon dioxide (Pco2), and partial pressure of oxygen (Po2) and the corresponding nontemperature-corrected values of these parameters in both arterial and venous blood. Values of temperature-corrected pH, temperature-corrected Pco2, bicarbonate concentrations, and base excess of extra cellular fluid did not differ significantly between arterial and venous blood, suggesting that, in anesthetized gyr falcons, venous blood gas analysis can be used in place of arterial blood gas analysis in clinical situations. Values for hematocrit, measured by the point-of-care analyzer, were significantly lower compared with those obtained by the microhematocrit method.

  6. Optoacoustic monitoring of central and peripheral venous oxygenation during simulated hemorrhage

    Science.gov (United States)

    Petrov, Andrey; Kinsky, Michael; Prough, Donald S.; Petrov, Yuriy; Petrov, Irene Y.; Henkel, S. Nan; Seeton, Roger; Salter, Michael G.; Khan, Muzna N.; Esenaliev, Rinat O.

    2014-03-01

    Circulatory shock may be fatal unless promptly recognized and treated. The most commonly used indicators of shock (hypotension and tachycardia) lack sensitivity and specificity. In the initial stages of shock, the body compensates by reducing blood flow to the peripheral (skin, muscle, etc.) circulation in order to preserve vital organ (brain, heart, liver) perfusion. Characteristically, this can be observed by a greater reduction in peripheral venous oxygenation (for instance, the axillary vein) compared to central venous oxygenation (the internal jugular vein). While invasive measurements of oxygenation are accurate, they lack practicality and are not without complications. We have developed a novel optoacoustic system that noninvasively determines oxygenation in specific veins. In order to test this application, we used lower body negative pressure (LBNP) system, which simulates hemorrhage by exerting a variable amount of suction on the lower body, thereby reducing the volume of blood available for central circulation. Restoration of normal blood flow occurs promptly upon cessation of LBNP. Using two optoacoustic probes, guided by ultrasound imaging, we simultaneously monitored oxygenation in the axillary and internal jugular veins (IJV). LBNP began at -20 mmHg, thereafter was reduced in a step-wise fashion (up to 30 min). The optoacoustically measured axillary oxygenation decreased with LBNP, whereas IJV oxygenation remained relatively constant. These results indicate that our optoacoustic system may provide safe and rapid measurement of peripheral and central venous oxygenation and diagnosis of shock with high specificity and sensitivity.

  7. [When is a venous blood gas analysis sufficient in the emergency department?

    Science.gov (United States)

    van Exsel, J A J M; Simons, S O; Kramers, C; Heijdra, Y F

    2017-01-01

    Blood gas analysis plays an important role in the initial assessment of a patient in the emergency ward. We present three different patient cases to illustrate when to opt for a venous or an arterial blood gas analysis. Arterial punctures are more painful and carry a higher risk of complications compared to venous punctures. It is possible to use a venous blood gas to screen for acute acid/base disturbances. Ventilatory compensation or anion gap cannot be calculated reliably with a venous blood gas. On the other hand, the diagnosis diabetic keto-acidosis can be made with a venous blood gas; this mode of sampling can also be used for lactate measurement at the emergency department as an independent prognostic marker for mortality. Venous blood gas analyses are not able to assess oxygenation. Pulse oximetry is a non-invasive alternative for arterial blood gas sampling. The use of a venous blood gas to assess a patient's ventilation is limited, whereas it can be used to diagnose carbomonoxide intoxication or methaemoglobinaemia.

  8. Field strength dependence of grey matter R2* on venous oxygenation.

    Science.gov (United States)

    Croal, Paula L; Driver, Ian D; Francis, Susan T; Gowland, Penny A

    2017-02-01

    The relationship between venous blood oxygenation and change in transverse relaxation rate (ΔR2*) plays a key role in calibrated BOLD fMRI. This relationship, defined by the parameter β, has previously been determined using theoretical simulations and experimental measures. However, these earlier studies have been confounded by the change in venous cerebral blood volume (CBV) in response to functional tasks. This study used a double-echo gradient echo EPI scheme in conjunction with a graded isocapnic hyperoxic sequence to assess quantitatively the relationship between the fractional venous blood oxygenation (1-Yv) and transverse relaxation rate of grey matter (ΔR2⁢GM*), without inducing a change in vCBV. The results demonstrate that the relationship between ΔR2* and fractional venous oxygenation at all magnet field strengths studied was adequately described by a linear relationship. The gradient of this relationship did not increase monotonically with field strength, which may be attributed to the relative contributions of intravascular and extravascular signals which will vary with both field strength and blood oxygenation. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  9. Severe hypoxemia during veno-venous extracorporeal membrane oxygenation: exploring the limits of extracorporeal respiratory support

    Directory of Open Access Journals (Sweden)

    Liane Brescovici Nunes

    2014-03-01

    Full Text Available OBJECTIVE: Veno-venous extracorporeal oxygenation for respiratory support has emerged as a rescue alternative for patients with hypoxemia. However, in some patients with more severe lung injury, extracorporeal support fails to restore arterial oxygenation. Based on four clinical vignettes, the aims of this article were to describe the pathophysiology of this concerning problem and to discuss possibilities for hypoxemia resolution. METHODS: Considering the main reasons and rationale for hypoxemia during veno-venous extracorporeal membrane oxygenation, some possible bedside solutions must be considered: 1 optimization of extracorporeal membrane oxygenation blood flow; 2 identification of recirculation and cannula repositioning if necessary; 3 optimization of residual lung function and consideration of blood transfusion; 4 diagnosis of oxygenator dysfunction and consideration of its replacement; and finally 5 optimization of the ratio of extracorporeal membrane oxygenation blood flow to cardiac output, based on the reduction of cardiac output. CONCLUSION: Therefore, based on the pathophysiology of hypoxemia during veno-venous extracorporeal oxygenation support, we propose a stepwise approach to help guide specific interventions.

  10. Proof of concept non-invasive estimation of peripheral venous oxygen saturation.

    Science.gov (United States)

    Khan, Musabbir; Pretty, Chris G; Amies, Alexander C; Balmer, Joel; Banna, Houda E; Shaw, Geoffrey M; Geoffrey Chase, J

    2017-05-19

    Pulse oximeters continuously monitor arterial oxygen saturation. Continuous monitoring of venous oxygen saturation (SvO2) would enable real-time assessment of tissue oxygen extraction (O2E) and perfusion changes leading to improved diagnosis of clinical conditions, such as sepsis. This study presents the proof of concept of a novel pulse oximeter method that utilises the compliance difference between arteries and veins to induce artificial respiration-like modulations to the peripheral vasculature. These modulations make the venous blood pulsatile, which are then detected by a pulse oximeter sensor. The resulting photoplethysmograph (PPG) signals from the pulse oximeter are processed and analysed to develop a calibration model to estimate regional venous oxygen saturation (SpvO2), in parallel to arterial oxygen saturation estimation (SpaO2). A clinical study with healthy adult volunteers (n = 8) was conducted to assess peripheral SvO2 using this pulse oximeter method. A range of physiologically realistic SvO2 values were induced using arm lift and vascular occlusion tests. Gold standard, arterial and venous blood gas measurements were used as reference measurements. Modulation ratios related to arterial and venous systems were determined using a frequency domain analysis of the PPG signals. A strong, linear correlation (r 2  = 0.95) was found between estimated venous modulation ratio (RVen) and measured SvO2, providing a calibration curve relating measured RVen to venous oxygen saturation. There is a significant difference in gradient between the SpvO2 estimation model (SpvO2 = 111 - 40.6*R) and the empirical SpaO2 estimation model (SpaO2 = 110 - 25*R), which yields the expected arterial-venous differences. Median venous and arterial oxygen saturation accuracies of paired measurements between pulse oximeter estimated and gold standard measurements were 0.29 and 0.65%, respectively, showing good accuracy of the pulse oximeter system. The main outcome of

  11. Hepatic venous oxygen content in alcoholic cirrhosis and non-cirrhotic alcoholic liver disease

    DEFF Research Database (Denmark)

    Bendtsen, F; Henriksen, Jens Henrik Sahl; Widding, A

    1987-01-01

    Blood gas analyses and hepatic blood flow were determined during hepatic vein catheterization in order to establish a possible hypoxic component in alcoholic liver disease. Fifty-six patients (9 non-cirrhotic liver disease, 14 cirrhosis Child-Turcotte class A, 23 class B, 10 class C) and 10 control......-hepatic venous difference of base excess was small and of the same size in all groups, indicating no enhanced production of lactic acid in the liver. Our results do not support the concept that hepatic venous oxygen content is low in alcoholic liver disease and thereby contributes to hypoxic liver damage....

  12. Filterability of freshly-collected sickle erythrocytes under venous oxygen pressure without exposure to air.

    Science.gov (United States)

    Shah, Siddharth; Acholonu, Rhonda Graves; Ohene-Frempong, Kwaku; Asakura, Toshio

    2015-12-01

    We previously found that blood samples collected from steady-state patients with sickle cell disease (SCD) without exposure to air contain a new type of reversibly sickled cells (RSCs) with blunt edges at a level of as high as 78%. Since partial oxygenation of once-deoxygenated sickled cells with pointy edges to near venous oxygen pressure generates similar sickled cells with blunt edges in vitro, we named them as partially oxygenated sickled cells (POSCs). On the other hand, partial deoxygenation of once-oxygenated SS cells to venous oxygen pressure generates partially deoxygenated sickled cells (PDSCs) with pointy edges. In this study, we obtained blood samples from 6 steady-state patients with SCD under venous oxygen pressure without exposure to air, subjected them to various oxygenation/deoxygenation/reoxygenation cycles, and studied their filterability through a membrane filter with pore diameter of 3μm, the theoretical minimum diameter of a capillary. Our results indicated that discocytes, POSCs with blunt edges, and irreversibly sickled cells could deform and pass through the filter, while PDSCs with pointy edges were rigid and could not. The filterability of SS cells seems to be related to the length and amount of deoxy-hemoglobin S fibers in the cells. Copyright © 2015. Published by Elsevier Inc.

  13. Brightness of venous blood in South American camelids: implications for jugular catheterization.

    Science.gov (United States)

    Grint, Nicola; Dugdale, Alexandra

    2009-01-01

    To compare the brightness of South American camelid venous blood to that of Equidae. Prospective clinical evaluation. Twelve South American camelids (eight llamas, four alpacas), eight horses and ponies (control group). Appropriately sized catheters were placed in the jugular vein of each animal under local anaesthesia. The blood spilt before the catheter was capped was caught on a white tile. A sample of blood was drawn for blood-gas analysis. The brightness of the blood (both on the tile and in the syringe) was matched to a colour chart (1 = darkest red, 8 = brightest red) by a single observer under bright light conditions. Packed cell volume (PCV) and partial pressure of oxygen (PvO(2)) in the blood were also measured on the syringe blood. Normally distributed data were compared using a two tailed t-test, and non-normally distributed data were compared using a Mann-Whitney U-test. Significance was set at p < 0.05. Camelid venous blood was significantly brighter red than that of horses and ponies both on the white tile (p = 0.0003) and in the syringe (p = 0.0001). PCV was significantly lower in camelids (32 +/- 4%) compared with horses (37 +/- 5%). Partial pressure of oxygen values were similar between groups. Jugular venous blood in alpacas and llamas is significantly brighter red than that of horses. Colour should not be used as a sole determinant of venous or arterial catheterization in this species.

  14. End expiratory oxygen concentrations to predict central venous oxygen saturation: an observational pilot study

    Directory of Open Access Journals (Sweden)

    Steuerwald Michael

    2006-09-01

    Full Text Available Abstract Background A non-invasive surrogate measurement for central venous oxygen saturation (ScVO2 would be useful in the ED for assessing therapeutic interventions in critically ill patients. We hypothesized that either linear or nonlinear mathematical manipulation of the partial pressure of oxygen in breath at end expiration (EtO2 would accurately predict ScVO2. Methods Prospective observational study of a convenience sample of hemodialysis patients age > 17 years with existing upper extremity central venous catheters were enrolled. Using a portable respiratory device, we collected both tidal breathing and end expiratory oxygen and carbon dioxide concentrations, volume and flow on each patient. Simultaneous ScVO2 measurements were obtained via blood samples collected from the hemodialysis catheter. Two models were used to predict ScVO2: 1 Best-fit multivariate linear regression equation incorporating all respiratory variables; 2 MathCAD to model the decay curve of EtO2 versus expiratory volume using the least squares method to estimate the pO2 that would occur at Results From 21 patients, the correlation between EtO2 and measured ScVO2 yielded R2 = 0.11. The best fit multivariate equation included EtCO2 and EtO2 and when solved for ScVO2, the equation yielded a mean absolute difference from the measured ScVO2 of 8 ± 6% (range -18 to +17%. The predicted ScVO2 value was within 10% of the actual value for 57% of the patients. Modeling of the EtO2 curve did not accurately predict ScVO2 at any lung volume. Conclusion We found no significant correlation between EtO2 and ScVO2. A linear equation incorporating EtCO2 and EtO2 had at best modest predictive accuracy for ScVO2.

  15. End expiratory oxygen concentrations to predict central venous oxygen saturation: an observational pilot study.

    Science.gov (United States)

    Jones, Alan E; Kuehne, Karl; Steuerwald, Michael; Kline, Jeffrey A

    2006-09-20

    A non-invasive surrogate measurement for central venous oxygen saturation (ScVO2) would be useful in the ED for assessing therapeutic interventions in critically ill patients. We hypothesized that either linear or nonlinear mathematical manipulation of the partial pressure of oxygen in breath at end expiration (EtO2) would accurately predict ScVO2. Prospective observational study of a convenience sample of hemodialysis patients age > 17 years with existing upper extremity central venous catheters were enrolled. Using a portable respiratory device, we collected both tidal breathing and end expiratory oxygen and carbon dioxide concentrations, volume and flow on each patient. Simultaneous ScVO2 measurements were obtained via blood samples collected from the hemodialysis catheter. Two models were used to predict ScVO2: 1) Best-fit multivariate linear regression equation incorporating all respiratory variables; 2) MathCAD to model the decay curve of EtO2 versus expiratory volume using the least squares method to estimate the pO2 that would occur at <20% of total lung capacity. From 21 patients, the correlation between EtO2 and measured ScVO2 yielded R2 = 0.11. The best fit multivariate equation included EtCO2 and EtO2 and when solved for ScVO2, the equation yielded a mean absolute difference from the measured ScVO2 of 8 +/- 6% (range -18 to +17%). The predicted ScVO2 value was within 10% of the actual value for 57% of the patients. Modeling of the EtO2 curve did not accurately predict ScVO2 at any lung volume. We found no significant correlation between EtO2 and ScVO2. A linear equation incorporating EtCO2 and EtO2 had at best modest predictive accuracy for ScVO2.

  16. Superior venous drainage in the "LifeBox": a portable extracorporeal oxygenator with a self-expanding venous cannula.

    Science.gov (United States)

    Berdajs, Denis; Born, Frank; Crosset, Monique; Horisberger, Judith; Künzli, Andreas; Ferrari, Enrico; Tozzi, Piergiorgo; von Segesser, Ludwig K

    2010-07-01

    In an experimental setting, the performance of the LifeBox, a new portable extracorporeal membrane oxygenator (ECMO) system suitable for patient transport, is presented. Standard rectilinear percutaneous cannulae are normally employed for this purpose, but have limited flow and pressure delivery due to their rigid structure. Therefore, we aimed to determine the potential for flow increase by using self-expanding venous cannulae. Veno-arterial bypass was established in three pigs (40.6+/-5.1 kg). The venous line of the cardiopulmonary bypass was established by cannulation of the external jugular vein. The arterial side of the circulation was secured by cannulation of the common carotid artery. Two different venous cannulae (SmartCanula 18/36F 430mm and Biomedicus 19F) were examined for their functional integrity when used in conjunction with the centrifugal pump (500-3000 RPM) of the LifeBox system. At 1500, 2000, 2500, and 3000 RPM, the blood flow increased steadily for each cannula, but remained higher in the self-expanding cannula. That is, the 19F rectilinear cannula achieved a blood flow of 0.93+/-0.14, 1.47+/-0.37, 1.9+/-0.68, and 1.5+/-0.9 l/min, respectively, and the 18/36F self-expanding cannula achieved 1.1+/-0.1, 1.9+/-0.33, 2.8+/-0.39 and 3.66+/-0.52 l/min. However, when tested for venous line pressure, the standard venous cannula achieved -29+/-10.7mmHg while the self-expanding cannula achieved -13.6 +/-4.3mmHg at 1500 RMP. As the RPM increased from 2500 to 3000, the venous line pressure accounted for -141.9+/-20 and -98+/-7.3mmHg for the 19F rectilinear cannula and -30.6+/-6.4 and -45+/-11.6mmHg for the self-expanding cannula. The self-expanding cannula exhibited superior venous drainage ability when compared to the performance of the standard rectilinear cannula with the use of the LifeBox. The flow rate achieved was approximately 40% greater than the standard drainage device, with a maximal pump flow recorded at 4.3l/min.

  17. Plasma ATP concentration and venous oxygen content in the forearm during dynamic handgrip exercise

    Directory of Open Access Journals (Sweden)

    Askew Christopher D

    2009-12-01

    Full Text Available Abstract Background It has been proposed that adenosine triphosphate (ATP released from red blood cells (RBCs may contribute to the tight coupling between blood flow and oxygen demand in contracting skeletal muscle. To determine whether ATP may contribute to the vasodilatory response to exercise in the forearm, we measured arterialised and venous plasma ATP concentration and venous oxygen content in 10 healthy young males at rest, and at 30 and 180 seconds during dynamic handgrip exercise at 45% of maximum voluntary contraction (MVC. Results Venous plasma ATP concentration was elevated above rest after 30 seconds of exercise (P Conclusions Collectively these results indicate that ATP in the plasma originated from the muscle microcirculation, and are consistent with the notion that deoxygenation of the blood perfusing the muscle acts as a stimulus for ATP release. That ATP concentration was elevated just 30 seconds after the onset of exercise also suggests that ATP may be a contributing factor to the blood flow response in the transition from rest to steady state exercise.

  18. Leukocytic Response and Peripheral Venous Blood Lymphocyte Apoptosis as a Marker of Tissue Ischemia in Acute Massive Blood Loss

    Directory of Open Access Journals (Sweden)

    N. V. Borovkova

    2013-01-01

    Full Text Available Objective: to estimate the level of peripheral venous blood lymphocyte apoptosis and intraoperative hypoxia in victims with acute massive blood loss. Subjects and methods. Twenty-two patients with open and close chest and abdominal traumas complicated by acute massive blood loss were examined. All the patients were emergently operated on to stop bleeding. Tissue metabolism was evaluated from gases, acid-base parameters, and plasma lactate, glucose, potassium, and sodium levels. Apoptosis of mononuclear cells was studied and dead leukocytes were counted using flow cytometry. Results. Preoperatively, the victims were found to have venous hypoxemia, hyperlactatemia, hyperglycemia, moderate leukocytosis, and higher dead leukocyte counts. There were also raised counts of lymphocytes coming into the process of apoptosis. A significant relationship was found between monocyte counts and hypoxia values. At the end of surgery, oxygen balance values became stable and exerted an effect on the count of leukocytes, the relative level of granulocytes, the relative and absolute counts of dead and damaged leukocytes, and the concentration of lymphocytes in the victims’ venous blood during the early stages of apoptosis, as evidenced by nonlinear regression models. Conclusion. The indicators of immunocompetent cell apoptosis and the count of venous blood dead leukocytes along with lactate levels and venous hypoxemia parameters reflect the degree of tissue hypoxia and may be used as specific markers.

  19. Clinical value and influencing factors of intraoperative monitoring of jugular venous oxygen saturation

    Directory of Open Access Journals (Sweden)

    Jie SONG

    2016-10-01

    Full Text Available Intraoperative jugular venous oxygen saturation (SjvO2 monitoring has been widely used in clinic, which can monitor cerebral blood flow (CBF and oxygen metabolism. Reverse puncture and catheterization through jugular vein for monitoring SjvO2 is easy to operate and can collect blood samples repeatedly. It is an effective method for real-time dynamic evaluation of cerebral oxygen supply-demand and neurological function. This article reviews the clinical significance and influencing factors of SjvO2 monitoring during operation. It notes in particular that SjvO2 can not be used as the only way to monitor CBF and oxygen metabolism, and a comprehensive evaluation should be done combining with the change of other parameters. DOI: 10.3969/j.issn.1672-6731.2016.10.014

  20. Central venous oxygenation: when physiology explains apparent discrepancies.

    Science.gov (United States)

    Squara, Pierre

    2014-11-10

    Central venous oxygen saturation (ScvO2) >70% or mixed venous oxygen saturation (SvO2) >65% is recommended for both septic and non-septic patients. Although it is the task of experts to suggest clear and simple guidelines, there is a risk of reducing critical care to these simple recommendations. This article reviews the basic physiological and pathological features as well as the metrological issues that provide clear evidence that SvO2 and ScvO2 are adaptative variables with large inter-patient variability. This variability is exemplified in a modeled population of 1,000 standard ICU patients and in a real population of 100 patients including 15,860 measurements. In these populations, it can be seen how optimizing one to three of the four S(c)vO2 components homogenized the patients and yields a clear dependency with the fourth one. This explains the discordant results observed in large studies where cardiac output was increased up to predetermined S(c)vO2 thresholds following arterial oxygen hemoglobin saturation, total body oxygen consumption needs and hemoglobin optimization. Although a systematic S(c)vO2 goal-oriented protocol can be statistically profitable before ICU admission, appropriate intensive care mandates determination of the best compromise between S(c)vO2 and its four components, taking into account the specific constraints of each individual patient.

  1. Relationship between Central and Peripheral Venous Oxygen Saturation and Lactate Levels: A Prospective Study.

    Science.gov (United States)

    Goyal, Nikhil; Taylor, Andrew R; Rivers, Emanuel P

    2016-06-01

    Optimization of tissue oxygen delivery to meet consumption demands is important in the resuscitation of critically ill patients. Central venous oxygen saturation (ScvO2) and lactate levels are often used to guide resuscitation; however, invasive monitoring is required for the former. Clinicians searching for less invasive alternatives may consider using peripheral venous oxygen saturation (SpvO2) and lactate levels as a substitute. To determine the relationship between SpvO2 and ScvO2 and peripheral and central lactate levels. All patients with a central venous catheter in an academic emergency department and intensive care unit were eligible for the study. Blood was obtained simultaneously from a central and peripheral vein and measured for oxygen saturation and lactate levels. Results were analyzed using intraclass correlation coefficient (ICC), Bland-Altman plots, and receiver operating characteristic curves. Seventy-nine paired blood samples were analyzed. SpvO2 and ScvO2 have moderate agreement: ICC = 0.53 (95% confidence interval [CI] 0.35-0.67). A Bland-Altman plot revealed substantial bias (-4.47; limits of agreement -38.6, 29.6). SpvO2 ≥ 85% was 90% specific for ScvO2 ≥ 70%, and SpvO2 of ≤ 55% had a 94% sensitivity for ScvO2 Central and peripheral venous lactate levels showed almost perfect agreement: ICC = 0.92 (95% CI 0.87-0.95), bias of 0.46 (limits of agreement -1.78-2.70). SpvO2 and ScvO2 have moderate agreement. There was excellent agreement between peripheral and central lactate levels, making them interchangeable. The clinical implications of these substitutions in real-time patient management require further study. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. In-vitro evaluation of the PediaSat continuous central venous oxygenation monitoring system.

    Science.gov (United States)

    Baulig, Werner; Spielmann, Nelly; Zaiter, Hassan; Lijovic, Tomislav; Bettex, Dominique; Bürki, Christoph; Weiss, Markus

    2010-03-01

    In-vitro performance of the PediaSat system for continuous monitoring of central venous oxygen saturation by spectrophotometry has been evaluated. PediaSat continuous fibre-optic oximetry catheters were inserted in a black testing chamber, connected with an extracorporeal circuit and filled with human whole blood. Oxygen inflow into the cardiopulmonary bypass system was varied, and the testing chamber was perfused with blood flow of 1000 ml min(-1). Oxygen saturation values measured by PediaSat (S PediaSat O2) were compared with cooximetry (S CO-OX O2) values from simultaneously taken blood samples by Bland-Altman and simple regression analyses. Fifty data pairs were obtained. S PediaSat O2 and S CO-OX O2 values ranged between 28-98 and 24.9-99.5%, respectively. Correlation between S PediSat O2 and S CO-OX O2 was high with an r2 value equal to 0.96 (P central venous oxygen saturation.

  3. Relationship between mixed venous oxygen saturation and regional cerebral oxygenation in awake, spontaneously breathing cardiac surgery patients.

    Science.gov (United States)

    Schön, J; Heringlake, M; Berger, K-U; Volker Groesdonk, H; Sedemund-Adib, B; Paarmann, H

    2011-10-01

    In search of a non-invasive method for estimation of the oxygen balance this prospective study evaluates the relationship between regional cerebral oxygenation (rScO2) and mixed venous oxygen saturation in awake, spontaneously breathing patients after cardiac surgery. After approval by the local ethical committee and written informed consent, 26 consecutive patients after cardiac surgery with cardiopulmonary bypass were enrolled. On intensive care unit (ICU), several hours after extubation, patients were connected to the INVOS 5100 cerebral monitor. Blood samples for determination of mixed venous oxygen saturation (SvO2) and central venous oxygen saturation (ScvO2) were drawn successively and rScO2 was documented. Patients were studied twice, breathing room air for the first measurement cycle, and breathing 4L/min supplemental oxygen by face mask, achieving a transcutaneous oxygen saturation above 98%, for a second measurement. Hemodynamic variables, hemoglobin and arterial carbon dioxide tension (PaCO2) remained stable between the two measurement cycles. Without oxygen, SvO2 and rScO2 showed a bias of -2.0%, limits of agreement (LOA) of -15.0 to 10.9% and a percentage error (PE) of 20.3%. SvO2 and ScvO2 showed a bias of -3.9%, LOA of -13.9 to 6.2% and PE 15.7%. With oxygen, the bias between SvO2 and rScO2 was -2.5%, LOA -14.2 to 9.2%, PE 17.2%. Between SvO2 and ScvO2 the bias was -4.1%, LOA -10.2 to 2.1%, PE 9.0%. The rScO2 measured by near infrared spectroscopy was sufficiently representing mixed venous oxygen saturation in awake, hemodynamically stable, spontaneously breathing patients after cardiac surgery. The agreement was comparable to the agreement between SvO2 and ScvO2 with smaller differences in the lower ranges of SvO2.

  4. Using venous blood gas analysis in the assessment of COPD exacerbations: a prospective cohort study.

    Science.gov (United States)

    McKeever, Tricia M; Hearson, Glenn; Housley, Gemma; Reynolds, Catherine; Kinnear, William; Harrison, Tim W; Kelly, Anne-Maree; Shaw, Dominick E

    2016-03-01

    Identifying acute hypercapnic respiratory failure is crucial in the initial management of acute exacerbations of COPD. Guidelines recommend obtaining arterial blood samples but these are more difficult to obtain than venous. We assessed whether blood gas values derived from venous blood could replace arterial at initial assessment. Patients requiring hospital treatment for an exacerbation of COPD had paired arterial and venous samples taken. Bland-Altman analyses were performed to assess agreement between arterial and venous pH, CO2 and HCO3-. The relationship between SpO2 and SaO2 was assessed. The number of attempts and pain scores for each sample were measured. 234 patients were studied. There was good agreement between arterial and venous measures of pH and HC)3- (mean difference 0.03 and -0.04, limits of agreement -0.05 to 0.11 and -2.90 to 2.82, respectively), and between SaO2 and SpO2 (in patients with an SpO2 of >80%). Arterial sampling required more attempts and was more painful than venous (mean pain score 4 (IQR 2-5) and 1 (IQR 0-2), respectively, pblood, and between pulse oximetry and arterial blood gas oxygen saturations. These agreements could allow the initial assessment of COPD exacerbations to be based on venous blood gas analysis and pulse oximetry, simplifying the care pathway and improving the patient experience. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  5. Clinical predictors of a low central venous oxygen saturation after major surgery: a prospective prevalence study.

    Science.gov (United States)

    Litton, E; Silbert, B; Ho, K M

    2015-01-01

    Optimising perioperative haemodynamic status may reduce postoperative complications. In this prospective prevalence study, we investigated the associations between standard haemodynamic parameters and a low central venous oxygen saturation (ScvO2) in patients after major surgery. A total of 201 patients requiring continuous arterial and central venous pressure monitoring after major surgery were recruited. Simultaneous arterial and central venous blood gases, haemodynamic and biochemical data and perfusion index were obtained from patients at a single time-point within 24 hours of surgery. A low ScvO2 (central venous pressure, haemoglobin concentrations, arterial pH and lactate concentrations, arterial oxygen (PaO2) and carbon dioxide tensions (PaCO2) were all associated with a low ScvO2 in the univariate analyses. In the multivariate analysis, only a higher perfusion index (odds ratio [OR] 0.87, 95% confidence interval [CI] 0.78 to 0.98), PaO2 (OR 0.98 per mmHg increment, 95% CI 0.97 to 0.99) and PaCO2 (OR 0.88 per mmHg increment, 95% CI 0.82 to 0.95) and a lower central venous pressure (OR 1.14 per mmHg increment, 95% CI 1.04 to 1.25) were significantly associated with a reduced risk of a low ScvO2, all in a linear fashion. In conclusion, PaO2, PaCO2, perfusion index and central venous pressure were significant predictors of a low ScvO2 in patients after major surgery including cardiac surgery.

  6. Usefulness of central venous oxygen saturation monitoring during bidirectional Glenn shunt.

    Science.gov (United States)

    Kakuta, Nami; Kawahito, Shinji; Mita, Naoji; Kambe, Noriko; Kasai, Asuka; Wakamatsu, Narutomo; Katayama, Toshiko; Soga, Tomohiro; Tada, Fumihiko; Kitaichi, Takashi; Kitagawa, Tetsuya; Kitahata, Hiroshi

    2013-01-01

    A PediaSat™ oximetry catheter (PediaSat: Edwards Lifesciences Co., Ltd., Irvine, CA, U. S. A.), which facilitates continuous measurement of central venous oxygen saturation (ScvO2), may be useful for surgery for pediatric congenital heart disease. We used PediaSat during a bidirectional Glenn shunt. The patient was a 13-month-old boy. Under a diagnosis of left single ventricle (pulmonary atresia, right ventricular hypoplasia, atrial septal defect) and residual left aortic arch/left superior vena cava, a modified right Blalock-Taussig shunt was performed. Cyanosis deteriorated, so a bidirectional Glenn shunt was scheduled. After anesthesia induction, a 4.5 Fr double-lumen (8 cm) PediaSat was inserted through the right internal jugular vein for continuous ScvO2 monitoring. Furthermore, the probe of a near-infrared, mixed blood oxygen saturation-measuring monitor was attached to the forehead for continuous monitoring of the regional brain tissue mixed blood oxygen saturation (rSO2) (INVOS™ 5100C, Covidien; Boulder, CO, U. S. A.). Blockage of the right pulmonary artery and right superior vena cava decreased the oxygen saturation, ScvO2, and rSO2, but increased the central venous pressure. Although changes in ScvO2 were parallel to those in rSO2, the former showed more marked changes. A combination of ScvO2 and rSO2 for monitoring during Glenn shunt may be safer.

  7. Correlation between arterial and venous blood gas analysis parameters in patients with acute exacerbation of chronic obstructive pulmonary disease

    Directory of Open Access Journals (Sweden)

    Novović Miloš

    2012-01-01

    Full Text Available Introduction. Arterial blood gas (ABG analyses have an important role in the assessment and monitoring of the metabolic and oxygen status of patients with acute exacerbation of chronic obstructive pulmonary disease (COPD. Arterial puncture could have a lot of adverse effects, while sampling of venous blood is simpler and is not so invasive. Objective. The aim of this study was to evaluate whether venous blood gas (VBG values of pH, partial pressure of carbon dioxide (PCO2, partial oxygen pressure (PO2, bicarbonate (HCO3, and venous and arterial blood oxygen saturation (SO2 can reliably predict ABG levels in patients with acute exacerbation of COPD. Methods. Forty-seven patients with a prior diagnosis of COPD were included in this prospective study. The patients with acute exacerbation of this disease were examined at the General Hospital EMS Department in Prijepolje. ABG samples were taken immediately after venous sampling, and both were analyzed. Results. The Pearson correlation coefficients between arterial and venous parameters were 0.828, 0.877, 0.599, 0.896 and 0.312 for pH, PCO2, PO2, HCO3 and SO2, respectively. The statistically significant correlation between arterial and venous pH, PCO2 and HCO3, values was found in patients with acute exacerbation of COPD (p<0.001. Conclusion. When we cannot provide arterial blood for analysis, venous values of the pH, Pv,CO2 and HCO3 parameters can be an alternative to their arterial equivalents in the interpretation of the metabolic status in patients with acute exacerbation of COPD, while the values of venous Pv,O2 and Sv,O2 cannot be used as predictors in the assessment of oxygen status of such patients.

  8. Correlation Between Pediatric Open Heart Surgery Outcomes and Arterial-mixed Venous Oxygen Saturation Differences

    Directory of Open Access Journals (Sweden)

    Mahmood Samadi

    2012-09-01

    Full Text Available Introduction: Low Cardiac Output Syndrome (LCOS contributes to postoperative morbidity and mortality. This article tries to find a predictive factor to interpret outcome after cardiac operation. Methods: In a cross-sectional study, 100 children with congenital heart disease undergoing cardiovascular surgery with cardiopulmonary bypass (CPB without significant left-to-right shunt were selected. Arterial and central venous oxygen saturation values were measured via blood samples simultaneously obtained in 6-hr intervals for a total of 24-hr during postoperative period at hours 0, 6, 12, 18, and 24. Postoperative ventilation support (intubation period and cardiovascular support were also obtained from the hospital records. Statistical analysis was later performed comparing the arterial-mixed venous oxygen saturation differences and durations of required ventilatory and cardiovascular support, both for the complicated and non-complicated patient groups. The data was processed with correlation Pearson and Mann-Whitney U tests in SPSS 15 software, P less than 0.05 was significant. Results: Mortality following cardiac operation is 6% and complications may happen in 45% of the cases. The highest Arterial-mixed venous oxygen saturation difference occurred immediately post operation (up to 57%. These measures were high up to 18 hours in complicated and non-complicated groups (36% vs. 31% ; P 0.05. Conclusion: Arterial-mixed venous oxygen saturation difference may be high as much as 57% or as low as 23%.These different measures, being higher up to 18 hours in complicated to non-complicated groups after 18 hours, can be related to tissue ischemia during surgery and cannot be discriminative.

  9. [Blood groups as a risk factor in venous thrombosis].

    Science.gov (United States)

    Hernández Cañete, C M; Alvarez Dieguez, R; González Sánchez M de la, C; Díaz Hernández, C; Sánchez Montiel, M E

    1993-01-01

    We report 173 patients with venous thrombosis (or post-thrombotic syndrome) demonstrated by phlebography. We show up the importance of blood groups as risk factor, being very significant the A group. Female sex is associated with a high incidence of this pathology. A frequent location is the left lower limb.

  10. Biomarkers of coagulation, fibrinolysis, endothelial function, and inflammation in arterialized venous blood

    DEFF Research Database (Denmark)

    Gram, Anne Sofie; Skov, Jane; Ploug, Thorkil

    2014-01-01

    Effects of venous blood arterialization on cardiovascular risk markers are still unknown. We evaluated biomarkers of inflammation, coagulation, fibrinolysis, and endothelial function in arterialized compared with regular venous blood. Cubital venipunctures were obtained from 10 healthy volunteers...

  11. Monitoring of renal venous PO2 and kidney oxygen consumption in rats by a near-infrared phosphorescence lifetime technique

    OpenAIRE

    Mik, Egbert; Johannes, Tanja; Ince, Can

    2008-01-01

    textabstractRenal oxygen consumption (V̇O2,ren) is an important parameter that has been shown to be influenced by various pathophysiological circumstances. VV̇O2,renhas to be repeatedly measured during an experiment to gain insight in the dynamics of (dys)regulation of oxygen metabolism. In small animals, the classical approach of blood gas analysis of arterial and venous blood samples is only limitedly applicable due to fragile vessels and a low circulating blood volume. We present a phospho...

  12. Brain oxygen saturation assessment in neonates using T2-prepared blood imaging of oxygen saturation and near-infrared spectroscopy.

    Science.gov (United States)

    Alderliesten, Thomas; De Vis, Jill B; Lemmers, Petra Ma; Hendrikse, Jeroen; Groenendaal, Floris; van Bel, Frank; Benders, Manon Jnl; Petersen, Esben T

    2017-03-01

    Although near-infrared spectroscopy is increasingly being used to monitor cerebral oxygenation in neonates, it has a limited penetration depth. The T2-prepared Blood Imaging of Oxygen Saturation (T2-BIOS) magnetic resonance sequence provides an oxygen saturation estimate on a voxel-by-voxel basis, without needing a respiratory calibration experiment. In 15 neonates, oxygen saturation measured by T2-prepared blood imaging of oxygen saturation and near-infrared spectroscopy were compared. In addition, these measures were compared to cerebral blood flow and venous oxygen saturation in the sagittal sinus. A strong linear relation was found between the oxygen saturation measured by magnetic resonance imaging and the oxygen saturation measured by near-infrared spectroscopy ( R2 = 0.64, p infrared spectroscopy oxygen saturation, and magnetic resonance imaging measures of frontal cerebral blood flow, whole brain cerebral blood flow and venous oxygen saturation in the sagittal sinus ( R2 = 0.71, 0.50, 0.65; p infrared spectroscopy and T2-prepared blood imaging of oxygen saturation, confirming the validity of using of these techniques for determining cerebral oxygenation.

  13. Erythrocyte volume in acidified venous blood from exercising limbs.

    Science.gov (United States)

    Van Beaumont, W.; Rochelle, R. H.

    1973-01-01

    Five male volunteers performed arm exercises in the sitting position by cranking the pedals of a bicycle ergometer at 50 revolutions per min. The initial mechanical work load of 0 kgm/min was increased every minute by 75 kgm/min until exhaustion occurred. The data obtained show a significant acidification of the venous blood from the working arms and a substantial increase in venous pCO2 during this type of muscular activity. However, the erythrocyte volume remained unaltered during the exercise.

  14. Arterio-venous differences in cord levels of catecholamines, glucose, lactate and blood gases.

    Science.gov (United States)

    Koh, Daisy K M; Hume, Robert; Eisenhofer, Graeme; Watson, Jennifer; Williams, Fiona L R

    2016-08-01

    Norepinephrine (NE) and epinephrine (EPI) levels are higher in cord arterial blood relative to venous blood, consistent with active mechanisms of placental-maternal clearance. There are no contemporary studies of cord arteriovenous blood levels of sulfated and non-sulfated catechols. To assess the arteriovenous differences in cord blood levels of dopamine (DA), the sulfated catecholamines and their sulfated and non-sulfated metabolites. To correlate levels of oxygen, H+/CO2, and glucose with cord catecholamine levels. Fifty-seven term infants, delivered by elective cesarean section, were recruited. Cord arterial and venous blood was sampled; levels of glucose, lactate, blood gases, six catechols and their sulfated conjugates were measured. With one exception (DOPA sulfate), mean cord arterial levels of sulfated and non-sulfated catechols were significantly higher than venous levels. Arterial lactate and glucose levels were independently associated with NE levels, but only lactate was associated with levels of EPI and DA. This study establishes that in vivo metabolic parameters of hypoxia, respiratory and metabolic acidosis are associated with catecholamine levels, a key relationship for perinatal adaptation and homeostasis, and findings that are consistent with in vitro studies of the regulators of catecholamine secretion.

  15. Prediction of arterial blood gas values from venous blood gas values in Asiatic black bears (Ursus thibetanus) anesthetized with intramuscular medetomidine and zolazepam-tiletamine.

    Science.gov (United States)

    Jeong, Dong-Hyuk; Yang, Jeong-Jin; Lee, Lyon; Yeon, Seong-Chan

    2017-10-20

    The objective of this study was to measure differences between arterial and venous blood gas parameters and to evaluate whether arterial blood gas values can be estimated from venous blood in Asiatic black bears (ABBs). Twelve healthy captive ABBs (8 males and 4 females; 8-16 years; 76.8-220 kg) were included in this study. The bears were immobilized with medetomidine and zolazepam-tiletamine using a dart gun. Arterial and venous samples were collected simultaneously at 5 and 35 min after recumbency (5- and 35-min points). Partial pressure of oxygen (PO2), partial pressure of carbon dioxide (PCO2), pH, bicarbonate (HCO3(-)), total carbon dioxide (TCO2), oxygen saturation of hemoglobin (SO2) and base excess (BEecf) were analyzed using a portable blood gas analyzer. There was no marked difference in measured and calculated variables over time in both venous and arterial blood except for PO2. However, arterial PO2, SO2 and pH were significantly higher and arterial PCO2, TCO2 and HCO3(-) were lower than those of venous samples at both 5- and 35-min points. In the regression analysis to estimate arterial values from venous values, PCO2, TCO2, HCO3(-), BEecf and pH significantly showed over 0.45 in coefficient of determination value (R(2)), and there were little differences between actual and predicted arterial values. Although there were limits in venous gas values replaced those of arterial blood, if we could not get the arterial samples, the regression formulas for arterial values from venous blood in this study would be useful clinically, except for PO2 and SO2.

  16. Correlation of central venous pressure with venous blood gas analysis parameters; a diagnostic study

    Directory of Open Access Journals (Sweden)

    Sima Rahim-Taleghani

    2017-03-01

    Full Text Available Objective: This study was conducted to assess the correlation between central venous pressure (CVP and venous blood gas (VBG analysis parameters, to facilitate management of severe sepsis and septic shock in emergency department. Material and methods: This diagnostic study was conducted from January 2014 until June 2015 in three major educational medical centers, Tehran, Iran. For patients selected with diagnosis of septic shock, peripheral blood sample was taken for testing the VBG parameters and the anion gap (AG was calculated. All the mentioned parameters were measured again after infusion of 500 cc of normal saline 0.9% in about 1 h. Results: Totally, 93 patients with septic shock were enrolled, 63 male and 30 female. The mean age was 72.53 ± 13.03 and the mean Shock Index (SI before fluid therapy was 0.79 ± 0.30. AG and pH showed significant negative correlations with CVP, While HCO3 showed a significant positive correlation with CVP. These relations can be affected by the treatment modalities used in shock management such as fluid therapy, mechanical ventilation and vasopressor treatment. Conclusion: It is likely that there is a significant statistical correlation between VBG parameters and AG with CVP, but further research is needed before implementation of the results of this study. Keywords: Shock, Septic, Central venous pressure, Blood gas analysis, Emergency department, Emergency medicine

  17. Hyperpolarized (129)Xe T (1) in oxygenated and deoxygenated blood

    Science.gov (United States)

    Albert, M. S.; Balamore, D.; Kacher, D. F.; Venkatesh, A. K.; Jolesz, F. A.

    2000-01-01

    The viability of the new technique of hyperpolarized (129)Xe MRI (HypX-MRI) for imaging organs other than the lungs depends on whether the spin-lattice relaxation time, T(1), of (129)Xe is sufficiently long in the blood. In previous experiments by the authors, the T(1) was found to be strongly dependent upon the oxygenation of the blood, with T(1) increasing from about 3 s in deoxygenated samples to about 10 s in oxygenated samples. Contrarily, Tseng et al. (J. Magn. Reson. 1997; 126: 79-86) reported extremely long T(1) values deduced from an indirect experiment in which hyperpolarized (129)Xe was used to create a 'blood-foam'. They found that oxygenation decreased T(1). Pivotal to their experiment is the continual and rapid exchange of hyperpolarized (129)Xe between the gas phase (within blood-foam bubbles) and the dissolved phase (in the skin of the bubbles); this necessitated a complicated analysis to extract the T(1) of (129)Xe in blood. In the present study, the experimental design minimizes gas exchange after the initial bolus of hyperpolarized (129)Xe has been bubbled through the sample. This study confirms that oxygenation increases the T(1) of (129)Xe in blood, from about 4 s in freshly drawn venous blood, to about 13 s in blood oxygenated to arterial levels, and also shifts the red blood cell resonance to higher frequency. Copyright 2000 John Wiley & Sons, Ltd. Abbreviations used BOLD blood oxygen level dependent NOE nuclear overhouses effect PO(2) oxygen partial pressure RBC red blood cells RF radio frequency SNR signal-to-noise ratio.

  18. Blood flow in the cerebral venous system: modeling and simulation.

    Science.gov (United States)

    Miraucourt, Olivia; Salmon, Stéphanie; Szopos, Marcela; Thiriet, Marc

    2017-04-01

    The development of a software platform incorporating all aspects, from medical imaging data, through three-dimensional reconstruction and suitable meshing, up to simulation of blood flow in patient-specific geometries, is a crucial challenge in biomedical engineering. In the present study, a fully three-dimensional blood flow simulation is carried out through a complete rigid macrovascular circuit, namely the intracranial venous network, instead of a reduced order simulation and partial vascular network. The biomechanical modeling step is carefully analyzed and leads to the description of the flow governed by the dimensionless Navier-Stokes equations for an incompressible viscous fluid. The equations are then numerically solved with a free finite element software using five meshes of a realistic geometry obtained from medical images to prove the feasibility of the pipeline. Some features of the intracranial venous circuit in the supine position such as asymmetric behavior in merging regions are discussed.

  19. Continous monitoring of central venous oxygen saturation in children and infants.

    Science.gov (United States)

    Vidmar, Ivan

    2010-01-01

    Maintenance of adequate tissue oxygenation is an important task in intensive care units. There are many variables which are measured for this purpose. Central venous oxygen saturation (ScvO2) monitoring has some advantages over the mixed venous oxygen saturation (SvO2) monitoring in children and infants as there is no need to insert a pulmonary catheter. The clinical usefulness seems promising.

  20. Noninvasive measurement of internal jugular venous oxygen saturation by photoacoustic imaging

    Science.gov (United States)

    Garcia-Uribe, Alejandro; Erpelding, Todd N.; Ke, Haixin; Reddy, Kavya; Sharma, Anshuman; Wang, Lihong V.

    2014-03-01

    The metabolic rate and oxygen consumption of the brain is reflected in jugular venous oxygen saturation. In many clinical conditions, such as head trauma, stroke, and low cardiac output states, the brain is at risk for hypoxic-ischemic injury. The current gold standard for monitoring brain oxygenation is invasive and requires jugular vein catheterization under fluoroscopic guidance; and therefore it is rarely used. Photo-acoustic tomography in combination with ultrasound can be used to estimate oxygen saturation of the internal jugular vein in real-time. This noninvasive method will enable earlier detection and prevention of impending hypoxic brain injury. A wavelength-tunable dye laser pumped by a Nd:YAG laser delivers light through an optical fiber bundle, and a modified commercial ultrasound imaging system (Philips iU22) detects both the pulse-echo ultrasound (US) and photoacoustic (PA) signals. A custom-built multichannel data acquisition system renders co-registered ultrasound and photoacoustic images at 5 frames per second. After the jugular vein was localized in healthy volunteers, dualwavelength PA images were used to calculate the blood hemoglobin oxygen saturation from the internal jugular vein in vivo. The preliminary results raise confidence that this emerging technology can be used clinically as an accurate, noninvasive indicator of cerebral oxygenation.

  1. Correlation of central venous pressure with venous blood gas analysis parameters; a diagnostic study.

    Science.gov (United States)

    Rahim-Taleghani, Sima; Fatemi, Alireza; Alavi Moghaddam, Mostafa; Shojaee, Majid; Abushouk, Abdelrahman Ibrahim; Forouzanfar, Mohammad Mehdi; Baratloo, Alireza

    2017-03-01

    This study was conducted to assess the correlation between central venous pressure (CVP) and venous blood gas (VBG) analysis parameters, to facilitate management of severe sepsis and septic shock in emergency department. This diagnostic study was conducted from January 2014 until June 2015 in three major educational medical centers, Tehran, Iran. For patients selected with diagnosis of septic shock, peripheral blood sample was taken for testing the VBG parameters and the anion gap (AG) was calculated. All the mentioned parameters were measured again after infusion of 500 cc of normal saline 0.9% in about 1 h. Totally, 93 patients with septic shock were enrolled, 63 male and 30 female. The mean age was 72.53 ± 13.03 and the mean Shock Index (SI) before fluid therapy was 0.79 ± 0.30. AG and pH showed significant negative correlations with CVP, While HCO3 showed a significant positive correlation with CVP. These relations can be affected by the treatment modalities used in shock management such as fluid therapy, mechanical ventilation and vasopressor treatment. It is likely that there is a significant statistical correlation between VBG parameters and AG with CVP, but further research is needed before implementation of the results of this study.

  2. Central venous oxygen saturation: analysis, clinical use and effects on mortality.

    Science.gov (United States)

    Reid, Megan

    2013-09-01

    The aim of this literature review was to provide a clear definition of central venous oxygen saturation (ScvO₂), highlight the differences between ScvO₂ and mixed venous oxygen saturation (SvO₂), show how it can be used clinically and the effect central venous oxygen saturation has on mortality. Many articles concentrate on the individual aspects of ScvO₂, such as its use in early goal-directed therapy, but few provide a full overview of what it means, how to interpret results and how it can be used clinically. Keywords were searched for including central venous oxygen saturation ScvO₂ mixed venous oxygen saturations ScvO₂ early goal-directed therapy sepsis and mortality. Where possible only publications within the last 10 years were used but key publications were not excluded if they were out with this time frame. Central venous oxygen saturation (ScvO₂) is a very important measurement which can be easily taken in a critical care environment by both medical and nursing staff. It provides an understanding of the patient's oxygen delivery, oxygen consumption and cardiac output. It has a key role within early goal-directed therapy and has been shown to decrease mortality when taken and analysed appropriately. This literature review will highlight to nursing staff within the critical care environment the importance of central venous oxygen saturation measurement and interpretation. By raising awareness of the importance of this measurement it is hoped nursing staff will be proactive in both taking this test and analysing the results, therefore facilitating better care for the septic, critically ill patient and improving outcomes for these patients. © 2013 British Association of Critical Care Nurses.

  3. Mixed venous oxygen saturation monitoring revisited: thoughts for critical care nursing practice.

    Science.gov (United States)

    Christensen, Martin

    2012-05-01

    Less invasive methods of determining cardiac output are now readily available. Using indicator dilution technique, for example has made it easier to continuously measure cardiac output because it uses the existing intra-arterial line. Therefore gone is the need for a pulmonary artery floatation catheter and with it the ability to measure left atrial and left ventricular work indices as well the ability to monitor and measure a mixed venous saturation (SvO(2)). The aim of this paper is to put forward the notion that SvO(2) provides valuable information about oxygen consumption and venous reserve; important measures in the critically ill to ensure oxygen supply meets cellular demand. In an attempt to portray this, a simplified example of the septic patient is offered to highlight the changing pathophysiological sequelae of the inflammatory process and its importance for monitoring SvO(2). SvO(2) monitoring, it could be argued, provides the gold standard for assessing arterial and venous oxygen indices in the critically ill. For the bedside ICU nurse the plethora of information inherent in SvO(2) monitoring could provide them with important data that will assist in averting potential problems with oxygen delivery and consumption. However, it has been suggested that central venous saturation (ScvO(2)) might be an attractive alternative to SvO(2) because of its less invasiveness and ease of obtaining a sample for analysis. There are problems with this approach and these are to do with where the catheter tip is sited and the nature of the venous admixture at this site. Studies have shown that ScvO(2) is less accurate than SvO(2) and should not be used as a sole guiding variable for decision-making. These studies have demonstrated that there is an unacceptably wide range in variance between ScvO(2) and SvO(2) and this is dependent on the presenting disease, in some cases SvO(2) will be significantly lower than ScvO(2). Whilst newer technologies have been developed to

  4. Central venous oxygen saturation and thoracic admittance during dialysis: new approaches to hemodynamic monitoring

    DEFF Research Database (Denmark)

    Cordtz, J.; Olde, B.; Solem, K.

    2008-01-01

    events are reflected in the central venous oxygen saturation (ScO(2)) and thoracic admittance (TA) during dialysis. Twenty ambulatory HD patients, 11 hypotension prone (HP) and 9 hypotension resistant, with central vascular access, were monitored during 3 HD sessions each. ScO(2), TA, finger blood...... in ScO(2) and TA correlated much closer than did changes in ScO(2) and DeltaBV (r=0.43 and 0.18, respectively). Our results suggest that an intradialytic decrease in cardiac output, as reflected by a fall in ScO(2), is a common feature to HD patients prone to IDH. In patients using a central vascular...... access, ScO(2) and TA measurements may be more specific to the pathophysiologic events preceding IDH than DeltaBV-the current standard monitoring method Udgivelsesdato: 2008/7...

  5. Arterialized and venous blood lactate concentration difference during different exercise intensities

    Directory of Open Access Journals (Sweden)

    Leandro C. Felippe

    2017-06-01

    Conclusion: These results suggest a delayed lactate appearance in the venous blood, which is accentuated at higher exercise intensities. The lactate measured in arterialized and venous blood is interchangeable only when blood samples are collected at least 10 minutes after the exercise starts.

  6. Peripheral venous blood gas analysis: An alternative to arterial blood gas analysis for initial assessment and resuscitation in emergency and intensive care unit patients.

    Science.gov (United States)

    Awasthi, Shilpi; Rani, Raka; Malviya, Deepak

    2013-01-01

    Arterial blood gas (ABG) analysis is the gold standard method for assessment of oxygenation and acid base analysis, yielding valuable information about a variety of disease process. This study is aimed to determine the extent of correlation between arterial and peripheral venous samples for blood gases and acid base status in critically ill and emergency department patients and to evaluate if venous sample may be a better alternative for initial assessment and resuscitation. The prospective study was conducted on 45 patients of either sex in the age group of 15-80 years of intensive care unit and emergency ward. Relevant history, presenting complaints, vital signs, and indication for testing were recorded. Arterial and peripheral venous samples were drawn simultaneously in a pre-heparinized syringe and analyzed immediately for blood gases and acid base status. Mean difference and Pearson's product moment correlation coefficient was used to compare the result. After statistical evaluation, the present study shows minimal mean difference and good correlation (r > 0.9) between arterial and peripheral venous sample for blood gases and acid base status. Correlation in PO2 measurement was poor (r blood may be a useful alternative to arterial blood during blood gas analysis obviating the need for arterial puncture in difficult clinical situation especially trauma patients, for initial emergency department assessment and early stages of resuscitation.

  7. Comparison of two analyzers to determine selected venous blood analytes of Quaker parrots (Myiopsitta monachus).

    Science.gov (United States)

    Rettenmund, Christy L; Heatley, J Jill; Russell, Karen E

    2014-06-01

    Point of care devices can assess electrolyte, blood gas, biochemical, and hematologic values in a critical care setting. Although these devices are commonly used in humans and companion mammals, few studies have assessed their use in avian species. This study compares electrolyte, hemoglobin (Hgb), hematocrit (Hct), acid-base, and venous blood gas parameters between the i-STAT and IRMA TruPoint blood gas analysis systems for 35 Quaker parrots. Agreement between the two analyzers and the effect of gender, time lag between sample analysis, and cartridge expiration were evaluated. Male birds had increased Hgb and Hct compared with females, independent of analyzer method. In expired i-STAT cartridges, only glucose significantly increased. Packed cell volume determined by centrifugation was higher than Hct, as calculated by either analyzer. The analyzers had good agreement for total carbon dioxide, bicarbonate, pH, and Hgb, fair agreement for potassium (K), ionized calcium (iCa), venous partial pressure of carbon dioxide, and base excess, and poor agreement for sodium (Na), venous partial pressure of oxygen (PO2), and oxygen saturation (SO2). Values for Na, iCa, PO2, and SO2 were significantly higher on the IRMA than the i-STAT, while K was significantly lower on the IRMA when compared with the i-STAT. The time lag between sample analyses on the i-STAT and IRMA did not be correlate to any analyte changes. Despite these differences, both the i-STAT and the IRMA appear to be acceptable clinical tools in avian critical care, although reference ranges for each analyzer should be created.

  8. Predicting arterial blood gas and lactate from central venous blood analysis in critically ill patients: a multicentre, prospective, diagnostic accuracy study.

    Science.gov (United States)

    Boulain, T; Garot, D; Vignon, P; Lascarrou, J-B; Benzekri-Lefevre, D; Dequin, P-F

    2016-09-01

    The estimation of arterial blood gas and lactate from central venous blood analysis and pulse oximetry [Formula: see text] readings has not yet been extensively validated. In this multicentre, prospective study performed in 590 patients with acute circulatory failure, we measured blood gases and lactate in simultaneous central venous and arterial blood samples at 6 h intervals during the first 24 h after insertion of central venous and arterial catheters. The study population was randomly divided in a 2:1 ratio into model derivation and validation sets. We derived predictive models of arterial pH, carbon dioxide partial pressure, oxygen saturation, and lactate, using clinical characteristics, [Formula: see text], and central venous blood gas values as predictors, and then tested their performance in the validation set. In the validation set, the agreement intervals between predicted and actual values were -0.078/+0.084 units for arterial pH, -1.32/+1.36 kPa for arterial carbon dioxide partial pressure, -5.15/+4.47% for arterial oxygen saturation, and -1.07/+1.05 mmol litre(-1) for arterial lactate (i.e. around two times our predefined clinically tolerable intervals for all variables). This led to ∼5% (or less) of extreme-to-extreme misclassifications, thus giving our predictive models only marginal agreement. Thresholds of predicted variables (as determined from the derivation set) showed high predictive values (consistently >94%), to exclude abnormal arterial values in the validation set. Using clinical characteristics, [Formula: see text], and central venous blood analysis, we predicted arterial blood gas and lactate values with marginal accuracy in patients with circulatory failure. Further studies are required to establish whether the developed models can be used with acceptable safety. © The Author 2016. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  9. Oxygen limitation of thermal tolerance in cod, Gadus morhua L., studied by magnetic resonance imaging and on-line venous oxygen monitoring.

    Science.gov (United States)

    Lannig, Gisela; Bock, Christian; Sartoris, Franz J; Pörtner, Hans O

    2004-10-01

    The hypothesis of an oxygen-limited thermal tolerance due to restrictions in cardiovascular performance at extreme temperatures was tested in Atlantic cod, Gadus morhua (North Sea). Heart rate, changes in arterial and venous blood flow, and venous oxygen tensions were determined during an acute temperature change to define pejus ("getting worse") temperatures that border the thermal optimum range. An exponential increase in heart rate occurred between 2 and 16 degrees C (Q(10) = 2.38 +/- 0.35). Thermal sensitivity was reduced beyond 16 degrees C when cardiac arrhythmia became visible. Flow-weighted magnetic resonance imaging (MRI) measurements of temperature-dependent blood flow revealed no exponential but a hyperbolic increase of blood flow with a moderate linear increase at temperatures >4 degrees C. Therefore, temperature-dependent heart rate increments are not mirrored by similar increments in blood flow. Venous Po(2) (Pv(O(2))), which reflects the quality of oxygen supply to the heart of cod (no coronary circulation present), followed an inverse U-shaped curve with highest Pv(O(2)) levels at 5.0 +/- 0.2 degrees C. Thermal limitation of circulatory performance in cod set in below 2 degrees C and beyond 7 degrees C, respectively, characterized by decreased Pv(O(2)). Further warming led to a sharp drop in Pv(O(2)) beyond 16.1 +/- 1.2 degrees C in accordance with the onset of cardiac arrhythmia and, likely, the critical temperature. In conclusion, progressive cooling or warming brings cod from a temperature range of optimum cardiac performance into a pejus range, when aerobic scope falls before critical temperatures are reached. These patterns might cause a shift in the geographical distribution of cod with global warming.

  10. Correlation between some arterial and venous blood gas parameters in healthy newborn Martina Franca donkey foals from birth to 96 hours of age.

    Science.gov (United States)

    Carluccio, A; Contri, A; Gloria, A; Veronesi, M C; Sfirro, M P; Parrillo, S; Robbe, D

    2017-01-01

    In neonatology, blood gas analysis is a useful tool in the evaluation of the health of newborns and plays a key role in early detection of critically ill subjects. Because blood gas analysis parameters have not previously been studied in any depth in donkey foals, this study was performed on 16 healthy Martina Franca donkey foals born after an uncomplicated delivery. Arterial and venous blood samples were collected at 5 minutes and at 12, 24, 72, and 96 hours of age. Blood gas analysis was performed by a portable analyzer, measuring arterial and venous total carbon dioxide, carbon dioxide partial pressure (pCO2), oxygen partial pressure (pO2), oxygen saturation (sO2), bicarbonate, base excess (BE), pH, and lactate (LT). Lower blood pH values, pO2 and sO2, and a higher level of lactate were found at birth in comparison with subsequent sampling times. This moderate acidotic profile disappeared at 12 hours, when all the parameters became constant until the end of the study period. As expected, significant differences between arterial and venous blood gas parameters related to the oxygenation, such as pO2 and sO2, and partially carbon dioxide partial pressure were found, whereas total carbon dioxide, pH, BE, and LT were comparable in arterial and venous blood samples. For these latter parameters, the highly significant correlation between arterial and venous findings suggests that venous samples could be an acceptable alternative to the arterial sample for blood gas analysis in newborn donkey foals, when the oxygenation status of the patient is not the first goal of patient analysis. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Central venous oxygen saturation for the diagnosis of low cardiac output in septic shock patients

    DEFF Research Database (Denmark)

    Perner, A; Haase, N; Wiis, J

    2010-01-01

    Simple diagnostic tests are needed to screen septic patients for low cardiac output because intervention is recommended in these patients. We assessed the diagnostic value of central venous oxygen saturation in the superior vena cava (ScvO(2)) for detecting low cardiac output in patients with sep...... with septic shock.......Simple diagnostic tests are needed to screen septic patients for low cardiac output because intervention is recommended in these patients. We assessed the diagnostic value of central venous oxygen saturation in the superior vena cava (ScvO(2)) for detecting low cardiac output in patients...

  12. Cardiac output and mixed venous oxygen content measurements by a tracer bolus method: theory.

    Science.gov (United States)

    Clark, J S; Lin, Y J; Criddle, M J; Cutillo, A G; Bigler, A H; Farr, F L; Renzetti, A D

    1997-09-01

    We present a bolus method of inert-gas delivery to the lungs that facilitates application of multiple inert gases and the multiple inert-gas-exchange technique (MIGET) model to noninvasive measurements of cardiac output (CO) and central mixed venous oxygen content Reduction in recirculation error is made possible by 1) replacement of sinusoidal input functions with impulse inputs and 2) replacement of steady-state analyses with transient analyses. Recirculation error reduction increases the inert-gas selection to include common gases without unusually high (and difficult to find) tissue-to-blood partition coefficients for maximizing the systemic filtering efficiency. This paper also presents a practical method for determining the recirculation contributions to inert expired profiles in animals and determining their specific contributions to errors in the calculations of CO and from simulations applied to published ventilation-perfusion ratio (V/Q) profiles. Recirculation errors from common gases were found to be reducible to the order of 5% or less for both CO and whereas simulation studies indicate that measurement bias contributions from recirculation, V/Q mismatch, and the V/Q extraction process can be limited to 15% for subjects with severe V/Q mismatch and high inspired oxygen fraction levels. These studies demonstrate a decreasing influence of V/Q mismatch on parameter extraction bias as the number of inert gases are increased. However, the influence of measurement uncertainty on parameter extraction error limits improvement to six gases.

  13. Gene expression profiles are different in venous and capillary blood: Implications for vaccine studies.

    Science.gov (United States)

    Stein, D F; O'Connor, D; Blohmke, C J; Sadarangani, M; Pollard, A J

    2016-10-17

    Detailed analysis of the immunological pathways leading to robust vaccine responses has become possible with the application of systems biology, including transcriptomic analysis. Venous blood is usually obtained for such studies but others have obtained capillary blood (e.g. finger-prick). Capillary samples are practically advantageous, especially in children. The aim of this study was to compare gene expression profiles in venous and capillary blood before, 12h and 24h after vaccination with 23-valent pneumococcal polysaccharide or trivalent inactivated seasonal influenza vaccines. Gene expression at baseline was markedly different between venous and capillary samples, with 4940 genes differentially expressed, and followed a different pattern of changes after vaccination. At baseline, multiple pathways were upregulated in venous compared to capillary blood, including transforming growth factor-beta receptor signalling and toll-like receptor cascades. After vaccination with the influenza vaccine, there was enrichment for T and NK cell related signatures in capillary blood, and monocyte signatures in venous blood. By contrast, after vaccination with the pneumococcal vaccination, there was enrichment of dendritic cells, monocytes and interferon related signatures in capillary blood, whilst at 24h there was enrichment for T and NK cell related signatures in venous blood. These data show differences between venous and capillary gene expression both at baseline, and post vaccination, which may impact on the conclusions regarding immunological mechanisms drawn from studies using these different sampling methodologies. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Influence of arterial dissolved oxygen level on venous oxygen saturation: don't forget the PaO2!

    Science.gov (United States)

    Legrand, Matthieu; Vallée, Fabrice; Mateo, Joaquim; Payen, Didier

    2014-06-01

    Dissolved oxygen (i.e., unbound to hemoglobin) is often neglected as a determinant of central venous oxygen saturation (ScvO2) in review articles and textbooks. These statements may lead to potential misinterpretation of SCvO2 value across FiO2 changes. In this study, we aimed to explore the influence of PaO2 and FiO2 on ScvO2 in ventilated critically ill patients. This was a prospective observational study in two surgical intensive care units. Mechanically ventilated and sedated patients with cardiac output and ScvO2 monitoring and PaO2/FiO2 > 200 with inspiratory oxygen (FiO2) ≤ 0.5 were enrolled (cohort [ScvO2]). A second cohort of brain-injured patients with jugular venous oxygen saturation monitoring was studied to assess the application of the results to regional circulation (cohort [SjvO2]). Central venous oxygen saturation was measured at baseline FiO2 and at FiO2 = 1. We finally estimated the participation of the dissolved oxygen (PadissolvO2) to the ScvO2 variations. Twenty patients formed the cohort ScvO2 and eight formed the cohort SjvO2. Central venous oxygen saturation rose from 71% (69%-76%) to 84% (78%-88%) after increasing FiO2, whereas PaO2 rose from 100 (85-124) mmHg to 387 (360-449) mmHg. The rise of ScvO2 was mostly ascribable to the dissolved oxygen. The increase of ScvO2 was not explained by changes in cardiac output or hemoglobin levels. Jugular venous oxygen saturation rose from 71% (58%-78%) to 83% (78%-89%) after increasing FiO2. Arterial dissolved oxygen level can significantly influence the ScvO2 value. Therefore, PaO2 should not be overlooked while considering the ScvO2 value as a therapeutic goal. Interpretation of ScvO2 variations in response to a therapeutic challenge (i.e., fluid challenge, inotropic drug initiation) should be performed at constant FiO2.

  15. Continuous monitoring of central venous oxygen saturation (Pediasat) in pediatric patients undergoing cardiac surgery: a validation study of a new technology.

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    Ranucci, Marco; Isgrò, Giuseppe; De La Torre, Teresa; Romitti, Federica; De Benedetti, Donatella; Carlucci, Concetta; Kandil, Hassan; Ballotta, Andrea

    2008-12-01

    Mixed venous oxygen saturation and central venous oxygen saturation are considered possible indicators of the adequacy of oxygen delivery with respect to the oxygen needs of critically ill adult and pediatric patients. The present study was aimed at validating the accuracy of a new technology (Pediasat central venous catheter) in providing a continuous measurement of the central venous oxygen saturation in pediatric patients. A prospective observational study. Thirty pediatric patients (age, 6 days-9 years) undergoing cardiac operations. Data obtained with the Pediasat during and after the operation were compared with simultaneously collected venous blood samples analyzed with standard laboratory techniques. A clinical research hospital. None. A Bland and Altman analysis was performed on 30 matched sets of data collected before cardiopulmonary bypass, during cardiopulmonary bypass, and during the intensive care unit stay. Before cardiopulmonary bypass, there was a bias of 0.003, with lower and upper limits of agreement, -5.84 and 5.84 (percentage error, 17.3%). During cardiopulmonary bypass, the bias was 0.57 and lower and upper limits of agreement were -7.7 and 8.7 (percentage error, 23.2%). At 2 hours after the arrival in the intensive care unit, the bias was -0.6 and the lower and upper limits of agreement were -8 and 6.8 (percentage error, 20.3%). Because of the minimal bias and the acceptable value of percentage error, the Pediasat may be considered as an accurate tool for the continuous measurement of the central venous oxygen saturation in neonates and pediatric patients during and after cardiac operations.

  16. VENOUS OCULAR BLOOD FLOW IN NORMAL TENSION AND HIGH TENSION GLAUCOMA

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    Natalia I Kurysheva

    2016-04-01

    Full Text Available Purpose: to study the eye’s venous blood flow and the correlation between clinical data and ocular blood flow in normal tension and high tension open angle glaucoma (POAG. Methods: Color Doppler imaging of arterial and venous blood flow was performed on 78 patients with normal tension glaucoma (NTG, 80 patients with high-pressure glaucoma (HPG and 60 control subjects. The statistical analysis included the calculation of the correlation between clinical data and ocular blood flow parameters, as well as Pearson’s correlation coefficient. The threshold P value for statistical significance was 0.05. Results: Ocular blood flow (both arterial and venous was significantly reduced in NTG and HTG, compared to the control group. While the arterial blood flow reduction was more significant in HTG than in NTG, a decrease in venous blood flow had a higher incidence in NTG. In contrast to the control group, POAG patients showed a correlation between clinical data and venous blood flow. The correlation was higher in NTG patients. Conclusions: The results obtained indicate the potential importance of venous blood flow in glaucoma pathogenesis, especially in NTG.

  17. Noninvasive optical quantification of absolute blood flow, blood oxygenation, and oxygen consumption rate in exercising skeletal muscle

    Science.gov (United States)

    Gurley, Katelyn; Shang, Yu; Yu, Guoqiang

    2012-07-01

    This study investigates a method using novel hybrid diffuse optical spectroscopies [near-infrared spectroscopy (NIRS) and diffuse correlation spectroscopy (DCS)] to obtain continuous, noninvasive measurement of absolute blood flow (BF), blood oxygenation, and oxygen consumption rate (\\Vdot O2) in exercising skeletal muscle. Healthy subjects (n=9) performed a handgrip exercise to increase BF and \\Vdot O2 in forearm flexor muscles, while a hybrid optical probe on the skin surface directly monitored oxy-, deoxy-, and total hemoglobin concentrations ([HbO2], [Hb], and THC), tissue oxygen saturation (StO2), relative BF (rBF), and relative oxygen consumption rate (r\\Vdot O2). The rBF and r\\Vdot O2 signals were calibrated with absolute baseline BF and \\Vdot O2 obtained through venous and arterial occlusions, respectively. Known problems with muscle-fiber motion artifacts in optical measurements during exercise were mitigated using a novel gating algorithm that determined muscle contraction status based on control signals from a dynamometer. Results were consistent with previous findings in the literature. This study supports the application of NIRS/DCS technology to quantitatively evaluate hemodynamic and metabolic parameters in exercising skeletal muscle and holds promise for improving diagnosis and treatment evaluation for patients suffering from diseases affecting skeletal muscle and advancing fundamental understanding of muscle and exercise physiology.

  18. Multiwavelength optoacoustic system for noninvasive monitoring of cerebral venous oxygenation: a pilot clinical test in the internal jugular vein

    Science.gov (United States)

    Petrov, Yuriy Y.; Petrova, Irina Y.; Patrikeev, Igor A.; Esenaliev, Rinat O.; Prough, Donald S.

    2006-06-01

    A noninvasive, high-resolution optoacoustic technique is a promising alternative to currently used invasive methods of brain oxygenation monitoring. We present the results of our pilot clinical test of this technique in healthy volunteers. Multiwavelength optoacoustic measurements (with nanosecond optical parametric oscillator as a source of radiation) were performed on the area of the neck overlying the internal jugular vein, a deeply located large vein that drains blood from the brain and from extracranial tissues. Optoacoustic signals induced in venous blood were measured with high resolution and signal-to-noise ratio despite the presence of a thick layer of overlying tissue (up to 10 mm). The characteristic parameters of the signal at different wavelengths correlated well with the spectrum of the effective attenuation coefficient of blood.

  19. Correlation of glucose level among venous, gingival and finger-prick blood samples in diabetic patients

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    Priyanka Chopra

    2011-01-01

    Full Text Available It is essential for a dental surgeon or a periodontist to detect blood glucose level for patients whose signs and symptoms are suggestive of diabetes. Seventy patients in the age group of 40 to 80 years of either sex were selected for the study. The study population included patients with type 1 or type 2 diabetes mellitus. Venous blood was used as a control group, whereas gingival blood and finger-prick blood constituted the study groups I and II, respectively. The percentage deviations of gingival blood glucose level measurements and finger-prick blood glucose level measurements from the standard venous blood glucose level measurements were recorded, which showed that 72.86% of gingival and 68.57% of finger-prick blood glucose level measurements were found to be within ΁15% of the standard venous blood glucose level measurements. All values exhibited significant correlations among each other, but correlations between glucose values obtained using venous and gingival blood samples were higher than the correlations between glucose values obtained using venous and finger-prick blood samples.

  20. Obtaining Coagulation Blood Samples From Central Venous Access Devices: A Review of the Literature.

    Science.gov (United States)

    Dalton, Kerri A; Aucoin, Julia; Meyer, Britt

    2015-08-01

    Central venous access devices are used for chemotherapy and other medication administration, blood product administration, parenteral nutrition, and for obtaining blood samples in patients where the vasculature is difficult to access. Patients may need additional blood samples prior to invasive procedures and when clinical situations arise during cancer care. In addition, monitoring coagulability through ongoing blood testing is common in patients with cancer and requires repeated sampling to adjust anticoagulant medications. The purpose of this review of the literature is to determine the best practices for collecting coagulation test samples from central venous access devices. The authors conducted a systematic review of the literature. The only method for obtaining reliable coagulation test results from central venous access devices is the flush then waste/discard method. This method has only been studied with peripherally inserted central catheters. Additional randomized, controlled trials with larger sample sizes are needed to determine the most appropriate method for drawing coagulation test results from central venous access devices.

  1. A pilot study of the effects of a perflubron emulsion, AF 0104, on mixed venous oxygen tension in anesthetized surgical patients.

    Science.gov (United States)

    Wahr, J A; Trouwborst, A; Spence, R K; Henny, C P; Cernaianu, A C; Graziano, G P; Tremper, K K; Flaim, K E; Keipert, P E; Faithfull, N S; Clymer, J J

    1996-01-01

    A pilot study of a perfluorochemical (PFC) emulsion was undertaken to determine whether administration of a perflubron emulsion could result in measurable changes in mixed venous oxygen tension. Seven adult surgical patients received a 0.9-g PFC/kg intravenous dose of perflubron emulsion after acute normovolemic hemodilution (ANH). Hemodynamic and oxygen transport data were collected before and after ANH, immediately after PFC infusion, and at approximate 15-min intervals throughout the surgical period. There were no clinically significant hemodynamic changes associated with the administration of the PFC emulsion. There was a significant increase in mixed venous oxygen tension (PVO2) after the PFC infusion, while cardiac output and oxygen consumption were unchanged. As surgery progressed, the hemoglobin concentration decreased with ongoing blood loss while PVO2 values remained at or above predosing levels. Peak perflubron blood levels were 0.8 g/dL immediately postinfusion, and approximately 0.3 g/dL at 1 h. This pilot study demonstrates that administration of perflubron emulsion results in measurable changes in mixed venous oxygen tension during intraoperative ANH.

  2. Relationship between retinal blood flow and arterial oxygen.

    Science.gov (United States)

    Cheng, Richard W; Yusof, Firdaus; Tsui, Edmund; Jong, Monica; Duffin, James; Flanagan, John G; Fisher, Joseph A; Hudson, Chris

    2016-02-01

    Vascular reactivity, the response of the vessels to a vasoactive stimulus such as hypoxia and hyperoxia, can be used to assess the vascular range of adjustment in which the vessels are able to compensate for changes in PO2. Previous studies in the retina have not accurately quantified retinal vascular responses and precisely targeted multiple PaO2 stimuli at the same time as controlling the level of carbon dioxide, thus precluding them from modelling the relationship between retinal blood flow and oxygen. The present study modelled the relationship between retinal blood flow and PaO2, showing them to be a combined linear and hyperbolic function. This model demonstrates that the resting tonus of the vessels is at the mid-point and that they have great vascular range of adjustment, compensating for decreases in oxygen above a PETCO2 of 32-37 mmHg but being limited below this threshold. Retinal blood flow (RBF) increases in response to a reduction in oxygen (hypoxia) but decreases in response to increased oxygen (hyperoxia). However, the relationship between blood flow and the arterial partial pressure of oxygen has not been quantified and modelled in the retina, particularly in the vascular reserve and resting tonus of the vessels. The present study aimed to determine the limitations of the retinal vasculature by modelling the relationship between RBF and oxygen. Retinal vascular responses were measured in 13 subjects for eight different blood gas conditions, with the end-tidal partial pressure of oxygen (PETCO2) ranging from 40-500 mmHg. Retinal vascular response measurements were repeated twice; using the Canon laser blood flowmeter (Canon Inc., Tokyo, Japan) during the first visit and using Doppler spectral domain optical coherence tomography during the second visit. We determined that the relationship between RBF and PaO2 can be modelled as a combination of hyperbolic and linear functions. We concluded that RBF compensated for decreases in arterial oxygen content

  3. Reduced deep regional cerebral venous oxygen saturation in hemodialysis patients using quantitative susceptibility mapping.

    Science.gov (United States)

    Chai, Chao; Liu, Saifeng; Fan, Linlin; Liu, Lei; Li, Jinping; Zuo, Chao; Qian, Tianyi; Haacke, E Mark; Shen, Wen; Xia, Shuang

    2018-02-01

    Cerebral venous oxygen saturation (SvO2) is an important indicator of brain function. There was debate about lower cerebral oxygen metabolism in hemodialysis patients and there were no reports about the changes of deep regional cerebral SvO2 in hemodialysis patients. In this study, we aim to explore the deep regional cerebral SvO2 from straight sinus using quantitative susceptibility mapping (QSM) and the correlation with clinical risk factors and neuropsychiatric testing. 52 hemodialysis patients and 54 age-and gender-matched healthy controls were enrolled. QSM reconstructed from original phase data of 3.0 T susceptibility-weighted imaging was used to measure the susceptibility of straight sinus. The susceptibility was used to calculate the deep regional cerebral SvO2 and compare with healthy individuals. Correlation analysis was performed to investigate the correlation between deep regional cerebral SvO2, clinical risk factors and neuropsychiatric testing. The deep regional cerebral SvO2 of hemodialysis patients (72.5 ± 3.7%) was significantly lower than healthy controls (76.0 ± 2.1%) (P deep regional cerebral SvO2 in patients. The Mini-Mental State Examination (MMSE) scores of hemodialysis patients were significantly lower than healthy controls (P deep regional cerebral SvO2 did not correlate with MMSE scores (P = 0.630). In summary, the decreased deep regional cerebral SvO2 occurred in hemodialysis patients and dialysis duration, parathyroid hormone, hematocrit, hemoglobin and red blood cell may be clinical risk factors.

  4. Central venous oxygen saturation during cardiopulmonary bypass predicts 3-year survival

    Science.gov (United States)

    Svenmarker, Staffan; Häggmark, Sören; Östman, Margareta; Holmgren, Anders; Näslund, Ulf

    2013-01-01

    OBJECTIVES Long-term survival after cardiac surgery is determined by a number of different risk factors. Central venous oxygen saturation (SvO2) measures the balance between oxygen delivery and demand. SvO2 levels in the intensive care situation are reported to be associated with patient outcome. The present report explores the connection between SvO2 during cardiopulmonary bypass (CPB) and survival after cardiac surgery. METHODS Retrospective analysis of one thousand consecutive cardiac surgical patients was undertaken. SvO2 during CPB was monitored online. Registry data combining specific risk factors with SvO2 were selected for Kaplan–Meier and Cox regression analysis to examine the influence on 30-day and 3-year survivals. RESULTS Nine-hundred and thirty-two patient records were eligible for analysis. SvO2 below 75% during CPB was associated with significantly shorter 30-day and 3-year survivals. Based on Kaplan–Meier statistics, the survival rate decreased by 3.1% (98.1–95.0), P = 0.011 and 6.1% (92.7–86.6), P = 0.003, respectively. The influence of SvO2 on 3-year survival remained statistically significant after controlling for a series of risk factors in the Cox regression analysis. Patients with SvO2 <75% carried a 2-fold (odds ratio 2.1) increased relative risk of shortened 3-year survival (P = 0.003). Other risk factors statistically significantly associated with 3-year survival were age, gender, duration of CPB, blood temperature, hypertension, haematocrit and type of surgical procedure. CONCLUSIONS We report decreased 30-day and 3-year survival expectancy for patients experiencing SvO2 lower than 75% during CPB. PMID:23065747

  5. [Partial anomalous pulmonary venous connection as incidental finding: Explanation for apparently paradoxical central venous blood gas analysis results].

    Science.gov (United States)

    Brandt, L; Artmeier-Brandt, U

    2015-10-01

    A partial anomalous pulmonary venous connection (PAPVC) is a congenital abnormality of the great thoracic vessels the incidence of which is underestimated and is associated with a left-right shunt. It rarely develops into a right-sided cardiac insufficiency. Because of the mostly low left-right shunt volume, a PAPVC is often asymptomatic and mostly incidentally detected in advanced age. Incorrect positioning of a central venous catheter or paradoxical blood gas parameters can serve to indicate the presence of a PAPVC. This article presents the case a 50-year-old patient with a PAPVC of the left upper lobe pulmonary vein draining into the left innominate vein without prior clinical symptoms. Blood gas analyses from the superior vena cava, where the catheter placement was confirmed by computed tomography angiography, showed unexplainable arterial values. The anatomical abnormality was confirmed by computed tomography.

  6. Hemoglobin measured by Hemocue and a reference method in venous and capillary blood: a validation study

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    Neufeld Lynnette

    2002-01-01

    Full Text Available Objective. To assess the comparability of hemoglobin concentration (Hb in venous and capillary blood measured by Hemocue and an automated spectrophotometer (Celldyn and to document the influence of type of blood (capillary or venous and analysis method on anemia prevalence estimates. Material and Methods. Between February and May 2000, capillary and venous samples were collected from 72 adults and children at Hospital del Niño Morelense (Morelos State Children's Hospital in Cuernavaca, Morelos, Mexico, and assessed for Hb using the Hemocue and Celldyn methods. Estimated Hb levels were compared using the concordance correlation coefficient and Student's t test for paired data. The sensitivity and specificity for anemia diagnosis were estimated and compared between type of blood and method of assessment. Results. Capillary blood had higher Hb (+0.5g/dl than venous blood in adults and children, as did samples assessed by Celldyn compared to Hemocue (+0.3g/dl. Specificity to detect anemia was adequate (>0.90 but sensitivity was low for capillary blood assessed by Hemocue (<0.80. Conclusions. The difference in Hb between venous and capillary blood is likely related to biological variability. Hemoglobin concentration in capillary blood assessed by Hemocue provides an adequate estimation of population anemia prevalence but may result in excess false negative diagnoses among individuals. The results of this study stress the importance of sample collection technique, particularly for children. Method of analysis and sampling site need to be taken into consideration in field studies.

  7. Correlation of brain tissue oxygen tension with cerebral near-infrared spectroscopy and mixed venous oxygen saturation during extracorporeal membrane oxygenation.

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    Tyree, Kreangkai; Tyree, Melissa; DiGeronimo, Robert

    2009-09-01

    The aim of this prospective, animal study was to compare brain tissue oxygen tension (PbtO(2)) with cerebral near infrared spectroscopy (NIRS) and mixed venous oxygen saturation (SVO(2)) during venoarterial extracorporeal membrane oxygenation (VA ECMO) in a porcine model. This was accomplished using twelve immature piglets with surgically implanted catheters placed in the superficial cerebral cortex to measure brain PbtO(2) and microdialysis metabolites. The NIRS sensor was placed overlying the forehead to measure cerebral regional saturation index (rSO(2)i) while SVO(2) was measured directly from the ECMO circuit. Animals were placed on VA ECMO followed by an initial period of stabilization, after which they were subjected to graded hypoxia and recovery. Our results revealed that rSO(2)i and SVO(2) correlated only marginally with PbtO(2) (R(2)=0.32 and R(2)=0.26, respectively) while the correlation between rSO(2)i and SVO( 2) was significantly stronger (R(2)=0.59). Cerebral metabolites and rSO(2)i were significantly altered during attenuation of PbtO( 2), p<0.05). A subset of animals, following exposure to hypoxia, experienced markedly delayed recovery of both rSO(2)i and PbtO( 2) despite rapid normalization of SVO(2). Upon further analysis, these animals had significantly lower blood pressure (p=0.001), lower serum pH (p=0.01), and higher serum lactate (p=0.02). Additionally, in this subgroup, rSO(2)i correlated better with PbtO(2) (R(2)=0.76). These findings suggest that, in our ECMO model, rSO(2)i and SVO( 2) correlate reasonably well with each other, but not necessarily with brain PbtO(2) and that NIRS-derived rSO(2)i may more accurately reflect cerebral tissue hypoxia in sicker animals.

  8. Prevalence-dependent decision limits for the early detection of type 2 diabetes mellitus in venous blood, venous plasma and capillary blood during glucose challenge.

    Science.gov (United States)

    Haeckel, Rainer; Raber, Rüdiger; Wosniok, Werner

    2006-01-01

    The glycemia decision limits recommended by WHO/ADA for type 2 diabetes detection are derived from clinical signs in advanced stages of the disease. Since insulin secretion patterns and sensitivitity are impaired at the beginning of type 2 diabetes, this stage may be better suited to identify decision limits with higher diagnostic efficiency than those currently applied. Oral glucose tolerance tests were performed in 300 subjects. Glucose concentrations were measured at 30-min intervals in venous plasma, venous blood and capillary blood. Insulin concentrations in venous plasma, an insulin sensitivity index and body mass index were used to indicate a type 2 diabetic state. A multiple logistic regression procedure was "trained" using only subjects "clearly" considered to be non-diseased or diseased based on an oral glucose tolerance test according to WHO criteria. This insulin algorithm was applied to the whole study group, leading to definitive classification into the non-diseased or the diseased group. This a posteriori classification was used to identify cutoff values with the highest diagnostic efficiency. The diagnostic efficiency was significantly higher when decision limits lower than the WHO recommendations for glucose concentrations were applied in a preselected subpopulation and in all three sample systems tested, e.g., 9.49 mmol/L (171 mg/dL) for venous plasma and 8.94 mmol/L (161 mg/dL) for capillary blood in the 2-h post-load state. The optimized and WHO 2-h cutoff values corresponded to a disease prevalence of 28% and approximately 5% (20% in the fasting state), respectively. Diagnostic efficiency was higher in the 2-h post-load than in the fasting state. Combining fasting values with 2-h post-load values did not further improve the diagnostic efficiency. Glucose concentrations determined from capillary blood were as efficient as those from venous blood or plasma. The number of diabetic subjects detected differed considerably between capillary blood and

  9. Central Venous-to-Arterial CO2 Gap Is a Useful Parameter in Monitoring Hypovolemia-Caused Altered Oxygen Balance: Animal Study.

    Science.gov (United States)

    Kocsi, Szilvia; Demeter, Gabor; Erces, Daniel; Nagy, Eniko; Kaszaki, Jozsef; Molnar, Zsolt

    2013-01-01

    Monitoring hypovolemia is an everyday challenge in critical care, with no consensus on the best indicator or what is the clinically relevant level of hypovolemia. The aim of this experiment was to determine how central venous oxygen saturation (ScvO2) and central venous-to-arterial carbon dioxide difference (CO2 gap) reflect hypovolemia-caused changes in the balance of oxygen delivery and consumption. Anesthetized, ventilated Vietnamese minipigs (n = 10) were given a bolus followed by a continuous infusion of furosemide. At baseline and then in five stages hemodynamic, microcirculatory measurements and blood gas analysis were performed. Oxygen extraction increased significantly, which was accompanied by a significant drop in ScvO2 and a significant increase in CO2 gap. There was a significant negative correlation between oxygen extraction and ScvO2 and significant positive correlation between oxygen extraction and CO2 gap. Taking ScvO2 6 mmHg values together to predict an oxygen extraction >30%, the positive predictive value is 100%; negative predicted value is 72%. Microcirculatory parameters, capillary perfusion rate and red blood cell velocity, decreased significantly over time. Similar changes were not observed in the sham group. Our data suggest that ScvO2 6 mmHg can be complementary tools in detecting hypovolemia-caused imbalance of oxygen extraction.

  10. Comparison of lactated Ringer's, gelatine and blood resuscitation on intestinal oxygen supply and mucosal tissue oxygen tension in haemorrhagic shock.

    Science.gov (United States)

    Knotzer, H; Pajk, W; Maier, S; Dünser, M W; Ulmer, H; Schwarz, B; Salak, N; Hasibeder, W R

    2006-10-01

    To evaluate the effects on intestinal oxygen supply, and mucosal tissue oxygen tension during haemorrhage and after fluid resuscitation with either blood (B; n=7), gelatine (G; n=8), or lactated Ringer's solution (R; n=8) in an autoperfused, innervated jejunal segment in anaesthetized pigs. To induce haemorrhagic shock, 50% of calculated blood volume was withdrawn. Systemic haemodynamics, mesenteric venous and systemic acid-base and blood gas variables, and lactate measurements were recorded. A flowmeter was used for measuring mesenteric arterial blood flow. Mucosal tissue oxygen tension (PO(2)muc), jejunal microvascular haemoglobin oxygen saturation (HbO(2)) and microvascular blood flow were measured. Measurements were performed at baseline, after haemorrhage and at four 20 min intervals after fluid resuscitation. After haemorrhage, animals were retransfused with blood, gelatine or lactated Ringer's solution until baseline pulmonary capillary wedge pressure was reached. After resuscitation, no significant differences in macrohaemodynamic parameters were observed between groups. Systemic and intestinal lactate concentration was significantly increased in animals receiving lactated Ringer's solution [5.6 (1.1) vs 3.3 (1.1) mmol litre(-1); 5.6 (1.1) vs 3.3 (1.2) mmol litre(-1)]. Oxygen supply to the intestine was impaired in animals receiving lactated Ringer's solution when compared with animals receiving blood. Blood and gelatine resuscitation resulted in higher HbO(2) than with lactated Ringer's resuscitation after haemorrhagic shock [B, 43.8 (10.4)%; G, 34.6 (9.4)%; R, 28.0 (9.3)%]. PO(2)muc was better preserved with gelatine resuscitation when compared with lactated Ringer's or blood resuscitation [20.0 (8.8) vs 13.8 (7.1) mm Hg, 15.2 (7.2) mm Hg, respectively]. Blood or gelatine infusion improves mucosal tissue oxygenation of the porcine jejunum after severe haemorrhage when compared with lactated Ringer's solution.

  11. Veno-Venous Extracorporeal Membrane Oxygenation for Continuous Renal Replacement in a Neonate with Propionic Acidemia.

    Science.gov (United States)

    Gander, Jeffrey W; Rhone, Erika T; Wilson, William G; Barcia, John P; Sacco, Melissa J

    2017-03-01

    The usual indications for extra corporeal membrane oxygenation (ECMO) are for respiratory or cardiac failure. Although continuous renal replacement therapy (CRRT) is frequently used when patients are on ECMO, the need for CRRT as the primary indication for ECMO is rare. A case of a neonate placed onto veno-venous ECMO for the use of CRRT to treat hyperammonemia from propionic acidemia is presented.

  12. A content validated questionnaire for assessment of self reported venous blood sampling practices

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    Bölenius Karin

    2012-01-01

    Full Text Available Abstract Background Venous blood sampling is a common procedure in health care. It is strictly regulated by national and international guidelines. Deviations from guidelines due to human mistakes can cause patient harm. Validated questionnaires for health care personnel can be used to assess preventable "near misses"--i.e. potential errors and nonconformities during venous blood sampling practices that could transform into adverse events. However, no validated questionnaire that assesses nonconformities in venous blood sampling has previously been presented. The aim was to test a recently developed questionnaire in self reported venous blood sampling practices for validity and reliability. Findings We developed a questionnaire to assess deviations from best practices during venous blood sampling. The questionnaire contained questions about patient identification, test request management, test tube labeling, test tube handling, information search procedures and frequencies of error reporting. For content validity, the questionnaire was confirmed by experts on questionnaires and venous blood sampling. For reliability, test-retest statistics were used on the questionnaire answered twice. The final venous blood sampling questionnaire included 19 questions out of which 9 had in total 34 underlying items. It was found to have content validity. The test-retest analysis demonstrated that the items were generally stable. In total, 82% of the items fulfilled the reliability acceptance criteria. Conclusions The questionnaire could be used for assessment of "near miss" practices that could jeopardize patient safety and gives several benefits instead of assessing rare adverse events only. The higher frequencies of "near miss" practices allows for quantitative analysis of the effect of corrective interventions and to benchmark preanalytical quality not only at the laboratory/hospital level but also at the health care unit/hospital ward.

  13. Continuous cardiac output and mixed venous oxygen saturation monitoring.

    Science.gov (United States)

    Cariou, A; Monchi, M; Dhainaut, J F

    1998-12-01

    Continuous assessment of cardiac output and SVO2 in the critically ill may be helpful in both the monitoring variations in the patient's cardiovascular state and in determining the efficacy of therapy. Commercially available continuous cardiac output (CCO) monitoring systems are based on the pulsed warm thermodilution technique. In vitro validation studies have demonstrated that this method provides higher accuracy and greater resistance to thermal noise than standard bolus thermodilution techniques. Numerous clinical studies comparing bolus with continuous thermodilution techniques have shown this technique similarly accurate to track each other and to have negligible bias between them. The comparison between continuous thermal and other cardiac output methods also demonstrates good precision of the continuous thermal technique. Accuracy of continuous oximetry monitoring using reflectance oximetry via fiberoptics has been assessed both in vitro and in vivo. Most of the studies testing agreement between continuous SVO2 measurements and pulmonary arterial blood samples measured by standard oximetry have shown good correlation. Continuous SVO2 monitoring is often used in the management of critically ill patients. The most recently designed pulmonary artery catheters are now able to simultaneously measure either SVO2 and CCO or SVO2 and right ventricular ejection fraction. This ability to view simultaneous trends of SVO2 and right ventricular performance parameters will probably allow the clinician to graphically see the impact of volume loading or inotropic therapy over time, as well as the influence of multiple factors, including right ventricular dysfunction, on SVO2. However, the cost-effectiveness of new pulmonary artery catheters application remains still questionable because no established utility or therapeutic guidelines are available.

  14. [Oxygen-transporting function of the blood circulation system in sevoflurane anesthesia during myocardial revascularization under extracorporeal circulation].

    Science.gov (United States)

    Skopets, A A; Lomivorotov, V V; Karakhalis, N B; Makarov, A A; Duman'ian, E S; Lomivorotova, L V

    2009-01-01

    The purpose of the study was to evaluate the efficiency of oxygen-transporting function of the circulatory system under sevoflurane anesthesia during myocardial revascularization operations under extracorporeal circulation. Twenty-five patients with coronary heart disease were examined. Mean blood pressure, heart rate, cardiac index, total peripheral vascular resistance index, pulmonary pressure, pulmonary wedge pressure, and central venous pressure were measured. Arterial and mixed venous blood oxygen levels, oxygen delivery and consumption index, arteriovenous oxygen difference, and glucose and lactate concentrations were calculated. The study has demonstrated that sevoflurane is an effective and safe anesthetic for myocardial revascularization operations in patients with coronary heart disease. The use of sevoflurane contributes to steady-state oxygen-transporting function of the circulatory system at all surgical stages.

  15. [When is a venous blood gas analysis sufficient in the emergency department?

    NARCIS (Netherlands)

    Exsel, J.A. van; Simons, S.O.; Kramers, C.; Heijdra, Y.F.

    2017-01-01

    Blood gas analysis plays an important role in the initial assessment of a patient in the emergency ward. We present three different patient cases to illustrate when to opt for a venous or an arterial blood gas analysis. Arterial punctures are more painful and carry a higher risk of complications

  16. Femoral Venous Blood pH Changes in Response to External ...

    African Journals Online (AJOL)

    Aim: To measure in vivo the femoral venous blood pH in response to external lower limb compression in cardiac catheterization patients. Patients and Method: The pH was measured in discrete samples of blood withdrawn from the femoral vein before, during and after insertion of the catheterized leg into the graduated ...

  17. Mixed venous oxygenation, exercise, body posture, and v/q ratio in chronic obstructive pulmonary disease.

    Science.gov (United States)

    Minh, V D; Chun, D; Dolan, G F; Lee, H M; Vasquez, P

    1981-09-01

    Mixed venous oxygenation (partial pressure, PVO2; saturation, SVO2) and its impact on pulmonary function at rest in the supine position (SUP), at rest in the standing position (STAND), and during maximal treadmill exercise (Emax), were studied in 41 stable patients with chronic obstructive pulmonary disease, using arterial and right heart (Swan-Ganz) catheterization. The patients represented a broad spectrum of disease severity (VC, 3.1 +/- 0.9 L; FEF 25-75, 1.0 +/- 0.7 L). It was found that: (a) venous oxygenation was uniform among different patients in the supine position at rest (PVO2, 33.8 +/- 2.4 mmHg' SVO2, 76.2 +/- 3.6%), regardless of the heterogeneity in airway obstruction, as previously reported by others; (b) venous oxygenation was also uniform in STAND (PVO2, 29.5 +/- 2.5 mmHg; SVO2, 58 +/- 3.9%) and treadmill Emax (PVO2, 22.4 +/- 3.3 mmHg; SVO2, 34.4 +/- 6%), an observation not previously reported; (c) the orthostatic mixed venous desaturation at rest was pronounced, and was nearly as great as that from STAND to Emax; (d) the potential effect of mixed venous desaturation on alveolar O2 partial pressure (PAO2) and end-capillary O2 saturation (SCO2) was not obvious from SUP to STAND, and from STAND to Emax conditions, being masked by an appropriate increase in overall V/Q ratio; (e) because of constant SCO2 and low interindividual variations of SVO2, there was a high correlation of arterial saturation (SaO2) to venous admixture (Qva/Qt, sum of true shunt and shuntlike components) for each of the conditions studied. Hence, because of high correlation of the equations relating SaO2 to Qva/Qt (r greater than 0.9), these relationships might be used for noninvasive prediction of Qva/Qt from SaO2 in patients with COPD.

  18. Improvement of Oxygenation in Severe Acute Respiratory Distress Syndrome With High-Volume Continuous Veno-venous Hemofiltration

    Science.gov (United States)

    Yang, Wenmin; Hong, Jie; Zeng, Qiyi; Tao, Jianping; Chen, Feiyan; Dang, Run; Liang, Yufeng; Wu, Zhiyuan; Yang, Yiyu

    2016-01-01

    The efficacy and therapeutic mechanisms of continuous renal replacement therapy (CRRT) for improvement of oxygenation in acute respiratory distress syndrome (ARDS) remain controversial. These questions were addressed by retrospective analysis of severe ARDS patients admitted to the pediatric intensive care unit of our hospital from 2009 to 2015 who received high-volume continuous veno-venous hemofiltration during mechanical ventilation. There was a significant improvement in partial oxygen pressure/fraction of inspired oxygen (PaO2/FiO2) 24 hours after CRRT onset compared with baseline (median change = 51.5; range = −19 to 450.5; P CRRT. White blood cell (WBC) count decreased in the subgroup with high baseline WBC count (P < .05). PaO2/FiO2 was higher in ARDS patients with extrapulmonary etiology than in those with pulmonary etiology (P < .05). Improvement in oxygenation is likely related to both restoration of fluid balance and clearance of inflammatory mediators. PMID:27336018

  19. Improvement of Oxygenation in Severe Acute Respiratory Distress Syndrome With High-Volume Continuous Veno-venous Hemofiltration

    Directory of Open Access Journals (Sweden)

    Wenmin Yang MD

    2016-05-01

    Full Text Available The efficacy and therapeutic mechanisms of continuous renal replacement therapy (CRRT for improvement of oxygenation in acute respiratory distress syndrome (ARDS remain controversial. These questions were addressed by retrospective analysis of severe ARDS patients admitted to the pediatric intensive care unit of our hospital from 2009 to 2015 who received high-volume continuous veno-venous hemofiltration during mechanical ventilation. There was a significant improvement in partial oxygen pressure/fraction of inspired oxygen (PaO2/FiO2 24 hours after CRRT onset compared with baseline (median change = 51.5; range = −19 to 450.5; P < .001 as well as decreases in FiO2, peak inspiratory pressure, positive end-expiratory pressure, and mean airway pressure (P < .05. The majority of patients had a negative fluid balance after 24 hours of CRRT. White blood cell (WBC count decreased in the subgroup with high baseline WBC count (P < .05. PaO2/FiO2 was higher in ARDS patients with extrapulmonary etiology than in those with pulmonary etiology (P < .05. Improvement in oxygenation is likely related to both restoration of fluid balance and clearance of inflammatory mediators.

  20. Mixed venous versus central venous oxygen saturation in patients undergoing on pump beating coronary artery bypass grafting

    Directory of Open Access Journals (Sweden)

    Alshaer Ahmad

    2010-01-01

    Full Text Available Objective: To examine the validity of central venous oxygen saturation (ScvO 2 as a numerical substitution of mixed venous oxygen saturation (SvO 2 in adult patients undergoing normothermic on pump beating coronary artery bypass grafting (CABG. Materials and Methods: Prospective clinical observational study was done at King Khalid University Hospital, King Saud University, Riyadh, Kingdom of Saudi Arabia. Thirty four adult patients scheduled for coronary artery surgery were included. Patients were monitored by a pulmonary artery catheter (PAC as a part of our routine intraoperative monitoring. SvO 2 and ScvO 2 were simultaneously measured 15 minutes (T1 and 30 minutes (T2 after induction of anesthesia, 15 and 30 minutes after initiation of cardiopulmonary bypass (T3 and T4, and 15 and 30 minutes after admission to intensive care unit (T5 and T6. Results: ScvO 2 showed higher reading than SvO 2 all through our study. Our results showed perfect positive statistically significant correlation between SvO 2 and ScvO 2 at all data points. Individual mean of difference (MOD between both the readings at study time showed MOD of 1.34 and 1.44 at T1 and T2 simultaneously. This MOD was statistically insignificant, but after on pump beating normothermic bypass was initiated; MOD was 5.2 and 4.4 at T3 and T4 with high statistical significance. In ICU, MOD continues to have high statistical significance, MOD was 6.3 at T5 and at T6 it was 4.6. Conclusions: In on pump beating CABG patients; ScvO 2 and SvO 2 are not interchangeable numerically. ScvO 2 is useful in the meaning of trend; our data suggest that ScvO 2 is equivalent to SvO 2 , only in the course of clinical decisions as long as absolute values are not required.

  1. [Early goal-directed therapy (EDGT) using continuous central venous oxygen saturation monitoring in a patient with septic shock].

    Science.gov (United States)

    Oyama, Yoshimasa; Goto, Koji; Yamamoto, Shunsuke; Kusaka, Jyunya; Hidaka, Seigo; Shingu, Chihiro; Noguchi, Takayuki

    2008-04-01

    Septic shock is an adverse clinical condition resulting in multiple organ failure from global tissue hypoxia. The importance of initial treatment is widely recognized. Thus, guidelines for septic shock recommend early goal-directed therapy (EGDT) during the first six hours of treatment. Central venous oxygen saturation monitoring is useful to maintain adequate tissue oxygen delivery. A newly developed central venous oximetry catheter (PreSep Oximetery Catheter, Edwards Lifesciences) allows continuous and easy monitoring of central venous oxygen saturation. This report shows the usefulness of this catheter in a patient who developed septic shock during an emergency operation for perforated bowel. By using EGDT perioperatively with continuous central venous oximetry, multiple organ failure might be successfully avoided.

  2. Physiology of cerebral venous blood flow: from experimental data in animals to normal function in humans.

    Science.gov (United States)

    Schaller, B

    2004-11-01

    In contrast to the cerebroarterial system, the cerebrovenous system is not well examined and only partly understood. The cerebrovenous system represents a complex three-dimensional structure that is often asymmetric and considerably represent more variable pattern than the arterial anatomy. Particular emphasis is devoted to the venous return to extracranial drainage routes. As the state-of-the-art-imaging methods are playing a greater role in visualizing the intracranial venous system at present, its clinically pertinent anatomy and physiology has gain increasing interest, even so only few data are available. For this reason, experimental research on specific biophysical (fluid dynamic, rheologic factors) and hemodynamic (venous pressure, cerebral venous blood flow) parameters of the cerebral venous system is more on the focus; especially as these parameters are different to the cerebral arterial system. Particular emphasis is devoted to the venous return to extracranial drainage routes. From the present point of view, it seems that the cerebrovenous system may be one of the most important factors that guarantee normal brain function. In the light of this increasing interest in the cerebral venous system, the authors have summarized the current knowledge of the physiology of the cerebrovenous system and discuss it is in the light of its clinical relevance.

  3. Agreement and Correlation between Arterial and Central Venous Blood Gas Following Coronary Artery Bypass Graft Surgery.

    Science.gov (United States)

    Esmaeilivand, Masoumeh; Khatony, Alireza; Moradi, Gholamreza; Najafi, Farid; Abdi, Alireza

    2017-03-01

    Arterial blood sampling, used to assess patients in acute conditions, may result in complications such as thrombosis and embolism. However, it can be replaced by venous blood sampling, but there is a dearth of information on this. To assess the correlation and agreement between the arterial and central venous blood gases analyses in patients undergoing elective Coronary Artery Bypass Graft (CABG) surgery. In this cross-sectional study, 100 ICU patients undergoing elective CABG surgery were recruited. 2 mm arterial and a 2 mm venous blood samples were obtained from each patient's arterial and central venous lines, respectively. To predict Arterial Blood Gas (ABG) values based on central Venous Blood Gas (VBG) values, the linear regression analysis was used and for evaluating their agreement Bland-Altman method was used. In total of 200 samples were obtained. The mean and Standard Deviation (SD) of age was 58.9±9.1 years and 51% of the participants were female. There was a strong correlation between ABG and central VBG values regarding pH, partial Pressure of Carbon Dioxide (PCO2), Bicarbonate (HCO3) and Base Excess (BE) (r= 0.73, r=0.74, r=0.67 and r=0.71, respectively; panalysis showed an excellent agreement between all the variables (panalysis cannot replace ABG analysis in measuring exact PO2 status, necessitating arterial sampling in some matters, but with respect to the accuracy of pulse oximetry measurements in determining the exact PO2 status, for the rest of the indices a central VBG rather than an ABG can be utilised for determining patient's acid-base status. Particularly in patients who are hospitalised for a long time and have a central venous catheter in place like patients who have undergone CABG, thus reducing the risk and need for invasive arterial sampling.

  4. Effect of Two Limb Positions on Venous Hemodynamics and Hidden Blood Loss following Total Knee Arthroplasty.

    Science.gov (United States)

    Li, Bin; Wang, Guangbin; Wang, Yanfang; Bai, Lunhao

    2017-01-01

    This study assessed the effects of limb position on venous hemodynamics and blood loss after primary total knee arthroplasty (TKA). First, the venous blood flow velocity was detected by color Doppler flow imaging in seven young volunteers after the leg was elevated 25 cm with the knee in full extension or mild flexion. Next, 108 consecutive TKA patients were randomized into flexion or extension groups. Both groups had the leg elevated 25 cm at the ankle over a specific backing pad for 72 hours postoperatively. In the flexion group, the knee was flexed mildly (extension group, the knee was extended fully. Perioperative total blood loss, hidden blood loss (HBL), knee swelling, range of motion (ROM), straight-leg raising action, and postoperative complications within 6 weeks of surgery were measured. Venous blood flow velocity in the mild flexion position was significantly faster than that in knee full extension position. Postoperative HBL and knee swelling were significantly lower in the flexion group than in the extension group, and ROM and straight-leg raising actions were significantly higher during early follow-up. No significant difference was observed in perioperative total blood loss or in ROM at 6 weeks postoperatively. The findings of this study indicate that elevating the leg with the knee flexed mildly can promote venous return and decrease the HBL and knee swelling following TKA. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  5. Accuracy of continuous central venous oxygen saturation monitoring in patients undergoing cardiac surgery.

    Science.gov (United States)

    Baulig, Werner; Dullenkopf, Alexander; Kobler, Andreas; Baulig, Barbara; Roth, Hans Rudolf; Schmid, Edith R

    2008-06-01

    Continuous assessment of central venous oxygen saturation (S(cevox)O(2)) with the CeVOX device (Pulsion Medical Systems, Munich, Germany) was evaluated against central venous oxygen saturation (S(cv)O(2)) determined by co-oximetry. In 20 cardiac surgical patients, a CeVOX fiberoptic probe was introduced into a standard central venous catheter placed in the right internal jugular vein and advanced 2-3 cm beyond the catheter tip. After in vivo calibration of the probe, S(cevox)O(2), S(cv)O(2), mixed venous oxygen saturation (S(mv)O(2)) haemoglobin (Hb), body temperature, heart rate, central venous and mean arterial pressure, and cardiac index were assessed simultaneously at 30 min intervals during surgery and at 60 min intervals during recovery in the intensive care unit. Agreement between S(cevox)O(2), and S(cv)O(2) was determined by Bland-Altman analysis. Simple regression analysis was used to assess the correlation of S(cevox)O(2), and S(cv)O(2) to Hb, body temperature and haemodynamic parameters. Values of S(cevox)O(2) and S(cv)O(2) (84 data pairs during surgery and 106 in the intensive care unit) ranged between 45-89% and 43-90%, respectively. Mean bias and limits of agreement of S(cevox)O(2) and S(cv)O(2) were -0.9 (-7.9/+6.1)% during surgery and -1.2 (-10.5/+8.1)% in the intensive care unit. In 37.9% of all measured data pairs, the difference between S(cevox)O(2) and S(cv)O(2) was beyond clinically acceptable limits (> or =1 s.d.). Mean bias was significantly influenced by cardiac index. Sensitivity and specificity of S(cevox)O(2) to detect substantial (> or =1 s.d.) changes in S(cv)O(2) were 89 and 82%, respectively. In adult patients during and after cardiac surgery, the current version of the CeVOX device might not be the tool to replace S(cv)O(2) determined by co-oxymetry, although sensitivity and specificity of S(cevox)O(2 )to predict substantial changes in S(cv)O(2) were acceptable.

  6. Hemoglobin measured by Hemocue and a reference method in venous and capillary blood: a validation study.

    Science.gov (United States)

    Neufeld, Lynnette; García-Guerra, Armando; Sánchez-Francia, Domingo; Newton-Sánchez, Oscar; Ramírez-Villalobos, María Dolores; Rivera-Dommarco, Juan

    2002-01-01

    To assess the comparability of hemoglobin concentration (Hb) in venous and capillary blood measured by Hemocue and an automated spectrophotometer (Celldyn) and to document the influence of type of blood (capillary or venous) and analysis method on anemia prevalence estimates. Between February and May 2000, capillary and venous samples were collected from 72 adults and children at Hospital del Niño Morelense (Morelos State Children's Hospital) in Cuernavaca, Morelos, Mexico, and assessed for Hb using the Hemocue and Celldyn methods. Estimated Hb levels were compared using the concordance correlation coefficient and Student's t test for paired data. The sensitivity and specificity for anemia diagnosis were estimated and compared between type of blood and method of assessment. Capillary blood had higher Hb (+0.5 g/dl) than venous blood in adults and children, as did samples assessed by Celldyn compared to Hemocue (+0.3 g/dl). Specificity to detect anemia was adequate (> 0.90) but sensitivity was low for capillary blood assessed by Hemocue (< 0.80). The difference in Hb between venous and capillary blood is likely related to biological variability. Hemoglobin concentration in capillary blood assessed by Hemocue provides an adequate estimation of population anemia prevalence but may result in excess false negative diagnoses among individuals. The results of this study stress the importance of sample collection technique, particularly for children. Method of analysis and sampling site need to be taken into consideration in field studies. The English version of this paper is available too at: http://www.insp.mx/salud/index.html.

  7. Designed Proteins as Optimized Oxygen Carriers for Artificial Blood

    Science.gov (United States)

    2013-02-01

    Optimized Oxygen Carriers for Artificial Blood PRINCIPAL INVESTIGATOR: Ronald L. Koder, Ph.D. CONTRACTING ORGANIZATION: The City...SUBTITLE 5a. CONTRACT NUMBER Designed Proteins as Optimized Oxygen Carriers for Artificial Blood 5b. GRANT NUMBER W81XWH...incorporation into the crosslinked particles that are the goal of year three. 15. SUBJECT TERMS Artificial Blood, Blood Substitute 16. SECURITY

  8. Central venous oxygen saturation in septic shock - a marker of cardiac output, microvascular shunting and/or dysoxia?

    DEFF Research Database (Denmark)

    Haase, Nicolai; Perner, Anders

    2011-01-01

    Shock therapy aims at increasing central venous oxygen saturation (ScvO2), which is a marker of inadequate oxygen delivery. In this issue of Critical Care, Textoris and colleagues challenge this notion by reporting that high levels of ScvO2 are associated with mortality in patients with septic...

  9. Retinal venous blood carbon monoxide response to bright light in male pigs: A preliminary study.

    Science.gov (United States)

    Oren, Dan A; Duda, Magdalena; Kozioł, Katarzyna; Romerowicz-Misielak, Maria; Koziorowska, Anna; Sołek, Przemysław; Nowak, Sławomir; Kulpa, Magdalena; Koziorowski, Marek

    2017-03-01

    The physical mechanism by which light is absorbed in the eye and has antidepressant and energizing effects in Seasonal Affective Disorder and other forms of psychiatric major depression is of scientific interest. This study was designed to explore one specific aspect of a proposed humoral phototransduction mechanism, namely that carbon monoxide (CO) levels increase in retinal venous blood in response to bright light. Eleven mature male pigs approximately six months of age were kept for 7days in darkness and fasted for 12h prior to surgery. Following mild sedation, anesthesia was induced. Silastic catheters were inserted into the dorsal nasal vein through the angular vein of the eye to reach the ophthalmic sinus, from which venous blood outflowing from the eye area was collected. The animals were exposed to 5000lx of fluorescent-generated white light. CO levels in the blood were analyzed by gas chromatography before and after 80min of light exposure. At baseline, mean CO levels in the retinal venous blood were 0.43±0.05(SE)nmol/ml. After bright light, mean CO levels increased to 0.54±0.06nmol/ml (two-tailed t-test pcarbon monoxide levels in ophthalmic venous blood. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Systematic review of the association of venous oxygenation and outcome in adult hospitalized patients

    DEFF Research Database (Denmark)

    Chemtob, R A; Eskesen, T G; Møller-Sørensen, H

    2016-01-01

    in 5590 papers of which 42 studies were deemed relevant. The majority of the studies in cardiac and abdominal surgery patients showed associations between low venous oxygen saturation and increased mortality and morbidity, in particular increased length of intensive care. However, the cut-off level...... mortality, morbidity and length of intensive care in patients following cardiac or abdominal surgery. However, the wide range of cut-off levels and low quality of evidence hampers the clinical application. In patients with septic shock, the present evidence does not support goal-directed therapy using...

  11. Can venous blood gas analysis be used for predicting seizure recurrence in emergency department?

    Science.gov (United States)

    Kılıc, Turgay Yılmaz; Yesilaras, Murat; Atilla, Ozge Duman; Sever, Mustafa; Aksay, Ersin

    2014-01-01

    Epileptic seizures account for 1%-2% of all admissions of patients to the emergency department (ED). The present study aimed to determine whether venous blood pH, bicarbonate, base excess, and lactate levels taken within 1 hour of the last seizure episode help to determine seizure recurrence in emergency departments. A cross-sectional study was conducted in the emergency department (ED) between January and July, 2012. Patients who were admitted to the emergency department consecutively were included in the study if they were 14 years or older and within 1 hour after last seizure. Demographics, seizure type, use of antiepileptic drugs, observation period at the emergency department, seizure recurrence, pH, bicarbonate, base excess, and lactate levels from venous blood gas analysis were determined. A total of 94 patients aged 14 years or older were included in the study. Of these patients, 10.6% (n=10) experienced recurrent seizures in the observation period at the emergency department. To predict recurrent seizures in ED, threshold venous blood gas values were determined as follows: pH7.65 mmol/L [sensitivity 80% (95%CI: 44-96), negative predictive value 96.6% (95%CI: 87-99)]. If venous blood gas analysis is made on pH, base excess, lactate and bicarbonate immediately one hour after the last epileptic seizure episode, it is possible to predict whether the patient will have seizure recurrence.

  12. Diurnal variations in lower leg subcutaneous blood flow rate in patients with chronic venous leg ulcers

    DEFF Research Database (Denmark)

    Sindrup, J H; Kastrup, J; Kristensen, J K

    1991-01-01

    The blood flow rate in subcutaneous adipose tissue was measured on the lower legs of 11 patients with chronic lower-leg venous insufficiency and ulceration and in eight age-matched control subjects for 12-20 h, under ambulatory conditions, using the 133Xe wash-out technique with portable Cadmium...

  13. Effects of Intravitreal Dexamethasone Implants on Retinal Oxygen Saturation, Vessel Diameter, and Retrobulbar Blood Flow Velocity in ME Secondary to RVO.

    Science.gov (United States)

    Eibenberger, Katharina; Schmetterer, Leopold; Rezar-Dreindl, Sandra; Wozniak, Piotr; Told, Reinhard; Mylonas, Georgios; Krall, Christoph; Schmidt-Erfurth, Ursula; Sacu, Stefan

    2017-10-01

    To investigate the effects of intravitreal 0.7 mg dexamethasone implants (Ozurdex) on arterial and venous oxygen saturation, retinal vessel diameter, and retrobulbar blood flow velocity in patients with macular edema (ME) due to retinal vein occlusion (RVO). This prospective, nonrandomized clinical trial included 40 eyes of 40 patients with ME due to RVO. Measurements of arterial and venous oxygen saturation and retinal vessel diameters were performed using the Dynamic Vessel Analyzer. The main outcome measure was the retinal arteriovenous oxygen difference, calculated as the difference between arterial and venous oxygenation. Color Doppler imaging was performed for measuring peak systolic velocity (PSV), end diastolic velocity (EDV), and resistive index (RI) in ophthalmic artery (OA), central retinal artery (CRA), and posterior ciliary arteries (PCAs). Follow-up was monthly for 6 months following an initial dexamethasone implant injection. As statistical analysis, a mixed model was performed to investigate the effect treatment. The arteriovenous oxygen difference showed a significant increase (P 0.05), while the venous oxygen saturation and diameter decreased significantly (P 0.05). In patients with RVO, intravitreal dexamethasone treatment leads to an increase in arteriovenous oxygen saturation difference indicating improved retinal oxygenation. Arterial oxygenation and vessel diameter showed no response, whereas venous oxygenation and vessel diameter decreased after treatment.

  14. Noninvasive cerebral blood oxygenation monitoring: clinical test of multiwavelength optoacoustic system

    Science.gov (United States)

    Petrov, Y. Y.; Prough, D. S.; Petrova, I.; Patrikeev, I. A.; Cicenaite, I.; Esenaliev, R. O.

    2007-02-01

    Continuous monitoring of cerebral blood oxygenation is critically important for treatment of patients with life-threatening conditions like severe brain injury or during cardiac surgery. We designed and built a novel multiwavelength optoacoustic system for noninvasive, continuous, and accurate monitoring of cerebral blood oxygenation. We use an Optical Parametric Oscillator as a light source. We successfully tested the system in vitro as well as in vivo in large animals (sheep) through thick tissues overlying blood vessels which drain venous blood out of the brain (e.g., superior sagittal sinus or jugular vein). Here we present the results of clinical tests of the system for continuous noninvasive cerebral blood oxygenation monitoring in the internal jugular vein of healthy volunteers. We applied our custom-built optoacoustic probe (which incorporated a wide-band acoustic transducer and an optical fiber) to the neck area overlying the internal jugular vein. We performed measurements with volunteers at 18 wavelengths in the near-infrared spectral range. Despite a thick layer of overlying connective tissue and low energy used in the experiments, we recorded signals with high signal-to-noise ratios for all volunteers. We found that the temporal (independent of signal amplitude) parameters of recorded profiles for different levels of blood oxygenation correlated well with the spectrum of effective attenuation coefficients of blood.

  15. Determination of reference intervals and comparison of venous blood gas parameters using standard and non-standard collection methods in 24 cats.

    Science.gov (United States)

    Bachmann, Karin; Kutter, Annette Pn; Schefer, Rahel Jud; Marly-Voquer, Charlotte; Sigrist, Nadja

    2017-08-01

    Objectives The aim of this study was to determine in-house reference intervals (RIs) for venous blood analysis with the RAPIDPoint 500 blood gas analyser using blood gas syringes (BGSs) and to determine whether immediate analysis of venous blood collected into lithium heparin (LH) tubes can replace anaerobic blood sampling into BGSs. Methods Venous blood was collected from 24 healthy cats and directly transferred into a BGS and an LH tube. The BGS was immediately analysed on the RAPIDPoint 500 followed by the LH tube. The BGSs and LH tubes were compared using paired t-test or Wilcoxon matched-pairs signed-rank test, Bland-Altman and Passing-Bablok analysis. To assess clinical relevance, bias or percentage bias between BGSs and LH tubes was compared with the allowable total error (TEa) recommended for the respective parameter. Results Based on the values obtained from the BGSs, RIs were calculated for the evaluated parameters, including blood gases, electrolytes, glucose and lactate. Values derived from LH tubes showed no significant difference for standard bicarbonate, whole blood base excess, haematocrit, total haemoglobin, sodium, potassium, chloride, glucose and lactate, while pH, partial pressure of carbon dioxide and oxygen, actual bicarbonate, extracellular base excess, ionised calcium and anion gap were significantly different to the samples collected in BGSs ( P blood base excess, haematocrit, total haemoglobin, sodium, potassium, chloride, glucose and lactate can be made based on blood collected in LH tubes and analysed within 5 mins. For pH, partial pressure of carbon dioxide and oxygen, extracellular base excess, anion gap and ionised calcium the clinically relevant alterations have to be considered if analysed in LH tubes.

  16. The PediaSat continuous central SvO2 monitoring system does not reliably indicate state or course of central venous oxygenation.

    Science.gov (United States)

    Baulig, Werner; Béttex, Dominique; Bürki, Christoph; Schmitz, Achim; Spielmann, Nelly; Woitzek, Katja; Weiss, Markus

    2010-08-01

    The present study compares the accuracy of a new continuous venous oxygenation monitoring system (PediaSat Oximetry Catheter) with laboratory blood oximetry in paediatric surgical patients. Children and adolescents undergoing cardiac, orthopaedic or craniofacial surgery with major blood loss were included. A 4.5 Fr two-lumen or 5.5 Fr three-lumen central venous oximetry catheter (SPediaSatcvO2) was inserted preoperatively into the superior vena cava. After in-vivo calibration of the PediaSat system, repeated blood samples were obtained from the distal port of the venous catheter and oximetrically analysed for haemoglobin and central venous oxygen saturation (SCO-OXcvO2). Central venous oxygen saturation values measured by the PediaSat (SPediaSatcvO2) were compared with co-oximetry (SCO-OXcvO2) values from the simultaneously taken blood samples by Bland-Altman and simple regression analyses. Overall, 142 data pairs from 27 patients, aged from 0.6 to 19.0 years (median 5.3 years) were analysed. SPediaSatcvO2 and SCO-OXcvO2 values ranged from 57 to 98% and from 57.1 to 95.8%, respectively. Correlation between SPediaSatcvO2 and SCO-OXcvO2 was poor with r equal to 0.28 (P < 0.0001). SPediaSatcvO2 overestimated SCO-OXcvO2 (mean bias +2.6%), but limits of agreement (+/-2 SD of bias) were unacceptably high (-14.4/+19.6%). Sensitivity and specificity of SPediaSatcvO2 to indicate a fall or rise of SCO-OXcvO2 between two subsequent measurements were only 0.42 and 0.24, respectively. In paediatric and adolescent patients undergoing major surgery, the PediaSat system did not reliably reflect SCO-OXcvO2 values and cannot replace repeated invasive ScvO2 assessments in the clinically relevant range of ScvO2.

  17. Photolytically driven generation of dissolved oxygen and increased oxyhemoglobin in whole blood.

    Science.gov (United States)

    Monzyk, Bruce F; Burckle, Eric C; Carleton, Linda M; Busch, James; Dasse, Kurt A; Martin, Peter M; Gilbert, Richard J

    2006-01-01

    The severely debilitating nature of chronic lung disease has long provided the impetus for the development of technologies to supplement the respiratory capacity of the human lung. Although conventional artificial lung technologies function by delivering pressurized oxygen to the blood through a system of hollow fibers or tubes, our approach uses photolytic energy to generate dissolved oxygen (DO) from the water already present in blood, thus eliminating the need for gas delivery. We have previously demonstrated that it is feasible to generate dissolved oxygen from water based on UVA illumination of a highly absorbent TiO2 thin film. In the current study, we extend this work by using photolytic energy to generate DO from whole blood, thus resulting in an increase of oxyhemoglobin as a function of back side TiO2 surface film illumination. Initial experiments, performed with Locke's Ringer solution, demonstrated effective film thickness and material selection for the conductive layer. The application of a small bias voltage was used to conduct photogenerated electrons from the aqueous phase to minimize electron recombination with the DO.Mixed arterial-venous bovine blood was flowed in a recirculating loop over TiO2 nanocrystalline films illuminated on the side opposite the blood (or "back side") to eliminate the possibility of any direct exposure of blood to light. After light exposure of the TiO2 film, the fraction of oxyhemoglobin in the blood rapidly increased to near saturation and remained stable throughout the trial period. Last, we evaluated potential biofouling of the DO generating surface by scanning electron microscopy, after photolytically energized DO generation in whole blood, and observed no white or red blood cell surface deposition, nor the accumulation of any other material at this magnification. We conclude that it is feasible to photolytically oxygenate the hemoglobin contained in whole blood with oxygen derived from the blood's own water content

  18. The accuracy of the central venous blood gas for acid-base monitoring.

    Science.gov (United States)

    Walkey, Allan J; Farber, Harrison W; O'Donnell, Charles; Cabral, Howard; Eagan, Janet S; Philippides, George J

    2010-01-01

    Routine use of central venous blood gases (VBGs) may reduce complications from prolonged arterial cannulation. We investigated the reliability of the VBG as a substitute for arterial blood gas (ABG) in multiple care settings. We developed a VBG adjustment rule of ABG pH = VBG pH + 0.05, ABG CO(2) = VBG PCO(2) -5 mm Hg from prior studies and validated this relationship with simultaneous venous and arterial blood obtained from 187 medical/surgical intensive care, cardiac catheterization laboratory, and coronary care unit patients with central venous access. The overall accuracy of a normal adjusted VBG (aVBG) to predict a normal ABG was 90%. After adjustment, the mean systematic difference (bias) between ABG and VBG pH decreased from 0.035 +/- 0.02 to -0.015 +/- 0.02 and PCO(2) bias decreased from -4.5 +/- 3.5 to 0.5 +/- 3.5. Intraclass correlation coefficients for agreement improved after applying the adjustment rule to venous pH (from 0.84 to 0.93, P central VBG.

  19. Continuous central venous oxygen saturation monitoring under varying physiological conditions in an animal model.

    Science.gov (United States)

    Kissoon, N; Spenceley, N; Krahn, G; Milner, R

    2010-09-01

    We compared saturations from a paediatric central venous oximetry catheter with co-oximetry values with changes in drug infusions, intravascular blood volume and hypoxia in an animal model. Piglets (large white) were anaesthetised, intubated and mechanically ventilated. PediaSat oximetry catheters were placed in the superior vena cava via jugular vein cut-down and in the inferior vena cava percutaneously via the femoral vein. A carotid arterial catheter was placed via cut-down for blood sampling and pressure monitoring. Anaesthesia was maintained with continuous thiopentone and supplemental morphine. Haemodynamics (heart rate, mean arterial blood, central venous pressure), fibreoptic ScvO2 (ScvO2-inferior) from inferior vena cava, fibreoptic ScvO2 (ScvO2-superior) from superior vena cava and blood gas oximetry (ScvO2-co-ox) were measured simultaneously at predetermined intervals during increasing adrenaline and sodium nitroprusside infusions and during increasing hypoxia and hypovolaemia. There was good agreement of both superior vena cava and inferior vena cava ScvO2 catheters with co-oximetry during adrenaline and sodium nitroprusside infusions. During the hypoxia study there was good agreement between the co-oximeter to ScvO2-superior catheter but poor agreement with to the inferior vena cava catheter samples. In the hypovolaemic phase of the experiment there was good agreement between the measured co-oximetry value and ScvO2-superior catheter until the mean blood pressure reached 43 mmHg. The oximetry catheter is capable of identifying changes in ScvO2 under physiological conditions usually encountered in clinical medicine but was less accurate at the extremes of physiology and when placed in the inferior vena cava catheter especially during hypovolaemia and hypoxia.

  20. Correlation Between Capillary and Venous Blood Glucose in the Lactose Tolerance Test.

    Science.gov (United States)

    Domínguez Jiménez, José Luis; Fernández Suárez, Antonio

    2016-01-01

    The lactose tolerance test is a classic method for the study of lactose malabsorption. However, the methodology used has not been standardized, and this leads to differences in results. The aim of this report was to analyze whether capillary blood glucose measurement is in agreement with venous blood glucose when performing lactose tolerance test. This is a prospective study of consecutive patients with suspected lactose malabsorption who had lactose tolerance test performed in venous and capillary blood simultaneously, using a load of 50 g lactose. Agreement was measured using the concordance correlation coefficient of Lin (95 % CI) and Bland-Altman plots. The degree of agreement was measured using the Kappa index. A value of p index of 0.59 (p lactose tolerance test in different studies for lactose malabsorption is incorrect, making it necessary to specify the analysis method.

  1. Cardiorespiratory effects of venous lipid micro embolization in an experimental model of mediastinal shed blood reinfusion

    Directory of Open Access Journals (Sweden)

    Dencker Magnus

    2009-09-01

    Full Text Available Abstract Background Retransfusion of the patient's own blood during surgery is used to reduce the need for allogenic blood transfusion. It has however been found that this blood contains lipid particles, which form emboli in different organs if the blood is retransfused on the arterial side. In this study, we tested whether retransfusion of blood containing lipid micro-particles on the venous side in a porcine model will give hemodynamic effects. Methods Seven adult pigs were used. A shed blood surrogate containing 400 ml diluted blood and 5 ml radioactive triolein was produced to generate a lipid embolic load. The shed blood surrogate was rapidly ( Results A more than 30-fold increase in pulmonary vascular resistance was observed, with subsequent increase in pulmonary artery pressure, and decrease in cardiac output and arterial pressure. This response was transient, but was followed by a smaller, persistent increase in pulmonary vascular resistance. Only a small portion of the infused triolein passed the lungs, and only a small fraction could be recirculated by increasing cardiac output and pulmonary pressure. Conclusion Infusion of blood containing lipid micro-emboli on the venous side leads to acute, severe hemodynamic responses that can be life threatening. Lipid particles will be trapped in the lungs, leading to persistent effects on the pulmonary vascular resistance.

  2. Relationship between contractions of the uterus and concentration of PGF2α in uterine venous blood after luteolysis in gilts.

    Science.gov (United States)

    Stefańczyk-Krzymowska, S; Wąsowska, B; Gilun, P; Muszak, J; Grzegorzewski, W

    2012-02-01

    The origin and physiological significance of high pulses of prostaglandin F2α (PGF2α) in uterine venous blood that occur 2-3 days after luteolysis are not well understood. We studied the relationship between contractions of the uterus evoked by exogenous oxytocin (OT) and PGF2α concentration in uterine venous blood on day 17 of the porcine oestrous cycle. The infusion of OT into the uterine artery produced an immediate increase in the uterine intraluminal pressure (UIP) (p uterine venous blood (p uterine artery slightly decreased PGF2α concentration in uterine venous blood, but it did not suppress uterine contraction or the rapid increase in PGF2α concentration in uterine venous blood just after OT infusion (p uterine venous blood occurring after OT infusion on day 17 of the porcine oestrous cycle are mainly caused by the excretion with venous blood from the remodelled uterus and that PGF2α synthesis may contribute to this. These results suggest that the high spikes in PGF2α concentration that occur 2-3 days after luteolysis in pigs, sheep, cows and mares all have a similar origin. © 2011 Blackwell Verlag GmbH.

  3. Arterio-venous flow between monochorionic twins determined during intra-uterine transfusion. Nonlinear decay of adult red blood cells

    Energy Technology Data Exchange (ETDEWEB)

    Gemert, Martin J C van; Wijngaard, Jeroen P H M van den [Laser Centre and Department of Obstetrics, Academic Medical Centre, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam (Netherlands); Pasman, Suzanne A; Vandenbussche, Frank P H A [Division of Fetal Medicine, Department of Obstetrics, Leiden University Medical Centre, Leiden (Netherlands); Lopriore, Enrico [Division of Neonatology, Department of Pediatrics, Leiden University Medical Centre, Leiden (Netherlands)], E-mail: m.j.vangemert@amc.uva.nl

    2008-07-07

    Recently, we derived equations relating the flow of adult red blood cells through a placental arterio-venous anastomosis with intra-uterine and post-natal measured adult hemoglobin concentrations. In this letter, we re-derived the equations, now including a more realistic nonlinear decay of adult red blood cells, and re-evaluated the measurement accuracy of the arterio-venous flow and the lifetime of the red blood cells. (letter to the editor)

  4. Skin Blood Perfusion and Oxygenation Colour Affect Perceived Human Health

    Science.gov (United States)

    Stephen, Ian D.; Coetzee, Vinet; Law Smith, Miriam; Perrett, David I.

    2009-01-01

    Skin blood perfusion and oxygenation depends upon cardiovascular, hormonal and circulatory health in humans and provides socio-sexual signals of underlying physiology, dominance and reproductive status in some primates. We allowed participants to manipulate colour calibrated facial photographs along empirically-measured oxygenated and deoxygenated blood colour axes both separately and simultaneously, to optimise healthy appearance. Participants increased skin blood colour, particularly oxygenated, above basal levels to optimise healthy appearance. We show, therefore, that skin blood perfusion and oxygenation influence perceived health in a way that may be important to mate choice. PMID:19337378

  5. Single-cell measurement of red blood cell oxygen affinity

    CERN Document Server

    Caprio, Di; Higgins, John M; Schonbrun, Ethan

    2015-01-01

    Oxygen is transported throughout the body by hemoglobin in red blood cells. While the oxygen affinity of blood is well understood and is routinely assessed in patients by pulse oximetry, variability at the single-cell level has not been previously measured. In contrast, single-cell measurements of red blood cell volume and hemoglobin concentration are taken millions of times per day by clinical hematology analyzers and are important factors in determining the health of the hematologic system. To better understand the variability and determinants of oxygen affinity on a cellular level, we have developed a system that quantifies the oxygen saturation, cell volume and hemoglobin concentration for individual red blood cells in high-throughput. We find that the variability in single-cell saturation peaks at an oxygen partial pressure of 2.5%, which corresponds to the maximum slope of the oxygen-hemoglobin dissociation curve. In addition, single-cell oxygen affinity is positively correlated with hemoglobin concentr...

  6. Mercury levels in cord blood and meconium of healthy newborns and venous blood of their mothers: Clinical, prospective cohort study

    Energy Technology Data Exchange (ETDEWEB)

    Unuvar, Emin [Istanbul University, Istanbul Medical Faculty, Department of Pediatrics, Istanbul (Turkey)]. E-mail: Eunuvar@superonline.com; Ahmadov, Hasan [Istanbul University, Istanbul Medical Faculty, Department of Pediatrics, Istanbul (Turkey); Kiziler, Ali Riza [Istanbul University, Istanbul Medical Faculty, Department of Pediatrics, Istanbul (Turkey); Istanbul University, Cerrahpasa Medical Faculty, Department of Biophysics, Istanbul (Turkey); Aydemir, Birsen [Istanbul University, Istanbul Medical Faculty, Department of Pediatrics, Istanbul (Turkey); Istanbul University, Cerrahpasa Medical Faculty, Department of Biophysics, Istanbul (Turkey); Toprak, Sadik [Gazi Osman Pasa University, Department of Forensic Pathology, Tokat (Turkey); Ulker, Volkan [Bakirkoy Government Hospital, Istanbul (Turkey); Ark, Cemal [Bakirkoy Government Hospital, Istanbul (Turkey)

    2007-03-01

    Objectives: The purpose of this study is to investigate the chronic mercury intoxication in pregnant women and newborns living in Istanbul, Turkey. Methods: The research was carried out as a prospective with 143 pregnant women and their newborns. Venous blood from the mother, cord blood from the neonate, and meconium were collected for mercury analysis. Frequency of fish and vegetable-eating and the number of teeth filled were investigated. Analyses were made in cold vapor Atomic Absorption Spectrophotometer (AAS, {mu}g/L). Results: Mercury levels were 0.38 {+-} 0.5 {mu}g/L (0-2.34) in venous blood of pregnant women, 0.50 {+-} 0.64 {mu}g/L (0-2.36) in umbilical cord blood and 9.45 {+-} 13.8 {mu}g/g (0-66.5) in meconium. Maternal blood mercury level was lower than the known toxic limit for humans (EPA, 5 {mu}g/L). Mercury levels of the maternal venous blood were significantly correlated with umbilical cord blood. The primary risk factors affecting mercury levels were eating fishmeals more than twice a week and having filled teeth more than five. The fact that the mother had a regular vegetable diet everyday reduced the mercury levels. Increased levels of mercury in the mother and umbilical cord blood could lead to retarded newborns' weight and height. Conclusion: Pregnant women living in Istanbul may be not under the risk of chronic mercury intoxication. Fish consumption more than twice per week and tooth-filling of mother more than five may increase mercury level. On the contrary, regular diet rich in vegetable decreases the mercury level.

  7. Midazolam sedates Passeriformes for field sampling but affects multiple venous blood analytes

    Directory of Open Access Journals (Sweden)

    Heatley JJ

    2015-01-01

    Full Text Available J Jill Heatley,1 Jennifer Cary,2,3 Lyndsey Kingsley,1 Hughes Beaufrere,4 Karen E Russell,5 Gary Voelker2,3 1Department of Small Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, 2Department of Wildlife and Fisheries Sciences, 3Texas A&M Biodiversity Research and Teaching Collections, Texas A&M University, College Station, TX, USA; 4Health Sciences Centre, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada; 5Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, College Station, TX, USA Abstract: Feasibility and effect of midazolam administration on blood analytes and for sedation of Passeriformes being collected in a larger study of genetic biodiversity was assessed. Midazolam (5.6±2.7 mg/kg was administered intranasally prior to sampling, euthanasia, and specimen preparation of 104 passerine birds. Each bird was assessed for sedation score and then multiple analytes were determined from jugular blood samples using the i-STAT® point of care analyzer at “bird side”. Most birds were acceptably sedated, sedation became more pronounced as midazolam dose increased, and only a single bird died. Electrolyte concentrations and venous blood gas analytes were affected by midazolam administration while blood pH, packed cell volume, hemoglobin, and calculated hematocrit were not. Intranasal midazolam gives adequate sedation and is safe for short-term use in free-living Passeriformes. Based on venous blood analyte data, sedation of Passeriformes prior to handling appears to reduce stress but also produces venous blood gas differences consistent with hypoventilation relative to birds which were not given midazolam. Further study is recommended to investigate midazolam's continued use in free-living avian species. Studies should include safety, reversal and recovery, effect upon additional endogenous analytes, and compatibility with studies of ecology and toxicology

  8. Average blood flow and oxygen uptake in the human brain during resting wakefulness

    DEFF Research Database (Denmark)

    Madsen, P L; Holm, S; Herning, M

    1993-01-01

    The Kety-Schmidt technique can be regarded as the reference method for measurement of global average cerebral blood flow (average CBF) and global average cerebral metabolic rate of oxygen (average CMRO2). However, in the practical application of the method, diffusion equilibrium for inert gas tra...... anatomy. However in the present study, no correlation between CMRO2 and cerebral venous anatomy as imaged by magnetic resonance angiography could be established. Our data show that the interindividual variation of CMRO2 is 11% (coefficient of variation)....

  9. Improving the validity of peripheral venous blood gas analysis as an estimate of arterial blood gas by correcting the venous values with SvO₂.

    Science.gov (United States)

    Lemoël, Fabien; Govciyan, Sandra; El Omri, Mouna; Marquette, Charles-Hugo; Levraut, Jacques

    2013-03-01

    Peripheral venous blood gas (pVBG) analysis in replacement of arterial blood gas (ABG) is limited by the unpredictable differences between arterial and venous values, especially for PCO2 and pH (ΔPCO2 and ΔpH). We hypothesized that, using the theoretical relationship linking SvO2 and blood flow, we could diminish the effect of local circulatory conditions on ΔPCO2 and ΔpH and thereby increase pVBG validity. This was a prospective cross-sectional study performed in emergency patients requiring a blood gas analysis in which ABG and pVBG were performed simultaneously. The data of 50 randomly selected patients (model group) were used for developing two equations to correct PvCO2 and pHv according to the peripheral SvO2 (SpvO2) level. The formulas derived were PvCO2cor = PvCO2 - 0.30 × (75 - SpvO2), and pHvcor = pHv + 0.001 × (75 - SpvO2). The validity of the corrected values was then tested on the remaining population (validation group). There were 281 patients included in the study, mainly for dyspnea. ΔPCO2 and ΔpH were strongly correlated with SpvO2 (r(2) = 0.62 and r(2) = 0.53, respectively, p 45 mm Hg (AUC ROC = 0.96 ± 0.01 vs. 0.89 ± 0.02, p 7.45 (AUC = 0.91 ± 0.02 vs. 0.81 ± 0.04, p < 0.001). The variability of ΔPCO2 and ΔpH is significantly lowered when the venous values are corrected according to the SpvO2 value, and pVBG is therefore more accurate and valid for detecting an arterial abnormality. Copyright © 2013 Elsevier Inc. All rights reserved.

  10. [Injuries to blood vessels near the heart caused by central venous catheters].

    Science.gov (United States)

    Abram, J; Klocker, J; Innerhofer-Pompernigg, N; Mittermayr, M; Freund, M C; Gravenstein, N; Wenzel, V

    2016-11-01

    Injuries to blood vessels near the heart can quickly become life-threatening and include arterial injuries during central venous puncture, which can lead to hemorrhagic shock. We report 6 patients in whom injury to the subclavian artery and vein led to life-threatening complications. Central venous catheters are associated with a multitude of risks, such as venous thrombosis, air embolism, systemic or local infections, paresthesia, hemothorax, pneumothorax, and cervical hematoma, which are not always immediately discernible. The subclavian catheter is at a somewhat lower risk of catheter-associated sepsis and symptomatic venous thrombosis than approaches via the internal jugular and femoral veins. Indeed, access via the subclavian vein carries a substantial risk of pneumo- and hemothorax. Damage to the subclavian vein or artery can also occur during deliberate and inadvertent punctures and result in life-threatening complications. Therefore, careful consideration of the access route is required in relation to the patient and the clinical situation, to keep the incidence of complications as low as possible. For catheterization of the subclavian vein, puncture of the axillary vein in the infraclavicular fossa is a good alternative, because ultrasound imaging of the target vessel is easier than in the subclavian vein and the puncture can be performed much further from the lung.

  11. Clinicopathologic analysis of Passeriform venous blood reflects transitions in elevation and habitat

    Directory of Open Access Journals (Sweden)

    Heatley JJ

    2013-06-01

    Full Text Available J Jill Heatley,1 Jennifer Cary,2 Karen E Russell,3 Gary Voelker2 1Department of Small Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, 2Department of Wildlife and Fisheries Sciences and Texas A&M Biodiversity Research and Teaching Collections, Texas A&M University, 3Department of Pathobiology, College of Veterinary Medicine and Biomedical Sciences, College Station, TX, USA Abstract: Jugular blood samples from 110 Passeriformes collected at several Texas locations were analyzed for multiple clinicopathologic parameters between April 2010 and August 2011. Electrolyte, blood gas, and select erythrocyte parameters were analyzed on site with a point of care analyzer, and gender, age, body condition score, location, and species were recorded. Many analytes exhibited a Gaussian distribution across species and are reported as a single range. Taxon affected electrolyte and red blood cell parameters, but not most blood gas or acid base variables. Migratory status affected select electrolytes but few blood gas variables. Red blood cell parameters were affected the most by variables of age, taxonomic group, and gender, but not migratory life history. We found significant changes in glucose and numerous acid base analytes in birds sampled from habitats with evolutionarily recent ecologic degradation. We advocate the use of these analytes, particularly venous blood gas values, as determined by a point of care analyzer, as reasonable biomarkers for determination of Passeriform population health, but also recommend that red blood cell parameters and electrolyte concentrations be controlled for age, species, and gender in future studies. Further, based on our investigation, venous blood gas values and acid base balance in Passeriformes can assess the health of an ecosystem. Keywords: avian, biochemistry, blood gas, electrolyte, hematology, Passerine

  12. Optical methods for correction of oxygen-transport characteristics of blood and their biomedical applications

    Science.gov (United States)

    Zalesskaya, G. A.; Akulich, N. V.; Marochkov, A. V.; Laskina, O. V.; Mit'kovskaya, N. P.

    2010-07-01

    We have carried out a comprehensive analysis of the spectral characteristics of blood and blood components, gas-exchange and oximetry parameters for venous and arterial blood, central hemodynamic parameters, and the results of a complete blood count and chemistry panel before and after extracorporeal UV irradiation of the blood (UBI, ultraviolet blood irradiation) or intravenous exposure of blood to low-intensity emission from an He-Ne laser (LBI, laser blood irradiation). We have demonstrated the possibility of correcting the oxygentransport characteristics of blood by laser optical methods based on photodissociation of blood oxyhemoglobin. We have shown that the therapeutic effects initiated both by UBI and LBI are based on a single mechanism: a change in the balance between production of active oxygen species and their inhibition by antioxidants. The data obtained are of interest not only for studying the primary (molecular) mechanisms of action for photohemotherapy and their effect on processes occurring in the living body, but also can provide a basis for designing next-generation laser optical instruments and for development of not yet existing methods for assessing the therapeutic efficacy of photohemotherapy.

  13. Simultaneous blood flow and blood oxygenation measurements using a combination of diffuse speckle contrast analysis and near-infrared spectroscopy

    Science.gov (United States)

    Seong, Myeongsu; Phillips, Zephaniah; Mai, Phuong Minh; Yeo, Chaebeom; Song, Cheol; Lee, Kijoon; Kim, Jae Gwan

    2016-02-01

    A combined diffuse speckle contrast analysis (DSCA)-near-infrared spectroscopy (NIRS) system is proposed to simultaneously measure qualitative blood flow and blood oxygenation changes in human tissue. The system employs an optical switch to alternate two laser sources at two different wavelengths and a CCD camera to capture the speckle image. Therefore, an optical density can be measured from two wavelengths for NIRS measurements and a speckle contrast can be calculated for DSCA measurements. In order to validate the system, a flow phantom test and an arm occlusion protocol for arterial and venous occlusion were performed. Shorter exposure times (oxyhemoglobin (OHb) and deoxyhemoglobin (RHb) during arterial occlusion (max RHb=0.0085±0.0024 mM/DPF, min OHb=-0.0057±0.0044 mM/DPF). The sensitivity of the system makes it a suitable modality to observe qualitative hemodynamic trends during induced physiological changes.

  14. Blood flow vs. venous pressure effects on filtration coefficient in oleic acid-injured lung.

    Science.gov (United States)

    Anglade, D; Corboz, M; Menaouar, A; Parker, J C; Sanou, S; Bayat, S; Benchetrit, G; Grimbert, F A

    1998-03-01

    On the basis of changes in capillary filtration coefficient (Kfc) in 24 rabbit lungs, we determined whether elevations in pulmonary venous pressure (Ppv) or blood flow (BF) produced differences in filtration surface area in oleic acid-injured (OA) or control (Con) lungs. Lungs were cyclically ventilated and perfused under zone 3 conditions by using blood and 5% albumin with no pharmacological modulation of vascular tone. Pulmonary arterial, venous, and capillary pressures were measured by using arterial, venous, and double occlusion. Before and during each Kfc-measurement maneuver, microvascular/total vascular compliance was measured by using venous occlusion. Kfc was measured before and 30 min after injury, by using a Ppv elevation of 7 cmH2O or a BF elevation from 1 to 2 l . min-1 . 100 g-1 to obtain a similar double occlusion pressure. Pulmonary arterial pressure increased more with BF than with Ppv in both Con and OA lungs [29 +/- 2 vs. 19 +/- 0.7 (means +/- SE) cmH2O; P Kfc (200 +/- 40 vs. 83 +/- 14%, respectively; P < 0.01) and microvascular/total vascular compliance ratio (86 +/- 4 vs. 68 +/- 5%, respectively; P < 0.01) increased more with BF than with Ppv. In conclusion, for a given OA-induced increase in hydraulic conductivity, BF elevation increased filtration surface area more than did Ppv elevation. The steep pulmonary pressure profile induced by increased BF could result in the recruitment of injured capillaries and could also shift downstream the compression point of blind (zone 1) and open injured vessels (zone 2).

  15. The oxygen status of the arterial blood in the critically ill.

    Science.gov (United States)

    Tulli, G; Vignali, G; Guadagnucci, A; Mondello, V

    1990-01-01

    In Critical Care medicine the concepts of Oxygen Delivery, Oxygen Consumption and Tissue Oxygenation have become fundamental in clinical practice but measurements of Oxygen Content and O2 Transport variables require invasive procedures that could be dangerous for critically ill patients and trigger a septic process. Derived indices obtained combining data from a Blood Gas Analyzer with the data from a multi-wavelength spectrophotometer and using the Ole Siggaard-Andersen pH/Blood Gas computerised algorithm might be the non-invasive answer. On 115 arterial blood samples from critically ill patients, we measured pH, pCO2, pO2, oxygen saturation, total hemoglobin concentration and fractions of carboxy- and methemoglobin. The new algorithm was used to calculate: active hemoglobin concentration, total oxygen concentration, actual half-saturation tension, 2,3-diphosphoglycerate concentration, estimated functional shunt, uncompensated mixed venous pO2 (assuming an arterio-venous oxygen difference of 2.3 mmol/L based on a standard oxygen consumption of 11.2 mmol/min and a standard cardiac output of 4.9 L/min) and the cardiac oxygen compensation factor. In Intensive Care all the oxygen parameters may be determined with sufficient accuracy and precision provided the oxygen saturation level is less than 0.97 and provided the definition of oxygen saturation is properly settled and measurements are performed according to the highest state of the art. However, in critically ill patients in evolution our aim is to maintain an 'optimal' paO2 on the plateau of the Oxygen Dissociation Curve (ODC) and the use of mechanical ventilation, high FIO2, fluid challenges and the rapid improvement of the patient's conditions can cause a value for sO2 greater than or less than 0.97 and an improvement or worsening of the paO2. The p50 calculation both in simultaneously drawn arterial and venous blood permits utilisation of derived indices (pO2uv-, CQ) for sO2 greater than 0.97. The Ole Siggaard

  16. Effects of Pulsatile Blood Flow on Oxygenator Performance.

    Science.gov (United States)

    Schraven, Lotte; Kaesler, Andreas; Flege, Christian; Kopp, Rüdger; Schmitz-Rode, Thomas; Steinseifer, Ulrich; Arens, Jutta

    2018-02-13

    Extracorporeal membrane oxygenation (ECMO) is mainly used for the therapy of acute respiratory distress syndrome and chronic obstructive lung disease. In the last years, the development of these systems underwent huge steps in optimization, but there are still problems with thrombus formation, clogging, and thus insufficient gas exchange. One idea of ECMO optimization is a pulsatile blood flow through the oxygenator, but this is still a controversy discussion. Analyzing available publications, it was not possible to identify a general statement about the effect of pulsatile blood flow on the gas exchange performance. The variety of parameters and circuit components have such a high influence on the outcome that a direct comparison of the studies is difficult. For this reason, we performed a structured study to evaluate the effects of pulsatile blood flow on the gas exchange performance of oxygenator. In in vitro tests according to DIN EN ISO 7199, we tested a small oxygenator (0.25 m 2 exchange surface, polymethylpentene fibers, 33 mL priming volume) with constant and pulsatile blood flow in comparison. Therefore, we varied the mean blood flow from 250 to 1200 mL/min, the amplitude of 0, 20, and 50%, and the frequency of 30, 60, and 90 bpm. The results demonstrate that the gas transfer for pulsatile and constant blood flow was similar (oxygen: 36-64 mL O2 /L Blood ; carbon dioxide 35-80 mL CO2 /L Blood ) for the same mean blood flow ranges. Over all, the results and analyses showed a statistically nonsignificant difference between pulsatile and nonpulsatile flow. Consequently, we conclude that the implementation of pulsatile blood flow has only a small to no effect on the gas exchange performance in an oxygenator. As the results were obtained using an oxygenator with a coiled fiber bundle, the test must be verified for a stacked fiber oxygenator. © 2018 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  17. A novel automated discontinuous venous blood monitoring system for ex vivo glucose determination in humans.

    Science.gov (United States)

    Schaller, R; Feichtner, F; Köhler, H; Bodenlenz, M; Plank, J; Wutte, A; Mader, J K; Ellmerer, M; Hellmich, R; Wedig, H; Hainisch, R; Pieber, T R; Schaupp, L

    2009-03-15

    Intensive insulin therapy reduces mortality and morbidity in critically ill patients but imposes great demands on medical staff who must take frequent blood samples for the determination of glucose levels. A solution to this resourcing problem would be provided by an automated blood monitoring system. The aim of the present clinical study was to evaluate such a system comprising an automatic blood sampling unit linked to a glucose biosensor. Our approach was to determine the correlation and system error of the sampling unit alone and of the combined system with respect to reference levels over 12h in humans. Two venous cannulae were inserted to connect the automatic and reference systems to the subjects. Blood samples were taken at 15 and 30 min intervals. The median Pearson coefficient of correlation between manually and automatically withdrawn blood samples was 0.982 for the sampling unit alone and 0.950 for the complete system. The biosensor had a linear range up to 20 mmoll(-1) and a 95% response time of blood sampling system reduced blood withdrawal failures through occluded catheters fourfold. In summary, automated blood sampling from a peripheral vein coupled with automatic glucose determination is a promising alternative to frequent manual blood sampling.

  18. Quantitative assessment of limb blood flow using Tc-99m labeled red blood cells. Radionuclide venous occlusion plethysmography (RAVOP)

    Energy Technology Data Exchange (ETDEWEB)

    Itoh, Kazuo; Shougase, Takashi; Kawamura, Naoyuki; Tsukamoto, Eriko; Nakada, Kunihiro; Sakuma, Makoto; Furudate, Masayori

    1987-10-01

    A quantitative assessment of limb blood flow using a non-diffusible radioindicator, Tc-99m labeled red blood cells, was reported. This was an application of venous occlusion plethysmography using radionuclide which was originally proposed by M. Fukuoka et al. The peripheral blood flow (mean +- s.e.) of 30 legs in a normal control group was 1.87 +- 0.08 ml/100 ml/min. In heart diseases (46 legs), it was 1.49 +- 0.13 ml/100 ml/min. The limb blood flow between a control group and heart diseases was statistically significant (p < 0.01) in the t-test. The peripheral blood flow at rest between diseased legs and normal legs in occlusive arterial disorders was also statistically significant (p < 0.01) in a paired t-test. RAVOP was done after the completion of objective studies such as radionuclide angiography or ventriculography. Technique and calculation of a blood flow were very easy and simple. RAVOP study which was originally proposed by Fukuoka et al. was reappraised to be hopeful for quantitative measurement of limb blood flow as a non-invasive technique using Tc-99m labeled red blood cells.

  19. HIV-1 viral load measurement in venous blood and fingerprick blood using Abbott RealTime HIV-1 DBS assay.

    Science.gov (United States)

    Tang, Ning; Pahalawatta, Vihanga; Frank, Andrea; Bagley, Zowie; Viana, Raquel; Lampinen, John; Leckie, Gregor; Huang, Shihai; Abravaya, Klara; Wallis, Carole L

    2017-07-01

    HIV RNA suppression is a key indicator for monitoring success of antiretroviral therapy. From a logistical perspective, viral load (VL) testing using Dried Blood Spots (DBS) is a promising alternative to plasma based VL testing in resource-limited settings. To evaluate the analytical and clinical performance of the Abbott RealTime HIV-1 assay using a fully automated one-spot DBS sample protocol. Limit of detection (LOD), linearity, lower limit of quantitation (LLQ), upper limit of quantitation (ULQ), and precision were determined using serial dilutions of HIV-1 Virology Quality Assurance stock (VQA Rush University), or HIV-1-containing armored RNA, made in venous blood. To evaluate correlation, bias, and agreement, 497 HIV-1 positive adult clinical samples were collected from Ivory Coast, Uganda and South Africa. For each HIV-1 participant, DBS-fingerprick, DBS-venous and plasma sample results were compared. Correlation and bias values were obtained. The sensitivity and specificity were analyzed at a threshold of 1000 HIV-1 copies/mL generated using the standard plasma protocol. The Abbott HIV-1 DBS protocol had an LOD of 839 copies/mL, a linear range from 500 to 1×107 copies/mL, an LLQ of 839 copies/mL, a ULQ of 1×107 copies/mL, and an inter-assay SD of ≤0.30 log copies/mL for all tested levels within this range. With clinical samples, the correlation coefficient (r value) was 0.896 between DBS-fingerprick and plasma and 0.901 between DBS-venous and plasma, and the bias was -0.07 log copies/mL between DBS-fingerprick and plasma and -0.02 log copies/mL between DBS-venous and plasma. The sensitivity of DBS-fingerprick and DBS-venous was 93%, while the specificity of both DBS methods was 95%. The results demonstrated that the Abbott RealTime HIV-1 assay with DBS sample protocol is highly sensitive, specific and precise across a wide dynamic range and correlates well with plasma values. The Abbott RealTime HIV-1 assay with DBS sample protocol provides an

  20. The influence of venous blood flow on the retinal ganglion cell complex in patients with primary open angle glaucoma

    Directory of Open Access Journals (Sweden)

    N. I. Kurysheva

    2014-07-01

    Full Text Available Purpose: To study the influence of venous blood flow on the ganglion cell complex (GCC in patients with preperimetric and perimetric open angle glaucoma.Methods: 74 patients were included in the research. 59 eyes and 62 eyes were diagnosed with preperimetric and perimetric open angle glaucoma respectively. The mean age was 56.5±10.5 years. 22 (12 female and 10 male healthy individuals constituted the control group. The ganglion cell complex and retinal nerve fibre layer were evaluated with the help of optical coherence tomography (RTVue-100 OCT, Optovue, Inc., Fremont, CA. Ocular blood flow was measured by Color Doppler Imaging (multifunctional VOLUSON 730 ProSystem. The statistical analysis included correlation between GCC and RNFL thickness in both glaucoma groups.Results: The results showed a statistically significant reduction of venous blood flow velocity in both glaucoma groups compared to the control group. No difference in venous blood flow parameters between two glaucoma groups was found, except resistance index, which was higher in perimetric group in comparison to preperimetric group. A correlation was also obtained between venous blood flow parameters and GCC and RNFL thickness in both glaucoma groups.Conclusion: Early GCC damage in glaucoma might occur due to venous blood flow reduction. This fact may be of great value in understanding glaucoma pathogenesis and search for novel treatment options.

  1. An everyday phrase may harm your patients: the influence of negative words on pain during venous blood sampling.

    Science.gov (United States)

    Ott, Johannes; Aust, Stefanie; Nouri, Kazem; Promberger, Regina

    2012-05-01

    Venous blood sampling is one of the most common diagnostic medical procedures performed in clinical practice. It has been shown that negatively loaded words may result in negative affective reactions and, consequently, in an increased perception of pain. We aimed to evaluate whether common warnings before venous blood sampling might induce unnecessary pain. We included 100 healthy participants (50 females, 50 males) who were randomized to one of the 2 study groups ("sting" vs. "beware"). Directly before insertion of the needle, the participants were warned with either the word "sting" or "beware." Venous blood sampling was performed according to a standardized protocol. Preinterventional and postinterventional blood pressure and heart rate, as well as pain scores after venous blood sampling, were evaluated. There were 98 participants, 26.2 ± 3.2 years of age, who were included into the analysis. Participants experienced significantly more pain after having been warned with the word "sting" compared with the word "beware." The numeric rating scale results were 2.7 ± 1.2 versus 1.9 ± 1.1, respectively (P=0.001). Words associated with pain increase the perception of pain during venous blood sampling. Omitting these words may be a simple and essential method by which to avoid unnecessary pain.

  2. Optoacoustic mapping of cerebral blood oxygenation in humans

    Science.gov (United States)

    Petrov, Yuriy; Prough, Donald S.; Petrov, Irene Y.; Richardson, C. Joan; Fonseca, Rafael A.; Robertson, Claudia S.; Esenaliev, Rinat O.

    2017-03-01

    Noninvasive, transcranial mapping, monitoring, and imaging are highly important for detection and management of cerebral abnormalities and neuroscience research. Mapping, imaging, and monitoring of cerebral blood oxygenation are necessary for diagnostics and management of patients with traumatic brain injury, stroke, and other neurological conditions. We proposed to use optoacoustic technology for noninvasive, transcranial monitoring and imaging. In this work, we developed optoacoustic systems for mapping of cerebral blood oxygenation in humans and tested them in adults and neonates. The systems provide noninvasive, transcranial optoacoustic measurements in the transmission (forward) and reflection (backward) modes in the near infrared spectral range. Novel, ultra-sensitive probes were built for detection of optoacoustic signals and measurement of blood oxygenation in neonates and adults. Cerebral oxygenation was measured at different lateral sites from the superior sagittal sinus (SSS), a large central cerebral vein, located immediately beneath the midline of the human skull. In neonates, cerebral oxygenation was measured through open anterior and posterior fontanelles. Optoacoustic signal detection at different locations allowed for mapping of cerebral blood oxygenation. Our future studies will be focused on 3D mapping of cerebral blood oxygenation.

  3. Oxygen dissociation curves of whole blood from the Egyptian free ...

    African Journals Online (AJOL)

    Tadarida aegyptiaca (mean body mass 13.5 g) is a fast flying insectivorous bat that hunts in open areas for extended periods, covering extensive distances during its foraging bouts. Whole blood samples taken from the wing arteries were analysed for 2,3-diphosphoglyceric acid, oxygen affinity and pH. The mean oxygen ...

  4. Blood flow, volume and arterio-venous passages in induced mammary tumours of the rat.

    Science.gov (United States)

    Hultborn, Ragnar

    2018-03-01

    To study blood flow, vascular volume and arterio-venous passages in induced mammary tumours of the rat to characterize parameters possibly responsible for tumour hyponutrition. Dimethylbenzanthracene-induced mammary tumours in Sprague-Dawley rats were studied. Regional blood flow was studied by use of the radioactive microsphere tracer technique using 141Cerium-labelled 15μm spheres coinjected into the left cardiac ventricle with 125Iodine-labelled 25μm spheres. Blood volume was studied by use of 125Iodine- or 99mTechnetium-labelled human serum albumin, the latter allowing autoradiography of tumour sections for visualization of flow and volume. Twenty-seven rats with 170 tumours had a mean tumour blood flow of 48 and 67mL×min-1×100g-1 using 15 and 25μm sphere data, respectively, indicating a significant passage through vessels between 15 and 25μm. The lungs showed a "nominal bronchial" blood flow of 260 and 135mL×min-1×100g-1 for the 15 and 25μm spheres, respectively, indicating pulmonary trapping, particularly of small spheres passing the systemic circulation in vessels larger than 15μm. There was a positive correlation between the total tumour blood flow within individual rats and trapped spheres of both dimensions in the lungs, indicating shunts also larger than 25μm. Normal tissues disclosed only small differences in regional blood flow as measured by the two spheres. Blood volume was studied in 20 rats with 120 tumours, with a vascular volume of 3.6mL×100g-1 representing a blood turnover >15 times/min. Blood volume co-localized with perfusion as seen in autoradiographs. In induced rat mammary tumours, a high fraction of blood, 28%, passes arterio-venous vessels between 15 and 25μm and there also exist passages >25μm. These findings indicate that the functional capacity of the tumour vascular bed might be impaired, adding to the abnormal microenvironment of tumours. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Hybrid model of arm for analysis of regional blood oxygenation in non-invasive optical diagnostics

    Science.gov (United States)

    Nowocień, Sylwester; Mroczka, Janusz

    2017-06-01

    The paper presents a new comprehensive approach to modeling and analysis of processes occurring during the blood flow in the arm's small vessels as well as non-invasive measurement method of mixed venous oxygen saturation. During the work, a meta-analysis of available physiological data was performed and based on its result a hybrid model of forearm vascular tree was proposed. The model, in its structure, takes into account a classical nonlinear hydro-electric analogy in conjunction with light-tissue interaction. Several geometries of arm vascular tree obtained from magnetic resonance angiography (MRA) image were analyzed which allowed to proposed the structure of electrical analog network. Proposed model allows to simulate the behavior of forearm blood flow from the vascular tree mechanics point of view, as well as effects of the impact of cuff and vessel wall mechanics on the recorded photoplethysmographic signals. In particular, it allows to analyze the reaction and anatomical effects in small vessels and microcirculation caused by occlusive maneuver in selected techniques, what was of particular interest to authors and motivation to undertake research in this area. Preliminary studies using proposed model showed that inappropriate selection of occlusion maneuver parameters (e.g. occlusion time, cuff pressure etc.), cause dangerous turbulence of blood flow in the venous section of the vascular tree.

  6. Risk of venous thromboembolism and myocardial infarction associated with factor V Leiden and prothrombin mutations and blood type

    DEFF Research Database (Denmark)

    Sode, Birgitte F; Allin, Kristine H; Dahl, Morten

    2013-01-01

    ABO blood type locus has been reported to be an important genetic determinant of venous and arterial thrombosis in genome-wide association studies. We tested the hypothesis that ABO blood type alone and in combination with mutations in factor V Leiden R506Q and prothrombin G20210A is associated...

  7. Central venous oxygen saturation in septic shock - a marker of cardiac output, microvascular shunting and/or dysoxia?

    DEFF Research Database (Denmark)

    Haase, Nicolai; Perner, Anders

    2011-01-01

    Shock therapy aims at increasing central venous oxygen saturation (ScvO2), which is a marker of inadequate oxygen delivery. In this issue of Critical Care, Textoris and colleagues challenge this notion by reporting that high levels of ScvO2 are associated with mortality in patients with septic...... shock. This is of obvious interest, but as their retrospective design has inherent limitations, the association should be confirmed in a prospective, multicenter study with protocolized ScvO2 measurements and detailed registration of potentially confounding factors....

  8. Influence of different storage times and temperatures on blood gas and acid-base balance in ovine venous blood.

    Science.gov (United States)

    Hussein, H A; Aamer, A A

    2013-01-01

    The present study was designed to investigate the effects of storage temperature and time on blood gas and acid-base balance of ovine venous blood. Ten clinically healthy sheep were used in this study. A total number of 30 blood samples, were divided into three different groups, and were stored in a refrigerator adjusted to +4 ºC (Group I, n = 10), at RT of about 22-25 ºC (Group II, n = 10) and in an incubator adjusted to 37 ºC (Group III, n = 10) for up to 48 h. Blood samples were analysed for blood gas and acid-base indices at 0, 1, 2, 3, 4, 5, 6, 12, 24 and 48 h of storage. In comparison to the baseline value (0), there were significant decreases of blood pH of samples stored at RT and in the incubator after 1 h (pbase excess decreased significantly for all the groups during the study especially in Groups II and III. In comparison with baseline values, in all groups, bicarbonate (HCO3) increased between 1 h and 6 h (pacid-base indices of the samples stored at refrigerator and RT were found within normal reference range and it may be of clinical diagnostic use for up to 6 h.

  9. DNA Content in Extracellular Vesicles Isolated from Porcine Coronary Venous Blood Directly after Myocardial Ischemic Preconditioning.

    Directory of Open Access Journals (Sweden)

    Kristina Svennerholm

    Full Text Available Extracellular vesicles (EV are nano-sized membranous structures released from most cells. They have the capacity to carry bioactive molecules and gene expression signals between cells, thus mediating intercellular communication. It is believed that EV confer protection after ischemic preconditioning (IPC. We hypothesize that myocardial ischemic preconditioning will lead to rapid alteration of EV DNA content in EV collected from coronary venous effluent.In a porcine myocardial ischemic preconditioning model, EV were isolated from coronary venous blood before and after IPC by differential centrifugation steps culminating in preparative ultracentrifugation combined with density gradient ultracentrifugation. The EV preparation was validated, the DNA was extracted and further characterized by DNA sequencing followed by bioinformatics analysis.Porcine genomic DNA fragments representing each chromosome, including mitochondrial DNA sequences, were detected in EV isolated before and after IPC. There was no difference detected in the number of sequenced gene fragments (reads or in the genomic coverage of the sequenced DNA fragments in EV isolated before and after IPC. Gene ontology analysis showed an enrichment of genes coding for ion channels, enzymes and proteins for basal metabolism and vesicle biogenesis and specific cardiac proteins.This study demonstrates that porcine EV isolated from coronary venous blood plasma contain fragments of DNA from the entire genome, including the mitochondria. In this model we did not find specific qualitative or quantitative changes of the DNA content in EV collected immediately after an in vivo myocardial IPC provocation. This does not rule out the possibility that EV DNA content changes in response to myocardial IPC which could occur in a later time frame.

  10. Arterial Blood, Rather Than Venous Blood, is a Better Source for Circulating Melanoma Cells

    Directory of Open Access Journals (Sweden)

    Mizue Terai

    2015-11-01

    Interpretation: Our data indicate that arterial blood specimens might be a better source of circulating uveal melanoma cells. Although less conveniently processed, perhaps arterial blood should be evaluated as sample source for measurement of CTCs.

  11. ABO blood group related venous thrombosis risk in patients with peripherally inserted central catheters.

    Science.gov (United States)

    Koo, Chung Mo; Vissapragada, Ravi; Sharp, Rebecca; Nguyen, Phi; Ung, Thomas; Solanki, Chrismin; Esterman, Adrian

    2018-02-01

    To investigate the association between ABO blood group and upper limb venous thrombosis (VT) risk in patients with peripherally inserted central catheters (PICC). Single centre retrospective cohort study. A cohort of patients who underwent PICC insertion from September 2010 to August 2014 were followed up for symptomatic VT presentations diagnosed by ultrasound. Blood group status was identified from hospital information systems. 2270 participants had 3020 PICCs inserted. There were 124 cases of symptomatic VT, an incident rate of 4% [95% confidence interval, CI (3-5%)]. Univariate analysis adjusting for the clustered sample showed that having chemotherapy, two or more previous PICCs, a larger catheter size, a diagnosis of cancer and having a blood group B were all associated with an increased risk of a VT. In the multivariate analysis, PICC diameter, cancer diagnosis and blood group B were all independently associated with increased risk of VT. Patients undergoing PICC insertion with a blood group B appear to have a higher risk of VT, independent of risks attached to the PICC procedure and cancer diagnosis. Without any existing guidelines for PICC-related VT, this investigation creates a platform for further research to be conducted in order to establish guidelines. Advances in knowledge: Previous studies investigating VT risk associated with blood group status related to large heterogeneous populations. In this article, we look at patients specifically with PICC, which reduces the heterogeneity in the cohort. In addition, due to the substantial number of patients enrolled, we had a chance to perform multivariate analyses with statistical significance.

  12. Vasopressin-induced changes in splanchnic blood flow and hepatic and portal venous pressures in liver resection.

    Science.gov (United States)

    Bown, L Sand; Ricksten, S-E; Houltz, E; Einarsson, H; Söndergaard, S; Rizell, M; Lundin, S

    2016-05-01

    To minimize blood loss during hepatic surgery, various methods are used to reduce pressure and flow within the hepato-splanchnic circulation. In this study, the effect of low- to moderate doses of vasopressin, a potent splanchnic vasoconstrictor, on changes in portal and hepatic venous pressures and splanchnic and hepato-splanchnic blood flows were assessed in elective liver resection surgery. Twelve patients were studied. Cardiac output (CO), stroke volume (SV), mean arterial (MAP), central venous (CVP), portal venous (PVP) and hepatic venous pressures (HVP) were measured, intraoperatively, at baseline and during vasopressin infusion at two infusion rates (2.4 and 4.8 U/h). From arterial and venous blood gases, the portal (splanchnic) and hepato-splanchnic blood flow changes were calculated, using Fick's equation. CO, SV, MAP and CVP increased slightly, but significantly, while systemic vascular resistance and heart rate remained unchanged at the highest infusion rate of vasopressin. PVP was not affected by vasopressin, while HVP increased slightly. Vasopressin infusion at 2.4 and 4.8 U/h reduced portal blood flow (-26% and -37%, respectively) and to a lesser extent hepato-splanchnic blood flow (-9% and -14%, respectively). The arterial-portal vein lactate gradient was not significantly affected by vasopressin. Postoperative serum creatinine was not affected by vasopressin. Short-term low to moderate infusion rates of vasopressin induced a splanchnic vasoconstriction without metabolic signs of splanchnic hypoperfusion or subsequent renal impairment. Vasopressin caused a centralization of blood volume and increased cardiac output. Vasopressin does not lower portal or hepatic venous pressures in this clinical setting. © 2016 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  13. Factors associated with nursing students' adherence to venous blood collection practice guidelines - A cross sectional study.

    Science.gov (United States)

    Nilsson, Karin; Brulin, Christine; Grankvist, Kjell; Juthberg, Christina

    2017-03-01

    Venous blood specimen collection is a common procedure that nursing students perform during pre-registration courses, and training for such collections takes place on campus as well as at clinical placements. However, levels of adherence to practice guidelines are still suboptimal among both nursing students and healthcare staff. We aimed to explore nursing students' adherence to the Swedish national venous blood specimen collection practice guidelines regarding patient identification and test request management and how this adherence is related to clinical experience, capability beliefs, research use, and the perceived social climate in clinical contexts. A survey with a cross-sectional design was conducted among 305 nursing students at a medium-sized university in Sweden. Descriptive statistics and logistic regression were used for data analysis. The survey showed that 82% of the students adhered to patient identification guideline practices and 80% to test request management practices. Factors associated with correct patient identification procedures were semester and frequency of research use. Factors associated with correct test request management were previous healthcare work experience, semester, and capability beliefs regarding academic abilities and evidence-based practice. We conclude that there is a need to develop educational tools to train students in research use and evidence-based practice in order to enhance guideline practice adherence and improve patient safety. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Survival Following Veno-Venous Extracorporeal Membrane Oxygenation and Mortality in a Diverse Patient Population.

    Science.gov (United States)

    Mosca, Matthew S; Narotsky, David L; Liao, Ming; Mochari-Greenberger, Heidi; Beck, James; Mongero, Linda; Bacchetta, Matthew

    2015-12-01

    Racial and ethnic disparities in cardiovascular disease are well established; however, there is limited information about survival differences following veno-venous extracorporeal membrane oxygenation (VV-ECMO) in contemporary adult populations. The purpose of this study was to assess survival at discharge, 30 days, and at 1 year following institution of VV-ECMO in an ethnically diverse population, and to examine potential risk factors for mortality. This was a single-center study of 41 patients (49% female, 27% minorities, 7% > 65 years) who received VV-ECMO between the years 2004 and 2013 at an academic medical center. Kaplan-Meier estimates were calculated to assess survival up to 1 year, and cox proportional hazard models were used to evaluate the association between risk factors, mortality, and confounders. Overall, 76% (n = 31) of VV-ECMO patients survived to discharge and 30 days and 71% (n = 29) survived to 1 year. Whites (n = 30) had a higher survival at 1 year compared to minorities (n = 11) (83% vs. 36%, respectively, p = .01). Minorities had a significantly increased risk of mortality at 30 days (hazard ratio [HR] = 5.07, 95% confidence interval [CI] = 1.42-18.09) and at 1 year (HR = 5.19, 95% CI = 1.63-16.55). Race/ethnicity remained a significant independent predictor of survival at 30 days except when history of shock or lung transplantation was included in adjusted regression models. VV-ECMO was associated with an excellent overall survival up to 1 year. Racial/ethnic minorities had a 5-fold increased risk for 30-day mortality, which was largely explained by a lower likelihood of lung transplantation and increased risk of shock.

  15. Continuous monitoring of central venous oxygen saturation predicts postoperative liver dysfunction after liver resection.

    Science.gov (United States)

    Meguro, Makoto; Mizuguchi, Toru; Kawamoto, Masaki; Nakamura, Yukio; Ota, Shigenori; Kukita, Kazuharu; Ishii, Masayuki; Tatsumi, Hiroomi; Hirata, Koichi

    2013-08-01

    We examined whether the data obtained by monitoring central venous oxygen saturation (ScvO2) and/or stroke volume variation (SVV) during hepatectomy, as measured with the FloTrac/Vigileo system, can predict postoperative liver dysfunction. This study included 33 patients with normal liver function who underwent hepatectomy between December 2007 and August 2010. Baseline ScvO2 and baseline SVV, as control values, were defined as the mean of ScvO2 and SVV, respectively, measured with the FloTrac/Vigileo system before hepatectomy. ScvO2 decrease (ΔScvO2) was defined as the difference between the baseline ScvO2 and the lowest intraoperative ScvO2 and SVV increase (ΔSVV) was defined as the difference between the baseline SVV and the highest intraoperative SVV. Moreover, mean ScvO2 and mean SVV were defined as the means of all ScvO2 and SVV values measured during surgery, respectively. We examined correlations of the new parameters with the highest postoperative values of total bilirubin (T. Bil). The cutoff values for ΔScvO2 and mean SVV for predicting the highest postoperative T. Bil level to be ≥ 3.0 mg/dL with the highest sensitivity and specificity were found to be 10.2% and 13.6%, respectively. The areas under curve in receiver-operating-characteristic analysis of ΔScvO2 and mean SVV were 0.797 and 0.757, respectively, showing significant differences. Our results suggest that ΔScvO2 and mean SVV can predict postoperative liver dysfunction. When ΔScvO2 and mean SVV exceed 10.2% and 13.6%, respectively, we advocate that adequate attention be paid to postoperative liver dysfunction, and that early intraoperative general circulatory management measures be implemented as needed. Copyright © 2013 Mosby, Inc. All rights reserved.

  16. An automated discontinuous venous blood sampling system for ex vivo glucose determination in humans.

    Science.gov (United States)

    Schaller, Roland; Feichtner, Franz; Köhler, Hans; Bodenlenz, Manfred; Plank, Johannes; Wutte, Andrea; Mader, Julia K; Ellmerer, Martin; Hainisch, Reinhard; Pieber, Thomas R; Schaupp, Lukas

    2009-01-01

    Intensive insulin therapy reduces mortality and morbidity in critically ill patients but places great demands on medical staff who must take frequent blood samples for the determination of glucose levels. A cost-effective solution to this resourcing problem could be provided by an effective and reliable automated blood sampling (ABS) system suitable for ex vivo glucose determination. The primary study aim was to compare the performance of a prototype ABS system with a manual reference system over a 30 h sampling period under controlled conditions in humans. Two venous cannulae were inserted to connect the ABS system and the reference system. Blood samples were taken with both systems at 15, 30, and 60 min intervals and analyzed using a Beckman glucose analyzer. During the study, blood glucose levels were altered through four meal ingestions. The median Pearson coefficient of correlation between manually and automatically withdrawn blood samples was 0.976 (0.953-0.996). The system error was -3.327 ± 5.546% (-6.03-0.49). Through Clark error grid analysis, 420 data pairs were analyzed, showing that 98.6% of the data were in zone A and 1.4% were in zone B. Insulin titration error grid analysis revealed an acceptable treatment in 100% of cases. A 17.5-fold reduction in the occurrence of blood-withdrawal failures through occluded catheters was moreover achieved by the added implementation in the ABS system of a "keep vein open" saline infusion. Our study showed that the ABS system described provides a user-friendly, reliable automated means for reproducible and accurate blood sampling from a peripheral vein for blood glucose determination and thus represents a promising alternative to frequent manual blood sampling. © Diabetes Technology Society

  17. Prediction of Venous Thromboembolism after Total Knee Arthroplasty Using Blood Coagulation-Fibrinolysis Markers: A Systematic Review

    Directory of Open Access Journals (Sweden)

    Hideaki Watanabe

    2015-06-01

    Full Text Available AIM: To account for changes in blood coagulation-fibrinolysis using blood markers after total knee arthroplasty with and without venous thromboembolism, and to determine the etiology of postoperative venous thromboembolism after total knee arthroplasty. MATERIALS AND METHODS: A systematic literature search was conducted during November and December 2014. The electronic databases searched were PubMed, MEDLINE®, and Cochrane Library. English only and no data restriction were used. The search keywords were total knee arthroplasty AND venous thromboembolism, deep vein thrombosis, pulmonary embolism AND D-dimer, SFMC, PAI-1 appearing in the title, abstract, or keyword fields. Eight articles were identified, and the full texts of these articles were read and analyzed for validity in blood coagulation-fibrinolysis markers with vs. without venous thromboembolism after total knee arthroplasty. RESULTS: Only D-dimer level has been a useful blood coagulationfibrinolysis marker in the detection of venous thromboembolism after total knee arthroplasty since the 1990s. However, the D-dimer cutoff value varies from 3 to 10μg/mL and sensitivity and specificity vary from 68% to 54.5% and from 94.4% to 90%, respectively. A recent study reported that the level of fibrin degradation products of leukocyte elastase released from activated leukocytes, e-XDP, was significantly elevated in patients with venous thromboembolism and noted that the sensitivity and specificity, both 75%, might be clinically important for a cutoff value of 8.2U/mL. CONCLUSION: D-dimer and e-XDP levels are significantly elevated in patients with venous thromboembolism after total knee arthroplasty. However, their clinical importance remains low.

  18. Performance and safety of femoral central venous catheters in pediatric autologous peripheral blood stem cell collection.

    Science.gov (United States)

    Cooling, Laura; Hoffmann, Sandra; Webb, Dawn; Yamada, Chisa; Davenport, Robertson; Choi, Sung Won

    2017-12-01

    Autologous peripheral blood hematopoietic progenitor cell collection (A-HPCC) in children typically requires placement of a central venous catheter (CVC) for venous access. There is scant published data regarding the performance and safety of femoral CVCs in pediatric A-HPCC. Seven-year, retrospective study of A-HPCC in pediatric patients collected between 2009 and January 2017. Inclusion criteria were an age ≤ 21 years and A-HPCC using a femoral CVC for venous access. Femoral CVC performance was examined by CD34 collection rate, inlet rate, collection efficiency (MNC-FE, CD34-FE), bleeding, flow-related adverse events (AE), CVC removal, and product sterility testing. Statistical analysis and graphing were performed with commercial software. A total of 75/119 (63%) pediatric patients (median age 3 years) met study criteria. Only 16% of children required a CVC for ≥ 3 days. The CD34 collect rate and CD34-FE was stable over time whereas MNC-FE decreased after day 4 in 80% of patients. CD34-FE and MNC-FE showed inter- and intra-patient variability over time and appeared sensitive to plerixafor administration. Femoral CVC showed fewer flow-related AE compared to thoracic CVC, especially in pediatric patients (6.7% vs. 37%, P = 0.0005; OR = 0.12 (95%CI: 0.03-0.45). CVC removal was uneventful in 73/75 (97%) patients with hemostasis achieved after 20-30 min of pressure. In a 10-year period, there were no instances of product contamination associated with femoral CVC colonization. Femoral CVC are safe and effective for A-HPCC in young pediatric patients. Femoral CVC performance was maintained over several days with few flow-related alarms when compared to thoracic CVCs. © 2017 Wiley Periodicals, Inc.

  19. Swimming performance, venous oxygen tension and cardiac performance of coronary-ligated rainbow trout, Oncorhynchus mykiss, exposed to progressive hypoxia

    DEFF Research Database (Denmark)

    Steffensen, J F; Farrell, A P

    1998-01-01

    We performed in vivo studies to examine the idea that cardiac work is impaired in rainbow trout (Oncorhynchus mykiss) below a certain venous PO2 threshold. We hypothesized that coronary-ligated fish, swimming continuously at a reasonably high water velocity (1.5 body lengths x s(-1)) and exposed...... to progressive hypoxia, would fatigue at higher venous PO2 and ambient water PO2 compared with sham-operated fish. However, we found that both the lowest venous PO2 that supported hypoxic swimming (9.9 torr for coronary-ligated fish and 11.1 torr for sham-operated fish) and the venous PO2 at fatigue (7.8 torr...... and 8.6 torr, respectively) were the same for coronary-ligated and sham-operated fish. Also, both groups quit swimming at the same water PO2 heart rate and hematocrit. Nevertheless, significant differences in cardiac performance did exist between the two groups. Whereas ventral aortic blood pressure...

  20. Influence of different storage times and temperatures on blood gas and acid-base balance in ovine venous blood

    Directory of Open Access Journals (Sweden)

    H.A. Hussein

    2013-01-01

    Full Text Available The present study was designed to investigate the effects of storage temperature and time on blood gas and acid-base balance of ovine venous blood. Ten clinically healthy sheep were used in this study. A total number of 30 blood samples, were divided into three different groups, and were stored in a refrigerator adjusted to +4 ºC (Group I, n = 10, at RT of about 22-25 ºC (Group II, n = 10 and in an incubator adjusted to 37 ºC (Group III, n = 10 for up to 48 h. Blood samples were analysed for blood gas and acid-base indices at 0, 1, 2, 3, 4, 5, 6, 12, 24 and 48 h of storage. In comparison to the baseline value (0, there were significant decreases of blood pH of samples stored at RT and in the incubator after 1 h (p<0.05, the pH value of refrigerated blood samples exhibited insignificant changes during the study (p<0.05. Mean values of pCO2 showed a significant increase in Group I and Group III after 1 h then a progressive decrease after 12 h in all Groups. Mean pO2 values were significantly higher for Group I after 2 h and for Groups II and III after 1 h (p<0.05. In general, base excess decreased significantly for all the groups during the study especially in Groups II and III. In comparison with baseline values, in all groups, bicarbonate (HCO3 increased between 1 h and 6 h (p<0.05, and later decreased at the end of the study (p<0.05. In conclusion, status of acid-base indices of the samples stored at refrigerator and RT were found within normal reference range and it may be of clinical diagnostic use for up to 6 h.

  1. The effect of phenylephrine on arterial and venous cerebral blood flow in healthy subjects

    DEFF Research Database (Denmark)

    Ogoh, Shigehiko; Sato, Kohei; Fisher, James P

    2011-01-01

    Sympathetic regulation of the cerebral circulation remains controversial. Although intravenous phenylephrine (PE) infusion reduces the near-infrared spectroscopy (NIRS)-determined measure of frontal lobe oxygenation (S(c) O(2) ) and increases middle cerebral artery mean blood velocity (MCA V...

  2. Formulation of Generalized Mass Transfer Correlations for Blood Oxygenator Design.

    Science.gov (United States)

    Low, Kenny W Q; Van Loon, Raoul; Rolland, Samuel A; Sienz, Johann

    2017-03-01

    This paper numerically investigates non-Newtonian blood flow with oxygen and carbon dioxide transport across and along an array of uniformly square and staggered arranged fibers at various porosity (ε) levels, focussing on a low Reynolds number regime (Re mass transfer correlations, expressed in the form of Sherwood number (Sh = f(ε, Re, Sc)), that identifies the link from local mass transfer investigations to full-device analyses. The development of a concentration field is initially investigated and expressions are established covering the range from a typical deoxygenated condition up to a full oxygenated condition. An important step is identified where a cut-off point in those expressions is required to avoid any under- or over-estimation on the Sherwood number. Geometrical features of a typical commercial blood oxygenator is adopted and results in general show that a balance in pressure drop, shear stress, and mass transfer is required to avoid potential blood trauma or clotting formation. Different definitions of mass transfer correlations are found for oxygen/carbon dioxide, parallel/transverse flow, and square/staggered configurations, respectively. From this set of correlations, it is found that transverse flow has better gas transfer than parallel flow which is consistent with reported literature. The mass transfer dependency on fiber configuration is observed to be pronounced at low porosity. This approach provides an initial platform when one is looking to improve the mass transfer performance in a blood oxygenator without the need to conduct any numerical simulations or experiments.

  3. The effect of dissolved oxygen on the relaxation rates of blood plasma: Implications for hyperoxia calibrated BOLD.

    Science.gov (United States)

    Ma, Yuhan; Berman, Avery J L; Pike, G Bruce

    2016-12-01

    To determine the contribution of paramagnetic dissolved oxygen in blood plasma to blood-oxygenation-level-dependent (BOLD) signal changes in hyperoxic calibrated BOLD studies. Bovine blood plasma samples were prepared with partial pressures of oxygen (pO 2 ) ranging from 110 to 600 mmHg. R 1 , R 2 , and R 2 * of the plasma with dissolved oxygen were measured using quantitative MRI sequences at 3 Tesla. Simulations were performed to predict the relative effects of dissolved oxygen and deoxyhemoglobin changes in hyperoxia calibrated BOLD. The relaxivities of dissolved oxygen in plasma were found to be r 1, O2 =1.97 ± 0.09 ×10 -4 s -1 mmHg -1 , r 2, O2 =2.3 ± 0.7 ×10 -4 s -1 mmHg -1 , and r 2, O2 * = 2.3 ± 0.7 ×10 -4 s -1 mmHg -1 . Simulations predict that neither the transverse nor longitudinal relaxation rates of dissolved oxygen contribute significantly to the BOLD signal during hyperoxia. During hyperoxia, the increases in R 2 and R 2 * of blood from dissolved oxygen in plasma are considerably less than the decreases in R 2 and R 2 * from venous deoxyhemoglobin. R 1 effects due to dissolved oxygen are also predicted to be negligible. As a result, dissolved oxygen in arteries should not contribute significantly to the hyperoxic calibrated BOLD signal. Magn Reson Med 76:1905-1911, 2016. © 2015 International Society for Magnetic Resonance in Medicine. © 2015 International Society for Magnetic Resonance in Medicine.

  4. Blood flow and oxygenation in peritendinous tissue and calf muscle during dynamic exercise in humans

    DEFF Research Database (Denmark)

    Boushel, Robert Christopher; Langberg, H; Green, Sara Marie Ehrenreich

    2000-01-01

    , and (2) whether blood flow is coupled to oxidative metabolism. 2. Seven individuals performed dynamic plantar flexion from 1 to 9 W. Radial artery and popliteal venous blood were sampled for O2, peritendinous blood flow was determined by 133Xe-washout, calf blood flow by plethysmography, cardiac output...

  5. The ABO blood group genotype and factor VIII levels as independent risk factors for venous thromboembolism.

    Science.gov (United States)

    Tirado, Isabel; Mateo, José; Soria, José Manuel; Oliver, Arturo; Martínez-Sánchez, Elisabeth; Vallvé, Cristina; Borrell, Monserrat; Urrutia, Teresa; Fontcuberta, Jordi

    2005-03-01

    Factor VIII (FVIII), von Willebrand factor (vWF) and the ABO blood groups have been associated with thrombosis. The ABO locus has functional effects on vWF and FVIII levels and is genetically correlated with FVIII, vWF and thrombosis. We carried out a case-control study to assess the role of FVIII, vWF and ABO types on thrombotic risk. We analyzed 250 patients with venous thrombosis and 250 unrelated controls. FVIII, vWF and other factors related to thrombophilia were measured, ABO groups were analyzed by genotyping. FVIII and vWF were higher in non-O individuals. Group O was more frequent in the controls (44.3% v 23.3%; difference 21.1%; 95% CI: 13.0-29.3%) and Group A in patients (59.2% v. 41.5%; difference 17.7%, 95% CI: 9.1-26.4%). Individuals carrying the A1 allele had a higher risk of thrombosis (OR 2.6; 95% CI, 1.8-3.8). The risk attributed to vWF disappeared after adjusting for the ABO group. Patients with FVIII above the 90th percentile had a high thrombotic risk (adjusted OR 3.7; 95% CI, 2.1-6.5), and a high risk of recurrence (OR 2.3; 95% CI: 1.3-4.1). In conclusion, high FVIII levels and non-O blood groups, likely those with the A1 allele, are independent risk factors for venous thromboembolism and should be considered in evaluating of thrombophilia.

  6. THE SUCCESSFUL TREATMENT OF A PERIPHERAL VENO-VENOUS EXTRACORPOREAL MEMBRANE OXYGENATION FOR SEVERE ACUTE RESPIRATORY FAILURE IN THE EARLY PERIOD AFTER ADULT LIVER TRANSPLANTATION

    Directory of Open Access Journals (Sweden)

    V. N. Poptsov

    2014-01-01

    Full Text Available Aim: of our clinical study was to present own experience of veno-venous extracorporeal membrane oxygenation (VV ECMO for the treatment of an adult patient (female, 28 yrs, 150 cm, 35 kg with acute respiratory distress syndrome (ARDS in the early period after liver transplantation against satisfactory liver graft function. Materials and methods. Double-lumen cannula 22 F was placed percutaneously in the right internal jugular vein. The ext- racorporeal contour reduced in length and the polymethylpeptene oxygenator (priming volume 175 ml were also. Results. In 1 hour after the beginning of VV ECMO, we registered the noted improvement of arterial blood gas and acid-base balance (regress of respiratory acidosis, improvement of arterial oxygenation which allowed us to use the «protective» mode of mechanical ventilation. Improvement of gas exchange and regress of clinical and radiological manifestations of ARDS allowed for VV ECMO weaning and decannulation on day 7. The patient was discharged from ICU and then from our Centre to a homestay respectively on the 9th and 16th day after VV ECMO weaning with the satisfactory liver graft and lungs function. Conclusion. VV ECMO can be successfully applied to correct the life-threatening acute respiratory failure in the early period after liver transplantation. 

  7. Extracorporeal Membrane Oxygenation in a 1,360-g Premature Neonate after Repairing Total Anomalous Pulmonary Venous Return

    Directory of Open Access Journals (Sweden)

    Youn Ju Rhee

    2016-10-01

    Full Text Available With advancements in complex repairs in neonates with complicated congenital heart diseases, extracorporeal membrane oxygenation (ECMO has been increasingly used as cardiac support. ECMO has also been increasingly used for low birth weight (LBW or very low birth weight (VLBW neonates. However, since prematurity and LBW are risk factors for ECMO, the appropriate indications for neonates with LBW, especially VLBW, are under dispute. We report a case of ECMO performed in a 1,360-g premature infant with VLBW due to cardiopulmonary bypass weaning failure after repairing infracardiac total anomalous pulmonary venous return.

  8. Importance of blood cultures from peripheral veins in pediatric patients with cancer and a central venous line

    DEFF Research Database (Denmark)

    Handrup, Mette Møller; Møller, Jens Kjølseth; Rutkjaer, Cecilie

    2015-01-01

    When an infection is suspected in a child with cancer and a central venous line (CVL), cultures are often only obtained from the CVL and not from a peripheral vein (PV). This study was undertaken to evaluate the importance of concomitant blood cultures from the CVL and a PV....

  9. [Digital blood flow measurement by venous occlusion plethysmography in Raynaud's phenomenon. Value of the rewarming test].

    Science.gov (United States)

    Cristol, R; Debray, J

    1986-01-01

    The fingertip blood flow measured by mercury strain gauge plethysmography with venous occlusion, at 22 degrees C room temperature, had significantly lower mean values in 190 patients with Raynaud's phenomenon (55 men aged 49 yrs +/- 16, 135 women aged 48 yrs +/- 16) than in 40 age and sex matched controls: 18 ml/100 ml/minute +/- 14.6 versus 35 ml/100 ml/minute +/- 15 at level p less than 0.01. The mean fingertip blood flow was significantly lower (p less than 0.01) in 31 cases of scleroderma and 32 cases of pulpar necrosis (respectively 13 ml +/- 13 and 11 ml +/- 8) than in 55 cases of primary Raynaud's disease (no detectable etiology and normal capillaroscopy 5 years after onset) or in 34 cases of mild Raynaud's phenomenon (respectively 21.6 +/- 16 and 24.4 +/- 18). A warming test (both hands in water at 45 degrees C during 3 minutes) was performed in 50 cases with low basal fingertip blood flow. It induced a "normalized" flow in 22 cases (mostly primary or mild Raynaud), a partly improved flow in 20 cases (mostly secondary Raynaud) and no improvement in 8 cases (scleroderma). The warming test appears to be clinically useful to assess the vasospasm and the vasodilating capabilities.

  10. The origin of mean arterial and jugular venous blood pressures in giraffes.

    Science.gov (United States)

    Mitchell, Graham; Maloney, Shane K; Mitchell, Duncan; Keegan, D James

    2006-07-01

    Using a mechanical model of the giraffe neck and head circulation consisting of a rigid, ascending, 'carotid' limb, a 'cranial' circulation that could be rigid or collapsible, and a descending, 'jugular' limb that also could be rigid or collapsible, we have analyzed the origin of the high arterial and venous pressures in giraffe, and whether blood flow is assisted by a siphon. When the tubes were rigid and the 'jugular' limb exit was lower than the 'carotid' limb entrance a siphon operated, 'carotid' hydrostatic pressures became more negative, and flow was 3.3 l min(-1) but ceased when the 'cranial' and 'jugular' limbs were collapsible or when the 'jugular' limb was opened to the atmosphere. Pumping water through the model produced positive pressures in the 'carotid' limb similar to those found in giraffe. Applying an external 'tissue' pressure to the 'jugular' tube during pump flow produced the typical pressures found in the jugular vein in giraffe. Constriction of the lowest, 'jugular cuff', portion of the 'jugular' limb showed that the cuff may augment the orthostatic reflex during head raising. Except when all tubes were rigid, pressures were unaffected by a siphon. We conclude that mean arterial blood pressure in giraffes is a consequence of the hydrostatic pressure generated by the column of blood in the neck, that tissue pressure around the collapsible jugular vein produces the known jugular pressures, and that a siphon does not assist flow through the cranial circulation.

  11. Systemic central venous oxygen saturation is associated with clot strength during traumatic hemorrhagic shock: A preclinical observational model

    Directory of Open Access Journals (Sweden)

    Brophy Donald F

    2010-12-01

    Full Text Available Abstract Background Clot strength by Thrombelastography (TEG is associated with mortality during trauma and has been linked to severity of tissue hypoperfusion. However, the optimal method for monitoring this important relationship remains undefined. We hypothesize that oxygen transport measurements will be associated with clot strength during traumatic shock, and test this hypothesis using a swine model of controlled traumatic shock. Methods N = 33 swine were subjected to femur fracture and hemorrhagic shock by controlled arterial bleeding to a predetermined level of oxygen debt measured by continuous indirect calorimetry. Hemodynamics, oxygen consumption, systemic central venous oxygenation (ScvO2, base excess, lactate, and clot maximal amplitude by TEG (TEG-MA as clot strength were measured at baseline and again when oxygen debt = 80 ml/kg during shock. Oxygen transport and metabolic markers of tissue perfusion were then evaluated for significant associations with TEG-MA. Forward stepwise selection was then used to create regression models identifying the strongest associations between oxygen transport and TEG-MA independent of other known determinants of clot strength. Results Multiple markers of tissue perfusion, oxygen transport, and TEG-MA were all significantly altered during shock compared to baseline measurements (p 2 demonstrated a strong bivariate association with TEG-MA measured during shock (R = 0.7, p 2 measured during shock was also selected by forward stepwise selection as an important covariate in linear regression models of TEG-MA after adjusting for the covariates fibrinogen, pH, platelet count, and hematocrit (Whole model R2 = 0.99, p ≤ 0.032. Conclusions Among multiple measurements of oxygen transport, only ScvO2 was found to retain a significant association with TEG-MA during shock after adjusting for multiple covariates. ScvO2 should be further studied for its utility as a clinical marker of both tissue hypoxia and clot

  12. The Use of the Ratio between the Veno-arterial Carbon Dioxide Difference and the Arterial-venous Oxygen Difference to Guide Resuscitation in Cardiac Surgery Patients with Hyperlactatemia and Normal Central Venous Oxygen Saturation

    Directory of Open Access Journals (Sweden)

    Wei Du

    2015-01-01

    Full Text Available Background: After cardiac surgery, central venous oxygen saturation (ScvO 2 and serum lactate concentration are often used to guide resuscitation; however, neither are completely reliable indicators of global tissue hypoxia. This observational study aimed to establish whether the ratio between the veno-arterial carbon dioxide and the arterial-venous oxygen differences (P(v−aCO 2 /C(a−vO 2 could predict whether patients would respond to resuscitation by increasing oxygen delivery (DO 2 . Methods: We selected 72 patients from a cohort of 290 who had undergone cardiac surgery in our institution between January 2012 and August 2014. The selected patients were managed postoperatively on the Intensive Care Unit, had a normal ScvO 2 , elevated serum lactate concentration, and responded to resuscitation by increasing DO 2 by >10%. As a consequence, 48 patients responded with an increase in oxygen consumption (VO 2 while VO 2 was static or fell in 24. Results: At baseline and before resuscitative intervention in postoperative cardiac surgery patients, a P(v−aCO 2 /C(a−vO 2 ratio ≥1.6 mmHg/ml predicted a positive VO 2 response to an increase in DO 2 of >10% with a sensitivity of 68.8% and a specificity of 87.5%. Conclusions: P(v−aCO 2 /C(a−vO 2 ratio appears to be a reliable marker of global anaerobic metabolism and predicts response to DO 2 challenge. Thus, patients likely to benefit from resuscitation can be identified promptly, the P(v−aCO 2 /C(a−vO 2 ratio may, therefore, be a useful resuscitation target.

  13. Peripheral venous and arterial blood gas analysis in adults: are they comparable? A systematic review and meta-analysis.

    Science.gov (United States)

    Byrne, Anthony L; Bennett, Michael; Chatterji, Robindro; Symons, Rebecca; Pace, Nathan L; Thomas, Paul S

    2014-02-01

    Peripheral venous blood gas (PVBG) analysis is increasingly being used as a substitute for arterial blood sampling; however, comparability has not been clearly established. To determine if the pH, PCO2 and PO2 obtained from PVBG analysis is comparable with arterial blood gas (ABG) analysis. A search was conducted of electronic databases as well as hand-searching of journals and reference lists through December 2012 to identify studies comparing PVBG with ABG analysis in adult subjects. A systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. A meta-analysis using a random effects model was used to calculate the average difference (bias) and the limits of agreement for the venous and arterial pH, PCO2 and PO2 . A total of 18 studies comprising 1768 subjects were included in the meta-analysis. There was considerable heterogeneity between studies with I(2) approaching 100%. There was little difference between the pH obtained from the PVBG and the ABG, with the arterial pH typically 0.03 higher than the venous pH (95% confidence interval 0.029-0.038). The venous and arterial PCO2 were not comparable because the 95% prediction interval of the bias for venous PCO2 was unacceptably wide, extending from -10.7 mm Hg to +2.4 mm Hg. The PO2 values compared poorly, the arterial PO2 typically 36.9 mm Hg greater than the venous with significant variability (95% confidence interval from 27.2 to 46.6 mm Hg). PVBG analysis compares well with ABG analysis for pH estimations in adults but not to the PCO2 or PO2 . These differences are sufficiently large to be of clinical significance. © 2014 The Authors. Respirology © 2014 Asian Pacific Society of Respirology.

  14. Exploring fractal behaviour of blood oxygen saturation in preterm babies

    Science.gov (United States)

    Zahari, Marina; Hui, Tan Xin; Zainuri, Nuryazmin Ahmat; Darlow, Brian A.

    2017-04-01

    Recent evidence has been emerging that oxygenation instability in preterm babies could lead to an increased risk of retinal injury such as retinopathy of prematurity. There is a potential that disease severity could be better understood using nonlinear methods for time series data such as fractal theories [1]. Theories on fractal behaviours have been employed by researchers in various disciplines who were motivated to look into the behaviour or structure of irregular fluctuations in temporal data. In this study, an investigation was carried out to examine whether fractal behaviour could be detected in blood oxygen time series. Detection for the presence of fractals in oxygen data of preterm infants was performed using the methods of power spectrum, empirical probability distribution function and autocorrelation function. The results from these fractal identification methods indicate the possibility that these data exhibit fractal nature. Subsequently, a fractal framework for future research was suggested for oxygen time series.

  15. When one port does not return blood: two case reports of rare causes for misplaced central venous catheters

    Directory of Open Access Journals (Sweden)

    Sandra Pereira

    2016-02-01

    Full Text Available We present two cases of misplaced central venous catheters having in common theabsence of free blood return from one lumen immediately after placement. The former is acase of right hydrothorax associated with central venous catheterization with the catheter tipin intra-pleural location. In this case the distal port was never patent. In the latter case therewas an increased aspiration pressure through the middle port due to a catheter looping.The absence of free flow on aspiration from one lumen of a central catheter should not beundervalued. In these circumstances the catheter should not be used and needs to be removed.

  16. Arterial blood oxygen saturation during blood pressure cuff-induced hypoperfusion

    Energy Technology Data Exchange (ETDEWEB)

    Kyriacou, P A [School of Engineering and Mathematical Sciences, City University, London EC1V 0HB (United Kingdom); Shafqat, K [School of Engineering and Mathematical Sciences, City University, London EC1V 0HB (United Kingdom); Pal, S K [St Andrew' s Centre for Plastic Surgery and Burns, Broomfield Hospital, Chelmsford, CM1 7ET (United Kingdom)

    2007-10-15

    Pulse oximetry has been one of the most significant technological advances in clinical monitoring in the last two decades. Pulse oximetry is a non-invasive photometric technique that provides information about the arterial blood oxygen saturation (SpO{sub 2}) and heart rate, and has widespread clinical applications. When peripheral perfusion is poor, as in states of hypovolaemia, hypothermia and vasoconstriction, oxygenation readings become unreliable or cease. The problem arises because conventional pulse oximetry sensors must be attached to the most peripheral parts of the body, such as finger, ear or toe, where pulsatile flow is most easily compromised. Pulse oximeters estimate arterial oxygen saturation by shining light at two different wavelengths, red and infrared, through vascular tissue. In this method the ac pulsatile photoplethysmographic (PPG) signal associated with cardiac contraction is assumed to be attributable solely to the arterial blood component. The amplitudes of the red and infrared ac PPG signals are sensitive to changes in arterial oxygen saturation because of differences in the light absorption of oxygenated and deoxygenated haemoglobin at these two wavelengths. From the ratios of these amplitudes, and the corresponding dc photoplethysmographic components, arterial blood oxygen saturation (SpO{sub 2}) is estimated. Hence, the technique of pulse oximetry relies on the presence of adequate peripheral arterial pulsations, which are detected as photoplethysmographic (PPG) signals. The aim of this study was to investigate the effect of pressure cuff-induced hypoperfusion on photoplethysmographic signals and arterial blood oxygen saturation using a custom made finger blood oxygen saturation PPG/SpO{sub 2} sensor and a commercial finger pulse oximeter. Blood oxygen saturation values from the custom oxygen saturation sensor and a commercial finger oxygen saturation sensor were recorded from 14 healthy volunteers at various induced brachial pressures

  17. Evaluation of a continuous blood glucose monitoring system using central venous microdialysis.

    Science.gov (United States)

    Schierenbeck, Fanny; Franco-Cereceda, Anders; Liska, Jan

    2012-11-01

    Glycemic control in critically ill patients has been shown to be beneficial. In this prospective study, we evaluated the accuracy and technical feasibility of a continuous glucose monitoring system using intravascular microdialysis. Fifty patients undergoing cardiac surgery were monitored using a 4 Fr intravenous microdialysis catheter (Eirus SLC™, Dipylon Medical AB, Solna, Sweden) percutaneously placed with the tip of the catheter positioned in the superior vena cava. The catheter was connected to the Eirus™ monitoring system, and the patients were monitored for up to 48 h postoperatively in the intensive care unit (ICU). As reference, arterial blood samples were taken every hour and analyzed in a blood gas analyzer. Data were available from 48 patients. A total of 994 paired (arterial blood gas microdialysis) samples were obtained. Glucose correlation coefficient (R2) was 0.85. Using Clarke error grid analysis, 100% of the paired samples were in region AB, and 99% were in region A. Mean glucose level was 8.3 mmol/liter (149 mg/dl), mean relative difference was 0.2%, and mean absolute relative difference was 5%. A total of 99.2% of the paired samples were correct according to International Organization for Standardization (ISO) criteria. Bland-Altman analysis showed that bias ± limits of agreement were 0.02 ± 1.1 mmol/liter (0.36 ± 20 mg/dl). Central venous microdialysis using the Eirus monitoring system is a highly accurate and reliable method for continuous blood glucose monitoring up to 48 h in ICU patients undergoing cardiac surgery. The system may thus be useful in critically ill ICU patients. © 2012 Diabetes Technology Society.

  18. Forearm blood flow measurements using computerized R-wave triggered strain-gauge venous occlusion plethysmography: unilateral vs. bilateral measurements.

    Science.gov (United States)

    Kamper, A M; de Craen, A J; Blauw, G J

    2001-09-01

    The human forearm is a well established model to study local vascular reactivity in humans in vivo, using strain-gauge venous occlusion plethysmography to measure blood flow and changes in blood flow in the forearm. To reduce the intra-individual variability of the forearm blood flow (FBF), it has been advocated that simultaneous measurements of contralateral forearm blood flow is obligatory. Therefore, the use of the calculated forearm ratio (FR) is recommended instead of using the actual FBF. In the present study we compared the intra-individual variability of forearm blood flow measurements and the forearm ratio, by using computerized R-wave triggered strain-gauge venous occlusion plethysmography, to test if bilateral expression of measurements is better than unilateral. Results were obtained in eight volunteers. Intra-arterial infused sodium nitroprusside induced a dose dependent increase in forearm blood flow and a dose dependent increase in the calculated forearm ratio. Intra-arterial infused norepinephrine induced a dose dependent decrease in forearm blood flow and a dose dependent decrease in the calculated forearm ratio. The differences between the variation coefficients of the forearm blood flow measurements and the calculated forearm ratio were different. These results support our hypothesis that by using a computerized, R-wave triggered system for unilateral forearm blood flow measurement is a more reliable outcome than the calculated forearm ratio derived from bilateral measurements.

  19. Simultaneous blood flow and blood oxygenation measurements using a combination of diffuse speckle contrast analysis and near-infrared spectroscopy.

    Science.gov (United States)

    Seong, Myeongsu; Phillips, Zephaniah; Mai, Phuong Minh; Yeo, Chaebeom; Song, Cheol; Lee, Kijoon; Kim, Jae Gwan

    2016-02-01

    A combined diffuse speckle contrast analysis (DSCA)-near-infrared spectroscopy (NIRS) system is proposed to simultaneously measure qualitative blood flow and blood oxygenation changes in human tissue. The system employs an optical switch to alternate two laser sources at two different wavelengths and a CCD camera to capture the speckle image. Therefore, an optical density can be measured from two wavelengths for NIRS measurements and a speckle contrast can be calculated for DSCA measurements. In order to validate the system, a flow phantom test and an arm occlusion protocol for arterial and venous occlusion were performed. Shorter exposure times (<1 ms ) show a higher drop (between 50% and 66%) and recovery of 1/K²S values after occlusion (approximately 150%), but longer exposure time (3 ms) shows more consistent hemodynamic changes. For four subjects, the 1/K²S values dropped to an average of 82.1±4.0% during the occlusion period and the average recovery of 1/K²S values after occlusion was 109.1±0.8% . There was also an approximately equivalent amplitude change in oxyhemoglobin (OHb) and deoxyhemoglobin (RHb) during arterial occlusion (max RHb=0.0085±0.0024 mM/DPF, min OHb=-0.0057±0.0044 mM/DPF). The sensitivity of the system makes it a suitable modality to observe qualitative hemodynamic trends during induced physiological changes.

  20. Noninvasive estimation of central venous pressure in anesthetized dogs by measurement of hepatic venous blood flow velocity and abdominal venous diameter.

    Science.gov (United States)

    Nelson, Nathan C; Drost, Wm Tod; Lerche, Phillip; Bonagura, John D

    2010-01-01

    Determination of central venous pressure (CVP) is relevant to patients with right heart disease, hypovolemia, and following intravenous fluid therapy. We hypothesized that changes in CVP in dogs could be predicted by measurements of hepatic vein diameter, caudal vena cava (CVC) diameter, and hepatic venous flow velocities. Nine healthy American Foxhounds were anesthetized. Following baseline recordings, intravenous fluids were administered to increase CVP. Volume administration created treatment periods with CVP ranges of 5, 10, 15, 20, and 25 mm Hg. Flow velocities in the right medial hepatic vein were recorded using pulsed wave Doppler ultrasound. Hepatic vein, CVC, and aorta diameters were determined with B-mode ultrasound. Variables were compared across the treatment periods by ANOVA for repeated measures. Relationships between CVP, Doppler, and B-mode variables were evaluated using Spearman's rank correlations, multiple linear regression, and repeated measures linear regression. The a-, S- and v-wave velocities were augmented significantly with volume loading. The best part (semipartial) correlation coefficients predicting increasing CVP were identified with v-wave velocity (0.823), S-wave velocity (-0.800), CVC diameter (0.855), and hepatic vein diameter (0.815). Multiple linear regression indicated that CVP in this study could be predicted best by a combination of CVC and hepatic vein diameter and the v-wave velocity (r = 0.928). Ultrasound imaging identified gallbladder and pancreatic edema consistently, likely related to acute volume loading. These findings may be applicable in the assessment of volume status, dogs with right heart disease, and during serial monitoring of dogs receiving fluid or diuretic therapy.

  1. LETTER TO THE EDITOR: Arterio-venous flow between monochorionic twins determined during intra-uterine transfusion. Nonlinear decay of adult red blood cells

    Science.gov (United States)

    van Gemert, Martin J. C.; Pasman, Suzanne A.; van den Wijngaard, Jeroen P. H. M.; Lopriore, Enrico; Vandenbussche, Frank P. H. A.

    2008-07-01

    Recently, we derived equations relating the flow of adult red blood cells through a placental arterio-venous anastomosis with intra-uterine and post-natal measured adult hemoglobin concentrations. In this letter, we re-derived the equations, now including a more realistic nonlinear decay of adult red blood cells, and re-evaluated the measurement accuracy of the arterio-venous flow and the lifetime of the red blood cells.

  2. Laboratory reference intervals for systolic blood pressure, rectal temperature, haematology, biochemistry and venous blood gas and electrolytes in healthy pet rabbits.

    Science.gov (United States)

    Gallego, Miguel

    2017-01-01

    Prospective data from 86 healthy pet rabbits were evaluated to establish reference intervals for hematology, biochemistry, urinalysis, venous blood gas and electrolytes, rectal temperature and systolic blood pressure. Reference intervals for rectal temperature (37.4-39.6 ºC) and systolic blood pressure (75-134 mm/Hg) were previously unreported in pet rabbits. Differences by more than 30% with reference intervals present in the bibliography were observed in the blood biochemistry and urinalysis, being attributed to the variability in methodological factors with the present study.

  3. The value of venous blood gas analysis in the diagnosis of diabetic ketoacidosis.

    Science.gov (United States)

    Rasheed, Jawad Ibrahim; Razak, Manal Khudder Abdul; Hussein, Ahmed Amer Abdul

    2017-12-01

    Newer blood gas analyzers have the ability to report electrolyte values and glucose in addition to pH, so this diagnostic process could be condensed in diagnosing diabetic ketoacidosis (DKA). We aimed to assess the accuracy of the venous blood gas (VBG) analysis with electrolytes for diagnosing DKA. This study prospectively identified a convenience sample of (60 patients) presented with DKA and tested their VBG and serum electrolytes. The diagnosis of DKA was made according to American Diabetes Association criteria. Serum chemistry electrolyte values were considered to be the criterion standard. Sensitivity and specificity of VBG electrolytes results were compared against this standard. In addition, correlation coefficients for individual electrolytes between VBG electrolytes and laboratory chemistry electrolytes were calculated. Paired VBG and serum chemistry panels were available for 60 patients, only 49 patients were included, In this study; 20% of cases were newly diagnosed diabetes mellitus. The total number of diabetic ketoacidosis was 14 patients (28.5%). The sensitivity and specificity of the VBG and electrolytes for diagnosing DKA was 92.9% (95% confidence interval [CI]=89% to 99%) and 97.1% (95% CI=92% to 100%), respectively. Correlation coefficients between VBG and serum chemistry were 0.91, 0.47, 0.61, 0.65, and 0.58 for blood sugar, sodium, potassium, chloride, and creatinine respectively. Findings of this study offer preliminary support for the possibility of using VBG sample rather than VBG sample and serum chemistry electrolytes together to rule out diabetic ketoacidosis. Copyright © 2017. Published by Elsevier Ltd.

  4. Revised protocol of extracorporeal membrane oxygenation (ECMO) therapy in severe ARDS. Recommendations of the Veno-venous ECMO Expert Panel appointed in February 2016 by the national consultant on anesthesiology and intensive care.

    Science.gov (United States)

    Lango, Romuald; Szkulmowski, Zbigniew; Maciejewski, Dariusz; Sosnowski, Andrzej; Kusza, Krzysztof

    2017-01-01

    Extracorporeal Membrane Oxygenation (ECMO) has become well established technique of the treatment of severe acute respiratory failure (Veno-Venous ECMO) or circulatory failure (Veno-Arterial ECMO) which enables effective blood oxygenation and carbon dioxide removal for several weeks. Veno-Venous ECMO (V-V ECMO ) is a lifesaving treatment of patients in whom severe ARDS makes artificial lung ventilation unlikely to provide satisfactory blood oxygenation for preventing further vital organs damage and progression to death. The protocol below regards exclusively veno-venous ECMO treatment as a support for blood gas conditioning by means of extracorporeal circuit in adult patients with severe ARDS. V-V ECMO does not provide treatment for acutely and severely diseased lungs, but it enables patient to survive the critical phase of severe ARDS until recovery of lung function. Besides avoiding patients death from hypoxemia, this technique can also prevent further progression of the lung damage due to artificial ventilation. Recent experience of ECMO treatment since the outbreak of AH1N1 influenza pandemic in 2009, along with technical progress and advancement in understanding pathophysiology of ventilator-induced lung injury, have contributed to significant improvement of the results of ECMO treatment. Putative factors related to increased survival include patients retrieval after connecting them to ECMO, and less intensive anticoagulation protocols. The aim of presenting this revised protocol was to improve the effects of ECMO treatment in patients with severe ARDS, to enhance ECMO accessibility for patients who might possibly benefit from this treatment, to reduce time until patient's connection to ECMO, and to avoid ECMO treatment in futile cases. The authors believe that this protocol, based on recent papers and their own experience, can provide help and advice both for the centers which develop V-V ECMO program, and for doctors who will refer their patients for the

  5. The effect of dissolved oxygen on the susceptibility of blood.

    Science.gov (United States)

    Berman, Avery J L; Ma, Yuhan; Hoge, Richard D; Pike, G Bruce

    2016-01-01

    It has been predicted that, during hyperoxia, excess O2 dissolved in arterial blood will significantly alter the blood's magnetic susceptibility. This would confound the interpretation of the hyperoxia-induced blood oxygenation level-dependent signal as arising solely from changes in deoxyhemoglobin. This study, therefore, aimed to determine how dissolved O2 affects the susceptibility of blood. We present a comprehensive model for the effect of dissolved O2 on the susceptibility of blood and compare it with another recently published model, referred to here as the ideal gas model (IGM). For validation, distilled water and samples of bovine plasma were oxygenated over a range of hyperoxic O2 concentrations and their susceptibilities were determined using multiecho gradient echo phase imaging. In distilled water and plasma, the measured changes in susceptibility were very linear, with identical slopes of 0.062 ppb/mm Hg of O2. This change was dramatically less than previously predicted using the IGM and was close to that predicted by our model. The primary source of error in the IGM is the overestimation of the volume fraction occupied by dissolved O2. Under most physiological conditions, the susceptibility of dissolved O2 can be disregarded in MRI studies employing hyperoxia. © 2015 Wiley Periodicals, Inc.

  6. Biophysical and physiological origins of blood oxygenation level-dependent fMRI signals

    Science.gov (United States)

    Kim, Seong-Gi; Ogawa, Seiji

    2012-01-01

    After its discovery in 1990, blood oxygenation level-dependent (BOLD) contrast in functional magnetic resonance imaging (fMRI) has been widely used to map brain activation in humans and animals. Since fMRI relies on signal changes induced by neural activity, its signal source can be complex and is also dependent on imaging parameters and techniques. In this review, we identify and describe the origins of BOLD fMRI signals, including the topics of (1) effects of spin density, volume fraction, inflow, perfusion, and susceptibility as potential contributors to BOLD fMRI, (2) intravascular and extravascular contributions to conventional gradient-echo and spin-echo BOLD fMRI, (3) spatial specificity of hemodynamic-based fMRI related to vascular architecture and intrinsic hemodynamic responses, (4) BOLD signal contributions from functional changes in cerebral blood flow (CBF), cerebral blood volume (CBV), and cerebral metabolic rate of O2 utilization (CMRO2), (5) dynamic responses of BOLD, CBF, CMRO2, and arterial and venous CBV, (6) potential sources of initial BOLD dips, poststimulus BOLD undershoots, and prolonged negative BOLD fMRI signals, (7) dependence of stimulus-evoked BOLD signals on baseline physiology, and (8) basis of resting-state BOLD fluctuations. These discussions are highly relevant to interpreting BOLD fMRI signals as physiological means. PMID:22395207

  7. Comparison of Interstitial Fluid pH, PCO2, PO2 with Venous Blood Values During Repetitive Handgrip Exercise

    Science.gov (United States)

    Hagan, Ronald Donald; Soller, Babs R.; Shear, Michael; Walz, Matthias; Landry, Michelle; Heard, Stephen

    2006-01-01

    We evaluated the use of a small, fiber optic sensor to measure pH, PCO2 and PO2 from forearm muscle interstitial fluid (IF) during handgrip dynamometry. PURPOSE: Compare pH, PCO2 and PO2 values obtained from venous blood with those from the IF of the flexor digitorum superficialis (FDS) during three levels of exercise intensity. METHODS: Six subjects (5M/1F), average age 29+/-5 yrs, participated in the study. A venous catheter was placed in the retrograde direction in the antecubital space and a fiber optic sensor (Paratrend, Diametrics Medical, Inc.) was placed through a 22 G catheter into the FDS muscle under ultrasound guidance. After a 45 min rest period, subjects performed three 5-min bouts of repetitive handgrip exercise (2s contraction/1 s relaxation) at attempted levels of 15%, 30% and 45% of maximal voluntary contraction. The order of the exercise bouts was random with the second and third bouts started after blood lactate had returned to baseline. Venous blood was sampled every minute during exercise and analyzed with an I-Stat CG-4+ cartridge, while IF fiber optic sensor measurements were obtained every 2 s. Change from pre-exercise baseline to end of exercise was computed for pH, PCO2 and PO2. Blood and IF values were compared with a paired t-test. RESULTS: Baseline values for pH, PCO2 and PO2 were 7.37+/-0.02, 46+/-4 mm Hg, and 36+/-6 mm Hg respectively in blood and 7.39+/-0.02, 44+/-6 mm Hg, and 35+/-14 mm Hg in IF. Average changes over all exercise levels are noted in the Table below. For each parameter the exercise-induced change was at least twice as great in IF as in blood. In blood and IF, pH and PCO2 increases were directly related to exercise intensity. Change in venous PO2 was unrelated to exercise intensity, while IF PO2 decreased with increases in exercise intensity. CONCLUSIONS: Measurement of IF pH, PCO2 and PO2 is more sensitive to exercise intensity than measurement of the same parameters in venous blood and provides continuous

  8. Improved gas exchange performance of the intravascular oxygenator by active blood mixing.

    Science.gov (United States)

    Tao, W; Schroeder, T; Bidani, A; Cardenas, V J; Nguyen, P D; Bradford, D W; Traber, D L; Zwischenberger, J B

    1994-01-01

    The intravascular oxygenator and carbon dioxide removal device (IVOX; CardioPulmonics, Salt Lake City, UT) has been shown to perform 30% of the gas exchange in animals and patients with acute respiratory failure. Among the factors that limit gas exchange is the mass transfer resistance in the blood phase. To determine if a reduction in mass transfer resistance by mixing venous blood can enhance the O2 transfer and CO2 removal by IVOX, a right atrium-pulmonary artery venovenous bypass circuit was used in sheep to model the adult vena cava. A size 9 IVOX (894 fibers with 0.41 m2 surface area, n = 5) was incorporated in the bypass circuit and the blood flow controlled by a roller pump ranging from 1 to 4 l/min. An intra-aortic balloon was placed near the shaft of the IVOX and pulsated at the rate adjusted to best improve CO2 removal (100-120 bpm). O2 transfer and CO2 removal were measured with balloon pulsation on and off at different flow rates. Results showed that blood mixing by pulsation of the balloon caused a 25-49% increase in O2 transfer by IVOX, and this increase remained relatively constant throughout the full flow range. CO2 removal was also increased by up to 35%, but at flows between 3.5 and 4 l/min, the effect of mixing was diminished. It is concluded that reduction in the mass transfer resistance by blood mixing improves gas exchange. Because O2 is more diffusion limited, it is more dependent upon mixing of blood for gas exchange than CO2. More design improvements to incorporate active mixing may further enhance the gas exchange performance of IVOX.

  9. Extracorporeal membrane oxygenation (ECMO)

    African Journals Online (AJOL)

    CO2 removal than it is at correcting hypoxaemia. Low-flow VV-ECMO may also be used primarily for ECCO2R. The potential for improvement in oxygenation with VV-ECMO is less than that with VA-ECMO and is due to an increase in the central venous oxygen saturation, such that the shunted blood elevates overall arterial ...

  10. Cerebral blood oxygenation measurements in neonates with optoacoustic technique

    Science.gov (United States)

    Herrmann, Stephen; Petrov, Irene Y.; Petrov, Yuriy; Richardson, C. Joan; Fonseca, Rafael A.; Prough, Donald S.; Esenaliev, Rinat O.

    2017-03-01

    Cerebral hypoxia is a major contributor to neonatal/infant mortality and morbidity including severe neurological complications such as mental retardation, cerebral palsy, motor impairment, and epilepsy. Currently, no technology is capable of accurate monitoring of neonatal cerebral oxygenation. We proposed to use optoacoustics for this application by probing the superior sagittal sinus (SSS), a large central cerebral vein. We developed and built a multi-wavelength, optical parametric oscillator (OPO) and laser diode optoacoustic systems for measurement of SSS blood oxygenation in the reflection mode through open anterior or posterior fontanelles and in the transmission mode through the skull in the occipital area. In this paper we present results of initial tests of the laser diode system for neonatal cerebral oxygenation measurements. First, the system was tested in phantoms simulating neonatal SSS. Then, using the data obtained in the phantoms, we optimized the system's hardware and software and tested it in neonates admitted in the Neonatal Intensive Care Unit. The laser diode system was capable of detecting SSS signals in the reflection mode through the open anterior and posterior fontanelles as well as in the transmission mode through the skull with high signal-to-noise ratio. Using the signals measured at different wavelengths and algorithms developed for oxygenation measurements, the laser diode system provided real-time, continuous oxygenation monitoring with high precision at all these locations.

  11. Blood oxygen- and carbon dioxide-carrying properties in captive penguins: effects of moulting and inter-specific comparison.

    Science.gov (United States)

    Maxime, Valérie; Hassani, Sami

    2014-02-01

    Venous blood gas-carrying properties were compared in the three captive species of penguins (king, gentoo and rockhopper) at Océanopolis (France). Captivity permitted to control environmental influences. Given their different ecology and diving behaviour in the wild, it was wondered whether milder conditions and dive privation have repercussions on parameters determining oxygen storage and acid-base status of these birds. In addition, this work provided the opportunity to study the effects of moulting in king penguins. This annual event that imposes deep metabolic adjustments is liable to affect blood gas levels. Because of the regular food supply and probably also of the blood sampling conditions, the blood pH of captive penguins was low. This effect was increased in moulting penguins and supposedly due to both the decreased energetic metabolism and the production of uric acid resulting from new feather synthesis. The decrease in the anion gap also revealed the use of plasmatic albumin for this synthesis. The elevated venous PO2 in all birds is not likely due to stress caused by sampling conditions. The other data, in accordance with those in the literature, show neither major influence of captivity nor fundamental interspecific differences, despite potential diving aptitude. Copyright © 2013 Elsevier Inc. All rights reserved.

  12. Agreement between mathematically arterialised venous versus arterial blood gas values in patients undergoing non-invasive ventilation: a cohort study.

    Science.gov (United States)

    Kelly, Anne-Maree; Klim, Sharon; Rees, Stephen E

    2014-10-01

    Blood gas analysis is important for assessment of ventilatory function. Traditionally, arterial analysis has been used. A method for mathematically arterialising venous blood gas values has been developed. Our aim was to validate this method in patients undergoing non-invasive ventilation (NIV) in an emergency department (ED). This post hoc substudy of a prospective cohort study included adult patients undergoing NIV for acute respiratory compromise. When arterial blood gas analysis was required for clinical purposes, a venous sample was also drawn. Mathematically arterialised values were calculated independent of arterial values. Primary outcome of interest was agreement between mathematically arterialised venous and arterial values for pH and pCO2. Bland-Altman agreement plot analysis was used. Eighty sample-pairs (58 patients) were studied. Mean difference for arterial pH (actual-calculated) was 0.01 pH units (95% limits of agreement: -0.04, 0.06). Mean difference for pCO2 (actual-calculated) was -0.06 kPa (95% limits of agreement: -1.34, 1.22). For patients undergoing NIV in an ED, agreement between mathematically arterialised venous values and arterial values was close for pH but only moderate for pCO2. Depending on clinician tolerance for agreement, this method may be a clinically useful alternative to arterial blood gas analysis in the ED. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  13. Evaluation of a continuous blood glucose monitoring system using a central venous catheter with an integrated microdialysis function.

    Science.gov (United States)

    Schierenbeck, Fanny; Öwall, Anders; Franco-Cereceda, Anders; Liska, Jan

    2013-01-01

    Glycemic control in critically ill patients has been the topic of an interesting debate during the last decade. An accurate continuous glucose monitoring system is essential to better understand this field. This prospective study thus evaluates the accuracy and technical feasibility of a continuous glucose monitoring system using intravascular microdialysis. Thirty patients undergoing cardiac surgery were monitored using a triple-lumen central venous catheter (Eirus TLC; Eirus Medical AB, Solna, Sweden) with an integrated microdialysis function. The catheter functions as a central venous catheter, enabling blood sampling and administration of infusions and medication while simultaneously providing continuous glucose monitoring. The patients were monitored for up to 48 h postoperatively. As reference, arterial blood gas samples were taken every hour and analyzed in a blood gas analyzer. Six hundred seven paired samples were obtained for analysis. Using Clarke Error Grid analysis, 100% of the paired samples were in Zones A+B, and 97% were in Zone A. Mean difference (bias) was -0.12 mmol/L, and mean absolute relative difference was 5.6%. Of the paired samples, 97.5% were correct according to International Organization for Standardization criteria. Bland-Altman analysis showed bias ± limits of agreement were -0.12 ± 0.7 mmol/L. No hypoglycemic episodes were observed. Central venous microdialysis is an accurate and reliable method for continuous blood glucose monitoring up to 48 h in patients undergoing cardiac surgery. With the microdialysis function integrated in a central venous catheter, no extra device for the continuous glucose monitoring is required. The system may be useful in critically ill patients.

  14. Commercial Hy-Line W-36 pullet and laying hen venous blood gas and chemistry profiles utilizing the portable i-STAT®1 analyzer

    Science.gov (United States)

    Schaal, T. P.; Arango, J.; Wolc, A.; Brady, J. V.; Fulton, J. E.; Rubinoff, I.; Ehr, I. J.; Persia, M. E.; O'Sullivan, N. P.

    2015-01-01

    Venous blood gas and chemistry reference ranges were determined for commercial Hy-Line W-36 pullets and laying hens utilizing the portable i-STAT®1 analyzer and CG8+ cartridges. A total of 632 samples were analyzed from birds between 4 and 110 wk of age. Reference ranges were established for pullets (4 to 15 wk), first cycle laying hens (20 to 68 wk), and second cycle (post molt) laying hens (70 to 110 wk) for the following traits: sodium (Na mmol/L), potassium (K mmol/L), ionized calcium (iCa mmol/L), glucose (Glu mg/dl), hematocrit (Hct% Packed Cell Volume [PCV]), pH, partial pressure carbon dioxide (PCO2 mm Hg), partial pressure oxygen (PO2 mm Hg), total concentration carbon dioxide (TCO2 mmol/L), bicarbonate (HCO3 mmol/L), base excess (BE mmol/L), oxygen saturation (sO2%), and hemoglobin (Hb g/dl). Data were analyzed using ANOVA to investigate the effect of production status as categorized by bird age. Trait relationships were evaluated by linear correlation and their spectral decomposition. All traits differed significantly among pullets and mature laying hens in both first and second lay cycles. Levels for K, iCa, Hct, pH, TCO2, HCO3, BE, sO2, and Hb differed significantly between first cycle and second cycle laying hens. Many venous blood gas and chemistry parameters were significantly correlated. The first 3 eigenvalues explained ∼2/3 of total variation. The first 2 principal components (PC) explained 51% of the total variation and indicated acid-balance and relationship between blood O2 and CO2. The third PC explained 16% of variation and seems to be related to blood iCa. Establishing reference ranges for pullet and laying hen blood gas and chemistry with the i-STAT®1 handheld unit provides a mechanism to further investigate pullet and layer physiology, evaluate metabolic disturbances, and may potentially serve as a means to select breeder candidates with optimal blood gas or chemistry levels on-farm. PMID:26706355

  15. Commercial Hy-Line W-36 pullet and laying hen venous blood gas and chemistry profiles utilizing the portable i-STAT®1 analyzer.

    Science.gov (United States)

    Schaal, T P; Arango, J; Wolc, A; Brady, J V; Fulton, J E; Rubinoff, I; Ehr, I J; Persia, M E; O'Sullivan, N P

    2016-02-01

    Venous blood gas and chemistry reference ranges were determined for commercial Hy-Line W-36 pullets and laying hens utilizing the portable i-STAT®1 analyzer and CG8+ cartridges. A total of 632 samples were analyzed from birds between 4 and 110 wk of age. Reference ranges were established for pullets (4 to 15 wk), first cycle laying hens (20 to 68 wk), and second cycle (post molt) laying hens (70 to 110 wk) for the following traits: sodium (Na mmol/L), potassium (K mmol/L), ionized calcium (iCa mmol/L), glucose (Glu mg/dl), hematocrit (Hct% Packed Cell Volume [PCV]), pH, partial pressure carbon dioxide (PCO2 mm Hg), partial pressure oxygen (PO2 mm Hg), total concentration carbon dioxide (TCO2 mmol/L), bicarbonate (HCO3 mmol/L), base excess (BE mmol/L), oxygen saturation (sO2%), and hemoglobin (Hb g/dl). Data were analyzed using ANOVA to investigate the effect of production status as categorized by bird age. Trait relationships were evaluated by linear correlation and their spectral decomposition. All traits differed significantly among pullets and mature laying hens in both first and second lay cycles. Levels for K, iCa, Hct, pH, TCO2, HCO3, BE, sO2, and Hb differed significantly between first cycle and second cycle laying hens. Many venous blood gas and chemistry parameters were significantly correlated. The first 3 eigenvalues explained ∼2/3 of total variation. The first 2 principal components (PC) explained 51% of the total variation and indicated acid-balance and relationship between blood O2 and CO2. The third PC explained 16% of variation and seems to be related to blood iCa. Establishing reference ranges for pullet and laying hen blood gas and chemistry with the i-STAT®1 handheld unit provides a mechanism to further investigate pullet and layer physiology, evaluate metabolic disturbances, and may potentially serve as a means to select breeder candidates with optimal blood gas or chemistry levels on-farm. © The Author 2015. Published by Oxford University

  16. Treatment of portal venous gas embolism with hyperbaric oxygen after accidental ingestion of hydrogen peroxide: a case report and review of the literature.

    Science.gov (United States)

    Papafragkou, Sotirios; Gasparyan, Anna; Batista, Richard; Scott, Paul

    2012-07-01

    It is well known that hydrogen peroxide ingestion can cause gas embolism. To report a case illustrating that the definitive, most effective treatment for gas embolism is hyperbaric oxygen therapy. We present a case of a woman who presented to the Emergency Department with acute abdominal pain after an accidental ingestion of concentrated hydrogen peroxide. Complete recovery from her symptoms occurred quickly with hyperbaric oxygen therapy. This is a case report of the successful use of hyperbaric oxygen therapy to treat portal venous gas embolism caused by hydrogen peroxide ingestion. Hyperbaric oxygen therapy can be considered for the treatment of symptomatic hydrogen peroxide ingestion. Copyright © 2012 Elsevier Inc. All rights reserved.

  17. A pilot study of the effects of a perflubron emulsion, AF 0104, on mixed venous oxygen tension in anesthetized surgical patients

    NARCIS (Netherlands)

    Wahr, J. A.; Trouwborst, A.; Spence, R. K.; Henny, C. P.; Cernaianu, A. C.; Graziano, G. P.; Tremper, K. K.; Flaim, K. E.; Keipert, P. E.; Faithfull, N. S.; Clymer, J. J.

    1996-01-01

    A pilot study of a perfluorochemical (PFC) emulsion was undertaken to determine whether administration of a perflubron emulsion could result in measurable changes in mixed venous oxygen tension. Seven adult surgical patients received a 0.9-g PFC/kg intravenous dose of perflubron emulsion after acute

  18. From artificial red blood cells, oxygen carriers, and oxygen therapeutics to artificial cells, nanomedicine, and beyond.

    Science.gov (United States)

    Chang, Thomas M S

    2012-06-01

    The first experimental artificial red blood cells have all three major functions of red blood cells (rbc). However, the first practical one is a simple polyhemoglobin (PolyHb) that only has an oxygen-carrying function. This is now in routine clinical use in South Africa and Russia. An oxygen carrier with antioxidant functions, PolyHb-catalase-superoxide dismutase, can fulfill two of the three functions of rbc. Even more complete is one with all three functions of rbc in the form of PolyHb-catalase-superoxide dismutase-carbonic anhydrase. The most advanced ones are nanodimension artificial rbc with either PEG-lipid membrane or PEG-PLA polymer membrane. Extensions into oxygen therapeutics include a PolyHb-tyrosinase that suppresses the growth of melanoma in a mice model. Another is a PolyHb-fibrinogen that is an oxygen carrier with platelet-like function. Research has now extended well beyond the original research on artificial rbc into many areas of artificial cells. These include nanoparticles, nanotubules, lipid vesicles, liposomes, polymer-tethered lipid vesicles, polymersomes, microcapsules, bioencapsulation, nanocapules, macroencapsulation, synthetic cells, and others. These are being used in nanotechnology, nanomedicine, regenerative medicine, enzyme/gene therapy, cell/stem cell therapy, biotechnology, drug delivery, hemoperfusion, nanosensers, and even by some groups in agriculture, industry, aquatic culture, nanocomputers, and nanorobotics.

  19. From artificial red blood cells, oxygen carriers, and oxygen therapeutics to artificial cells, nanomedicine, and beyond

    Science.gov (United States)

    Chang, Thomas M. S.

    2013-01-01

    The first experimental artificial red blood cells have all three major functions of red blood cells (rbc). However, the first practical one is a simple polyhemoglobin (PolyHb) that only has an oxygen-carrying function. This is now in routine clinical use in South Africa and Russia. An oxygen carrier with antioxidant functions, PolyHb-catalase-superoxide dismutase, can fulfill two of the three functions of rbc. Even more complete is one with all three functions of rbc in the form of PolyHb-catalase-superoxide dismutase-carbonic anhydrase. The most advanced ones are nanodimension artificial rbc with either PEG-lipid membrane or PEG-PLA polymermembrane. Extensions in to oxygen therapeutics include a PolyHb-tyrosinase that suppresses the growth of melanoma in a mice model. Another is a PolyHb-fibrinogen that is an oxygen carrier with platelet-like function. Research has now extended well beyond the original research on artificial rbc into many areas of artificial cells. These include nanoparticles, nanotubules, lipid vesicles, liposomes, polymer-tethered lipid vesicles, polymersomes, microcapsules, bioencapsulation, nanocapules, macroencapsulation, synthetic cells, and others. These are being used in nanotechnology, nanomedicine, regenerative medicine, enzyme/gene therapy, cell/stem cell therapy, biotechnology, drug delivery, hemoperfusion, nanosensers, and even by some groups in agriculture, industry, aquatic culture, nanocomputers, and nanorobotics. PMID:22409281

  20. Diagnostic accuracy of venous blood gas electrolytes for identifying diabetic ketoacidosis in the emergency department.

    Science.gov (United States)

    Menchine, Michael; Probst, Marc A; Agy, Chad; Bach, Dianne; Arora, Sanjay

    2011-10-01

    Diagnosing diabetic ketoacidosis (DKA) has traditionally required a venous blood gas (VBG) to obtain serum pH and a serum chemistry panel to obtain electrolyte values. Because newer blood gas analyzers have the ability to report electrolyte values and glucose in addition to pH, this diagnostic process could theoretically be condensed. However, neither the diagnostic accuracy of the VBG for DKA nor the agreement between the VBG electrolytes and the serum chemistry electrolytes, including sodium, chloride, and bicarbonate, has been evaluated in the context of acute hyperglycemia. The purpose of this study was to assess the accuracy of VBG electrolytes for diagnosing DKA using serum chemistry electrolytes measures as the criterion standard and to describe the correlation between VBG and serum chemistry electrolytes in a sample of hyperglycemic patients seen in the emergency department (ED). The authors prospectively identified a convenience sample of ED patients with serum blood glucose ≥ 250 mg/dL and examined their paired VBG and serum chemistry electrolytes. The diagnosis of DKA was made by using American Diabetes Association (ADA) criteria including serum glucose ≥ 250 mg/dL, serum anion gap > 10 mEq/L, bicarbonate ≤ 18 mEq/L, serum pH ≤ 7.30, and presence of ketosis. Serum chemistry electrolyte values were considered to be the criterion standard. Diagnostic test characteristics of VBG electrolytes including sensitivity and specificity were compared against this standard. In addition, correlation coefficients for individual electrolytes and anion gap between VBG and chemistry electrolytes were calculated. Paired VBG and serum chemistry panels were available for 342 patients, of whom 46 (13.5%) had DKA. The sensitivity and specificity of the VBG electrolytes for diagnosing DKA was 97.8% (95% confidence interval [CI] = 88.5% to 99.9%) and 100% (95% CI = 98.8% to 100%), respectively. One case of DKA was missed by the VBG. Correlation coefficients between VBG

  1. Blood transfusion in preterm infants improves intestinal tissue oxygenation without alteration in blood flow.

    Science.gov (United States)

    Banerjee, J; Leung, T S; Aladangady, N

    2016-11-01

    The objective of the study was to investigate the splanchnic blood flow velocity and oximetry response to blood transfusion in preterm infants according to postnatal age. Preterm infants receiving blood transfusion were recruited to three groups: 1-7 (group 1; n = 20), 8-28 (group 2; n = 21) and ≥29 days of life (group 3; n = 18). Superior mesenteric artery (SMA) peak systolic (PSV) and diastolic velocities were measured 30-60 min pre- and post-transfusion using Doppler ultrasound scan. Splanchnic tissue haemoglobin index (sTHI), tissue oxygenation index (sTOI) and fractional tissue oxygen extraction (sFTOE) were measured from 15-20 min before to post-transfusion using near-infrared spectroscopy. The mean pretransfusion Hb in group 1, 2 and 3 was 11, 10 and 9 g/dl, respectively. The mean (SD) pretransfusion SMA PSV in group 1, 2 and 3 was 0·63 (0·32), 0·81 (0·33) and 0·97 (0·40) m/s, respectively, and this did not change significantly following transfusion. The mean (SD) pretransfusion sTOI in group 1, 2 and 3 was 36·7 (19·3), 44·6 (10·4) and 41·3 (10·4)%, respectively. The sTHI and sTOI increased (P transfusion in all groups. On multivariate analysis, changes in SMA PSV and sTOI following blood transfusion were not associated with PDA, feeding, pretransfusion Hb and mean blood pressure. Pretransfusion baseline splanchnic tissue oximetry and blood flow velocity varied with postnatal age. Blood transfusion improved intestinal tissue oxygenation without altering mesenteric blood flow velocity irrespective of postnatal ages. © 2016 International Society of Blood Transfusion.

  2. [Effect of hyperventilation on cerebral blood flow and metabolism in man; continuous monitoring of arterio-cerebral venous glucose differences (author's transl)].

    Science.gov (United States)

    Gottstein, U; Zahn, U; Held, K; Gabriel, F H; Textor, T; Berghoff, W

    1976-04-15

    CBF decreases when arterial PCO2 is lowered by physiological, pathological or therapeutically induced hyperventilation. This is accompanied by an undelayed compensatory increase of oxygen-av-differences. Continuous monitoring of enzymatically determined glucose-av-differences of the brain during hyperventilation has for the first time shown that there is an undelayed fall of the cerebral venous glucose content, too. This indicates that the brain cells extract an augmented amount of glucose per ml blood during decreased CBF. Therefore glucose metabolism of the brain is not impaired during non-critical CBF reduction. However, when arterial PCO2 falls below 25 mmHg a detrimental effect on CBF and cerebral metabolism has to be expected. CBF will then decrease below the critical threshold for an undisturbed oxygen supply, and the respiratory alcalosis will lead to a disturbed oxygen delivery due to the Bohr-effect. As a consequence both of these factors will reduce the energy-yielding oxydative glycolysis and augment the little energy producing anaerobic glycolysis with a concomitant increase of lactate formation, resulting in a tissue and spinal fluid lactate acidosis. From our results it is therefore concluded that induced hyperventilation should be avoided, and that central hyperventilation in diseased states has to be considered as an additional threat to the brain.

  3. Effects of Hemoglobin-Based Oxygen Carriers on Blood Coagulation

    Directory of Open Access Journals (Sweden)

    Kimia Roghani

    2014-12-01

    Full Text Available For many decades, Hemoglobin-based oxygen carriers (HBOCs have been central in the development of resuscitation agents that might provide oxygen delivery in addition to simple volume expansion. Since 80% of the world population lives in areas where fresh blood products are not available, the application of these new solutions may prove to be highly beneficial (Kim and Greenburg 2006. Many improvements have been made to earlier generation HBOCs, but various concerns still remain, including coagulopathy, nitric oxide scavenging, platelet interference and decreased calcium concentration secondary to volume expansion (Jahr et al. 2013. This review will summarize the current challenges faced in developing HBOCs that may be used clinically, in order to guide future research efforts in the field.

  4. Cerebral blood flow and oxygen metabolism in the Rett syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Yoshikawa, Hideto; Fueki, Noboru; Suzuki, Hisaharu; Sakuragawa, Norio; Iio, Masaaki (National Central Hospital for Mental, Nervous and Muscular Disorders, Tokyo (Japan))

    1992-05-01

    Positron emission tomography (PET) was performed on six patients with the Rett syndrome and the results were compared with the concurrent clinical status of the patients. The cerebral metabolic rate of oxygen (CMRO{sub 2}) was low in five patients, and oxygen extraction fraction (OEF) was low in four patients; both had a tendency to decline with advancing age. Although the cause is unknown, it is suggested that impaired oxidative metabolism exists in the Rett syndrome. An analysis of the distribution among brain regions showed that the ratios of values for the frontal cortex to those for the temporal cortex for both the cerebral blood flow (CBF) and CMRO{sub 2} were lower than those for the controls, which may indicate the loss of of hyperfrontality in the Rett syndrome. Distribution of brain metabolism may be immature in the Rett syndrome. (author).

  5. Perioperative bleeding and blood transfusion are major risk factors for venous thromboembolism following bariatric surgery.

    Science.gov (United States)

    Nielsen, Alexander W; Helm, Melissa C; Kindel, Tammy; Higgins, Rana; Lak, Kathleen; Helmen, Zachary M; Gould, Jon C

    2017-11-03

    Morbidly obese patients are at increased risk for venous thromboembolism (VTE) after bariatric surgery. Perioperative chemoprophylaxis is used routinely with bariatric surgery to decrease the risk of VTE. When bleeding occurs, routine chemoprophylaxis is often withheld due to concerns about inciting another bleeding event. We sought to evaluate the relationship between perioperative bleeding and postoperative VTE in bariatric surgery. The American College of Surgeons-National Surgical Quality Improvement Program (NSQIP) dataset between 2012 and 2014 was queried to identify patients who underwent bariatric surgery. Gastric bypass (n = 28,145), sleeve gastrectomy (n = 30,080), bariatric revision (n = 324), and biliopancreatic diversion procedures (n = 492) were included. Univariate and multivariate regressions were used to determine perioperative factors predictive of postoperative VTE within 30 days in patients who experience a bleeding complication necessitating transfusion. The rate of bleeding necessitating transfusion was 1.3%. Bleeding was significantly more likely to occur in gastric bypass compared to sleeve gastrectomy (1.6 vs. 1.0%) (p surgeries, increased age, length of stay, operative time, and comorbidities including hypertension, dyspnea with moderate exertion, partially dependent functional status, bleeding disorder, transfusion prior to surgery, ASA class III/IV, and metabolic syndrome increased the perioperative bleeding risk (p Bariatric surgery patients who receive postoperative blood transfusion are at a significantly increased risk for VTE. The etiology of VTE in those who are transfused is likely multifactorial and possibly related to withholding chemoprophylaxis and the potential of a hypercoagulable state induced by the transfusion. In those who bleed, consideration should be given to reinitiating chemoprophylaxis when safe, extending treatment after discharge, and screening ultrasound.

  6. A New Method to Measure Portal Venous and Hepatic Arterial Blood Flow Patients Intraoperatively

    Science.gov (United States)

    Jakab, F.; Ráth, Z.; Schmal, F.; Nagy, P.; Faller, J.

    1996-01-01

    The intraoperative measurement of the afferent circulation of the liver, namely the hepatic artery flow and portal venous flow was carried out upon 14 anesthetized patients having carcinoma in the splanchnic area, mainly in the head of the pancreas by means of transit time ultrasonic volume flowmeter. The hepatic artery flow, portal venous flow and total hepatic flow were 0.377±0.10; 0.614±0.21; 0.992±0.276 l/min respectively. The ratio of hepatic arterical flow to portal venous flow was 0.66±0.259 There was a sharp, significant increase in hepatic arterial flow (29.8±6.1%, p<0,01) after the temporary occlusion of the portal vein, while the temporary occlusion of hepatic artery did not have any significant effect on portal venous circulation. The interaction between hepatic arterial flow and portal venous flow is a much disputed question, but according to the presented data here, it is unquestionable, that the decrease of portal venous flow immediately results a significant increase in hepatic artery circulation. PMID:8809586

  7. On-line blood viscosity monitoring in vivo with a central venous catheter, using electrical impedance technique.

    Science.gov (United States)

    Pop, Gheorghe A M; Bisschops, Laurens L A; Iliev, Blagoy; Struijk, Pieter C; van der Hoeven, Johannes G; Hoedemaekers, Cornelia W E

    2013-03-15

    Blood viscosity is an important determinant of microvascular hemodynamics and also reflects systemic inflammation. Viscosity of blood strongly depends on the shear rate and can be characterized by a two parameter power-law model. Other major determinants of blood viscosity are hematocrit, level of inflammatory proteins and temperature. In-vitro studies have shown that these major parameters are related to the electrical impedance of blood. A special central venous catheter was developed to measure electrical impedance of blood in-vivo in the right atrium. Considering that blood viscosity plays an important role in cerebral blood flow, we investigated the feasibility to monitor blood viscosity by electrical bioimpedance in 10 patients during the first 3 days after successful resuscitation from a cardiac arrest. The blood viscosity-shear rate relationship was obtained from arterial blood samples analyzed using a standard viscosity meter. Non-linear regression analysis resulted in the following equation to estimate in-vivo blood viscosity (Viscosity(imp)) from plasma resistance (R(p)), intracellular resistance (R(i)) and blood temperature (T) as obtained from right atrium impedance measurements: Viscosity(imp)=(-15.574+15.576R(p)T)SR ((-.138RpT-.290Ri)). This model explains 89.2% (R(2)=.892) of the blood viscosity-shear rate relationship. The explained variance was similar for the non-linear regression model estimating blood viscosity from its major determinants hematocrit and the level of fibrinogen and C-reactive protein (R(2)=.884). Bland-Altman analysis showed a bias between the in-vitro viscosity measurement and the in-vivo impedance model of .04 mPa s at a shear rate of 5.5s(-1) with limits of agreement between -1.69 mPa s and 1.78 mPa s. In conclusion, this study demonstrates the proof of principle to monitor blood viscosity continuously in the human right atrium by a dedicated central venous catheter equipped with an impedance measuring device. No safety

  8. When one port does not return blood: two case reports of rare causes for misplaced central venous catheters.

    Science.gov (United States)

    Pereira, Sandra; Preto, César; Pinho, Carla; Vasconcelos, Pedro

    2016-01-01

    We present two cases of misplaced central venous catheters having in common the absence of free blood return from one lumen immediately after placement. The former is a case of right hydrothorax associated with central venous catheterization with the catheter tip in intra-pleural location. In this case the distal port was never patent. In the latter case there was an increased aspiration pressure through the middle port due to a catheter looping. The absence of free flow on aspiration from one lumen of a central catheter should not be undervalued. In these circumstances the catheter should not be used and needs to be removed. Copyright © 2014 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. All rights reserved.

  9. Blood Transfusion Strategies in Patients Undergoing Extracorporeal Membrane Oxygenation

    Directory of Open Access Journals (Sweden)

    Hyoung Soo Kim

    2017-02-01

    Full Text Available Extracorporeal membrane oxygenation (ECMO is frequently associated with bleeding and coagulopathy complications, which may lead to the need for transfusion of multiple blood products. However, blood transfusions are known to increase morbidity and mortality, as well as hospital cost, in critically ill patients. In current practice, patients on ECMO receive a transfusion, on average, of 1-5 packed red blood cells (RBCs/day, with platelet transfusion accounting for the largest portion of transfusion volume. Generally, adult patients require more transfusions than neonates or children, and patients receiving venovenous ECMO for respiratory failure tend to need smaller transfusion volumes compared to those receiving venoarterial ECMO for cardiac failure. Observation studies have reported that a higher transfusion volume was associated with increased mortality. To date, the evidence for transfusion in patients undergoing ECMO is limited; most knowledge on transfusion strategies was extrapolated from studies in critically ill patients. However, current data support a restrictive blood transfusion strategy for ECMO patients, and a low transfusion trigger seems to be safe and reasonable.

  10. [Studies of the blood antioxidant system and oxygen-transporting properties of human erythrocytes during 105-day isolation].

    Science.gov (United States)

    Brazhe, N A; Baĭzhumanov, A A; Parshina, E Iu; Iusipovich, A I; Akhalaia, M Ia; Iarlykova, Iu V; Labetskaia, O I; Ivanova, S M; Morukov, B V; Maksimov, G V

    2011-01-01

    Effects of strict 105-d isolation on blood antioxidant status, erythrocyte membrane processes and oxygen-binding properties of hemoglobin were studied in 6 male volunteers (25 to 40 y.o.) in ground-based simulation of a mission to Mars (experiment Mars-105). The parameters were measured using venous blood samples collected during BDC, on days 35, 70 and 105 of the experiment and on days 7 and 14-15 after its completion. Methods of biochemistry (determination of enzyme activity and thin-layer chromatography) and biophysical (laser interference microscopy, Raman spectroscopy) showed changes in relative content of lipid and phospholipid fractions suggesting growth of membrane microviscosity and increase in TBA-AP (active products of lipids peroxidation interacting with thiobarbituric acid). A significant increase in glucose-6-phosphate dehydrogenase and superoxide dismutase activities against reduction of catalase activity points to both reparative processes in erythrocytes and disbalance between the number of evolving active forms of oxygen and antioxidant protection mechanisms in cells. Hemoglobin sensitivity of oxygen and blood level of oxyhemoglobin were found to increase, too. It is presumed that adaptation of organism to stresses experienced during and after the experiment may destroy balance of the antioxidant protection systems which is conducive to oxidation of membrane phospholipids, alteration of their content, increase of membrane microviscosity and eventual failure of the gas-exchange function of erythrocytes.

  11. Erythrocytes and the regulation of human skeletal muscle blood flow and oxygen delivery: role of erythrocyte count and oxygenation state of haemoglobin.

    Science.gov (United States)

    González-Alonso, José; Mortensen, Stefan P; Dawson, Ellen A; Secher, Niels H; Damsgaard, Rasmus

    2006-04-01

    Blood flow to dynamically contracting myocytes is regulated to match O(2) delivery to metabolic demand. The red blood cell (RBC) itself functions as an O(2) sensor, contributing to the control of O(2) delivery by releasing the vasodilators ATP and S-nitrosohaemoglobin with the offloading of O(2) from the haemoglobin molecule. Whether RBC number is sensed remains unknown. To investigate the role of RBC number, in isolation and in combination with alterations in blood oxygenation, on muscle and systemic perfusion, we measured local and central haemodynamics during one-legged knee-extensor exercise ( approximately 50% peak power) in 10 healthy males under conditions of normocythaemia (control), anaemia, anaemia + plasma volume expansion (PVX), anaemia + PVX + hypoxia, polycythaemia, polycythaemia + hyperoxia and polycythaemia + hypoxia, which changed either RBC count alone or both RBC count and oxyhaemoglobin. Leg blood flow (LBF), cardiac output (Q) and vascular conductance did not change with either anaemia or polycythaemia alone. However, LBF increased with anaemia + PVX (28 +/- 4%) and anaemia + PVX + hypoxia (46 +/- 6%) and decreased with polycythaemia + hyperoxia (18 +/- 5%). LBF and Q with anaemia + PVX + hypoxia (8.0 +/- 0.5 and 15.8 +/- 0.7 l min(-1), respectively) equalled those during maximal knee-extensor exercise. Collectively, LBF and vascular conductance were intimately related to leg arterial-venous (a-v) O(2) difference (r(2)= 0.89-0.93; P < 0.001), suggesting a pivotal role of blood O(2) gradients in muscle microcirculatory control. The systemic circulation accommodated to the changes in muscle perfusion. Our results indicate that, when coping with severe haematological challenges, local regulation of skeletal muscle blood flow and O(2) delivery primarily senses alterations in the oxygenation state of haemoglobin and, to a lesser extent, alterations in the number of RBCs and haemoglobin molecules.

  12. Blood oxygenation level-dependent MRI for assessment of renal oxygenation

    Directory of Open Access Journals (Sweden)

    Neugarten J

    2014-11-01

    Full Text Available Joel Neugarten, Ladan Golestaneh Renal Division, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, NY, USA Abstract: Blood oxygen level-dependent magnetic resonance imaging (BOLD MRI has recently emerged as an important noninvasive technique to assess intrarenal oxygenation under physiologic and pathophysiologic conditions. Although this tool represents a major addition to our armamentarium of methodologies to investigate the role of hypoxia in the pathogenesis of acute kidney injury and progressive chronic kidney disease, numerous technical limitations confound interpretation of data derived from this approach. BOLD MRI has been utilized to assess intrarenal oxygenation in numerous experimental models of kidney disease and in human subjects with diabetic and nondiabetic chronic kidney disease, acute kidney injury, renal allograft rejection, contrast-associated nephropathy, and obstructive uropathy. However, confidence in conclusions based on data derived from BOLD MRI measurements will require continuing advances and technical refinements in the use of this technique. Keywords: kidney, hypoxia, oxygenation, diabetes mellitus, chronic kidney disease, acute kidney injury, contrast-associated nephropathy, BOLD MRI

  13. Measured and calculated variables of global oxygenation in healthy neonatal foals.

    Science.gov (United States)

    Wong, David M; Hepworth-Warren, Kate L; Sponseller, Beatrice T; Howard, Joan M; Wang, Chong

    2017-02-01

    OBJECTIVE To assess multiple central venous and arterial blood variables that alone or in conjunction with one another reflect global oxygenation status in healthy neonatal foals. ANIMALS 11 healthy neonatal foals. PROCEDURES Central venous and arterial blood samples were collected from healthy neonatal foals at 12, 24, 36, 48, 72, and 96 hours after birth. Variables measured from central venous and arterial blood samples included oxygen saturation of hemoglobin, partial pressure of oxygen, lactate concentration, partial pressure of carbon dioxide, and pH. Calculated variables included venous-to-arterial carbon dioxide gap, estimated oxygen extraction ratio, ratio of partial pressure of oxygen in arterial blood to the fraction of inspired oxygen, bicarbonate concentration, base excess, and blood oxygen content. RESULTS Significant differences between arterial and central venous blood obtained from neonatal foals were detected for several variables, particularly partial pressure of oxygen, oxygen saturation of hemoglobin, and oxygen content. In addition, the partial pressure of carbon dioxide in central venous blood samples was significantly higher than the value for corresponding arterial blood samples. Several temporal differences were detected for other variables. CONCLUSIONS AND CLINICAL RELEVANCE Results of this study provided information about several variables that reflect global oxygenation in healthy neonatal foals. Values for these variables in healthy foals can allow for comparison with values for critically ill foals in future studies. Comparison of these variables between healthy and ill foals may aid in treatment decisions and prognosis of clinical outcome for critically ill foals.

  14. Effect of hyperbaric oxygen therapy on complete blood count.

    Science.gov (United States)

    Gunes, Ali Erdal; Aktas, Samil

    2017-01-01

    Complete blood count (CBC) is a routine diagnostic procedure for patients and a part of routine health inspection for healthy individuals. The effect of hyperbaric oxygen (HBO₂) on CBC is not known. The objective of this study was to determine the effects of HBO₂ on blood parameters in CBC with long-term HBO₂ therapy. In this study, patients received HBO₂ at the department of Underwater and Hyperbaric Clinical Medicine. CBC results were obtained at specific time points during HBO₂ therapy. The study recruited a total of 140 patients who met the research inclusion criteria. Patients were treated for 55.5 ± 41 days. During the treatment period, they underwent HBO₂ sessions for an average of 35.9 ± 24.9 times. Five groups were created as follows: before the treatment; between 1-20 sessions; between 21-40 sessions; between 41-60 sessions; and more than 60 sessions. The results of the present study showed that a number of alterations occurred in CBC values in patients who received HBO₂. HBO₂ reduces the number of platelets, but this was not clinically significant. According to the results, HBO₂ does not have any effect on hemoglobin, hematocrit, red blood cells, mean corpuscular volume, mean corpuscular hemoglobin, red blood cell distribution width, mean corpuscular hemoglobin concentration, platelet count, platelet distribution width and mean platelet volume. Except for a temporary reduction in platelet count, HBO₂ has no effect on CBC parameters. Medical professionals may use the outcome of this study in their routine examinations, as it suggests that the changes in CBC driven by HBO₂ are not statistically significant, and could be disregarded. More research is needed to examine the effects of HBO₂ on other blood parameters. Copyright© Undersea and Hyperbaric Medical Society.

  15. [Prognostic significance of leukocyte count in the venous blood in the acute stage of cerebral aneurism rupture].

    Science.gov (United States)

    Kalinkin, A A; Petrikov, S S; Khamidova, L T; Krylov, V V

    To determine a prognostic role of leukocyte count in the venous blood in the acute stage of cerebral aneurysm (CA) rupture. Fifty-one patients with CA rupture, aged from 20 to 65 years, hospitalized in the first 72 h over the period from 01.10.12 to 01.02.16 were examined. The severity of disease and anatomical form of hemorrhage was corresponded to III-IV degree on the W. Hunt - R. Hess scale and Fisher scale. All patients underwent surgery. Outcomes after open and endovascular surgeries were similar. Normal leukocyte number in the venous blood at admission was identified in 12 (24%) of patients (on average 7.3±1.4·109/L), leukocytosis in 39 (76%) (14.3±3.1·109/L) (pLeukocyte number in the acute stage of CA rupture was correlated with the frequency and severity of the vessel spasm. In 28 (55%) of patients with ischemic lesions of the brain matter, mean leukocyte number in the first 72 h after hemorrhage was higher by 2-24% (3±4.8·109/L) compared to patients without ischemia (11.9±2.5·109/L) (p=0.06). The level of leukocytes in survivors was lower by 3 - 28% (122±3.4·109/L) compared to patients with fatal outcome and patients with severe neurological deficit after the surgery (14.5±3.9·109/L) (p>0.05). The increase in leukocyte number in the venous blood in the first 72 h after CA rupture ≥10,1·109/L is a reliable risk factor of marked vessel spasm. The level of leukocytes in patients with cerebral ischemia and poor prognosis in the first 72h after aneurysmal hemorrhage was higher by 2-28% compared to survivors without neurological impairment or mild neurological deficit.

  16. Effect of body position and ventilation on umbilical artery and venous blood flows during delayed umbilical cord clamping in preterm lambs.

    Science.gov (United States)

    Hooper, Stuart B; Crossley, Kelly J; Zahra, Valerie A; van Vonderen, Jeroen; Moxham, Alison; Gill, Andrew W; Kluckow, Martin; Te Pas, Arjan B; Wallace, Euan M; Polglase, Graeme R

    2017-07-01

    While delayed umbilical cord clamping (UCC) is thought to facilitate placental to infant blood transfusion, the physiological factors regulating flow in the umbilical arteries and veins during delayed UCC is unknown. We investigated the effects of gravity, by changing fetal height relative to the placenta, and ventilation on umbilical blood flows and the cardiovascular transition during delayed UCC at birth. Catheters and flow probes were implanted into preterm lambs (128 days) prior to delivery to measure pulmonary, carotid, umbilical artery (UaBF) and umbilical venous (UvBF) blood flows. Lambs were placed either 10 cm below or 10 cm above the ewe. Ventilation commenced 2-3 min before UCC and continued for 30 min after UCC. Gravity reduced umbilical and cerebral flows when lambs were placed below the midline, but the reduction in UaBF and UvBF was similar. Ventilation during delayed UCC reduced UvBF and UaBF by similar amounts, irrespective of the lamb's position, such that flows into and out of the placenta remained balanced. The effects of ventilation on umbilical flows were much greater than the effects of gravity, but no net placental to lamb blood transfusion could be detected under any condition. Cardiovascular parameters, cerebral oxygen kinetics and final blood volumes were similar in both groups 5 min after UCC. Gravity caused small transient effects on umbilical and cerebral flow, but given changes were similar in umbilical arteries and veins, no net placental transfusion was detected. Ventilation during delayed UCC has a markedly greater influence on cardiovascular function in the newborn. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  17. Comparison of POCT and central laboratory blood glucose results using arterial, capillary, and venous samples from MICU patients on a tight glycemic protocol.

    Science.gov (United States)

    Petersen, John R; Graves, Donna F; Tacker, Danyel H; Okorodudu, Anthony O; Mohammad, Amin A; Cardenas, Victor J

    2008-10-01

    Point of care (POC) glucose meters are routinely used to monitor glucose levels for patients on tight glycemic control therapy. We determined if glucose values were different for a POC glucose meter as compared to the main clinical laboratory for medical intensive care unit patients on a tight glycemic protocol and whether the site of blood sampling had a significant impact on glucose values. Eighty-four patients (114 paired samples) who were on a tight glycemic protocol in the period November 2005 through August 2006 were enrolled. After simultaneous blood draws, we compared the glucose levels for the glucose meter (arterial/venous/capillary), blood gas (arterial/venous), and central clinical laboratory (serum/plasma from arterial/venous samples). The mean glucose levels of all arterial/venous/fingerstick samples using the glucose meter demonstrated a positive bias of 0.7-0.9 mmol/l (12.6-16.2 mg/dl) (pcentral laboratory venous plasma. There was also a smaller positive (0.1-0.3 mmol/l or 1.8-5.4 mg/dl, pvenous blood gas samples and laboratory arterial serum/plasma glucose samples. Using Parkes error grid analysis we were able to show that the bias for arterial or venous POC glucose results would have not impacted clinical care. This was not the case, however, for fingerstick sampling where a high bias could have significantly impacted clinical care. Additionally, in 3 fingerstick samples a severe underestimation (central laboratory plasma result) was found. Glucose meters using arterial/venous whole blood may be utilized in the MICU; however, due to the increased variability of results we do not recommend the routine use of capillary blood sampling for monitoring glucose levels in the MICU setting.

  18. Coupling between arterial and venous cerebral blood flow during postural change

    DEFF Research Database (Denmark)

    Ogoh, Shigehiko; Washio, Takuro; Sasaki, Hiroyuki

    2016-01-01

    circulation, this study addressed both arterial and venous flow responses in the "anterior" and "posterior" parts of the brain when 9 healthy subjects (5 men) were seated and flow was manipulated by hyperventilation and inhalation of 6% carbon dioxide (CO2). From a supine to a seated position, both internal...

  19. 129Xe chemical shift in human blood and pulmonary blood oxygenation measurement in humans using hyperpolarized 129Xe NMR

    OpenAIRE

    Norquay, G.; Leung, G; Stewart, N J; Wolber, J.; Wild, J.M.

    2016-01-01

    Purpose To evaluate the dependency of the 129Xe?red blood cell (RBC) chemical shift on blood oxygenation, and to use this relation for noninvasive measurement of pulmonary blood oxygenation in vivo with hyperpolarized 129Xe NMR. Methods Hyperpolarized 129Xe was equilibrated with blood samples of varying oxygenation in vitro, and NMR was performed at 1.5 T and 3 T. Dynamic in vivo NMR during breath hold apnea was performed at 3 T on two healthy volunteers following inhalation of hyperpolarized...

  20. Radioimmunoassay of estrone, estradiol, estriol, progesterone, cortisol and prolactin in maternal venous blood and the cord blood of the newborn child

    Energy Technology Data Exchange (ETDEWEB)

    Fritschi, J.

    1980-01-01

    The estrone analyses showed that E/sub 1/ levels are not sex-dependent. The Prog/E/sub 2/ ratio changed when the children were in states of exceptional stress; analogous findings were obtained in the acidose group. Due to the wide range of variations of E/sub 3/, it was found to be impossible to determine the stage of pregnancy from the E/sub 3/ level. Progesterone levels were significantly higher in the blood of the umbilical vein than in the umbilical artery. Prolactine levels of both the umbilical vein and the umbilical artery are significantly higher than in the mother's venous blood. Cortisol levels differed with the type of delivery, especially when comparing Caesareon with normal delivery. Also, differences were found between deliveries with more or less stress. There is no significant difference between E/sub 2//prog ratios measured during induced labour, immature delivery, application of analgetics; instead, cortisol levels are best correlated with the clinical criteria of birth stress, especially during the expulsion period in which stress factors are highest. Further, there is a correlation between the cortisol levels of the umbilical vein and the mother's venous-blood.

  1. The effects of hypotension on differences between the results of simultaneous venous and arterial blood gas analysis.

    Science.gov (United States)

    Shirani, Farhad; Salehi, Reza; Naini, Afsoon Emami; Azizkhani, Reza; Gholamrezaei, Ali

    2011-02-01

    Analysis of venous blood gas (VBG) can represent arterial blood gas (ABG) analysis in patients with various diseases. The effects of hypotension on differences between the results of simultaneous venous and arterial blood gas analyses were reviewed. This observational, cross-sectional study was conducted from March to October 2010 in emergency departments of two university hospitals in Tehran (Iran) on consecutive adult patients for whom ABG had been indicated for diagnosis/treatment. Arterial and peripheral venous bloods were simultaneously sampled with blood pressure measurement. The VBG-ABG amount of difference regarding pH, HCO(3), PCO(2), PO(2), SO(2), and Base Excess (BE) was compared between those with and without hypotension. During the study, 192 patients (51.6 ± 23.6 years, 67.7% males) were entered into the hypotension (n = 78) and normotensive groups (n = 114). The average VBG-ABG amount of difference (95% limits of agreement) in the hypotension versus normotensive group were -0.030 (-0.09 to 0.03) vs. -0.016 (-0.1 to 0.068) for pH (p = 0.01), 1.79 (-1.91 to 5.49) vs. 1.32 (-1.94 to 4.58) mEq/L for HCO(3) (p = 0.032), 2.69 (-20.43 to 25.81) vs. 2.03 (-7.75 to 11.81) mmHg for PCO(2) (p = 0.295), -35.97 (-130.17 to 58.23) vs. -32.65 (-104.79 to 39.49) mmHg for PO(2) (p = 0.293), -18.58 (-14.66 to 51.82) vs. -9.06 (-31.28 to 13.16) percent (p analysis regarding pH, HCO(3), and BE, though the amount of increase does not seem to be clinically important. Studying the precise effects of replacing ABG with VBG on the clinical decision-making and the following outcomes is worth-while.

  2. Comparison of Coagulation Parameters, Anticoagulation, and Need for Transfusion in Patients on Interventional Lung Assist or Veno-Venous Extracorporeal Membrane Oxygenation.

    Science.gov (United States)

    Weingart, Christian; Lubnow, Matthias; Philipp, Alois; Bein, Thomas; Camboni, Daniele; Müller, Thomas

    2015-09-01

    Clinical data on anticoagulation needs of modern extracorporeal membrane oxygenation (ECMO) and its impact on coagulation are scarce. Therefore, we analyzed coagulation-related parameters, need for transfusion, and management of anticoagulation in adult patients with severe acute respiratory failure during treatment with either pumpless interventional lung assist (iLA) or veno-venous ECMO (vv-ECMO). Sixty-three patients treated with iLA and 192 patients treated with vv-ECMO at Regensburg University Hospital between January 2005 and May 2011 were analyzed. Data related to anticoagulation, transfusion, and coagulation parameters were collected prospectively by the Regensburg ECMO registry. Except for a higher, sequential organ failure assessment (SOFA) score in the ECMO group (12 [9-15] vs. 11 [7-14], P = 0.007), a better oxygenation, and a lower dosage of vasopressors in the iLA patients, both groups had similar baseline characteristics. No difference was noted in terms of outcome and overall transfusion requirements. Factors of the plasmatic coagulation system were only marginally altered over time and did not differ between groups. Platelet counts in ECMO-treated patients, but not in those treated with iLA, dropped significantly during extracorporeal support. A more intense systemic anticoagulation with a mean activated partial thromboplastin time (aPTT) > 53 s led to a higher need for transfusions compared with the group with a mean aPTT membrane oxygenators was not affected. Need for red blood cell (RBC) transfusion was highest in patients with extrapulmonary sepsis (257 mL/day), and was significantly lower in primary pulmonary adult respiratory distress syndrome (ARDS) (102 mL/day). Overall, 110 (0-274) mL RBC was transfused in the ECMO group versus 146 (41-227) mL in the iLA group per day on support. The impact of modern iLA and ECMO systems on coagulation allows comparatively safe long-term treatment of adult patients with acute respiratory

  3. Photoacoustic measurements of red blood cell oxygen saturation in blood bags in situ

    Science.gov (United States)

    Pinto, Ruben N.; Bagga, Karan; Douplik, Alexandre; Acker, Jason P.; Kolios, Michael C.

    2017-03-01

    Red blood cell (RBC) transfusion is a critical component of the health care services. RBCs are stored in blood bags in hypothermic temperatures for a maximum of 6 weeks post donation. During this in vitro storage period, RBCs have been documented to undergo changes in structure and function due to mechanical and biochemical stress. Currently, there are no assessment methods that monitor the quality of RBCs within blood bags stored for transfusion. Conventional assessment methods require the extraction of samples, consequently voiding the sterility of the blood bags and potentially rendering them unfit for transfusions. It is hypothesized that photoacoustic (PA) technology can provide a rapid and non-invasive indication of RBC quality. In this study, a novel PA setup was developed for the acquisition of oxygen saturation (SO2) of two blood bags in situ. These measurements were taken throughout the lifespan of the blood bags (42 days) and compared against the clinical gold standard method of the blood gas analyzer (BGA). SO2 values of the blood bags increased monotonically throughout the storage period. A strong correlation between PA SO2 and BGA SO2 was found, however, PA values were on average 3.5% lower. Both techniques found the bags to increase by an SO2 of approximately 20%, and measured very similar rates of SO2 change. Future work will be focused on determining the cause of discrepancy between SO2 values acquired from PA versus BGA, as well as establishing links between the measured SO2 increase and other changes in RBC in situ.

  4. Regional blood flow distribution and oxygen metabolism during mesenteric ischemia and congestion.

    Science.gov (United States)

    Cruz, Ruy J; Garrido, Alejandra G; Ribeiro, Cristiane M F; Harada, Tomoyuki; Rocha-e-Silva, Mauricio

    2010-06-01

    Acute mesenteric ischemia is a potentially fatal vascular emergency with mortality rates ranging between 60% and 80%. Several studies have extensively examined the hemodynamic and metabolic effects of superior mesenteric artery occlusion. On the other hand, the cardiocirculatory derangement and the tissue damage induced by intestinal outflow obstruction have not been investigated systematically. For these reasons we decided to assess the initial impact of venous mesenteric occlusion on intestinal blood flow distribution, and correlate these findings with other systemic and regional perfusion markers. Fourteen mongrel dogs were subjected to 45 min of superior mesenteric artery (SMAO) or vein occlusion (SMVO), and observed for 120 min after reperfusion. Systemic hemodynamics were evaluated using Swan-Ganz and arterial catheters. Regional blood flow (ultrasonic flow probes), intestinal O(2)-derived variables, and mesenteric-arterial and tonometric-arterial pCO(2) gradients (D(mv-a)pCO(2) and D(t-a)pCO(2)) were also calculated. SMVO was associated with hypotension and low cardiac output. A significant increase in the regional pCO(2) gradients was also observed in both groups during the ischemic period. After reperfusion, a progressive reduction in D(mv-a)pCO(2) occurred in the SMVO group; however, no improvement in D(t-a)pCO(2) was observed. The histopathologic injury scores were 2.7 +/- 0.5 and 4.8 +/- 0.2 for SMAO and SMVO, respectively. SMV occlusion promoted early and significant hemodynamic and metabolic derangement at systemic and regional levels. Additionally, systemic pCO(2) gradient is not a reliable parameter to evaluate the local intestinal oxygenation. Finally, the D(t-a)pCO(2) correlates with histologic changes during intestinal congestion or ischemia. However, minor histologic changes cannot be detected using this methodology. Copyright (c) 2010 Elsevier Inc. All rights reserved.

  5. Medical science in Siberia: Oxygen exchange in the Far North

    Science.gov (United States)

    Kulikov, V.; Yegunova, M.

    1979-01-01

    Differences in oxygen conditions between the native and migrant Siberian population were studied in relation to respiratory function, arterial and venous blood indicators and acid-base indicators. Significant adaptation differences were ascertained between the two populations.

  6. Biochemical assessment of growth factors and circulation of blood components contained in the different fractions obtained by centrifugation of venous blood.

    Science.gov (United States)

    Corigiano, M; Ciobanu, G; Baldoni, E; Pompa, G

    2014-01-01

    The aim of this study was to evaluate a biochemical marker with different elements of a normal blood serum and centrifuged blood serum after a different rotation system. For this technique, we used five fractions of a blood Concentrated Growth Factors system (bCGF) and a particular device for the different rotation program. Blood samples were collected from 10 volunteers aged between 35 and 55 in the Operative Unit of the “Sapienza” University of Rome with only a fraction of different biochemical elements. Through an individual blood phase separator tube of venous blood, active factions of serum and 4 fractions of red buffy coat were taken. The biochemical markers with 14 elements were examined at times: P1-11 minutes, P2-12minutes, P3-15 minutes. Exclusively biological materials which are normally applied in the regeneration techniques for different defects and lesions were used with this technique. After specific rotation programs, a different result was obtained for each cycle: P1, P2, P3. In test tubes obtained by separated blood, we observed a higher concentration of proteins, ions, and other antigens compared to normal blood plasma. Examining the biochemical results of different elements, we observed an increase (P≤0,01). Since each person’s DNA is different, we could not have the same results in 5 fractions of blood concentration, we did, however, find a good increase in only a fraction of proteins, immunoglobulin and different ions. We obtained five fractions after centrifugation, and we had an increase in different biochemical elements compared to normal blood (P≤0,01) which is significant at different times. These biochemical elements were stimulated by different growth factors, which are used by the immune system, and they induced the formation of hard and soft tissues and good regeneration.

  7. Hemoglobin measured by Hemocue and a reference method in venous and capillary blood: a validation study Hemoglobina medida por Hemocue y por un método de referencia en sangre venosa y capilar: estudio de validación

    OpenAIRE

    Lynnette Neufeld; Armando García-Guerra; Domingo Sánchez-Francia; Oscar Newton-Sánchez; María Dolores Ramírez-Villalobos; Juan Rivera-Dommarco

    2002-01-01

    Objective. To assess the comparability of hemoglobin concentration (Hb) in venous and capillary blood measured by Hemocue and an automated spectrophotometer (Celldyn) and to document the influence of type of blood (capillary or venous) and analysis method on anemia prevalence estimates. Material and Methods. Between February and May 2000, capillary and venous samples were collected from 72 adults and children at Hospital del Niño Morelense (Morelos State Children's Hospital) in Cuernavaca, Mo...

  8. BLOOD COMPATIBILITY OF 2 DIFFERENT TYPES OF MEMBRANE-OXYGENATOR DURING CARDIOPULMONARY BYPASS IN INFANTS

    NARCIS (Netherlands)

    GU, YJ; BOONSTRA, PW; AKKERMAN, C; MUNGROOP, H; TIGCHELAAR, [No Value; VANOEVEREN, W

    1994-01-01

    The contact of blood with the artificial extracorporeal circuit causes a systemic inflammatory response due to blood activation. In this study, we compared two different paediatric membrane oxygenators used for extracorporeal circulation: a hollow fibre membrane oxygenator (Dideco Masterflo D-701,

  9. Regional cerebral blood flow measurements in schizophrenics by /sup 133/Xe inhalation and intra-venous injection method

    Energy Technology Data Exchange (ETDEWEB)

    Matsuda, Hiroshi; Seki, Hiroyasu; Sumiya, Hisashi; Ishida, Hiroko; Taki, Junichi; Hisada, Kinichi; Kurachi, Masayoshi; Kobayashi, Katsuji; Yamaguchi, Nariyoshi (Kanazawa Univ. (Japan). School of Medicine)

    1984-12-01

    Regional cerebral blood flow measurements were performed in 25 schizophrenic patients and 25 healthy volunteers by /sup 133/Xe inhalation and intra-venous injection method. Schizophrenic patients were classified into the following three groups. Group I: 8 patients without auditory hallucination measured by 2-dimensional /sup 133/Xe inhalation method. Group II: 6 patients with auditory hallucination measured by the same method as in Group I. Group III: 11 patients, including 2 patients with auditory hallucination measured by 3-dimensional /sup 133/Xe intra-venous injection method at the level of OM+5 cm. Bilateral regional percent values, which were obtained by dividing regional values by hemispheric mean or sectional mean values, for frontal lobes in Group I and II were significantly lower than those in the controls. In addition, bilateral regional percent values for bilateral temporal lobes in Group II were significantly higher than those in the controls. In Group III, regional percent values for right frontal lobes and those for posterior part of central gray matter showed significant decrease and increase, respectively. These findings would suggest that the negative symptoms of schizophrenia are related to the hypofrontal and positive ones to the hypertemporoparietal activity.

  10. The cost-effectiveness of venous-converted acid-base and blood gas status in pulmonary medical departments

    Directory of Open Access Journals (Sweden)

    Lars Oddershede

    2010-12-01

    Full Text Available Lars Oddershede1, Sabrina Storgaard Petersen1, Asgerd Krogh Kristensen2, Jan Freddy Pedersen3, Stephen Edward Rees1, Lars Ehlers41Department of Health Science and Technology, Aalborg University, Aalborg, Denmark; 2Department of Pulmonary Medicine, Aalborg Hospital Section South, Aalborg, Denmark; 3Department of Clinical Biochemistry, Aalborg Hospital Section South, Aalborg, Denmark; 4Health Economics and Management, Aalborg University, Aalborg, DenmarkIntroduction: The current use of arterial punctures, when obtaining arterial blood gas and acid-base status of patients, are associated with a risk of side effects such as pain and hematoma, and a small risk of more severe complications. This analysis investigated the cost-effectiveness of a new method, where less painful venous-converted tests are used as an alternative to arterial punctures.Methods: A cost–utility analysis was conducted from the Danish hospital perspective using a Markov model. The model represents the admission of a typical patient suffering from chronic obstructive pulmonary disease to the Department of Pulmonary Medicine, Aalborg Hospital. Evidence of the effect of the venous-converted tests’ pain reduction was converted into short-term gain in quality-adjusted life years (QALYs, using the Danish EuroQol-5 Dimension value set. A Monte Carlo second order simulation of 10,000 hypothetical patients was conducted for a midsized and a small department.Results: Monte Carlo simulation of the incremental cost-effectiveness ratio (ICER was dominant for a midsized department, and for a small department the mean was £10,645 per QALY gained. The scatter plot of ICERs revealed that at a willingness-to-pay (WTP of £30,000 per QALY gained, the venous conversion method is >95% cost-effective in a midsized department and 51% in a small department.Conclusion: It was concluded that the venous conversion method should be applied to hospitals with midsized pulmonary departments, and could be

  11. A porous media theory for characterization of membrane blood oxygenation devices

    Science.gov (United States)

    Sano, Yoshihiko; Adachi, Jun; Nakayama, Akira

    2013-07-01

    A porous media theory has been proposed to characterize oxygen transport processes associated with membrane blood oxygenation devices. For the first time, a rigorous mathematical procedure based a volume averaging procedure has been presented to derive a complete set of the governing equations for the blood flow field and oxygen concentration field. As a first step towards a complete three-dimensional numerical analysis, one-dimensional steady case is considered to model typical membrane blood oxygenator scenarios, and to validate the derived equations. The relative magnitudes of oxygen transport terms are made clear, introducing a dimensionless parameter which measures the distance the oxygen gas travels to dissolve in the blood as compared with the blood dispersion length. This dimensionless number is found so large that the oxygen diffusion term can be neglected in most cases. A simple linear relationship between the blood flow rate and total oxygen transfer rate is found for oxygenators with sufficiently large membrane surface areas. Comparison of the one-dimensional analytic results and available experimental data reveals the soundness of the present analysis.

  12. [Early evaluation of anaemia in patients with acute gastrointestinal bleeding: venous blood gas analysis compared to conventional laboratory].

    Science.gov (United States)

    Benítez Cantero, José Manuel; Jurado García, Juan; Ruiz Cuesta, Patricia; González Galilea, Angel; Muñoz García-Borruel, María; García Sánchez, Valle; Gálvez Calderón, Carmen

    2013-10-19

    Evaluation of patients with acute gastrointestinal bleeding (AGB) requires early clinical evaluation and analysis. The aim of this study is to evaluate early concordance of hemoglobin (Hb) and hematocrit (HTC) levels determined by conventional venous blood gas analysis (VBG) and by conventional Laboratory in Emergencies (LAB). Observational and prospective study of patients admitted in the Gastrointestinal Haemorrhage Unit with both high and low AGB. Demographic and clinical variables and simultaneous venous blood samples were obtained to determine Hb and HTC by VBG and LAB. Concordance in both methods was analysed by intra-class correlation coefficient (ICC) and Bland-Altman analysis. One hundred and thirty-two patients were included: 87 (65.9%) males, average age 66.8 years. VBG overestimated Hb in 0.49 g/dl (95% confidence interval: 0.21-0.76) with respect to LAB. Concordance was very high in Hb (ICC 0.931) and high in HTC (0.899), with the Bland-Altman graphs showing both concordance and overestimation of Hb levels determined by VBG. In 19 patients (14.39%), Hb by VBG exceeded in more than 1g/dL the final determination obtained by LAB. Early determination of Hb and HTC in patients with AGB by VBG provides reliable results in the initial evaluation of anaemia. VBG systematically overestimates Hb values by less than 0.5 g/dl, and therefore clinical and hemodynamic evaluation of the bleeding patient should prevail over analytical results. Copyright © 2012 Elsevier España, S.L. All rights reserved.

  13. Relationship between muscle oxygenation by NIRS and blood lactate

    Energy Technology Data Exchange (ETDEWEB)

    Xu Guodong [School of Physical Education, Jianghan University, Hubei Wuhan 430056 (China); Mao Zongzhen; Ye Yanjie; Lv Kunru, E-mail: xguodong@wipe.edu.cn [School of Health Sciences, Wuhan Institute of Physical Education, Hubei Wuhan 430079 (China)

    2011-01-01

    The aim of the study was to investigate the relationship of muscle oxygenation in term of oxy-hemoglobin concentration change ({Delta}HbO{sub 2}) by NIRS and blood lactate (BLA) in local skeletal muscle and evaluate the capability of NIRS in the research of exercise physiology Twenty-three athlete in the national fin-swimming team took the increasing load training on the power bicycle while their {Delta}HbO{sub 2} and BLA were simultaneously recorded. The initial powers used in the training were set as 100 w for males and 40 w for females. During the experiment, the power kept constant for 3 min before each abrupt increment of 30 w until the limit of the athlete's capability. Statistical analysis and data visualization were performed. Following the increasing load training, {Delta}HbO{sub 2} step-likely increased in the phase of aerobic metabolism but linearly decreased in the phase of anaerobic metabolism. The variation tendency of BLA was the same as {Delta}HbO{sub 2} and the concurrency of crucial turning points between {Delta}HbO{sub 2} and BLA was revealed. This relationship between {Delta}HbO{sub 2} and BLA presented in the increasing load training suggested that {Delta}HbO{sub 2} might be capable for taking the place of the invasively measured parameter BLA. Considering that {Delta}HbO{sub 2} can be noninvasively measured by NIRS, {Delta}HbO{sub 2} has the potential in the evaluation of athletes' physiological function and training effect on the athletes and accordingly NIRS can be well used in this field.

  14. Relationship between muscle oxygenation by NIRS and blood lactate

    Science.gov (United States)

    Xu, Guodong; Mao, Zongzhen; Ye, Yanjie; Lv, Kunru

    2011-01-01

    The aim of the study was to investigate the relationship of muscle oxygenation in term of oxy-hemoglobin concentration change (ΔHbO2) by NIRS and blood lactate (BLA) in local skeletal muscle and evaluate the capability of NIRS in the research of exercise physiology Twenty-three athlete in the national fin-swimming team took the increasing load training on the power bicycle while their ΔHbO2 and BLA were simultaneously recorded. The initial powers used in the training were set as 100 w for males and 40 w for females. During the experiment, the power kept constant for 3 min before each abrupt increment of 30 w until the limit of the athlete's capability. Statistical analysis and data visualization were performed. Following the increasing load training, ΔHbO2 step-likely increased in the phase of aerobic metabolism but linearly decreased in the phase of anaerobic metabolism. The variation tendency of BLA was the same as ΔHbO2 and the concurrency of crucial turning points between ΔHbO2 and BLA was revealed. This relationship between ΔHbO2 and BLA presented in the increasing load training suggested that ΔHbO2 might be capable for taking the place of the invasively measured parameter BLA. Considering that ΔHbO2 can be noninvasively measured by NIRS, ΔHbO2 has the potential in the evaluation of athletes' physiological function and training effect on the athletes and accordingly NIRS can be well used in this field.

  15. Hypoxemia, oxygen content, and the regulation of cerebral blood flow

    Science.gov (United States)

    Bain, Anthony R.; Rieger, Mathew G.; Bailey, Damian M; Ainslie, Philip N.

    2015-01-01

    This review highlights the influence of oxygen (O2) availability on cerebral blood flow (CBF). Evidence for reductions in O2 content (CaO2) rather than arterial O2 tension (PaO2) as the chief regulator of cerebral vasodilation, with deoxyhemoglobin as the primary O2 sensor and upstream response effector, is discussed. We review in vitro and in vivo data to summarize the molecular mechanisms underpinning CBF responses during changes in CaO2. We surmise that 1) during hypoxemic hypoxia in healthy humans (e.g., conditions of acute and chronic exposure to normobaric and hypobaric hypoxia), elevations in CBF compensate for reductions in CaO2 and thus maintain cerebral O2 delivery; 2) evidence from studies implementing iso- and hypervolumic hemodilution, anemia, and polycythemia indicate that CaO2 has an independent influence on CBF; however, the increase in CBF does not fully compensate for the lower CaO2 during hemodilution, and delivery is reduced; and 3) the mechanisms underpinning CBF regulation during changes in O2 content are multifactorial, involving deoxyhemoglobin-mediated release of nitric oxide metabolites and ATP, deoxyhemoglobin nitrite reductase activity, and the downstream interplay of several vasoactive factors including adenosine and epoxyeicosatrienoic acids. The emerging picture supports the role of deoxyhemoglobin (associated with changes in CaO2) as the primary biological regulator of CBF. The mechanisms for vasodilation therefore appear more robust during hypoxemic hypoxia than during changes in CaO2 via hemodilution. Clinical implications (e.g., disorders associated with anemia and polycythemia) and future study directions are considered. PMID:26676248

  16. Technical complications during veno-venous extracorporeal membrane oxygenation and their relevance predicting a system-exchange--retrospective analysis of 265 cases.

    Directory of Open Access Journals (Sweden)

    Matthias Lubnow

    Full Text Available OBJECTIVES: Technical complications are a known hazard in veno-venous extracorporeal membrane oxygenation (vvECMO. Identifying these complications and predictive factors indicating a developing system-exchange was the goal of the study. METHODS: Retrospective study on prospectively collected data of technical complications including 265 adult patients (Regensburg ECMO Registry, 2009-2013 with acute respiratory failure treated with vvECMO. Alterations in blood flow resistance, gas transfer capability, hemolysis, coagulation and hemostasis parameters were evaluated in conjunction with a system-exchange in all patients with at least one exchange (n = 83. RESULTS: Values presented as median (interquartile range. Patient age was 50(36-60 years, the SOFA score 11(8-14.3 and the Murray lung injury Score 3.33(3.3-3.7. Cumulative ECMO support time 3411 days, 9(6-15 days per patient. Mechanical failure of the blood pump (n = 5, MO (n = 2 or cannula (n = 1 accounted for 10% of the exchanges. Acute clot formation within the pump head (visible clots, increase in plasma free hemoglobin (frHb, serum lactate dehydrogenase (LDH, n = 13 and MO (increase in pressure drop across the MO, n = 16 required an urgent system-exchange, of which nearly 50% could be foreseen by measuring the parameters mentioned below. Reasons for an elective system-exchange were worsening of gas transfer capability (n = 10 and device-related coagulation disorders (n = 32, either local fibrinolysis in the MO due to clot formation (increased D-dimers [DD], decreased platelet count; n = 24, or device-induced hyperfibrinolysis (increased DD, decreased fibrinogen [FG], decreased platelet count, diffuse bleeding tendency; n = 8, which could be reversed after system-exchange. Four MOs were exchanged due to suspicion of infection. CONCLUSIONS: The majority of ECMO system-exchanges could be predicted by regular inspection of the complete ECMO circuit, evaluation of gas exchange, pressure drop

  17. [Studying the influence of some reactive oxygen species on physical and chemical parameters of blood].

    Science.gov (United States)

    Martusevich, A K; Martusevich, A A; Solov'eva, A G; Peretyagin, S P

    2014-01-01

    The aim of this work was to estimate the dynamics of blood physical and chemical parameters when blood specimens were processed by singlet oxygen in vitro. Our experiments were executed with whole blood specimens of healthy people (n=10). Each specimen was divided into five separate portions of 5 ml. The first portion was a control (without any exposures). The second one was processed by an oxygen-ozone mixture (at ozone concentration of 500 mcg/l, the third portion--by oxygen, and the fourth and fifth ones were processed by a gas mixture with singlet oxygen (50 and 100% of generator power). In blood samples after processing we studied the activity of lactate dehydrogenase, aldehyde dehydrogenase and superoxide dismutase, erythrocyte and plasma levels of glucose and lactate, acid-base balance and the partial pressure of gases in blood. It was found out, that blood processing by singlet oxygen leads to optimization of energy, detoxication and antioxidant enzymes functioning with changes in plasma and erythrocyte level of glucose and lactate, normalization of blood gases level and acid-base balance. Our results show, that the effect of singlet oxygen on enzyme activity is more pronounced than exposure to an oxygen-ozone gas mixture.

  18. Does topical wound oxygen (TWO2) offer an improved outcome over conventional compression dressings (CCD) in the management of refractory venous ulcers (RVU)? A parallel observational comparative study.

    LENUS (Irish Health Repository)

    Tawfick, W

    2009-07-01

    Topical wound oxygen (TWO(2)) may help wound healing in the management of refractory venous ulcers (RVU). The aim of this study was to measure the effect of TWO(2) on wound healing using the primary end-point of the proportion of ulcers healed at 12 weeks. Secondary end-points were time to full healing, percentage of reduction in ulcer size, pain reduction, recurrence rates and Quality-Adjusted Time Spent Without Symptoms of disease and Toxicity of Treatment (Q-TWiST).

  19. 129 Xe chemical shift in human blood and pulmonary blood oxygenation measurement in humans using hyperpolarized 129 Xe NMR.

    Science.gov (United States)

    Norquay, Graham; Leung, General; Stewart, Neil J; Wolber, Jan; Wild, Jim M

    2017-04-01

    To evaluate the dependency of the 129 Xe-red blood cell (RBC) chemical shift on blood oxygenation, and to use this relation for noninvasive measurement of pulmonary blood oxygenation in vivo with hyperpolarized 129 Xe NMR. Hyperpolarized 129 Xe was equilibrated with blood samples of varying oxygenation in vitro, and NMR was performed at 1.5 T and 3 T. Dynamic in vivo NMR during breath hold apnea was performed at 3 T on two healthy volunteers following inhalation of hyperpolarized 129 Xe. The 129 Xe chemical shift in RBCs was found to increase nonlinearly with blood oxygenation at 1.5 T and 3 T. During breath hold apnea, the 129 Xe chemical shift in RBCs exhibited a periodic time modulation and showed a net decrease in chemical shift of ∼1 ppm over a 35 s breath hold, corresponding to a decrease of 7-10 % in RBC oxygenation. The 129 Xe-RBC signal amplitude showed a modulation with the same frequency as the 129 Xe-RBC chemical shift. The feasibility of using the 129 Xe-RBC chemical shift to measure pulmonary blood oxygenation in vivo has been demonstrated. Correlation between 129 Xe-RBC signal and 129 Xe-RBC chemical shift modulations in the lung warrants further investigation, with the aim to better quantify temporal blood oxygenation changes in the cardiopulmonary vascular circuit. Magn Reson Med 77:1399-1408, 2017. © 2016 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. © 2016 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine.

  20. 129Xe chemical shift in human blood and pulmonary blood oxygenation measurement in humans using hyperpolarized 129Xe NMR

    Science.gov (United States)

    Norquay, Graham; Leung, General; Stewart, Neil J.; Wolber, Jan

    2016-01-01

    Purpose To evaluate the dependency of the 129Xe‐red blood cell (RBC) chemical shift on blood oxygenation, and to use this relation for noninvasive measurement of pulmonary blood oxygenation in vivo with hyperpolarized 129Xe NMR. Methods Hyperpolarized 129Xe was equilibrated with blood samples of varying oxygenation in vitro, and NMR was performed at 1.5 T and 3 T. Dynamic in vivo NMR during breath hold apnea was performed at 3 T on two healthy volunteers following inhalation of hyperpolarized 129Xe. Results The 129Xe chemical shift in RBCs was found to increase nonlinearly with blood oxygenation at 1.5 T and 3 T. During breath hold apnea, the 129Xe chemical shift in RBCs exhibited a periodic time modulation and showed a net decrease in chemical shift of ∼1 ppm over a 35 s breath hold, corresponding to a decrease of 7–10 % in RBC oxygenation. The 129Xe‐RBC signal amplitude showed a modulation with the same frequency as the 129Xe‐RBC chemical shift. Conclusion The feasibility of using the 129Xe‐RBC chemical shift to measure pulmonary blood oxygenation in vivo has been demonstrated. Correlation between 129Xe‐RBC signal and 129Xe‐RBC chemical shift modulations in the lung warrants further investigation, with the aim to better quantify temporal blood oxygenation changes in the cardiopulmonary vascular circuit. Magn Reson Med 77:1399–1408, 2017. © 2016 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. PMID:27062652

  1. Tracer input for kinetic modelling of liver physiology determined without sampling portal venous blood in pigs

    Science.gov (United States)

    Winterdahl, Michael; Sørensen, Michael; Mortensen, Frank Viborg; Alstrup, Aage Kristian Olsen; Munk, Ole Lajord

    2010-01-01

    Purpose Quantification of hepatic tracer kinetics by PET requires measurement of tracer input from the hepatic artery (HA) and portal vein (PV). We wished to develop a method for estimating dual tracer input without the necessity to sample PV blood. Methods Pigs weighing 40 kg were given bolus doses of C15O (CO), 2-[18F]fluoro-2-deoxy-D-glucose (FDG), [11C]-methylglucose (MG), 2-[18F]fluoro-2-deoxy-D-galactose (FDGal) or H215O (H2O). Tracer concentration 3-min time courses were measured in the femoral artery and PV by blood sampling. Blood flow was measured in the HA and PV using flow-meters. A model for transfer of tracer through the splanchnic circulation was used to estimate values of a tracer-specific model parameter β. Tracer-specific mean values of β were used to estimate tracer concentration time courses in the PV from the measured arterial concentration. A model-derived dual-input was calculated using the mean HA flow fraction (0.25) and validated by comparison of the use of the measured dual-input and a kinetic model with a fixed ”true” K1true, i.e. clearance of tracer from blood to liver cells. Results The rank order of the means of β was CO tracer input, which is of great importance for the assessment of processes such as transfer across the plasma-hepatocyte membrane or hepatic blood perfusion, can be well approximated in pigs without the necessity to sample PV blood and measure hepatic blood flow; only arterial blood sampling is needed. PMID:20882283

  2. Cerebral blood flow decreases with time whereas cerebral oxygen consumption remains stable during hypothermic cardiopulmonary bypass in humans

    Energy Technology Data Exchange (ETDEWEB)

    Prough, D.S.; Rogers, A.T.; Stump, D.A.; Roy, R.C.; Cordell, A.R.; Phipps, J.; Taylor, C.L. (Wake Forest Univ., Winston-Salem, NC (USA))

    1991-02-01

    Recent investigations demonstrate that cerebral blood flow (CBF) progressively declines during hypothermic, nonpulsatile cardiopulmonary bypass (CPB). If CBF declines because of brain cooling, the cerebral metabolic rate for oxygen (CMRO2) should decline in parallel with the reduction in CBF. Therefore we studied the response of CBF, the cerebral arteriovenous oxygen content difference (A-VDcereO2) and CMRO2 as a function of the duration of CPB in humans. To do this, we compared the cerebrovascular response to changes in the PaCO2. Because sequential CBF measurements using xenon 133 (133Xe) clearance must be separated by 15-25 min, we hypothesized that a time-dependent decline in CBF would accentuate the CBF reduction caused by a decrease in PaCO2, but would blunt the CBF increase associated with a rise in PaCO2. We measured CBF in 25 patients and calculated the cerebral arteriovenous oxygen content difference using radial arterial and jugular venous bulb blood samples. Patients were randomly assigned to management within either a lower (32-48 mm Hg) or higher (50-71 mm Hg) range of PaCO2 uncorrected for temperature. Each patient underwent two randomly ordered sets of measurements, one at a lower PaCO2 and the other at a higher PaCO2 within the respective ranges. Cerebrovascular responsiveness to changes in PaCO2 was calculated as specific reactivity (SR), the change in CBF divided by the change in PaCO2, expressed in mL.100 g-1.min-1.mm Hg-1.

  3. High spatial resolution magnetic resonance imaging of experimental cerebral venous thrombosis with a blood pool contrast agent.

    Science.gov (United States)

    Spuentrup, E; Wiethoff, A J; Parsons, E C; Spangenberg, P; Stracke, C P

    2010-06-01

    The purpose of this study was to investigate the feasibility of clot visualization in small sinus and cortical veins with contrast enhanced MRA in a cerebral venous thrombosis animal model using a blood pool contrast agent, Gadofosveset, and high spatial resolution imaging. For induction of cerebral venous thrombosis a recently developed combined interventional and microsurgical model was used. Cerebral sinus and cortical vein thrombosis was induced in six pigs. Two further pigs died during the procedure. Standard structural, time-of-flight- and phase contrast-angiograms were followed by fast time resolved high resolution 3D MRA (4D MRA) and subsequent high spatial resolution 3D MRA in the equilibrium phase with and without addition of parallel imaging. Visualization of the clots using the different sequences was subjectively compared and contrast-to-noise ratio (CNR) was assessed. In the remaining six animals the procedure and MR-imaging protocol including administration of Gadofosveset was successfully completed. The 3D high resolution MRA in the equilibrium phase without the addition of parallel imaging was superior to all the other applied MR measurement techniques in terms of visualization of the clots. Only applying this sequence bridging vein thromboses were also seen as a small filling defect with a high CNR of >18. Only the non-accelerated high spatial resolution 3D MRA in the equilibrium in conjunction with the blood pool agent Gadofosveset allows for high-contrast visualization of very small clots in the cerebral sinus and cortical veins. STATEMENT CLINICAL IMPACT: Detection of cortical vein thrombosis is of high clinical impact. Conventional MRI sequences often fail to visualize the clot. We could demonstrate that, in contrast to conventional sequences, with high spatial resolution 3D MRA in the equilibrium in conjunction with the blood pool agent Gadofosveset very small clots in the cerebral sinus and cortical veins could be successfully visualized. We

  4. Gas exchange efficiency of an oxygenator with integrated pulsatile displacement blood pump for neonatal patients.

    Science.gov (United States)

    Schlanstein, Peter C; Borchardt, Ralf; Mager, Ilona; Schmitz-Rode, Thomas; Steinseifer, Ulrich; Arens, Jutta

    2014-01-01

    Oxygenators have been used in neonatal extracorporeal membrane oxygenation (ECMO) since the 1970s. The need to develop a more effective oxygenator for this patient cohort exists due to their size and blood volume limitations. This study sought to validate the next design iteration of a novel oxygenator for neonatal ECMO with an integrated pulsatile displacement pump, thereby superseding an additional blood pump. Pulsating blood flow within the oxygenator is generated by synchronized active air flow expansion and contraction of integrated silicone pump tubes and hose pinching valves located at the oxygenator inlet and outlet. The current redesign improved upon previous prototypes by optimizing silicone pump tube distribution within the oxygenator fiber bundle; introduction of an oval shaped inner fiber bundle core, and housing; and a higher fiber packing density, all of which in combination reduced the priming volume by about 50% (50 to 27 mL and 41 to 20 mL, respectively). Gas exchange efficiency was tested for two new oxygenators manufactured with different fiber materials: one with coating and one with smaller pore size, both capable of long-term use (OXYPLUS® and CELGARD®). Results demonstrated that the oxygen transfer for both oxygenators was 5.3-24.7 mlO2/min for blood flow ranges of 100-500 mlblood/min. Carbon dioxide transfer for both oxygenators was 3.7-26.3 mlCO2/min for the same blood flow range. These preliminary results validated the oxygenator redesign by demonstrating an increase in packing density and thus in gas transfer, an increase in pumping capacity and a reduction in priming volume.

  5. Veno-venous extracorporeal membrane oxygenation using an innovative dual-lumen cannula following implantation of a total artificial heart.

    Science.gov (United States)

    Youdle, Jemma; Penn, Sarah; Maunz, Olaf; Simon, Andre

    2017-01-01

    We report our first clinical use of the new Protek Duo TM cannula for peripheral veno-venous extra-corporeal life support (ECLS). A 53-year-old male patient underwent implantation of a total artificial heart (TAH) for biventricular failure. However, due to the development of post-operative respiratory dysfunction, the patient required ECLS for six days.

  6. Red blood cell transfusions and tissue oxygenation in anemic hematology outpatients

    NARCIS (Netherlands)

    Yuruk, Koray; Bartels, Sebastiaan A.; Milstein, Dan M. J.; Bezemer, Rick; Biemond, Bart J.; Ince, Can

    2012-01-01

    BACKGROUND: There is little clinical evidence that red blood cell (RBC) transfusions improve oxygen availability at the microcirculatory level. We tested the hypotheses that anemia in chronically anemic patients with relatively healthy microcirculation would be associated with low tissue hemoglobin

  7. The Cumulative Influence of Hyperoxia and Hypercapnia on Blood Oxygenation and R2

    NARCIS (Netherlands)

    Faraco, Carlos C.; Strother, Megan K.; Siero, JCW; Arteaga, Daniel F.; Scott, Allison O.; Jordan, Lori C.; Donahue, Manus J.

    2015-01-01

    Cerebrovascular reactivity (CVR)-weighted blood-oxygenation-level-dependent magnetic resonance imaging (BOLD-MRI) experiments are frequently used in conjunction with hyperoxia. Owing to complex interactions between hyperoxia and hypercapnia, quantitative effects of these gas mixtures on BOLD

  8. Membrane oxygenator heat exchanger failure detected by unique blood gas findings

    National Research Council Canada - National Science Library

    Hawkins, Justin L

    2014-01-01

    .... One of these components is the heat exchanger of the membrane oxygenator. In this compartment, unsterile water from the heater cooler device is separated from the sterile blood by stainless steel, aluminum, or by polyurethane...

  9. Effect of blood transfusion on intestinal blood flow and oxygenation in extremely preterm infants during first week of life.

    Science.gov (United States)

    Banerjee, Jayanta; Leung, Terence S; Aladangady, Narendra

    2016-04-01

    Extremely preterm infants receive frequent blood transfusions in the first week of life. The aim of this study was to measure the effect of blood transfusion on intestinal blood flow and oxygenation during the first week of life in extremely preterm infants. Superior mesenteric artery (SMA) peak systolic velocity (PSV) and diastolic velocities were measured 30 to 60 minutes before and after transfusion. Splanchnic tissue hemoglobin index (sTHI), splanchnic tissue oxygenation index (sTOI), and splanchnic fractional tissue oxygen extraction (sFTOE) were measured continuously from 15 to 20 minutes before to after transfusion along with vital variables. Twenty infants were studied (median gestational age, 26 weeks). Ten infants were partially fed (15-68 mL/kg/day). Heart rate and SaO2 remained unaltered; blood pressure increased significantly (p transfusion. Mean SMA PSV (p = 0.63) and diastolic velocity (p = 0.65) remained unaltered. Mean pretransfusion SMA PSV was similar in partially fed (0.78 m/sec) compared to unfed infants (0.52 m/sec; p = 0.06) and the response to transfusion was not dissimilar. There was a significant increase in sTHI (mean difference, 32.3%; p transfusion. There was no significant difference in sTHI or sTOI between fed and unfed infants and their response to transfusion. Blood transfusion increased blood pressure and intestinal tissue oxygenation but did not alter blood flow velocities. Partial feeding had no impact on intestinal blood flow and tissue oxygenation changes. © 2015 AABB.

  10. Successful microsurgical lip replantation: Monitoring venous congestion by blood glucose measurements in the replanted lip

    Directory of Open Access Journals (Sweden)

    Kazufumi Tachi

    2018-03-01

    Full Text Available Replantation of an amputated lip using microvascular anastomosis is the best option for restoration of the defect. However, the amputated region often lacks veins with appropriate diameters for microvascular anastomoses and typically necessitates both postoperative exsanguination using medicinal leeches and a blood transfusion. We present a case of the successful replantation of an avulsed lip in which postoperative congestion was evaluated objectively by measuring blood glucose levels in the replanted region. The patient presented to our hospital with an upper lip avulsion that was caused by a dog bite. The lip was replanted by the microvascular anastomoses of one artery and two veins using interposed vein grafts. The replanted lip showed signs of congestion on postoperative day one; exsanguination using medicinal leeches was attempted, while blood glucose levels were measured every three hours. Critical congestion, which did not occur in this patient, was defined as a blood glucose level lower than 40 mg/dL. Lip replantation was successful without any complications in this patient.

  11. Non-invasive estimation of cerebrospinal fluid pressure waveforms by means of retinal venous pulsatility and central aortic blood pressure.

    Science.gov (United States)

    Golzan, S Mojtaba; Kim, Mi Ok; Seddighi, Amir Saied; Avolio, Alberto; Graham, Stuart L

    2012-09-01

    Current techniques used for cerebrospinal fluid pressure (CSFp) measurements are invasive. They require a surgical procedure for placement of a pressure catheter in the brain ventricles or in the brain tissue. The human eye provides direct visualisation of its physiological structures and due to its anatomical connection with CSF via the retrolaminar optic nerve it may provide accessible information about CSFp. A total of 25 subjects were included in this study. 15 subjects were used to characterise the relationship between intraocular pressure (IOP), spontaneous retinal venous pulsatility (SRVP), and CSFp. IOP was manipulated and SRVP amplitudes recorded dynamically using the dynamic vessel analyzer (DVA). The relationship between IOP and SRVP amplitude was established to estimate CSFp. Additionally Doppler blood flow velocity of the middle cerebral artery and arterial blood pressure (ABP) were acquired for all subjects. This was to compare and validate our findings with an alternative approach (ICM+) which uses these values to estimate CSFp. A CSFp waveform was extracted from central blood pressure (CBP) waveform by removing its cardiac component frequency. Furthermore to calibrate the CSFp to CBP waveform ratio, invasive CSFp, and ABP was measured from 10 subjects with brain tumours who had a range of normal to elevated CSFp (i.e., 0-30 mmHg). Results show good agreement between the two methods (correlation r (2) = 0.55) Mean estimated CSFp for the two techniques did not show any significant difference (p > 0.05). A significant correlation between CBP pulse (CBPp) and invasive CSFp pulse (CSFpp) was observed (i.e., CSFpp = 0.0654CBBp + 3.91, p invasively and may provide a novel method to estimate CSF waveforms non-invasively.

  12. An H-infinity approach to optimal control of oxygen and carbon dioxide contents in blood

    Science.gov (United States)

    Rigatos, Gerasimos; Siano, Pierluigi; Selisteanu, Dan; Precup, Radu

    2016-12-01

    Nonlinear H-infinity control is proposed for the regulation of the levels of oxygen and carbon dioxide in the blood of patients undergoing heart surgery and extracorporeal blood circulation. The levels of blood gases are administered through a membrane oxygenator and the control inputs are the externally supplied oxygen, the aggregate gas supply (oxygen plus nitrogen), and the blood flow which is regulated by a blood pump. The proposed control method is based on linearization of the oxygenator's dynamical model through Taylor series expansion and the computation of Jacobian matrices. The local linearization points are defined by the present value of the oxygenator's state vector and the last value of the control input that was exerted on this system. The modelling errors due to linearization are considered as disturbances which are compensated by the robustness of the control loop. Next, for the linearized model of the oxygenator an H-infinity control input is computed at each iteration of the control algorithm through the solution of an algebraic Riccati equation. With the use of Lyapunov stability analysis it is demonstrated that the control scheme satisfies the H-infinity tracking performance criterion, which signifies improved robustness against modelling uncertainty and external disturbances. Moreover, under moderate conditions the asymptotic stability of the control loop is also proven.

  13. Retinal hemodynamic oxygen reactivity assessed by perfusion velocity, blood oximetry and vessel diameter measurements

    DEFF Research Database (Denmark)

    Klefter, Oliver Niels; Lauritsen, Anne Øberg; Larsen, Michael

    2015-01-01

    PURPOSE: To test the oxygen reactivity of a fundus photographic method of measuring macular perfusion velocity and to integrate macular perfusion velocities with measurements of retinal vessel diameters and blood oxygen saturation. METHODS: Sixteen eyes in 16 healthy volunteers were studied at two...... measurements may provide comprehensive information about retinal metabolism....

  14. Cerebral tissue oxygen saturation and extraction in preterm infants before and after blood transfusion

    NARCIS (Netherlands)

    van Hoften, Jacorina C. R.; Verhagen, Elise A.; Keating, Paul; ter Horst, Hendrik J.; Bos, Arend F.

    Objective Preterm infants often need red blood cell (RBC) transfusions. The aim of this study was to determine whether haemoglobin levels before transfusion were associated with regional cerebral tissue oxygen saturation (r(c)SO(2)) and fractional tissue oxygen extraction (FTOE) and whether RBC

  15. Clinicopathologic analysis of Passeriform venous blood reflects transitions in elevation and habitat

    OpenAIRE

    Heatley JJ; Cary J; Russell KE; Voelker G

    2013-01-01

    J Jill Heatley,1 Jennifer Cary,2 Karen E Russell,3 Gary Voelker2 1Department of Small Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, 2Department of Wildlife and Fisheries Sciences and Texas A&M Biodiversity Research and Teaching Collections, Texas A&M University, 3Department of Pathobiology, College of Veterinary Medicine and Biomedical Sciences, College Station, TX, USA Abstract: Jugular blood samples from 110 Passeriformes collected at sev...

  16. Monitoring of Tissue Oxygenation: an Everyday Clinical Challenge

    Directory of Open Access Journals (Sweden)

    Zsolt Molnar

    2018-01-01

    Full Text Available Purpose of reviewThe aim of this article is to study the overview of pathophysiology and clinical application of central venous oxygen saturation monitoring in critically ill patients and during the perioperative period.Recent findingsThere are several clinical studies and animal experiments evaluating the effects of goal-directed hemodynamic stabilization on critically ill patients. Recent systematic reviews and meta-analyses found that advanced hemodynamic endpoints-targeted management has a positive effect on outcome in high-risk surgical patients. As all interventions aim to improve tissue oxygenation, it is of utmost importance to monitor the balance between oxygen delivery and consumption. For this purpose, central venous blood gas analysis provides an easily available tool in the everyday clinical practice. The adequate interpretation of central venous oxygen saturation renders the need of careful evaluation of several physiological and pathophysiological circumstances. When appropriately evaluated, central venous oxygen saturation can be a valuable component of a multimodal individualized approach, in which components of oxygen delivery are put in the context of the patients’ individual oxygen consumption. In addition to guide therapy, central venous oxygen saturation may also serve as an early warning sign of inadequate oxygen delivery, which would otherwise remain hidden from the attending physician.SummaryWith the incorporation of central venous oxygen saturation in the everyday clinical routine, treatment could be better tailored for the patients’ actual needs; hence, it may also improve outcome.

  17. Whole-Body Vibration and Blood Flow and Muscle Oxygenation: A Meta-Analysis

    Science.gov (United States)

    Games, Kenneth E.; Sefton, JoEllen M.; Wilson, Alan E.

    2015-01-01

    Context: The use and popularity of whole-body vibration (WBV) has increased in recent years, but there is a lack of consensus in the literature about the effectiveness of the treatment. Objective: To quantitatively examine the effects of WBV on muscle oxygenation and peripheral blood flow in healthy adults. Data Sources: We searched Web of Science and PubMed databases and reference lists from relevant articles using the key terms whole body vibration, whole-body vibration, WBV, blood flow, peripheral blood flow, oxygenation, muscle oxygenation, circulation, circulatory, near infrared spectroscopy, NIRS, and power Doppler. Key terms were searched using single word and combination searches. No date range was specified. Study Selection: Criteria for inclusion were (1) use of a commercially available WBV device, (2) a human research model, (3) a pre-WBV condition and at least 1 WBV experimental condition, and (4) reporting of unstandardized means and standard deviations of muscle oxygenation or peripheral blood flow. Data Extraction: Means, standard deviations, and sample sizes were extracted from the text, tables, and figures of included studies. A total of 35 and 90 data points were extracted for the muscle-oxygenation and blood-flow meta-analyses, respectively. Data for each meta-analysis were combined and analyzed using meta-analysis software. Weighted, random-effects meta-analyses using the Hedges g metric were completed for muscle oxygenation and blood flow. We then conducted follow-up analyses using the moderator variables of vibration type, vibration time, vibration frequency, measurement location, and sample type. Data Synthesis: We found 18 potential articles. Further examination yielded 10 studies meeting the inclusion criteria. Whole-body vibration was shown to positively influence peripheral blood flow. Additionally, the moderators of vibration type and frequency altered the influence of WBV on blood flow. Overall, WBV did not alter muscle oxygenation

  18. Whole-body vibration and blood flow and muscle oxygenation: a meta-analysis.

    Science.gov (United States)

    Games, Kenneth E; Sefton, JoEllen M; Wilson, Alan E

    2015-05-01

    The use and popularity of whole-body vibration (WBV) has increased in recent years, but there is a lack of consensus in the literature about the effectiveness of the treatment. To quantitatively examine the effects of WBV on muscle oxygenation and peripheral blood flow in healthy adults. We searched Web of Science and PubMed databases and reference lists from relevant articles using the key terms whole body vibration, whole-body vibration, WBV, blood flow, peripheral blood flow, oxygenation, muscle oxygenation, circulation, circulatory, near infrared spectroscopy, NIRS, and power Doppler. Key terms were searched using single word and combination searches. No date range was specified. Criteria for inclusion were (1) use of a commercially available WBV device, (2) a human research model, (3) a pre-WBV condition and at least 1 WBV experimental condition, and (4) reporting of unstandardized means and standard deviations of muscle oxygenation or peripheral blood flow. Means, standard deviations, and sample sizes were extracted from the text, tables, and figures of included studies. A total of 35 and 90 data points were extracted for the muscle-oxygenation and blood-flow meta-analyses, respectively. Data for each meta-analysis were combined and analyzed using meta-analysis software. Weighted, random-effects meta-analyses using the Hedges g metric were completed for muscle oxygenation and blood flow. We then conducted follow-up analyses using the moderator variables of vibration type, vibration time, vibration frequency, measurement location, and sample type. We found 18 potential articles. Further examination yielded 10 studies meeting the inclusion criteria. Whole-body vibration was shown to positively influence peripheral blood flow. Additionally, the moderators of vibration type and frequency altered the influence of WBV on blood flow. Overall, WBV did not alter muscle oxygenation; however, when the measurement site was considered, muscle oxygenation increased or

  19. Hepatic encephalopathy is associated with decreased cerebral oxygen metabolism and blood flow, not increased ammonia uptake

    DEFF Research Database (Denmark)

    Dam, Gitte; Keiding, Susanne; Munk, Ole Lajord

    2013-01-01

    Studies have shown decreased cerebral oxygen metabolism (CMRO(2)) and blood flow (CBF) in patients with cirrhosis with hepatic encephalopathy (HE). It remains unclear, however, whether these disturbances are associated with HE or with cirrhosis itself and how they may relate to arterial blood amm...

  20. The increase in the cardiodepressant activity and vasopressin concentration in the sella turcica venous blood during vagal afferents stimulation or after angiotensin II infusion

    Energy Technology Data Exchange (ETDEWEB)

    Goraca, A.; Orlowska-Majdak, M.; Traczyk, W.Z. [Akademia Medyczna, Lodz (Poland). Katedra Fizjologii

    1996-12-31

    It has previously been demonstrated that the cardiodepressant activity is present in the bovine hypothalamic extract and in the fluid incubating the posterior pituitary lobe {sup i}n situ{sup .} The present study was an attempt to reveal if the cardiodepressant factor and vasopressin were simultaneously released from the pituitary into blood. The samples of venous blood flowing from the sella turcica and, for comparison, from the posterior paw were collected in anesthetized rats. Blood from the sella turcica was collected with a fine cannula inserted into the internal maxillary vein. The concentration of vasopressin in blood plasma was determined by radioimmunoassay and cardiodepressant activity-using a biological test on a spontaneously discharged pacemaker tissue of the right auricle of the right heart atrium. Stimulation of the central ends of the cut vagus nerves or intra-arterial infusion of angiotensin II simultaneously caused an increase in the cardiodepressant activity and vasopressin concentration in the sella turcica venous blood. The cardiodepressant activity and vasopressin concentration was also enhanced to some degree in blood outflowing from the posterior paw. Present results indicate that both vasopressin and the cardiodepressant factor are released into blood from the posterior pituitary lobe. (author). 37 refs, 4 figs.

  1. Effects of normovolaemic haemodilution on middle cerebral artery blood flow velocity and oxygen delivery.

    Science.gov (United States)

    Karadibak, K; Gökmen, N; Erbayraktar, S; Göktay, Y; Taplu, A; Arkan, A; Erkan, N

    2002-05-01

    Assessment of the effects of normovolaemic haemodilution on middle cerebral artery blood flow velocity with transcranial Doppler ultrasonography, intracranial pressure, cerebral perfusion pressure, arterial oxygen content and cerebral oxygen delivery. Normovolaemic haemodilution was induced in rabbits under general anaesthesia, and the haematocrit was allowed to decrease to 30% in Group 1 (n = 6) and to 20% in Group 2 (n = 6). Peak systolic and diastolic velocities, mean blood flow velocity, and pulsatility and resistance indices of the middle cerebral artery were measured by transcranial Doppler ultrasonography. Changes in intracranial pressure, cerebral perfusion pressure, arterial oxygen content and cerebral oxygen delivery were also assessed. In Group 2, middle cerebral artery blood flow velocity increased from 0.4 +/- 0.01 to 0.51 +/- 0.02 m s(-1) after the induction of normovolaemic haemodilution (P = 0.04), while arterial oxygen content decreased from 16.2 +/- 0.1 to 8.5 +/- 0.1 mLdL(-1) (P = 0.002). The decrease in cerebral oxygen delivery from 6.5 +/- 0.2 to 4.3 +/- 0.2 was also significant (P = 0.02). However, no associated changes in intracranial pressure and cerebral perfusion pressure could be demonstrated. Normovolaemic haemodilution resulted in an increase in the mean blood flow velocity of the middle cerebral artery. However, this increase did not compensate for the consequences of the altered oxygen delivery to the brain when the haematocrit was reduced to 20%.

  2. Prolonged cold storage of red blood cells by oxygen removal and additive usage

    Energy Technology Data Exchange (ETDEWEB)

    Bitensky, Mark W. (Boston, MA); Yoshida, Tatsuro (Newton, MA)

    1998-01-01

    Prolonged cold storage of red blood cells by oxygen removal and additive usage. A cost-effective, 4.degree. C. storage procedure that preserves red cell quality and prolongs post-transfusion in vivo survival is described. The improved in vivo survival and the preservation of adenosine triphosphate levels, along with reduction in hemolysis and membrane vesicle production of red blood cells stored at 4.degree. C. for prolonged periods of time, is achieved by reducing the oxygen level therein at the time of storage; in particular, by flushing the cells with an inert gas, and storing them in an aqueous solution which includes adenine, dextrose, mannitol, citrate ion, and dihydrogen phosphate ion, but no sodium chloride, in an oxygen-permeable container which is located in an oxygen-free environment containing oxygen-scavenging materials.

  3. Prolonged cold storage of red blood cells by oxygen removal and additive usage

    Energy Technology Data Exchange (ETDEWEB)

    Bitensky, M.W.; Yoshida, Tatsuro

    1998-08-04

    Prolonged cold storage of red blood cells by oxygen removal and additive usage. A cost-effective, 4 C storage procedure that preserves red cell quality and prolongs post-transfusion in vivo survival is described. The improved in vivo survival and the preservation of adenosine triphosphate levels, along with reduction in hemolysis and membrane vesicle production of red blood cells stored at 4 C for prolonged periods of time, is achieved by reducing the oxygen level therein at the time of storage; in particular, by flushing the cells with an inert gas, and storing them in an aqueous solution which includes adenine, dextrose, mannitol, citrate ion, and dihydrogen phosphate ion, but no sodium chloride, in an oxygen-permeable container which is located in an oxygen-free environment containing oxygen-scavenging materials. 8 figs.

  4. Study of the FMRI blood oxygen level dependent effect by near-infrared spectroscopy

    Science.gov (United States)

    Toronov, Vladislav; Webb, Andrew; Walker, Scott; Gupta, Rajarsi; Choi, Jee H.; Gratton, Enrico; Hueber, Dennis M.

    2003-10-01

    In order to study the behavior of cerebral physiological parameters and to further the understanding of the fMRI blood-oxygen-level-dependent (BOLD) effect, we have recorded simultaneously multi-source frequency-domain near-infrared and BOLD fMRI signals during motor functional activation in humans. From the near-infrared data we obtained information on the changes in cerebral blood volume and oxygenation. In order to relate our observations to changes in cerebral blood flow we employed the "balloon" model of cerebral perfusion. Our data showed that the deoxyhemoglobin concentration is the major factor determining the time course of the BOLD signal.

  5. The effects of venous cannulation technique and cardioplegia type on plasma potassium concentration and arterial blood pressure during cardiopulmonary bypass.

    LENUS (Irish Health Repository)

    Coleman, E T

    2012-02-03

    The cannulation method and cardioplegia solution used during cardiopulmonary bypass (CPB) may both influence plasma potassium concentrations ([K+]) and mean arterial blood pressure (MAP). Bi-caval or right atrial cannulation methods are routinely used in conjunction with crystalloid or blood cardioplegia. We investigated the influence of cannulation method and cardioplegia solutions on plasma [K+] and MAP during cardiopulmonary bypass. Sixty consecutive patients undergoing elective coronary artery bypass grafting (CABG) using CPB were studied. They were randomly divided into three groups of 20 patients. Patients in Group A underwent bi-caval venous cannulation and received crystalloid cardioplegia. Group B patients underwent right atrial cannulation and received crystalloid cardioplegia. Group C patients underwent right atrial cannulation and received blood cardioplegia. In each case. cardioplegia was administered antegrade via the aortic root. Plasma [K+], MAP. and hemoglobin concentration (Hb) were measured over an 8-min period following cardioplegia administration (pilot studies indicated pressure changes occuring post cardioplegia administration up to this time). The combination of bi-caval cannulation and crystalloid cardioplegia (Group A) was associated with the least increase in plasma [K+] and no decrease in MAP. The maximum [K+] for this Group was 4.2 mmol\\/L (4.6% increase). The minimum mean pressure was 57 mmHg (13.6% increase). Both right atrial cannulation groups (B and C) showed a large rise in plasma [K+] and a decrease in MAP. Group B maximum [K+] was 5.2 mmol\\/L (27.5% increase). Group C was also 5.2 mmol\\/L (26.0% increase). Group C showed the largest pressure decrease, the minimum mean pressure was 45 mmHg (21.3% decrease). The Group B minimum mean pressure was 45 mmHg (8.7% decrease). Our results show that patients undergoing CPB operations who are deemed to be at increased risk of suffering adverse effects from hypotensive episodes may

  6. Influence of intranasal and carotid cooling on cerebral temperature balance and oxygenation

    DEFF Research Database (Denmark)

    Nybo, Lars; Wanscher, Michael; Secher, Niels H.

    2014-01-01

    The present study evaluated the influence of intranasal cooling with balloon catheters, increased nasal ventilation, or percutaneous cooling of the carotid arteries on cerebral temperature balance and oxygenation in six healthy male subjects. Aortic arch and internal jugular venous blood temperat......The present study evaluated the influence of intranasal cooling with balloon catheters, increased nasal ventilation, or percutaneous cooling of the carotid arteries on cerebral temperature balance and oxygenation in six healthy male subjects. Aortic arch and internal jugular venous blood...

  7. Cerebral oxygen extraction, oxygen consumption, and regional cerebral blood flow during the aura phase of migraine

    DEFF Research Database (Denmark)

    Friberg, L; Olesen, Jes; Lassen, N A

    1994-01-01

    The aura phase of migraine is associated with focal blood flow changes, but it has been largely unknown whether these changes are correlated to changes in the cerebral metabolism.......The aura phase of migraine is associated with focal blood flow changes, but it has been largely unknown whether these changes are correlated to changes in the cerebral metabolism....

  8. Oxygen radical-scavenging capacities of peptides from swine blood ...

    African Journals Online (AJOL)

    In China, about five hundred million swine are slaughtered yearly, which represents about 45% of the world´s production. Swine blood is generally discarded except for the small amount that is used in soybean curd and other food products. This not only wastes resources, but also contaminates the environment. In this study ...

  9. Oxygen radical-scavenging capacities of peptides from swine blood

    African Journals Online (AJOL)

    USER

    2010-08-02

    Aug 2, 2010 ... process of the organism and may induce cancer, inflammation, and cardiovascular disease (Gutteridge. 1994 and Tabatabaie et al. 2003). Oxidative ... E-mail: fangjun1973@yahoo.com.cn. Abbreviations: PSB, Peptides of swine blood; DM, diabetes mellitus; BHA, butylated hydroxyanisole; BHT, butylated.

  10. Venous or arterial blood components trigger more brain swelling, tissue death after acute subdural hematoma compared to elderly atrophic brain with subdural effusion (SDE) model rats.

    Science.gov (United States)

    Wajima, Daisuke; Sato, Fumiya; Kawamura, Kenya; Sugiura, Keisuke; Nakagawa, Ichiro; Motoyama, Yasushi; Park, Young-Soo; Nakase, Hiroyuki

    2017-09-01

    Acute subdural hematoma (ASDH) is a frequent complication of severe head injury, whose secondary ischemic lesions are often responsible for the severity of the disease. We focused on the differences of secondary ischemic lesions caused by the components, 0.4ml venous- or arterial-blood, or saline, infused in the subdural space, evaluating the differences in vivo model, using rats. The saline infused rats are made for elderly atrophic brain with subdural effusion (SDE) model. Our data showed that subdural blood, both venous- and arterial-blood, aggravate brain edema and lesion development more than SDE. This study is the first study, in which different fluids in rats' subdural space, ASDH or SDE are compared with the extension of early and delayed brain damage by measuring brain edema and histological lesion volume. Blood constituents started to affect the degree of ischemia underneath the subdural hemorrhage, leading to more pronounced breakdown of the blood-brain barrier and brain damage. This indicates that further strategies to treat blood-dependent effects more efficiently are in view for patients with ASDH. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Red blood cells in sports: effects of exercise and training on oxygen supply by red blood cells.

    Science.gov (United States)

    Mairbäurl, Heimo

    2013-01-01

    During exercise the cardiovascular system has to warrant substrate supply to working muscle. The main function of red blood cells in exercise is the transport of O2 from the lungs to the tissues and the delivery of metabolically produced CO2 to the lungs for expiration. Hemoglobin also contributes to the blood's buffering capacity, and ATP and NO release from red blood cells contributes to vasodilation and improved blood flow to working muscle. These functions require adequate amounts of red blood cells in circulation. Trained athletes, particularly in endurance sports, have a decreased hematocrit, which is sometimes called "sports anemia." This is not anemia in a clinical sense, because athletes have in fact an increased total mass of red blood cells and hemoglobin in circulation relative to sedentary individuals. The slight decrease in hematocrit by training is brought about by an increased plasma volume (PV). The mechanisms that increase total red blood cell mass by training are not understood fully. Despite stimulated erythropoiesis, exercise can decrease the red blood cell mass by intravascular hemolysis mainly of senescent red blood cells, which is caused by mechanical rupture when red blood cells pass through capillaries in contracting muscles, and by compression of red cells e.g., in foot soles during running or in hand palms in weightlifters. Together, these adjustments cause a decrease in the average age of the population of circulating red blood cells in trained athletes. These younger red cells are characterized by improved oxygen release and deformability, both of which also improve tissue oxygen supply during exercise.

  12. Image-guided optical measurement of blood oxygen saturation within capillary vessels (Conference Presentation)

    Science.gov (United States)

    Akons, Kfir; Zeidan, Adel; Yeheskely-Hayon, Daniella; Minai, Limor; Yelin, Dvir

    2016-03-01

    Values of blood oxygenation levels are useful for assessing heart and lung conditions, and are frequently monitored during routine patient care. Independent measurement of the oxygen saturation in capillary blood, which is significantly different from that of arterial blood, is important for diagnosing tissue hypoxia and for increasing the accuracy of existing techniques that measure arterial oxygen saturation. Here, we developed a simple, non-invasive technique for measuring the reflected spectra from individual capillary vessels within a human lip, allowing local measurement of the blood oxygen saturation. The optical setup includes a spatially incoherent broadband light that was focused onto a specific vessel below the lip surface. Backscattered light was imaged by a camera for identifying a target vessel and pointing the illumination beam to its cross section. Scattered light from the vessel was then collected by a single-mode fiber and analyzed by a fast spectrometer. Spectra acquired from small capillary vessels within a volunteer lip showed the characteristic oxyhemoglobin absorption bands in real time and with a high signal-to-noise ratio. Measuring capillary oxygen saturation using this technique would potentially be more accurate compared to existing pulse oximetry techniques due to its insensitivity to the patient's skin color, pulse rate, motion, and medical condition. It could be used as a standalone endoscopic technique for measuring tissue hypoxia or in conjunction with conventional pulse oximetry for a more accurate measurement of oxygen transport in the body.

  13. Multi-modal in vivo imaging of brain blood oxygenation, blood flow and neural calcium dynamics during acute seizures

    Science.gov (United States)

    Ringuette, Dene; Jeffrey, Melanie A.; Carlen, Peter L.; Levi, Ofer

    2016-03-01

    Dysfunction of the vascular endothelium has been implicated in the development of epilepsy. To better understand the relation between vascular function and seizure and provide a foundation for interpreting results from functional imaging in chronic disease models, we investigate the relationship between intracellular calcium dynamics and local cerebral blood flow and blood oxygen saturation during acute seizure-like events and pharmacological seizure rescue. To probe the relation between the aforementioned physiological markers in an acute model of epilepsy in rats, we integrated three different optical modalities together with electrophysiological recordings: Laser speckle contrast imaging (LSCI) was used to study changes in flow speeds, Intrinsic optical signal imaging (IOSI) was used to monitor changes in oxygenated, de-oxygenated, and total hemoglobin concentration, and Calcium-sensitive dye imaging was used to monitor intracellular calcium dynamics. We designed a dedicated cortical flow chamber to remove superficial blood and dye resulting from the injection procedure, which reduced spurious artifacts. The near infrared light used for IOSI and LSCI was delivered via a light pipe integrated with the flow chamber to minimize the effect of fluid surface movement on illumination stability. Calcium-sensitive dye was injected via a glass electrode used for recording the local field potential. Our system allowed us to observe and correlate increases in intracellular calcium, blood flow and blood volume during seizure-like events and provide a quantitative analysis of neurovascular coupling changes associated with seizure rescue via injection of an anti-convulsive agent.

  14. Monitoring of renal venous PO2 and kidney oxygen consumption in rats by a near-infrared phosphorescence lifetime technique

    NARCIS (Netherlands)

    E.G. Mik (Egbert); T. Johannes (Tanja); C. Ince (Can)

    2008-01-01

    textabstractRenal oxygen consumption (V̇O2,ren) is an important parameter that has been shown to be influenced by various pathophysiological circumstances. VV̇O2,renhas to be repeatedly measured during an experiment to gain insight in the dynamics of (dys)regulation of oxygen metabolism. In small

  15. An MRI study of the differences in the rate of thrombolysis between red blood cell-rich and platelet-rich components of venous thrombi ex vivo.

    Science.gov (United States)

    Vidmar, Jernej; Blinc, Aleš; Kralj, Eduard; Balažic, Jože; Bajd, Franci; Serša, Igor

    2011-11-01

    To test whether T(1)-weighted MRI can detect the differences in the rate of thrombolysis induced by recombinant tissue plasminogen activator (rt-PA) between platelet-rich regions and red blood cell (RBC)-rich regions of venous thrombi ex vivo. Each of 21 venous thrombi ex vivo (8 pulmonary emboli and 13 in situ thrombi) was dissected along the longitudinal axis. Half of it was analyzed for the presence of platelet, fibrin, and RBC components by immunohistochemistry and the other half was imaged serially by high-resolution T(1)-weighted three-dimensional MRI to assess the progression of thrombolysis. The MR images were analyzed for proportions of the remaining platelet-rich and RBC-rich regions. Laminated platelet-rich regions, corresponding to Zahn lines, were confirmed immunohistochemically and by MRI in 18/21 venous thrombi. In T(1)-weighted MR images (TE/TR = 10/105 ms) the mean signal intensity of platelet-rich regions was on average 2.3 higher than that of RBC-rich regions. The rate of thrombolysis in platelet-rich regions was on average 30% lower than in RBC-rich regions. After 120 min of thrombolysis the proportion of lysed platelet-rich regions was 0.27 ± 0.04 versus 0.40 ± 0.08 in RBC regions, which resulted in 1.4% decrease of lysed thrombus volume per 1% increase of platelet-rich content. Venous thrombi are most often composed of interspersed platelet-rich and RBC-rich regions. T(1) -weighted MRI is capable of noninvasive discrimination between those two components of venous thrombi ex vivo which have a different susceptibility to thrombolysis by rt-PA. Copyright © 2011 Wiley Periodicals, Inc.

  16. Effect of anesthesia on renal R2* measured by blood oxygen level-dependent MRI

    OpenAIRE

    Niles, David J.; Gordon, Jeremy W.; Fain, Sean B.

    2015-01-01

    Blood oxygen level-dependent (BOLD) MRI is increasingly used to assess renal tissue oxygenation during disease based on the transverse relaxation rate (R2*). In preclinical small animal models, the requisite use of anesthesia during imaging may lead to functional changes which influence R2* and confound results. The purpose of this study is to evaluate the effects of four common anesthetic compounds on renal R2* in healthy mice. Five female ICR mice were imaged with BOLD MRI approximately 25 ...

  17. [The effect of exercise on blood gases and oxygen transport in patients with chronic obstructive pulmonary disease].

    Science.gov (United States)

    Zeng, G B

    1990-02-01

    The effect of exercise on pulmonary gas exchange and oxygen transport was studied in 42 patients with COPD. Arterial PO2 increased and arterial PCO2 did not change significantly in 25 patients (group A). Arterial PO2 decreased and arterial PCO2 increased in the remaining 17 patients (group B). In group A, P(A-a)O2,Qs/Qt decreased remarkably, oxygen transport and oxygen extrication increased significantly during exercise when compared with that of group B. Our data imply that PO2 changes of COPD patients during exercise may be related to the patient's ventilation, pulmonary gas exchange and mixed venous PO2 levels.

  18. Limitations of quantitative photoacoustic measurements of blood oxygenation in small vessels

    Energy Technology Data Exchange (ETDEWEB)

    Sivaramakrishnan, Mathangi [Optical Imaging Laboratory, Department of Biomedical Engineering, Texas A and M University 3120 TAMU, College Station, TX 77843-3120 (United States); Maslov, Konstantin [Optical Imaging Laboratory, Department of Biomedical Engineering, Texas A and M University 3120 TAMU, College Station, TX 77843-3120 (United States); Zhang, Hao F [Optical Imaging Laboratory, Department of Biomedical Engineering, Texas A and M University 3120 TAMU, College Station, TX 77843-3120 (United States); Stoica, George [Department of Pathobiology, Texas A and M University, College Station, TX 77843-5547 (United States); Wang, Lihong V [Optical Imaging Laboratory, Department of Biomedical Engineering, Texas A and M University 3120 TAMU, College Station, TX 77843-3120 (United States)

    2007-03-07

    We investigate the feasibility of obtaining accurate quantitative information, such as local blood oxygenation level (sO{sub 2}), with a spatial resolution of about 50 {mu}m from spectral photoacoustic (PA) measurements. The optical wavelength dependence of the peak values of the PA signals is utilized to obtain the local blood oxygenation level. In our in vitro experimental models, the PA signal amplitude is found to be linearly proportional to the blood optical absorption coefficient when using ultrasonic transducers with central frequencies high enough such that the ultrasonic wavelengths are shorter than the light penetration depth into the blood vessels. For an optical wavelength in the 578-596 nm region, with a transducer central frequency that is above 25 MHz, the sensitivity and accuracy of sO{sub 2} inversion is shown to be better than 4%. The effect of the transducer focal position on the accuracy of quantifying blood oxygenation is found to be negligible. In vivo oxygenation measurements of rat skin microvasculature yield results consistent with those from in vitro studies, although factors specific to in vivo measurements, such as the spectral dependence of tissue optical attenuation, dramatically affect the accuracy of sO{sub 2} quantification in vivo.

  19. Chronic venous insufficiency of the lower limbs: suitability of transcutaneous blood gas monitoring as an endpoint to evaluate the outcome of pharmacological treatment with calcium dobesilate.

    Science.gov (United States)

    Marinello, J; Videla, S

    2004-12-01

    This pilot clinical trial was designed to further investigate the effects of calcium dobesilate in the treatment of chronic venous insufficiency (CVI) by means of a novel endpoint, transcutaneous oxygen pressure (TcPO2), and to evaluate the suitability of this endpoint for future research. Patients with mild to moderate CVI without active ulcers were randomized to receive calcium dobesilate 1000 mg/day, 2000 mg/day or placebo for 12 weeks. The primary efficacy endpoint was TcPO2 in the distal third of the internal side of the leg. Secondary endpoints included assessment of venous reflux and clinical symptoms. Patients in the dobesilate 1000 mg/day and placebo groups showed a mild increase in TcPO2 (adjusted mean change 2.67 mmHg and 1.56 mmHg, respectively), while those treated with 2000 mg/day of the active drug showed a decrease (adjusted mean change -0.53 mmHg). Conversely, clinical symptoms and venous reflux improved in all groups, especially with dobesilate, but differences with placebo were not significant. Treatment was very well tolerated. Although the absence of significant differences prevented confirmation of sensitivity, a trend favoring calcium dobesilate in clinical and hemodynamic parameters was observed. This improvement was not reflected by TcPO2. 2004 Prous Science.

  20. Veno-venous extracorporeal membrane oxygenation using a double-lumen bi-caval cannula for severe respiratory failure post total artificial heart implantation.

    Science.gov (United States)

    Miessau, J; Yang, Q; Unai, S; Entwistle, J W C; Cavarocchi, N C; Hirose, H

    2015-07-01

    We report a unique utilization of a double-lumen, bi-caval Avalon cannula for veno-venous (VV) extracorporeal membrane oxygenation (ECMO) during placement of a total artificial heart (TAH, SynCardia, Tucson, AZ). A 22-year-old female with post-partum cardiomyopathy was rescued on veno-arterial (VA) ECMO because of cardiogenic shock. The inability to wean ECMO necessitated implantation of the TAH as a bridge to transplant. In addition, the patient continued to have respiratory failure and concomitant VV ECMO was planned with the implant. During TAH implantation, the Avalon cannula was placed percutaneously from the right internal jugular vein into the inferior vena cava (IVC) under direct vision while the right atrium was open. During VV ECMO support, adequate flows on both ECMO and TAH were maintained without adverse events. VV ECMO was discontinued, without reopening the chest, once the patient's respiratory failure improved. However, the patient subsequently developed a profound respiratory acidosis and required VV ECMO for CO2 removal. The Avalon cannula was placed in the femoral vein to avoid accessing the internal jugular vein and risking damage to the TAH. The patient's oxygenation eventually improved and the cannula was removed at the bedside. The patient was supported for 22 days on VV ECMO and successfully weaned from the ventilator prior to her orthotropic heart transplantation. © The Author(s) 2014.

  1. Relationship between blood oxygenation and lactate in human skeletal muscle revealed by near-infrared spectroscopy

    Science.gov (United States)

    Xu, Guodong; Luo, Qingming; Ge, Xinfa; Gong, Hui; Zeng, Shaoqun

    2002-04-01

    Near-infrared spectroscopy (NIRS) is a focus of attention in the research field of biomedical photonics. The concentration of HbO2 in human skeletal muscle has been measured noninvasive NIRS using a portable tissue oximeter continuously when the subjects did incremental exercises on a power bicycle. Blood lactate is one of traditional physical research subjects which is applied most widely. We study blood volume in the tissue of sportsmen when they are subjected by the incremental physical load, simultaneously detecting some parameters such as the heart rate, maximal oxygen absorption and the concentration of blood lactate. As the intensity of exercises was heightened, the concentration of blood lactate and blood volume in tissue increased, while the concentration of HbO2 decreased. Thus the rudimental characteristics of energy consumption and supply during hypoxia and aerobic exercises are investigated. By discovering the relationship between blood lactate in human skeletal muscle and blood oxygenation, a novel approach for measuring blood lactate noninvasively and assessing the sports ability could be provided. Furthermore, it is possible to assess the fatigue state with tissue oximeter to monitor the human sports intensity noninvasively and dynamically.

  2. Effect of blood collection by the push-pull technique from an indwelling catheter versus direct venipuncture on venous blood gas values before and after administration of alfaxalone or propofol in dogs.

    Science.gov (United States)

    Barr, Ciara A; Gianotti, Giacomo; Graffeo, Carly E; Drobatz, Kenneth J; Silverstein, Deborah C

    2017-11-15

    OBJECTIVE To compare the effect of blood collection by a push-pull technique from an indwelling IV catheter versus direct venipuncture on venous blood gas values before and after administration of alfaxalone or propofol to dogs. DESIGN Prospective randomized clinical study. ANIMALS 30 healthy client-owned dogs that weighed ≥ 10 kg (22 lb) and were anesthetized for elective surgical procedures. PROCEDURES All dogs were premedicated with methadone (0.5 mg/kg [0.2 mg/lb], IM), and 20 to 30 minutes later, anesthesia was induced with either alfaxalone (1 to 3 mg/kg [0.5 to 1.4 mg/lb], IV to effect; n = 15) or propofol (2 to 6 mg/kg [0.9 to 2.7 mg/lb], IV to effect; 15). Immediately prior to premedication and after anesthesia induction, paired blood samples were collected from the cephalic veins; 1 by direct venipuncture and 1 by use of a push-pull technique from a 20-gauge catheter. All blood samples underwent venous blood gas analysis immediately after collection. Results were compared between sample collection techniques before and after anesthesia induction and between anesthesia induction protocols. RESULTS All results were within established reference ranges. For many variables, statistically significant but clinically irrelevant differences were detected between samples collected by direct venipuncture and those collected by the push-pull technique but not between the 2 anesthesia induction protocols. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated the push-pull technique was an acceptable method for collection of blood samples from dogs for venous blood gas analysis that could be used instead of direct venipuncture for patients with patent IV catheters.

  3. [Artificial oxygen carriers as an alternative to red blood cell transfusion].

    Science.gov (United States)

    Habler, O; Pape, A; Meier, J; Zwissler, B

    2005-08-01

    The expected cost-explosion in transfusion medicine (increasing imbalance between donors and recipients, treatment of transfusion-associated complications) increases the socio-economic significance of the development of safe and effective synthetic oxygen carriers as an alternative to the transfusion of allogeneic red blood cells. Currently two types of artificial oxygen carriers have been tested for safety and efficacy in cases of severe anemia otherwise requiring transfusion. Solutions based on human or bovine hemoglobin (HBOC) possess vasoconstrictor properties in addition to their oxygen transport capacity. The impact of vasoconstriction on tissue perfusion and organ function is however not yet fully understood. Nevertheless, in 2001 the bovine HBOC Hemopure was approved in South Africa for treatment of acutely anemic surgical patients. The purely synthetic perfluorocarbon (PFC) emulsions increase the physically dissolved portion of arterial oxygen content. Due to their particulate nature (emulsion droplets) PFCs may only be infused in low doses to avoid overload and malfunction of phagocytic cells of the reticulo-endothelial system. As part of a multimodal blood conservation program (including normovolemic hemodilution and hyperoxia) the low-dose administration of Oxygent effectively increases intraoperative anemia tolerance. Although reduction of perioperative allogeneic blood transfusion has already been demonstrated for HBOC and PFC, the global clinical establishment of artificial oxygen carriers is not to be expected in the near future.

  4. [The application of combined central venous pressure and oxygen metabolism parameters monitoring in diagnosing septic shock-induced left ventricular dysfunction].

    Science.gov (United States)

    Cui, Keliang; Wang, Xiaoting; Zhang, Hongmin; Chai, Wenzhao; Liu, Dawei

    2015-10-01

    To evaluate the value of central venous pressure (CVP), central venous oxygen saturation (ScvO₂) and venous-arterial carbon dioxide partial pressure gradient (Pv-aCO₂)) in the diagnosis of septic shock-induced left ventricular dysfunction. Consecutive patients with septic shock were enrolled from September 2013 to September 2014 in ICU at Peking Union Medical College Hospital. The data of CVP, Pv-aCO₂) and ScvO₂) were recorded and analyzed. According to the left ventricular ejection fraction (LVEF) tested by bedside echocardiography, the patients were divided into two groups: new onset of left ventricular dysfunction (LVEF < 50%) group and non-left ventricular dysfunction (LVEF ≥ 50%) group. A diagnostic model was created by logistic regression. The diagnostic performance and cut-off values of CVP, Pv-aCO₂, ScvO₂) were determined using receiver operating characteristic (ROC) curve analysis. Among 93 patients enrolled, 39 were diagnosed with left ventricular dysfunction. In the new onset group, CVP [(12.5 ± 3.9) mmHg (1 mmHg = 0.133 kPa) vs (10.4 ± 2.5) mmHg; P = 0.005] and Pv-aCO₂[(7.5 ± 3.9) mmHg vs (4.5 ± 2.6) mmHg; P < 0.001] were significantly higher than those in the non-left ventricular dysfunction group, while Scv2 [(62.4 ± 10.5)% vs (72.6 ± 9.0)%; P < 0.001] was significantly lower. As far as the diagnostic value of these three parameters were concerned for left ventricular dysfunction, the sensitivity of CVP ≥ 12.5 mmHg was 46.2%, specificity 81.5% with an area under ROC curve (AUCROC) 0.674; the sensitivity of Pv-aCO₂≥ 5.0 mmHg 76.9%, specificity 37.0%, AUCROC 0.738; the sensitivity of ScvO₂≤ 65.8% 64.1%, specificity 78.6%, AUCROC 0.775. When the cut-off values were determined by ROC, the diagnostic performance of the model was ≥ 0.377 with the sensitivity, specificity and AUCROC 82.1%, 79.6% and 0.835, respectively. In patients with septic shock, the logistic regression model established by CVP, Pv-aCO₂and Scv

  5. SponTaneous Respiration using IntraVEnous anaesthesia and Hi-flow nasal oxygen (STRIVE Hi) maintains oxygenation and airway patency during management of the obstructed airway: an observational study.

    Science.gov (United States)

    Booth, A W G; Vidhani, K; Lee, P K; Thomsett, C-M

    2017-03-01

    High-flow nasal oxygen (HFNO) has been shown to benefit oxygenation, ventilation and upper airway patency in a range of clinical scenarios, however its use in spontaneously breathing patients during general anaesthesia has not been described. Spontaneous respiration using i.v. anaesthesia is the primary technique used at our institution for tubeless airway surgery. We hypothesized that the addition of HFNO would increase our margin of safety, particularly during management of an obstructed airway. A retrospective observational study was conducted using a SponTaneous Respiration using IntraVEnous anaesthesia and High-flow nasal oxygen (STRIVE Hi) technique to manage 30 adult patients undergoing elective laryngotracheal surgery. Twenty-six patients (87%) presented with significant airway and/or respiratory compromise (16 were stridulous, 10 were dyspnoeic). No episodes of apnoea or complete airway obstruction occurred during the induction of anaesthesia using STRIVE Hi. The median [IQR (range)] lowest oxygen saturation during the induction period was 100 [99–100 (97–100)] %. The median [IQR (range)] overall duration of spontaneous ventilation was 44 [40–49.5 (18–100)] min. The median [IQR (range)] end-tidal carbon dioxide (ETCO2) level at the end of the spontaneous ventilation period was 6.8 [6.4–7.1 (4.8–8.9)] kPa. The mean rate of increase in ETCO2 was 0.03 kPa min−1. STRIVE Hi succeeded in preserving adequate oxygen saturation, end-tidal carbon dioxide and airway patency. We suggest that the upper and lower airway benefits attributed to HFNO, are ideally suited to a spontaneous respiration induction, increasing its margin of safety. STRIVE Hi is a modern alternative to the traditional inhalation induction.

  6. Low blood flow at onset of moderate intensity exercise does not limit muscle oxygen uptake

    DEFF Research Database (Denmark)

    Nyberg, Michael Permin; Mortensen, Stefan Peter; Saltin, Bengt

    2010-01-01

    The effect of low blood flow at onset of moderate intensity exercise on the rate of rise in muscle oxygen uptake was examined. Seven male subjects performed a 3.5 minute one-legged knee-extensor exercise bout (24+/-1 (+/-S.D.) W) without (CON) and with (double blockade; DB) arterial infusion...

  7. Influence of sildenafil on blood oxygen saturation of the obstructed bladder

    NARCIS (Netherlands)

    J.R. Scheepe (Jeroen); A. Amelink (Arjen); K.P. Wolffenbuttel (Katja); D.J. Kok (Dirk)

    2014-01-01

    textabstractBackground: Blood oxygen saturation (BOS) is decreased in a low-compliant, overactive obstructed bladder. The objective of this study is to determine the effect of Sildenafil (SC) on bladder function and BOS) in an in vivo animal model of bladder outlet obstruction. Methods. Thirty-two

  8. An Experiment to Introduce Mass Transfer Concepts Using a Commercial Hollow Fiber Blood Oxygenator

    Science.gov (United States)

    McIver, Keith; Merrill, Thomas; Farrell, Stephanie

    2017-01-01

    A commercial hollow fiber blood oxygenation laboratory experiment was used to introduce lower level engineering students to mass balances in a two-phase system. Using measured values of concentration and flow rate, students calculated the rate of mass transfer from the gas phase and into the liquid phase, and compared the two values to determine…

  9. Method of measuring blood oxygenation based on spectroscopy of diffusely scattered light

    Science.gov (United States)

    Kleshnin, M. S.; Orlova, A. G.; Kirillin, M. Yu.; Golubyatnikov, G. Yu.; Turchin, I. V.

    2017-05-01

    A new approach to the measurement of blood oxygenation is developed and implemented, based on an original two-step algorithm reconstructing the relative concentration of biological chromophores (haemoglobin, water, lipids) from the measured spectra of diffusely scattered light at different distances from the radiation source. The numerical experiments and approbation of the proposed approach using a biological phantom have shown the high accuracy of the reconstruction of optical properties of the object in question, as well as the possibility of correct calculation of the haemoglobin oxygenation in the presence of additive noises without calibration of the measuring device. The results of the experimental studies in animals agree with the previously published results obtained by other research groups and demonstrate the possibility of applying the developed method to the monitoring of blood oxygenation in tumour tissues.

  10. Capillary compared to venous blood sampling in clozapine treatment: patients׳ and healthcare practitioners׳ experiences with a point-of-care device.

    Science.gov (United States)

    Bogers, Jan P A M; Bui, Hong; Herruer, Martien; Cohen, Dan

    2015-03-01

    Underuse of the antipsychotic clozapine for schizophrenia is an impediment to improving outcomes for patients. Because of its possible severe side effects, including granulocytopenia or even agranulocytosis, clozapine treatment entails regular WBC monitoring, which can be a major drawback for patients and practitioners. The HemoCue WBC DIFF system is a point-of-care device using capillary blood sampling which provides WBC counts with differentials, including granulocytes. We investigated if capillary sampling instead of conventional venous sampling might diminish the burden for patients and practitioners and motivate them to continue clozapine treatment. A randomized cross-over trial design was used to compare the two sampling methods. Patients׳ subjective experiences of various aspects of blood sampling were rated on a 10-cm visual analogue scale (VAS). Patients and practitioners were also asked if they had any preference for venous or capillary sampling and patients were asked if the sampling method influenced their motivation to continue clozapine treatment. Seventy-three patients were included in this study. Three dropped out before completion. The VAS ratings on all five aspects and the total burden experienced showed a consistent pattern favouring capillary blood sampling (psampling at a laboratory and practitioners also preferred it. Using this method might therefore boost clozapine prescription rates. Copyright © 2014 Elsevier B.V. and ECNP. All rights reserved.

  11. Diagnostic value of nitric oxide, lipoprotein(a), and malondialdehyde levels in the peripheral venous and cavernous blood of diabetics with erectile dysfunction.

    Science.gov (United States)

    El-Latif, M A; Makhlouf, A A; Moustafa, Y M; Gouda, T E; Niederberger, C S; Elhanbly, S M

    2006-01-01

    Diabetes mellitus (DM) is the single most common cause of erectile dysfunction (ED) seen in clinical practice. Evaluation of penile arterial insufficiency in diabetic patients currently entails expensive and invasive testing. We assessed the diagnostic value of certain peripheral and cavernous blood markers as predictors of penile arterial insufficiency in diabetic men with ED. This study was conducted on a total of 51 subjects in three groups: 26 impotent diabetics, 15 psychogenic impotent men and 10 normal age matched control males. All subjects underwent standard ED evaluation including estimation of postprandial blood sugar and serum lipid profile. Peripheral venous levels of nitric oxide (NO), lipoprotein(a) (LP(a)), malondialdehyde (MDA) and glycosylated hemoglobin (HbA1c) were obtained in all subjects. Patients in the two impotent groups underwent additional measurement of NO, LP(a) and MDA levels in cavernous blood. They also underwent intracavernosal injection (ICI) of a trimix (papaverine, prostaglandin E1 and phentolamine mixture) and pharmaco-penile duplex ultrasonography (PPDU). Compared to patients in the psychogenic group, diabetic men had significantly lower erectile response to ICI (P<0.001), lower peak systolic velocity (PSV) (P<0.001), and smaller increase in cavernosal artery diameter (CAD) (P<0.001). Peripheral and cavernous levels of both LP(a) and MDA were higher in the diabetic group as compared to the psychogenic ED group (P<0.001), while the values of peripheral venous and cavernous NO were lower (P<0.001) in the diabetic men. Comparison of biochemical marker assays with the PPDU results showed a significant negative correlation between both venous and cavernous LP(a) and MDA levels on the one hand, and PSV, and the percentage of CAD increase on the other. At the same time, peripheral and cavernous NO levels had a significant positive correlation with the same parameters. Lipoprotein(a), MDA and NO levels were better predictors of low PSV

  12. Analysis of the dynamics of venous blood flow in the context of lower limb temperature distribution and tissue composition in the elderly

    Directory of Open Access Journals (Sweden)

    Skomudek A

    2017-08-01

    Full Text Available Aleksandra Skomudek,1,2 Iwona Gilowska,1,3 Ryszard Jasiński,4 Krystyna Rożek-Piechura4 1Department of Physical Education and Physiotherapy, Opole University of Technology, Opolskie, 2Department of Clinical Physiotherapy, 3Department of Biochemistry and Physiology, 4Department of Physiotherapy and Occupational Therapy in Conservative and Interventional Medicine, University of Physical Education in Wroclaw, Wroclaw, Poland Objective: The elderly are particularly vulnerable to degenerative diseases, such as circulatory and respiratory system and vascular system diseases. The objective of this study was therefore to evaluate the distribution of temperature and the dynamics of venous blood flow in the lower limbs (LLs and to assess the interdependence of these parameters in terms of the somatic components in males and females participating in activities at the University of the Third Age. Materials and methods: The study included 60 females (mean age 67.4 years and 40 males (mean age 67.5 years. A body composition assessment was performed using the bioimpedance technique – Tanita BC-418MA. The following parameters were examined: fat%, fat mass, fat-free mass, and total body water. The minimal, maximal, and mean temperature values and their distributions were examined using infrared thermographic camera VarioCAM Head. Measurements of the venous refilling time and the work of the LL venous pump were examined using a Rheo Dopplex II PPG. Results: In males, the mean value of the right LL temperature was 30.58 and the mean value of the left LL was 30.28; the P-value was 0.805769. In females, the mean value of the right LL temperature was 29.58 and the mean value of the left limb was 29.52; the P-value was 0.864773. In males, the right limb blood flow was 34.17 and the left limb blood flow was 34.67; the P-value was 0.359137. In females, the right limb blood flow was 26.89 and the left limb blood flow was 26.09; the P-value was 0.796348. Conclusion

  13. Simultaneous two-photon imaging of cerebral oxygenation and capillary blood flow in atherosclerotic mice

    Science.gov (United States)

    Lu, Xuecong; Li, Baoqiang; Moeini, Mohammad; Lesage, Frédéric

    2017-02-01

    Gradual changes in brain microvasculature and cerebral capillary blood flow occurring with atherosclerosis may significantly contribute to cognition decline due to their role in brain tissue oxygenation. However, previous stud- ies of the relationship between cerebral capillary blood flow and brain tissue oxygenation are limited. This study aimed to investigate vascular and concomitant changes in brain tissue pO2 with atherosclerosis. Experiments in young healthy C57B1/6 mice (n=6 , WT), young atherosclerotic mice (n=6 , ATX Y) and old atherosclerotic mice (n=6 , ATX O) were performed imaging on the left sensory-motor cortex at resting state under urethane (1.5 g/kg) anesthesia using two-photon fluorescence microscopy. The results showed that pO2 around capillaries, correlated with red blood cell (RBC) flux, increased with atherosclerosis.

  14. Cerebral hemodynamics at altitude: effects of hyperventilation and acclimatization on cerebral blood flow and oxygenation.

    Science.gov (United States)

    Sanborn, Matthew R; Edsell, Mark E; Kim, Meeri N; Mesquita, Rickson; Putt, Mary E; Imray, Chris; Yow, Heng; Wilson, Mark H; Yodh, Arjun G; Grocott, Mike; Martin, Daniel S

    2015-06-01

    Alterations in cerebral blood flow (CBF) and cerebral oxygenation are implicated in altitude-associated diseases. We assessed the dynamic changes in CBF and peripheral and cerebral oxygenation engendered by ascent to altitude with partial acclimatization and hyperventilation using a combination of near-infrared spectroscopy, transcranial Doppler ultrasound, and diffuse correlation spectroscopy. Peripheral (Spo2) and cerebral (Scto2) oxygenation, end-tidal carbon dioxide (ETCO2), and cerebral hemodynamics were studied in 12 subjects using transcranial Doppler and diffuse correlation spectroscopy (DCS) at 75 m and then 2 days and 7 days after ascending to 4559 m above sea level. After obtaining baseline measurements, subjects hyperventilated to reduce baseline ETCO2 by 50%, and a further set of measurements were obtained. Cerebral oxygenation and peripheral oxygenation showed a divergent response, with cerebral oxygenation decreasing at day 2 and decreasing further at day 7 at altitude, whereas peripheral oxygenation decreased on day 2 before partially rebounding on day 7. Cerebral oxygenation decreased after hyperventilation at sea level (Scto2 from 68.8% to 63.5%; Phyperventilation after 2 days at altitude (Scto2 from 65.6% to 69.9%; P=.001), and did not change after hyperventilation after 7 days at altitude (Scto2 from 62.2% to 63.3%; P=.35). An intensification of the normal cerebral hypocapnic vasoconstrictive response occurred after partial acclimatization in the setting of divergent peripheral and cerebral oxygenation. This may help explain why hyperventilation fails to improve cerebral oxygenation after partial acclimatization as it does after initial ascent. The use of DCS is feasible at altitude and provides a direct measure of CBF indices with high temporal resolution. Copyright © 2015 Wilderness Medical Society. Published by Elsevier Inc. All rights reserved.

  15. The Effect of the Venous Pressure to the Blood Pressure Signals Measured by the Electronic Palpation Method

    Science.gov (United States)

    2001-10-25

    amplitudes starts to increase would represent the venous pressure at rest. REFERENCES [1] S. Nissilä, M. Sorvisto, H. Sorvoja, E. Vieri- Gashi ...Conference of the IEEE Engineering in Medicine and Biology Society, Vol. 20, No. 4, pp. 1723- 1726, Oct 1998. [2] E. Vieri- Gashi , P. Kärjä –Koskenkari, S

  16. Venous ulcer: what is new?

    Science.gov (United States)

    Raffetto, Joseph D; Marston, William A

    2011-01-01

    The pathophysiology of venous dermal abnormality in chronic venous ulcers is reflective of a complex interplay that involves sustained venous hypertension, inflammation, changes in the microcirculation, cytokine and matrix metalloproteinase activation, and altered cellular function. Red blood cells and macromolecules extravasate into the interstitium and activate endothelial cells. Endothelial expression of specific adhesion molecules recruits leukocytes and causes diapedesis of these cells into the dermal microvasculature, promoting an inflammatory response with activation of cytokines and proteinases. Altered cell function enhances a state of vulnerability in the surrounding tissues, initiating specific changes associated with venous disease. Ultimately, the persistent inflammatory-proteinase activity leads to advanced chronic venous insufficiency and ulcer formation. The mainstay of therapy in venous ulcer abnormality is correction of the underlying venous hypertension through compression therapy and/or surgery. Understanding the science involved in the pathophysiology of venous ulcer formation has led to the development of adjunctive treatment directed at the dysregulated molecular pathways. Randomized clinical trials are critical for determining the most effective evidence-based treatments for venous ulcer, and this review discusses important trials that have had a significant impact on venous ulcer healing. In addition, the authors have included subsections referred to as "Translational Implications for Therapy" in the basic science sections of the review to help bridge the basic science knowledge with clinical applications that may help to modulate the molecular abnormalities in the pathophysiologic cascade leading to venous ulcers.

  17. Meal-induced changes in splanchnic blood flow and oxygen uptake in middle-aged healthy humans

    DEFF Research Database (Denmark)

    Madsen, Jan Lysgård; Søndergaard, SB; Møller, Søren

    2006-01-01

    healthy men (52-76 years). Splanchnic blood flow was measured during hepatic vein catheterization by indirect Fick principle with indocyanine green as the indicator. Splanchnic oxygen uptake was calculated from splanchnic blood flow and the arteriovenous oxygen difference. RESULTS: The meal induced...

  18. [Oxygen transport function of the blood in acute disorders of gas metabolism and of the acid-base state].

    Science.gov (United States)

    Bragin, V I; Danilov, E N; Rusanov, G A; Shcherbakha, N A; Aleksandrov, V I

    1980-01-01

    The oxygen-transport function of blood in hyperoxia and acute disturbances of the acid-alkali condition was studied in "oxygenator--desoxygenator" as a model. It has been established that in acidosis there occurs decreased intensity of glycolysis in erythrocytes, accumulation of 2,3 diphosphoglyceric acid which decreases affinity of hemoglobin for oxygen. It does not occur in alcalosis.

  19. Perfluorocarbon emulsion improves oxygen transport of normal and sickle cell human blood in vitro.

    Science.gov (United States)

    Torres Filho, Ivo P; Pedro, José Ricardo P; Narayanan, Srinivasan V; Nguyen, Nguyen M; Roseff, Susan D; Spiess, Bruce D

    2014-07-01

    Perfluorocarbons (PFC) are compounds with high gas solubility that could help deliver O2 to tissues and have been suggested as adjunct therapy to ischemia. Using a newly designed in vitro system, we tested the hypothesis that a third generation PFC emulsion (Oxycyte) increased O2 transport of blood by measuring changes in O2 extraction ratio. The system included a computer-controlled pump and blood-gas exchange chambers to oxygenate and deoxygenate the blood from nine sickle cell disease (SCD) patients and five healthy donors. The flowing blood reached various levels of hemoglobin O2 saturation and O2 partial pressures (PO2), measured using a CO-oximeter and a blood gas analyzer. The mixtures were kept at physiological blood pressure and temperature, constant flow, normobaric conditions, and FiO2 = 0.30. After adding PFC, the measurements suggested an increase in the transport of O2 and CO. Addition of PFC resulted in larger PO2 difference from 15 ± 2 mmHg to 23 ± 2 mmHg. Using normal blood and blood from SCD patients, the average O2 extraction ratio (O2ER) after PFC was significantly higher than baseline. Addition of saline did not cause statistically significant changes. The data suggest increased (facilitated) O2 transport by this PFC emulsion in both normal and SCD blood. © 2013 Wiley Periodicals, Inc.

  20. Blood gas analyzer utility in evaluating oxygen kinetics of the aqueous humor

    Directory of Open Access Journals (Sweden)

    Ismail Ersan

    2015-04-01

    Full Text Available Purpose: To measure the partial pressure of oxygen (PO2 and carbon dioxide (PCO2 and the pH of aqueous humor (AH and arterial blood samples from rabbits using a blood gas analyzer. Methods: Twenty New Zealand rabbits were anesthetized intramuscularly with ketamine and xylazine and were then allowed to breathe room air. Using a gas blood analyzer, arterial blood and AH samples were analyzed for PO2, PCO2, and pH. Results: The mean arterial blood pressure was 87.14 ± 15.0 mmHg. The mean blood and AH PO2 were 95.18 ± 11.76 mmHg and 88.83 ± 9.92 mmHg, the mean blood and AH PCO2 were 25.86 ± 5.46 mmHg and 29.50 ± 5.36 mmHg, and the mean blood and AH pH were 7.38 ± 0.06 and 7.33 ± 0.09, respectively. Conclusion: Conclusions: The blood gas analyzer was easily employed to evaluate the aqueous humor in rabbits. When comparing the results of studies evaluating aqueous PO2, care should be taken to determine the methods used in these studies.

  1. Membrane oxygenator heat exchanger failure detected by unique blood gas findings.

    Science.gov (United States)

    Hawkins, Justin L

    2014-03-01

    Failure of components integrated into the cardiopulmonary bypass circuit, although rare, can bring about catastrophic results. One of these components is the heat exchanger of the membrane oxygenator. In this compartment, unsterile water from the heater cooler device is separated from the sterile blood by stainless steel, aluminum, or by polyurethane. These areas are glued or welded to keep the two compartments separate, maintaining sterility of the blood. Although quality control testing is performed by the manufacturer at the factory level, transport presents the real possibility for damage. Because of this, each manufacturer has included in the instructions for use a testing procedure for testing the integrity of the heat exchanger component. Water is circulated through the heat exchanger before priming and a visible check is made of the oxygenator bundle to check for leaks. If none are apparent, then priming of the oxygenator is performed. In this particular case, this procedure was not useful in detecting communication between the water and blood chambers of the oxygenator.

  2. Effects of anesthetic agents on brain blood oxygenation level revealed with ultra-high field MRI.

    Directory of Open Access Journals (Sweden)

    Luisa Ciobanu

    Full Text Available During general anesthesia it is crucial to control systemic hemodynamics and oxygenation levels. However, anesthetic agents can affect cerebral hemodynamics and metabolism in a drug-dependent manner, while systemic hemodynamics is stable. Brain-wide monitoring of this effect remains highly challenging. Because T(2*-weighted imaging at ultra-high magnetic field strengths benefits from a dramatic increase in contrast to noise ratio, we hypothesized that it could monitor anesthesia effects on brain blood oxygenation. We scanned rat brains at 7T and 17.2T under general anesthesia using different anesthetics (isoflurane, ketamine-xylazine, medetomidine. We showed that the brain/vessels contrast in T(2*-weighted images at 17.2T varied directly according to the applied pharmacological anesthetic agent, a phenomenon that was visible, but to a much smaller extent at 7T. This variation is in agreement with the mechanism of action of these agents. These data demonstrate that preclinical ultra-high field MRI can monitor the effects of a given drug on brain blood oxygenation level in the absence of systemic blood oxygenation changes and of any neural stimulation.

  3. [Venous ulcer].

    Science.gov (United States)

    Böhler, Kornelia

    2016-06-01

    Venous disorders causing a permanent increase in venous pressure are by far the most frequent reason for ulcers of the lower extremity. With a prevalence of 1 % in the general population rising to 4 % in the elderly over 80 and its chronic character, 1 % of healthcare budgets of the western world are spent on treatment of venous ulcers. A thorough investigation of the underlying venous disorder is the prerequisite for a differenciated therapy. This should comprise elimination of venous reflux as well as local wound management. Chronic ulcers can successfully be treated by shave therapy and split skin grafting. Compression therapy is a basic measure not only in venous ulcer treatment but also in prevention of ulcer recurrence. Differential diagnosis which have to be considered are arterial ulcers, vasculitis and neoplasms.

  4. Intrapartum fetal surveillance : Monitoring fetal oxygenation with fetal blood sampling and umbilical cord blood analysis

    NARCIS (Netherlands)

    van den Berg, P; Slager, E; Fauser, B; VanGeijn, H; Brolmann, H; Vervest, H

    2005-01-01

    Although electronic fetal heart rate monitoring remains the most popular technique for fetal surveillance during labour, there is much concern about the ever rising Caesarean section rate, probably partly due to this practice. Fetal blood sampling is still the gold standard when it comes to

  5. The effect of venous and arterial occlusion of the arm on changes in tissue hemodynamics, oxygenation, and ultra-weak photon emission.

    Science.gov (United States)

    Scholkmann, Felix; Schraa, Olaf; van Wijk, Roeland; Wolf, Martin

    2013-01-01

    Ultra-weak photon emission (UPE) is a general feature of living -biological systems. To gain further insights into the origin of UPE and its physiological significance, the aim of the present study was to investigate the connection between hemodynamics (HD), oxygenation (OX), and UPE. Therefore, during venous and arterial occlusion (VO, AO), changes of UPE and surrogates of HD as well as OX were measured simultaneously using two photomultipliers and near-infrared spectroscopy, respectively. We showed that (1) changes in UPE correlate significantly nonlinearly with changes in oxyhemoglobin (Δ[O(2)Hb]), deoxyhemoglobin (Δ[HHb]), and hemoglobin difference (Δ[HbD] = Δ[O(2)Hb]-Δ[HHb]), indicating a complex association between UPE and tissue HD/OX; (2) UPE decreases significantly during AO but not during VO; (3) UPE increases significantly after AO; and (4) the view that ROS are the source of UPE is generally supported by the present study, although some findings remain unexplained in the context of the theory of ROS-mediated UPE generation. In conclusion, the present study revealed new insights into the interplay between HD, OX, and UPE and opens up new questions that have to be addressed by future studies.

  6. Arterio-venous concentration difference of [51Cr]EDTA after a single injection in man. Significance of renal function and local blood flow

    DEFF Research Database (Denmark)

    Rehling, M; Hyldstrup, Lars; Henriksen, Jens Henrik

    1989-01-01

    introduced in the measurement of renal plasma clearance and total plasma clearance by using venous blood samples instead of arterial. In 13 patients with GFR ranging from 29 to 150 ml min-1, Ca was higher than Cv immediately after the injection. After mean 38 min (range 12-82 min) the two curves crossed......, and 180-300 min post-injection (p.i.) Cv was 5.9% higher than Ca (range 0.5-13.9%, P less than 0.001). The more reduced renal function, the smaller was the concentration difference. The areas under the arterial and the venous plasma concentration curves did not differ significantly at either 0-infinity......, whereas the difference was very sensitive to even small changes in forearm blood flow within the physiological range. For measurement of renal plasma clearance it is recommended to use one long period: from the time of injection until 300 min p.i. or longer. If the clearance period is too short, the use...

  7. Non-arterial assessment of blood gas status in patients with chronic pulmonary disease.

    Science.gov (United States)

    Elborn, J S; Finch, M B; Stanford, C F

    1991-10-01

    Assessment of blood gas status is important in the management of patients with chronic pulmonary disease. Arterial puncture is often painful and may damage the arterial wall. Measurement of oxygen saturation by transcutaneous oximetry offers a non-invasive alternative to arterial methods but does not allow assessment of partial pressure of carbon dioxide. We have examined the value of oximetry and dorsal hand venous carbon dioxide as an alternative to arterial puncture. Transcutaneous oxygen saturation correlated with arterial oxygen saturation (r = 0.76, p less than 0.001) with an error of 2.1% and dorsal hand venous carbon dioxide tension correlated with the arterial tension (r = 0.84, p less than 0.001) with an error of 8%. Changes in oximetric oxygen saturation and venous carbon dioxide tension following oxygen therapy reflected arterial values. Assessment of blood gas status using oximetry and dorsal hand venous carbon dioxide tension is a useful alternative to arterial puncture.

  8. A miniaturized extracorporeal membrane oxygenator with integrated rotary blood pump: preclinical in vivo testing.

    Science.gov (United States)

    Kopp, Ruedger; Bensberg, Ralf; Arens, Jutta; Steinseifer, Ulrich; Schmitz-Rode, Thomas; Rossaint, Rolf; Henzler, Dietrich

    2011-01-01

    Extracorporeal membrane oxygenation can achieve sufficient gas exchange in severe acute respiratory distress syndrome. A highly integrated extracorporeal membrane oxygenator (HEXMO) was developed to reduce filling volume and simplify management. Six female pigs were connected to venovenous HEXMO with a total priming volume of 125 ml for 4 hours during hypoxemia induced by a hypoxic inspired gas mixture. Animals were anticoagulated with intravenous heparin. Gas exchange, hemodynamics, hemolysis, and coagulation activation were examined. One device failed at the magnetic motor coupling of the integrated diagonal pump. In the remaining five experiments, the oxygenation increased significantly (arterial oxygen saturation [SaO2] from 79 ± 5% before HEXMO to 92% ± 11% after 4 hours) facilitated by a mean oxygen transfer of 66 ± 29 ml/dl through the oxygenator. The CO2 elimination by the HEXMO reduced arterial PaCO2 only marginal. Extracorporeal blood flow was maintained at 32% ± 6% of cardiac output. Hemodynamic instability or hemolysis was not observed. The plasmatic coagulation was only mildly activated without significant platelet consumption. The HEXMO prototype provided sufficient gas exchange to prevent hypoxemia. This proof of concept study supports further development and design modifications to increase performance and to reduce coagulation activation for potential long-term application.

  9. Blood flow and oxygenation in peritendinous tissue and calf muscle during dynamic exercise in humans

    DEFF Research Database (Denmark)

    Boushel, R; Langberg, Henning; Green, Stefan Mathias

    2000-01-01

    1. Circulation around tendons may act as a shunt for muscle during exercise. The perfusion and oxygenation of Achilles' peritendinous tissue was measured in parallel with that of calf muscle during exercise to determine (1) whether blood flow is restricted in peritendinous tissue during exercise...... with a rise in leg vascular conductance and microvascular haemoglobin volume, despite elevated systemic vascular resistance. 4. The parallel rise in calf muscle and peritendinous blood flow and fall in O2 saturation during exercise indicate that blood flow is coupled to oxidative metabolism in both tissue...... by dye dilution, arterial pressure by an arterial catheter-transducer, and muscle and peritendinous O2 saturation by spatially resolved spectroscopy (SRS). 3. Calf blood flow rose 20-fold with exercise, reaching 44 +/- 7 ml (100 g)-1 min-1 (mean +/- s.e.m. ) at 9 W, while Achilles' peritendinous flow...

  10. [Hemoglobin-based oxygen carriers and trials to substitute red blood cells].

    Science.gov (United States)

    Smani, Y; Labrude, P; Vigneron, C; Faivre, B

    2007-11-01

    The idea to develop a blood substitute was stimulated by the need of military in the last two world wars and by transmission of pathogenic germs (Hepatitis B in 1960, HIV in 1980 and Hepatitis C in 1990) during blood transfusion that limited the donor blood transfusion. There are two main groups of blood substitutes: perfluorocarbon emulsions and hemoglobin-based oxygen carriers (HBOC). These latter are of natural origin: human, bovine or recombinant and undergo three modifications types: chemicals (intramolecular cross-linking, polymerisation, conjugation to macromolecules and combination of several chemical modifications), genetics or technological by microencapsulation. HBOCs are in different phases of clinical trials and some of them present side effects (hemodynamic and oxidative). The understanding of these effects and the possibility of correcting them, condition their use on a large scale and the economic consequences, which they can generate.

  11. Peripheral venous blood neutrophil-to-lymphocyte ratio predicts survival in patients with advanced gastric cancer treated with neoadjuvant chemotherapy

    Directory of Open Access Journals (Sweden)

    Chen L

    2017-05-01

    Full Text Available Li Chen,1 Yanjiao Zuo,1 Lihua Zhu,2 Yuxin Zhang,3 Sen Li,1 Fei Ma,4 Yu Han,5 Hongjiang Song,1 Yingwei Xue11Department of Gastrointestinal Surgery, Harbin Medical University Cancer Hospital, Harbin Medical University, Harbin, Heilongjiang, 2Department of Pathogen Biology, School of Basic Medical Sciences, North China University of Science and Technology, Tangshan, Hebei, 3Department of General Surgery, Mudanjiang First People’s Hospital, Mudanjiang, 4Department of Breast Surgery, 5Department of Gastrointestinal Oncology, Harbin Medical University Cancer Hospital, Harbin Medical University, Harbin, Heilongjiang, People’s Republic of ChinaBackground: Accurate and useful predictors of gastric carcinoma treated with neoadjuvant chemotherapy are lacking at present. We aim to explore the potential prognostic significance of the neutrophil-to-lymphocyte ratio (NLR in advanced gastric cancer receiving S-1 plus oxaliplatin (SOX or oxaliplatin and capecitabine (XELOX regimen.Methods: We enrolled 91 patients with advanced gastric cancer treated with neoadjuvant chemotherapy from August 2008 to September 2015. The peripheral venous blood samples were collected before neoadjuvant chemotherapy. The NLR was divided into two groups: low NLR <2.17 group and high NLR ≥2.17 group. Univariate analysis on disease-free survival (DFS and overall survival (OS were generated using the Kaplan–Meier method and compared using the log-rank test. Prognostic factors were assessed by univariate analyses, and the independent prognostic factors were evaluated using multivariate analysis (Cox’s proportional-hazards regression model.Results: The univariate analysis showed that median DFS and median OS were worse for high NLR values than low NLR values before neoadjuvant chemotherapy (median DFS: 19.97 and 26.87 months, respectively, P=0.299; median OS: 25.83 and 29.73 months, respectively, P=0.405. Multivariate analysis showed that the NLR before neoadjuvant

  12. Appropriate timing of blood sampling for blood gas analysis in the ventilated rabbit.

    Science.gov (United States)

    Sei, Kiguna; Fujita, Masanori; Okawa, Shinpei; Hirasawa, Takeshi; Kushibiki, Toshihiro; Sasa, Hidenori; Furuya, Kenichi; Ishihara, Miya

    2016-12-01

    Arterial and venous blood gas analyses (BGAs) are essential to evaluate devices that measure biological oxygenation. The appropriate timing of blood sampling for BGA after respiratory rate (RR) change in animal experiments has not been reported. This study investigated the appropriate timing of blood sampling for BGA in ventilated rabbits and whether venous samples are an alternative to arterial samples. Under general anesthesia, 14 rabbits (body weight, 3.02 ± 0.09 kg) were ventilated and their RR was changed (40/min, 30/min, and 20/min). Blood was sampled through cervical arterial and venous catheters. Experiment 1: in seven rabbits, arterial BGA was measured at 0, 0.5, 1, 2, 3, 5, 10, 15, and 20 min after the RR change. Experiment 2: in seven different rabbits, simultaneous arterial and venous BGA were measured at 0, 2, 5, 10, 15, and 20 min after the RR change. Oxygen partial pressure (PO2) and saturation (SO2) of the arterial blood stabilized 0.5 min after the RR changed. In venous BGA, no index stabilized during observation. The arterial and venous values of the carbon dioxide partial pressure (PCO2) and pH had significant correlations (arterial PCO2 = 0.9316 × venous PCO2-4.4425 [r = 0.9178]; arterial pH = 1.0835 × venous pH-0.5795 [r = 0.9453]). In ventilated rabbits, arterial PO2 and SO2 stabilized in 0.5 min. No venous value stabilized after the RR change. Only the PCO2 and pH of venous samples may be an alternative to arterial samples under the defined formula. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

  13. Eigenspectra optoacoustic tomography achieves quantitative blood oxygenation imaging deep in tissues

    Science.gov (United States)

    Tzoumas, Stratis; Nunes, Antonio; Olefir, Ivan; Stangl, Stefan; Symvoulidis, Panagiotis; Glasl, Sarah; Bayer, Christine; Multhoff, Gabriele; Ntziachristos, Vasilis

    2016-06-01

    Light propagating in tissue attains a spectrum that varies with location due to wavelength-dependent fluence attenuation, an effect that causes spectral corruption. Spectral corruption has limited the quantification accuracy of optical and optoacoustic spectroscopic methods, and impeded the goal of imaging blood oxygen saturation (sO2) deep in tissues; a critical goal for the assessment of oxygenation in physiological processes and disease. Here we describe light fluence in the spectral domain and introduce eigenspectra multispectral optoacoustic tomography (eMSOT) to account for wavelength-dependent light attenuation, and estimate blood sO2 within deep tissue. We validate eMSOT in simulations, phantoms and animal measurements and spatially resolve sO2 in muscle and tumours, validating our measurements with histology data. eMSOT shows substantial sO2 accuracy enhancement over previous optoacoustic methods, potentially serving as a valuable tool for imaging tissue pathophysiology.

  14. Impaired Muscle Oxygenation and Elevated Exercise Blood Pressure in Hypertensive Patients: Links With Vascular Stiffness.

    Science.gov (United States)

    Dipla, Konstantina; Triantafyllou, Areti; Koletsos, Nikolaos; Papadopoulos, Stavros; Sachpekidis, Vasileios; Vrabas, Ioannis S; Gkaliagkousi, Eugenia; Zafeiridis, Andreas; Douma, Stella

    2017-08-01

    This study examined in vivo (1) skeletal muscle oxygenation and microvascular function, at rest and during handgrip exercise, and (2) their association with macrovascular function and exercise blood pressure (BP), in newly diagnosed, never-treated patients with hypertension and normotensive individuals. Ninety-one individuals (51 hypertensives and 40 normotensives) underwent office and 24-hour ambulatory BP, arterial stiffness, and central aortic BP assessment, followed by a 5-minute arterial occlusion and a 3-minute submaximal handgrip exercise. Changes in muscle oxygenated and deoxygenated hemoglobin and tissue oxygen saturation were continuously monitored by near-infrared spectroscopy and beat-by-beat BP by Finapres. Hypertensives had higher (Pexercising at the same submaximal intensity, hypertensives required a significantly greater (Pexercise. © 2017 American Heart Association, Inc.

  15. Effects of oxygenation and the stress hormones adrenaline and cortisol on the viscosity of blood from the trout oncorhynchus mykiss

    DEFF Research Database (Denmark)

    Sørensen, Bodil; Weber, Roy

    1995-01-01

    Although the concentrations of the stress hormones adrenaline and cortisol in rainbow trout (Oncorhynchus mykiss) blood increase upon hypoxic exposure, the combined effects of these hormones and O2 lack upon fish blood rheology have not been investigated. Deoxygenated blood taken by caudal puncture...... exhibited lower viscosities than oxygenated samples at low shear rates, whereas the opposite was true at high shear rates. However, blood from cannulated trout had similar viscosities in its deoxygenated and oxygenated states. In the deoxygenated state, addition of adrenaline lowered viscosity at low shear...... rates and increased it at high shear rates, resembling the effects of deoxygenation observed in blood taken by venepuncture. In oxygenated blood on the contrary, no marked adrenaline effects were observed. In deoxygenated blood, addition of cortisol lowered viscosity at all measured shear rates compared...

  16. Improving aeration for efficient oxygenation in sea bass sea cages. Blood, brain and gill histology

    Directory of Open Access Journals (Sweden)

    Berillis Panagiotis

    2016-01-01

    Full Text Available An air diffusion based system (Airx was developed to control the dissolved oxygen levels in aquaculture sea cages. The system was introduced and then tested for 37 days in a sea bass sea cage (aerated cage. A second sea bass sea cage, without the AirX, was used as a control. Oxygen levels were measured in both cages at the start of the trial, before the AirX system was introduced, and during the working period of the AirX system. Fish samples were collected 15 days after the AirX system was introduced and at the end of the experiment. Blood smears were prepared and examined microscopically. Erythrocyte major axis, minor axis and area of fish erythrocytes were measured. Leucocyte differentiation was also examined. In the control cage, the fish had significantly larger red blood cells when compared with the red blood cells of the fish in the aerated cage. Histological examination of the gills and brain revealed no morphological differences or alterations between the two groups of fish. This study demonstrated that an air diffuser system could improve the water quality of fish farmed in sea cages and enhance sea bass physiological performance, especially if DO levels fall below 60% oxygen saturation.

  17. Central Venous Catheter (Central Line)

    Science.gov (United States)

    ... venous catheter (KATHeter), also known as a central line or CVC, is long, soft, thin, hollow tube ... into a large vein (blood vessel). A central line is much like an intravenous (IV) catheter that ...

  18. Clinical overview of venous thromboembolism

    African Journals Online (AJOL)

    circulation, causing either partial or complete obstruction of pulmonary blood flow (in 4–13% of ... Keywords:anticoagulants, deep vein thrombosis, DVT, embolus, NOAC, PE, pulmonary embolism, thromboprophylaxis, thrombus, venous thromboembolism ... Cigarette smoking, including passive smoking. Hypercoagulability ...

  19. Acrolein-Induced Increases in Blood Pressure and Heart Rate Are Coupled with Decreased Blood Oxygen Levels During Exposure in Hypertensive Rats

    Science.gov (United States)

    Exposure to air pollution increases the risk of cardiovascular morbidity and mortality, especially in individuals with pre-existing cardiovascular disease. Recent studies link exposure to air pollution with reduced blood oxygen saturation suggesting that hypoxia is a potential me...

  20. Cerebral blood flow and oxygen metabolism in patients with Parkinson's disease

    Energy Technology Data Exchange (ETDEWEB)

    Kitamura, Shin; Ujike, Takashi; Kuroki, Soemu; Sakamoto, Shizuki; Soeda, Toshiyuki; Terashi, Akiro; Iio, Masaaki.

    1988-10-01

    The purpose of this study was to determine functional changes in the cerebral cortex and basal ganglia in Parkinson's disease (PD). Cerebral blood flow (CBF), oxygen extraction fraction (OEF), and cerebral metabolic rate of oxygen (CMRO/sub 2/) were determined using 0-15 positron emission tomography in 10 PD patients and five age-matched healthy volunteers. There was a tendency among PD patients towards a decreased CBF and CMRO/sub 2/ in the cerebral cortex and basal ganglia. These values were significantly lower in the frontal cortex in the PD group than the control group. There was no difference in OEF between the groups. A more decreased cerebral oxygen metabolism was observed in patients staged as severer on the scale of Hoehn and Yahr. There was no correlation between cerebral oxygen metabolism and tremor, rigidity, or bradykinesis. A decreased cerebral oxygen metabolism was associated with mental disorders, such as depression, hallucination, and dementia. These results may provide an important clue for the understanding of mesocortical dopaminergic pathway and the relationship between PD and dementia. (N.K.).

  1. Beyond intracranial pressure: optimization of cerebral blood flow, oxygen, and substrate delivery after traumatic brain injury.

    Science.gov (United States)

    Bouzat, Pierre; Sala, Nathalie; Payen, Jean-François; Oddo, Mauro

    2013-07-10

    Monitoring and management of intracranial pressure (ICP) and cerebral perfusion pressure (CPP) is a standard of care after traumatic brain injury (TBI). However, the pathophysiology of so-called secondary brain injury, i.e., the cascade of potentially deleterious events that occur in the early phase following initial cerebral insult-after TBI, is complex, involving a subtle interplay between cerebral blood flow (CBF), oxygen delivery and utilization, and supply of main cerebral energy substrates (glucose) to the injured brain. Regulation of this interplay depends on the type of injury and may vary individually and over time. In this setting, patient management can be a challenging task, where standard ICP/CPP monitoring may become insufficient to prevent secondary brain injury. Growing clinical evidence demonstrates that so-called multimodal brain monitoring, including brain tissue oxygen (PbtO2), cerebral microdialysis and transcranial Doppler among others, might help to optimize CBF and the delivery of oxygen/energy substrate at the bedside, thereby improving the management of secondary brain injury. Looking beyond ICP and CPP, and applying a multimodal therapeutic approach for the optimization of CBF, oxygen delivery, and brain energy supply may eventually improve overall care of patients with head injury. This review summarizes some of the important pathophysiological determinants of secondary cerebral damage after TBI and discusses novel approaches to optimize CBF and provide adequate oxygen and energy supply to the injured brain using multimodal brain monitoring.

  2. Aminoguanidine effects on nerve blood flow, vascular permeability, electrophysiology, and oxygen free radicals

    Energy Technology Data Exchange (ETDEWEB)

    Kihara, Mikihiro; Schmelzer, J.D.; Poduslo, J.F.; Curran, G.L.; Nickander, K.K.; Low, P.A. (Mayo Foundation, Rochester, MN (United States))

    1991-07-15

    Since advanced glycosylation end products have been suggested to mediate hyperglycemia-induced microvascular atherogenesis and because aminoguanidine (AG) prevents their generation, the authors examined whether AG could prevent or ameliorate the physiologic and biochemical indices of streptozotocin (STZ)-induced experimental diabetic neuropathy. Four groups of adult Sprague-Dawley rats were studied: group I received STZ plus AG, group II received STZ plus AG, group III received STZ alone, and group IV was a control. They monitored conduction and action potential amplitudes serially in sciatic-tibial and caudal nerves, nerve blood flow, oxygen free radical activity (conjugated dienes and hydroperoxides), and the product of the permeability coefficient and surface area to {sup 125}I-labeled albumin. STZ-induced diabetes (group III) caused a 57% reduction in nerve blood flow and in abnormal nerve conduction and amplitudes and a 60% increase in conjugated dienes. Nerve blood flow was normalized by 8 weeks with AG (groups I and II) and conduction was significantly improved, in a dose-dependent manner, by 16 and 24 weeks in sciatic-tibial and caudal nerves, respectively. The permeability coefficient was not impaired, suggesting a normal blood-nerve barrier function for albumin, and the oxygen free-radical indices were not ameliorated by AG. They suggest that AG reverses nerve ischemia and more gradually improves their electrophysiology by an action on nerve microvessels. AG may have potential in the treatment of diabetic neuropathy.

  3. CONFIABILIDAD DE LOS CÁLCULOS ESPECIALES DE LA OXIGENACIÓN DE MUESTRAS VENOSAS CENTRALES EN CIRUGÍA CARDÍACA / Reliability of the special calculations of oxygenation from central venous samples in cardiac surgery

    Directory of Open Access Journals (Sweden)

    Pedro A. Hidalgo Menéndez

    2010-09-01

    Full Text Available Resumen Introducción y objetivos: Diferentes mecanismos se implican en la captación, transporte, entrega y utilización del oxígeno en los organismos vivos, y cada uno de ellos puede afectarse en el enfermo grave. El propósito de este trabajo fue conocer la confiabilidad de los cálculos especiales de la oxigenación, procedentes de muestras venosas centrales. Método: Se realizó un estudio prospectivo con 22 pacientes a los que se les practicó cirugía cardíaca, en los que se compararon los cálculos especiales obtenidos de muestras venosas centrales con los venosos-mixtos. Resultados: Se encontró correlación estadística significativa entre la diferencia arteriovenosa de oxígeno, el cortocircuito y la saturación venosa de hemoglobina oxigenada. Sin embargo, se halló un bajo por ciento de fiabilidad al aplicarles los criterios protocolizados; pero fue factible mediante ecuaciones de regresión, lograr una corrección altamente significativa (p < 0,01, que elevó la fiabilidad a más del 90 %. Conclusiones: Las muestras venosas centrales constituyen una alternativa recomendable para obtener cálculos especiales de la oxigenación durante la cirugía cardíaca. / Abstract Introduction and Objectives: Different mechanisms are involved in the uptake, transportation, delivery and utilization of oxygen in living organisms, and each of them may be affected in the severely ill patient. The purpose of this study was to determine the reliability of the special calculations of oxygenation, from central venous samples. Methods: A prospective study was performed on 22 patients who underwent cardiac surgery, and in which special calculations obtained from central venous samples were compared to mixed-venous samples calculations. Results: A statistically significant correlation among the arteriovenous oxygen difference, the shunt and the venous hemoglobin oxygen saturation was found. However, a small percentage of reliability was found when

  4. A role for peripherally inserted central venous catheters in the prevention of catheter-related blood stream infections in patients with hematological malignancies.

    Science.gov (United States)

    Sakai, Toshiro; Kohda, Kyuhei; Konuma, Yuichi; Hiraoka, Yasuko; Ichikawa, Yukari; Ono, Kaoru; Horiguchi, Hiroto; Tatekoshi, Ayumi; Takada, Kouichi; Iyama, Satoshi; Kato, Junji

    2014-12-01

    Central venous catheter-related blood stream infections (CR-BSIs) are a serious complication in patients with hematological malignancies. However, it remains unclear whether there is a difference in the rate of CR-BSI associated with the conventional type of central venous catheters (cCVCs) and peripherally inserted CVCs (PICCs) in such patients. To address this question, we retrospectively investigated the incidence of CR-BSIs associated with PICCs versus cCVCs in patients with hematological malignancies. We used PICCs in all consecutive patients requiring CVC placement between February 2009 and February 2013. We compared the CR-BSI rate in patients with PICCs with that in patients with cCVCs treated between September 2006 and January 2009 (control group). Eighty-four patients received PICCs and 85 received cCVCs. The most common reason for removal due to catheter-related complications was CR-BSI. The CR-BSI rate in the PICC group was significantly lower than that in the cCVC group (PICCs: 1.23/1000 catheter days; cCVCs: 5.30/1000 catheter days; P Catheter-related complications other than CR-BSIs occurred at an extremely low rate in the PICC group. The median catheter-related complication-free survival duration was significantly longer in the PICC group than in the cCVC group. Our study shows that PICCs are useful in patients with hematological malignancies.

  5. Assessment of liver circulation by quantitative scintiangiography: Evaluation of the relative contribution of the hepatic arterial and portal venous blood flows to liver perfusion

    Energy Technology Data Exchange (ETDEWEB)

    Molino, G.; Squadrone, E.; Baccegal, M.; Magnani, C.

    1989-04-01

    Quantitative hepatic scintiangiography was previously used for evaluating the relative contribution of hepatic arterial and portal venous blood flows to the hepatic circulation. The present study compares 3 different procedures (automatic and manual integration, and slope fitting methods) for analyzing the hepatic time activity curves obtained after bolus i.v. injection of 370 MBq /sup 99m/Tc-diethylentriaminopentacetic acid. Twenty five subjects were studied: Five controls, ten cirrhotics, and ten portal hypertensive patients previously submitted to side to side portacaval anastomosis. The correspondence between results given by the different methods was satisfactory only in shunted patients, and the reproducibility of computed parameters was quite poor for all procedures. Accordingly, none of the methods can be considered as supporting reliable quantitative pathophysiological evaluations. However, the hepatic arterial/portal venous flow ratio was found to be increased in liver cirrhosis and in shunted patients and therefore, in spite of the limitations underlined before and of the absence of data on the reproducibility of consecutive injections, hepatic scintiangiography may be of some clinical utility.

  6. Tissue blood flow and oxygen consumption measured with near-infrared frequency-domain spectroscopy

    Science.gov (United States)

    Paunescu, Lelia Adelina

    2001-12-01

    For decades, researchers have contributed with new ways of applying physics' principles to medicine. Moreover, researchers were involved in developing new, non-invasive instrumentation for medical applications. Recently, application of optical techniques in biology and medicine became an important field. Researchers found a non- invasive approach of using visible and near-infrared light as a probe for tissue investigation. Optical methods can contribute to medicine by offering the possibility of rapid, low-resolution, functional images and real-time devices. Near-infrared spectroscopy (NIRS) is a useful technique for the investigation of biological tissues because of the relatively low absorption of water and high absorption of oxy- and deoxy-hemoglobin in the near- infrared region of 750-900 nm. Due to these properties, the near-infrared light can penetrate biological tissues in the range of 0.5-2 cm, offering investigation possibility of deep tissues and differentiate among healthy and diseased tissues. This work represents the initial steps towards understanding and improving of the promising near- infrared frequency-domain technique. This instrument has a very important advantage: it can be used non-invasively to investigate many parts of the human body, including the brain. My research consists primarily of in vivo measurements of optical parameters such as absorption and reduced scattering coefficients and consequently, blood parameters such as oxy, deoxy, and total hemoglobin concentrations, tissue oxygen saturation, blood flow and oxygen consumption of skeletal muscle of healthy and diseased subjects. This research gives a solid background towards a ready- to-use instrument that can continuously, in real-time, measure blood parameters and especially blood oxygenation. This is a very important information in emergency medicine, for persons under intensive care, or undergoing surgery, organ transplant or other interventions.

  7. On-line blood viscosity monitoring in vivo with a central venous catheter, using electrical impedance technique

    NARCIS (Netherlands)

    Pop, G.A.M.; Bisschops, L.L.A.; Iliev, B.; Struijk, P.C.; Hoeven, J.G. van der; Hoedemaekers, C.W.E.

    2013-01-01

    Blood viscosity is an important determinant of microvascular hemodynamics and also reflects systemic inflammation. Viscosity of blood strongly depends on the shear rate and can be characterized by a two parameter power-law model. Other major determinants of blood viscosity are hematocrit, level of

  8. Imaging the effects of oxygen saturation changes in voluntary apnea and hyperventilation on susceptibility-weighted imaging.

    Science.gov (United States)

    Chang, K; Barnes, S; Haacke, E M; Grossman, R I; Ge, Y

    2014-06-01

    Cerebrovascular oxygenation changes during respiratory challenges have clinically important implications for brain function, including cerebral autoregulation and the rate of brain metabolism. SWI is sensitive to venous oxygenation level by exploitation of the magnetic susceptibility of deoxygenated blood. We assessed cerebral venous blood oxygenation changes during simple voluntary breath-holding (apnea) and hyperventilation by use of SWI at 3T. We performed SWI scans (3T; acquisition time of 1 minute, 28 seconds; centered on the anterior commissure and the posterior commissure) on 10 healthy male volunteers during baseline breathing as well as during simple voluntary hyperventilation and apnea challenges. The hyperventilation and apnea tasks were separated by a 5-minute resting period. SWI venograms were generated, and the signal changes on SWI before and after the respiratory stress tasks were compared by means of a paired Student t test. Changes in venous vasculature visibility caused by the respiratory challenges were directly visualized on the SWI venograms. The venogram segmentation results showed that voluntary apnea decreased the mean venous blood voxel number by 1.6% (P hyperventilation increased the mean venous blood voxel number by 2.7% (P < .0001). These results can be explained by blood CO2 changes secondary to the respiratory challenges, which can alter cerebrovascular tone and cerebral blood flow and ultimately affect venous oxygen levels. These results highlight the sensitivity of SWI to simple and noninvasive respiratory challenges and its potential utility in assessing cerebral hemodynamics and vasomotor responses. © 2014 by American Journal of Neuroradiology.

  9. EFFECTS OF BLOOD LACTATE ON OXYGEN UPTAKE KINETICS DURING RECOVERY AFTER SPRINT IN HUMANS

    Directory of Open Access Journals (Sweden)

    Tokuo Yano

    2012-07-01

    Full Text Available The purpose of this study was to examine the effects of blood lactate level (La on oxygen uptake ( ·VO2 kinetics during recovery after short-term exercise with maximal effort (sprint. Three sprints were performed on a cycle ergometer with a load of 8% f body weight at maximal rotation rate. ·VO2 kinetics and oxygen debt were determined after three sprint tests: one 10-s cycling sprint, five repeated 10-s cycling sprints with 6-min intervals and one 30-s cycling sprint. There was no significant difference between peak power outputs in the 10-s sprint and five sprints. There was no difference in ·VO2 kinetics during recovery from one sprint and during recovery after five sprints. La peaked at 5 min. The peak value of La was significantly lower in one sprint (4.41 ± 0.9 mM than in five sprints (7.01 ± 2.2 mM. Thus, despite a difference in La, there was no difference between ·VO2 kinetics during recovery after one sprint and after five sprints. There was a significant difference in ·VO2 between the five sprints and 30-s sprint from 70 s to 320 s during recovery, but there were no significant differences in La after 5 min of recovery. There were two phases in ·VO2. They consisted of fast oxygen debt and slow oxygen debt. There were also no differences in slow and fast oxygen debts between the two 10-s sprints despite significant differences in blood lactate during recovery. Peak La in the five sprints was not significantly different from that in the 30-s sprint (8.68 ± 1.2 mM. However, slow oxygen debt was significantly greater in the 30-s sprint than in the five sprints. It is concluded that ·VO2 kinetics during recovery are not affected by an increase in blood lactate.

  10. Cerebral blood flow and oxygen metabolism in dementia with Lewy bodies

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Yoshitomo; Takahashi, Satoshi; Yonezawa, Hisashi [Iwate Medical Univ., Morioka (Japan). School of Medicine

    2000-06-01

    Regional cerebral blood flow (rCBF), oxygen metabolism (rCMRO{sub 2}) and the oxygen extraction fraction (rOEF) were measured using the steady-state {sup 15}O technique and positron emission tomography (PET) in six patients with dementia with Lewy bodies (DLB), and compared with ten patients with Alzheimer disease (AD) and six normal controls. In the AD patients, rCBF and rCMRO{sub 2} were significantly decreased in the frontal, parietal, and temporal cortices compared with controls. In DLB patients, rCBF and rCMRO{sub 2} were decreased in the frontal, parietal, temporal, and occipital cortices compared with controls, and were decreased more diffusely than in AD patients. rCBF and rCMRO{sub 2} were significantly decreased in occipital cortex compared with AD patients. rOEF was significantly increased in the parieto-temporal cortex in AD patients compared with controls. In DLB patients, rOEF was significantly increased not only in the parieto-temporal cortex but also in the occipital and frontal cortices compared with controls, and was significantly increased in the occipital cortex compared with AD patients. The diffuse reduction of cerebral blood flow and oxygen metabolism including the occipital cortex may be related to visual hallucination and other visuospatial deficits frequently seen in DLB patients. The increase in rOEF may be mainly due to the reduction in the vascular bed associated with decreased activity in the vasodilatory cholinergic system. (author)

  11. Comparison of extracapillary and endocapillary blood flow oxygenators for open heart surgery in dogs: efficiency of gas exchange and platelet conservation.

    Science.gov (United States)

    Hoshi, Katsuichiro; Tanaka, Ryou; Shibazaki, Akira; Nagashima, Yukiko; Hirao, Hidehiro; Namiki, Ryosuke; Takashima, Kazuaki; Noishiki, Yasuharu; Yamane, Yoshihisa

    2003-03-01

    The goal of the current study was to compare the efficiency of gas exchange and platelet conservation of a new extracapillary blood flow oxygenator versus an endocapillary blood flow oxygenator during open heart surgery with extracorporeal circulation in dogs. Dilation and remodeling of the right ventricular outflow tract of dogs was performed using a patch graft technique to simulate pulmonary stenosis. Sequential pre- and post-operative blood analysis revealed that gas exchange efficiency and platelet conservation was significantly greater with the extracapillary blood flow oxygenator than with the endocapillary blood flow oxygenator. However, the priming volume of the extracapillary blood flow oxygenator was significantly greater, leading to hemodilution. We conclude that while the extracapillary blood flow oxygenator provided benefits in terms of gas exchange and platelet conservation, development of a smaller extracapillary blood flow type oxygenator to reduce hemodilution effects would be beneficial.

  12. Meal-induced changes in splanchnic blood flow and oxygen uptake in middle-aged healthy humans

    DEFF Research Database (Denmark)

    Madsen, Jan L; Søndergaard, Susanne B; Møller, Søren

    2006-01-01

    healthy men (52-76 years). Splanchnic blood flow was measured during hepatic vein catheterization by indirect Fick principle with indocyanine green as the indicator. Splanchnic oxygen uptake was calculated from splanchnic blood flow and the arteriovenous oxygen difference. RESULTS: The meal induced...... in middle-aged healthy humans. Our data may be relevant for the evaluation of corresponding data from patients with suspected chronic intestinal ischaemia....

  13. Comparison of arterial and venous blood gases and the effects of analysis delay and air contamination on arterial samples in patients with chronic obstructive pulmonary disease and healthy controls.

    LENUS (Irish Health Repository)

    O'Connor, T M

    2012-01-31

    BACKGROUND: Arterial blood gases (ABGs) are often sampled incorrectly, leading to a \\'mixed\\' or venous sample. Delays in analysis and air contamination are common. OBJECTIVES: We measured the effects of these errors in patients with chronic obstructive pulmonary disease (COPD) exacerbations and controls. METHODS: Arterial and venous samples were analyzed from 30 patients with COPD exacerbation and 30 controls. Venous samples were analysed immediately and arterial samples separated into non-air-contaminated and air-contaminated specimens and analysed at 0, 30, 60, 90 and 180 min. RESULTS: Mean venous pH was 7.371 and arterial pH was 7.407 (p < 0.0001). There was a correlation between venous and arterial pH (r = 0.5347, p < 0.0001). The regression equation to predict arterial pH was: arterial pH = 4.2289 + 0.43113 . venous pH. There were no clinically significant differences in arterial PO associated with analysis delay. A statistically significant decline in pH was detected at 30 min in patients with COPD exacerbation (p = 0.0042) and 90 min in controls (p < 0.0001). A clinically significant decline in pH emerged at 73 min in patients with COPD exacerbation and 87 min in controls. Air contamination was associated with a clinically significant increase in PO in all samples, including those that were immediately analyzed. CONCLUSIONS: Arterial and venous pH differ significantly. Venous pH cannot accurately replace arterial pH. Temporal delays in ABG analysis result in a significant decline in measured pH. ABGs should be analysed within 30 min. Air contamination leads to an immediate increase in measured PO, indicating that air-contaminated ABGs should be discarded.

  14. Changes in hemoglobin-oxygen affinity with shape variations of red blood cells

    Science.gov (United States)

    Chowdhury, Aniket; Dasgupta, Raktim; Majumder, Shovan K.

    2017-10-01

    Shape variations of red blood cells (RBCs) are known to occur upon exposure to various drugs or under diseased conditions. The commonly observed discocytic RBCs can be transformed to echinocytic or stomatocytic shape under such conditions. Raman spectra of the three major shape variations, namely discocyte, echinocyte, and stomatocyte, of RBCs were studied while subjecting the cells to oxygenated and deoxygenated conditions. Analysis of the recorded spectra suggests an increased level of hemoglobin (Hb)-oxygen affinity for the echinocytes. Also, some level of Hb degradation could be noticed for the deoxygenated echinocytes. The effects may arise from a reduced level of intracellular adenosine triphosphate in echinocytic cells and an increased fraction of submembrane Hb.

  15. Eigenspectra optoacoustic tomography achieves quantitative blood oxygenation imaging deep in tissues

    CERN Document Server

    Tzoumas, Stratis; Olefir, Ivan; Stangl, Stefan; Symvoulidis, Panagiotis; Glasl, Sarah; Bayer, Christine; Multhoff, Gabriele; Ntziachristos, Vasilis

    2015-01-01

    Light propagating in tissue attains a spectrum that varies with location due to wavelength-dependent fluence attenuation by tissue optical properties, an effect that causes spectral corruption. Predictions of the spectral variations of light fluence in tissue are challenging since the spatial distribution of optical properties in tissue cannot be resolved in high resolution or with high accuracy by current methods. Spectral corruption has fundamentally limited the quantification accuracy of optical and optoacoustic methods and impeded the long sought-after goal of imaging blood oxygen saturation (sO2) deep in tissues; a critical but still unattainable target for the assessment of oxygenation in physiological processes and disease. We discover a new principle underlying light fluence in tissues, which describes the wavelength dependence of light fluence as an affine function of a few reference base spectra, independently of the specific distribution of tissue optical properties. This finding enables the introd...

  16. Artificial oxygen carriers as red blood cell substitutes: a selected review and current status.

    Science.gov (United States)

    Kim, Hae Won; Greenburg, A Gerson

    2004-09-01

    Two distinct approaches are being explored in red blood cell substitute (RCS) development: hemoglobin-based oxygen carriers (HBOCs) and perfluorocarbon-based oxygen carriers (PFBOCs). HBOCs are based on intra- and/or intermolecularly "engineered" human or animal hemoglobins (Hbs), optimized for O2 delivery and longer intravascular circulation. Some are currently being evaluated in Phase II/III clinical studies. PFBOCs are aqueous emulsions of perfluorocarbon derivatives that dissolve relatively large amounts of O2. A PFBOC based on a 60% (wt/vol) emulsion of perfluorooctyl bromide has been evaluated in Phase II/III clinical trials. Although current PFBOC products generally require patients to breathe O2 enriched air, they render certain advantages since they are totally synthetic. This article provides a short review of the basic principles, approaches, and current status of RCS development. Results of preclinical and clinical studies including recent Phase II/III clinical studies are discussed.

  17. Impaired cerebral blood flow and oxygenation during exercise in type 2 diabetic patients

    DEFF Research Database (Denmark)

    Kim, Yu-Sok; Seifert, Thomas; Brassard, Patrice

    2015-01-01

    Endothelial vascular function and capacity to increase cardiac output during exercise are impaired in patients with type 2 diabetes (T2DM). We tested the hypothesis that the increase in cerebral blood flow (CBF) during exercise is also blunted and, therefore, that cerebral oxygenation becomes...... affected and perceived exertion increased in T2DM patients. We quantified cerebrovascular besides systemic hemodynamic responses to incremental ergometer cycling exercise in eight male T2DM and seven control subjects. CBF was assessed from the Fick equation and by transcranial Doppler-determined middle...... at higher workloads in T2DM patients and their work capacity and increase in cardiac output were only ~80% of that established in the control subjects. CBF and cerebral oxygenation were reduced during exercise in T2DM patients (P

  18. Venous Ulcers

    Science.gov (United States)

    Caprini, J.A.; Partsch, H.; Simman, R.

    2013-01-01

    Venous leg ulcers are the most frequent form of wounds seen in patients. This article presents an overview on some practical aspects concerning diagnosis, differential diagnosis and treatment. Duplex ultrasound investigations are essential to ascertain the diagnosis of the underlying venous pathology and to treat venous refluxes. Differential diagnosis includes mainly other vascular lesions (arterial, microcirculatory causes), hematologic and metabolic diseases, trauma, infection, malignancies. Patients with superficial venous incompetence may benefit from endovenous or surgical reflux abolition diagnosed by Duplex ultrasound. The most important basic component of the management is compression therapy, for which we prefer materials with low elasticity applied with high initial pressure (short-stretch bandages and Velcro-strap devices). Local treatment should be simple, absorbing and not sticky dressings keeping adequate moisture balance after debridement of necrotic tissue and biofilms are preferred. After the ulcer is healed compression therapy should be continued in order to prevent recurrence. PMID:26236636

  19. A pilot randomised controlled trial of peripheral fractional oxygen extraction to guide blood transfusions in preterm infants

    OpenAIRE

    Wardle, S; Garr, R; Yoxall, C; Weindling, A

    2002-01-01

    Background: Peripheral fractional oxygen extraction (FOE) may be a better indicator of the need for transfusion than the haemoglobin concentration (Hb) because it is a measure of the adequacy of oxygen delivery to meet demand. A randomised controlled trial of the use of peripheral FOE to guide the need for blood transfusions in preterm infants was carried out to test this hypothesis.

  20. Cutaneous oxygen uptake and its relation to skin blood perfusion and ambient salinity in the plaice, Pleuronectes platessa

    DEFF Research Database (Denmark)

    Steffensen, J F; Lomholt, J P

    1985-01-01

    Oxygen uptake across plaice skin was unaffected by temporary arrest of skin blood flow. This indicates that oxygen taken up across the skin is consumed by the skin itself. Weight specific rate of O2-consumption of skin is estimated to be 1.7-1.9 times that of the entire fish. Total resting O2...

  1. Extra corporeal membrane oxygenation in newborns : implications for brain and lung

    NARCIS (Netherlands)

    Heijst, Adrianus Franciscus Jacobus van

    2004-01-01

    Extracorporeal membrane oxygenation (ECMO) is a rescue treatment for newborns with severe respiratory insufficiency. In veno-arterial ECMO, venous blood is drained from the right atrium, oxygenated in an artificial lung and reinfused in the aorta. For vascular access the right internal jugular vein

  2. Central venous-to-arterial carbon dioxide difference and the effect of venous hyperoxia: A limiting factor, or an additional marker of severity in shock?

    Science.gov (United States)

    Saludes, P; Proença, L; Gruartmoner, G; Enseñat, L; Pérez-Madrigal, A; Espinal, C; Mesquida, J

    2017-12-01

    Central venous-to-arterial carbon dioxide difference (P cva CO 2 ) has demonstrated its prognostic value in critically ill patients suffering from shock, and current expert recommendations advocate for further resuscitation interventions when P cva CO 2 is elevated. P cva CO 2 combination with arterial-venous oxygen content difference (P cva CO 2 /C av O 2 ) seems to enhance its performance when assessing anaerobic metabolism. However, the fact that PCO 2 values might be altered by changes in blood O 2 content (the Haldane effect), has been presented as a limitation of PCO 2 -derived variables. The present study aimed at exploring the impact of hyperoxia on P cva CO 2 and P cva CO 2 /C av O 2 during the early phase of shock. Prospective interventional study. Ventilated patients suffering from shock within the first 24 h of ICU admission. Patients requiring FiO 2  ≥ 0.5 were excluded. At inclusion, simultaneous arterial and central venous blood samples were collected. Patients underwent a hyperoxygenation test (5 min of FiO 2 100%), and arterial and central venous blood samples were repeated. Oxygenation and CO 2 variables were calculated at both time points. Twenty patients were studied. The main cause of shock was septic shock (70%). The hyperoxygenation trial increased oxygenation parameters in arterial and venous blood, whereas PCO 2 only changed at the venous site. Resulting P cva CO 2 and P cva CO 2 /C av O 2 significantly increased [6.8 (4.9, 8.1) vs. 7.6 (6.7, 8.5) mmHg, p 0.001; and 1.9 (1.4, 2.2) vs. 2.3 (1.8, 3), p venous site within the trial (ρ -0.46, p 0.04; ρ 0.6, p venous hyperoxia. Elevated P cva CO 2 /C av O 2 values were associated with higher PO 2 transmission to the venous compartment, suggesting higher shunting phenomena.

  3. Correlação entre gasometria atrial direita e índice cardíaco no pós-operatório de cirurgia cardíaca Correlation between right atrial venous blood gasometry and cardiac index in cardiac surgery postoperative period

    Directory of Open Access Journals (Sweden)

    João Jackson Duarte

    2010-06-01

    Full Text Available OBJETIVO: Determinar a confiabilidade em se correlacionar o índice cardíaco com os dados fornecidos pela gasometria do sangue venoso atrial direito em pacientes submetidos à cirurgia cardíaca, durante o período pós-operatório. MÉTODOS: A partir das amostras de sangue arterial e venoso do átrio direito, colhidas no pós-operatório de cirurgia cardíaca, foram determinados os parâmetros de oxigênio do sangue venoso do átrio direito. Estes parâmetros foram então comparados com o índice cardíaco determinado pela termodiluição. RESULTADOS: Houve boa correlação entre a saturação de oxigênio do sangue venoso do átrio direito (SvO2, diferença artério-venosa do conteúdo de oxigênio do sangue colhido no átrio direito e o índice cardíaco aferido pela termodiluição, com boa sensibilidade e especificidade e alto valor preditivo positivo e negativo. A pressão do sangue do átrio direito (PvO2 apresentou baixa sensibilidade na estimativa de baixo débito cardíaco. CONCLUSÃO: No pós-operatório de cirurgia cardíaca, a SvO2e a diferença artério-venosa do conteúdo de oxigênio (C(avO2 apresentaram-se como parâmetros confiáveis correlacionados a baixo débito cardíaco. A PvO2 foi pouco sensível no diagnóstico de baixo débito no pós-operatório de cirurgia cardíaca.OBJECTIVE: To determine, even during postoperative period, the confiability of the cardiac index correlate with the data data given by a central atrial venous blood gasometry in patients who underwent cardiac surgery. METHODS: From the sample of arterial and venous blood of right atrium gathered in postoperative of cardiac surgery, it was determinated the hemoglobin concentration and the gasometric study through what was observed of the venous oxygen saturation (SvO2 and the partial pressure of oxygen from venous blood gathered in right atrium (PvO2, add to the calculation of artery-venous difference of the oxygen content - radial artery / right atrium (C

  4. Challenges in understanding the impact of blood pressure management on cerebral oxygenation in the preterm brain

    Directory of Open Access Journals (Sweden)

    Aminath eAzhan

    2012-12-01

    Full Text Available Systemic hypotension in preterm infants has been related to increased mortality, cerebrovascular lesions and neurodevelopmental morbidity. Treatment of hypotension with inotropic medications aims at preservation of end organ perfusion and oxygen delivery, especially the brain. The common inotropic medications in preterm infants include dopamine, dobutamine, adrenalin, with adjunctive use of corticosteroids in cases of refractory hypotension. Whether maintenance of mean arterial blood pressure (MAP by use of inotropic medication is neuroprotective or not remains unclear. This review explores the different inotropic agents and their effects on perfusion and oxygenation in the preterm brain, in clinical studies as well as in animal models. Dopamine and adrenalin, because of their -adrenergic vasoconstrictor actions, have raised concerns of reduction in cerebral blood flow (CBF. Several studies in hypotensive preterm infants have shown that dopamine elevates CBF together with increased MAP, in keeping with limited cerebro-autoregulation. Adrenaline is also effective in raising cerebral perfusion together with MAP in preterm infants. Experimental studies in immature animals show no cerebro-vasoconstrictive effects of dopamine or adrenaline, but demonstrate the consistent findings of increased cerebral perfusion and oxygenation with the use of dopamine, dobutamine and adrenaline, alongside with raised MAP. Both clinical and animal studies report the transitory effects of adrenaline in increasing plasma lactate, and blood glucose, which might render its use as a 2nd line therapy. To investigate the cerebral effects of inotropic agents in long-term outcome in hypotensive preterm infants, carefully designed prospective research possibly including preterm infants with permissive hypotension is required. Preterm animal models would be useful in investigating the relationship between the physiological effects of inotropes and histopathology outcomes in

  5. Blood oxygen affinity increases during digestion in the South American rattlesnake, Crotalus durissus terrificus.

    Science.gov (United States)

    Bovo, Rafael P; Fuga, Adriana; Micheli-Campbell, Mariana A; Carvalho, José E; Andrade, Denis V

    2015-08-01

    Digesting snakes experience massive increases in metabolism that can last for many days and are accompanied by adjustments in the oxygen transport cascade. Accordingly, we examined the oxygen-binding properties of the blood in the South American rattlesnake (Crotalus durissus terrificus) during fasting and 24 and 48h after the snakes have ingested a rodent meal corresponding to 15% (±2%) of its own body mass. In general, oxygen-hemoglobin (Hb-O2) affinity was significantly increased 24h post-feeding, and then returned toward fasting values within 48h post-feeding. Content of organic phosphates ([NTP] and [NTP]/[Hb]), hemoglobin cooperativity (Hill's n), and Bohr Effect (ΔlogP50/ΔpH) were not affected by feeding. The postprandial increase in Hb-O2 affinity in the South American rattlesnake can be almost entirely ascribed by the moderate alkaline tide that follows meal ingestion. In general, digesting snakes were able to regulate blood metabolites at quite constant levels (e.g., plasma osmolality, lactate, glucose, and total protein levels). The level of circulating lipids, however, was considerably increased, which may be related to their mobilization, since lipids are known to be incorporated by the enterocytes after snakes have fed. In conclusion, our results indicate that the exceptional metabolic increment exhibited by C. d. terrificus during meal digestion is entirely supported by the aerobic pathways and that among the attending cardiorespiratory adjustments, pulmonary Hb-O2 loading is likely improved due to the increment in blood O2 affinity. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. Differences in prefrontal blood oxygenation during an acute multitasking stressor in ecstasy polydrug users.

    Science.gov (United States)

    Roberts, C A; Wetherell, M A; Fisk, J E; Montgomery, C

    2015-01-01

    Cognitive deficits are well documented in ecstasy (3,4-methylenedioxymethamphetamine; MDMA) users, with such deficits being taken as evidence of dysregulation of the serotonin (5-hydroxytryptamine; 5-HT) system. More recently neuroimaging has been used to corroborate these deficits. The present study aimed to assess multitasking performance in ecstasy polydrug users, polydrug users and drug-naive individuals. It was predicted that ecstasy polydrug users would perform worse than non-users on the behavioural measure and this would be supported by differences in cortical blood oxygenation. In the study, 20 ecstasy-polydrug users, 17 polydrug users and 19 drug-naive individuals took part. On day 1, drug use history was taken and questionnaire measures were completed. On day 2, participants completed a 20-min multitasking stressor while brain blood oxygenation was measured using functional near infrared spectroscopy (fNIRS). There were no significant differences between the three groups on the subscales of the multitasking stressor. In addition, there were no significant differences on self-report measures of perceived workload (NASA Task Load Index). In terms of mood, ecstasy users were significantly less calm and less relaxed compared with drug-naive controls. There were also significant differences at three voxels on the fNIRS, indicating decreased blood oxygenation in ecstasy users compared with drug-naive controls at voxel 2 (left dorsolateral prefrontal cortex), voxel 14 and voxel 16 (right dorsolateral prefrontal cortex), and compared with polydrug controls at V14. The results of the present study provide support for changes in brain activation during performance of demanding tasks in ecstasy polydrug users, which could be related to cerebral vasoconstriction.

  7. Blood gas analysis of the jejunum in the supercharge technique: to what degree does circulation improve?

    Science.gov (United States)

    Ueda, Kazuki; Kajikawa, Akiyoshi; Suzuki, Yasutoshi; Okazaki, Mutsumi; Nakagawa, Masahiro; Iida, Shoko

    2007-05-01

    The supercharge technique has become widely prevalent in the field of esophageal reconstruction. Despite the logical advantages with this technique, the actual degree of its effect on the blood circulation is not clear. There may be cases in which the supercharge technique is not necessary for survival of the jejunum. To decide whether or not the supercharge technique is indicated, it is crucial to know how effective it is in improving blood flow to the jejunum. The effect of the additional vessel anastomosis in the pedicled jejunal transfer was evaluated by blood gas analysis of the venous blood in the mesenteric vein. In 27 patients undergoing pedicled jejunal transfer with additional vessel anastomosis using the internal mammary vessels for reconstruction of the thoracic esophagus, intraoperative blood sampling was performed three times: before anastomosis, after venous anastomosis, and after venous and arterial anastomosis. The venous partial pressure of oxygen showed little increase after the venous anastomosis (mean, 115.7 percent; p = 0.0022). In contrast, venous partial pressure of oxygen increased markedly after the arterial and venous anastomosis in most of the patients (mean, 177.8 percent; p < 0.0001). Similarly, venous partial pressure of carbon dioxide, after both anastomoses, decreased to a lower level than before the additional anastomosis in most patients (mean, 93.1 percent; p = 0.035). The authors conclude that the additional anastomosis of both the artery and the vein is recommended if it is possible.

  8. Cerebral oxygen metabolism and cerebral blood flow in man during light sleep (stage 2)

    DEFF Research Database (Denmark)

    Madsen, P L; Schmidt, J F; Holm, S

    1991-01-01

    We measured cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO2) during light sleep (stage 2) in 8 young healthy volunteers using the Kety-Schmidt technique with 133Xe as the inert gas. Measurements were performed during wakefulness and light sleep as verified by standard....... They differ in respect of arousal threshold as a stronger stimulus is required to awaken a subject from deep sleep as compared to light sleep. Our results suggest that during non-rapid eye movement sleep cerebral metabolism and thereby cerebral synaptic activity is correlated to cerebral readiness rather than...

  9. Arterial Spin Labeling and Blood Oxygen Level-Dependent MRI Cerebrovascular Reactivity in Cerebrovascular Disease

    DEFF Research Database (Denmark)

    Smeeing, Diederik P J; Hendrikse, Jeroen; Petersen, Esben T

    2016-01-01

    BACKGROUND: The cerebrovascular reactivity (CVR) results of blood oxygen level-dependent (BOLD) and arterial spin labeling (ASL) MRI studies performed in patients with cerebrovascular disease (steno-occlusive vascular disease or stroke) were systematically reviewed. SUMMARY: Thirty-one articles...... found a significant lower ASL CVR in the ipsilateral hemispheres of patients compared to controls. KEY MESSAGES: This review brings support for a reduced BOLD and ASL CVR in the ipsilateral hemisphere of patients with cerebrovascular disease. We suggest that future studies will be performed in a uniform...... way so reference values can be established and could be used to guide treatment decisions in patients with cerebrovascular disease....

  10. Lactate delivery (not oxygen) limits hepatic gluconeogenesis when blood flow is reduced.

    Science.gov (United States)

    Sumida, Ken D; Urdiales, Jerry H; Donovan, Casey M

    2006-01-01

    The purpose of this study was to determine, using the isolated liver perfusion technique, whether the limiting factor for hepatic gluconeogenesis (GNG) from lactate was precursor delivery or oxygen availability during reduced flow rates of 0.85 or 0.60 ml.min(-1).g liver(-1). After a 24-h fast, three different experimental protocols were employed. Protocol 1 examined the impact on GNG when reservoir lactate concentration was maintained but oxygen delivery was elevated via increases in hematocrit (Hct). Elevating the Hct from 22.5+/- 0.8% to 30.9+/- 0.4% at a blood flow of 0.89+/- 0.01 ml.min(-1).g liver(-1) increased the oxygen consumption (Vo(2)) but did not augment GNG. Similarly, when the Hct was elevated from 22.5+/- 0.8% to 41.5+/- 0.7% at 0.59+/- 0.04 ml.min(-1).g liver(-1), Vo(2) was increased, but GNG was unaffected. Protocol 2 examined the impact on GNG when Hct was maintained but precursor delivery was elevated via increases in reservoir lactate concentration ([LA]). Specifically, elevating the [LA] from 2.31+/- 0.07 to 3.61+/- 0.33 mM at a flow rate of 0.82+/- 0.04 ml.min(-1).g liver(-1) significantly increased GNG. Similarly, elevating the [LA] from 2.31+/- 0.07 to 4.24+/- 0.37 mM at a flow rate of 0.58+/- 0.02 ml.min(-1).g liver(-1) increased GNG. Finally, we examined the impact of increasing both the oxygen and lactate delivery (Protocol 3). Again, Vo(2) was elevated with increased oxygen delivery, but GNG was not augmented beyond that observed with elevations in lactate delivery alone, i.e., Protocol 2. The results indicate that, during decrements in blood flow, GNG is limited primarily by precursor delivery, not oxygen availability.

  11. The dual roles of red blood cells in tissue oxygen delivery

    DEFF Research Database (Denmark)

    Jensen, Frank Bo

    2009-01-01

    Vertebrate red blood cells (RBCs) seem to serve tissue oxygen delivery in two distinct ways. Firstly, RBCs enable the adequate transport of O2 between respiratory surfaces and metabolizing tissues by means of their high intracellular concentration of hemoglobin (Hb), appropriate allosteric...... interactions between Hb ligand-binding sites, and an adjustable intracellular chemical environment that allows fine-tuning of Hb O2 affinity. Secondly, RBCs may sense tissue O2 requirements via their degree of deoxygenation when they travel through the microcirculation and release vasodilatory compounds...... that enhance blood flow in hypoxic tissues. This latter function could be important in matching tissue O2 delivery with local O2 demand. Three main mechanisms by which RBCs can regulate their own distribution in the microcirculation have been proposed. These are: (1) deoxygenation-dependent release of ATP from...

  12. Leakage of Oxygen from Blood and Water Samples Stored in Plastic and Glass Syringes

    Science.gov (United States)

    Scott, Peter V.; Horton, J. N.; Mapleson, W. W.

    1971-01-01

    Theory and experiment showed that samples of blood and water stored in 2-ml and 5-ml syringes made of polypropylene, polystyrene, or S.A.N. co-polymer exchanged oxygen with their surroundings. In the first hour the exchange was due mainly to equilibration with the plastic of the syringe and only in small degree to permeation through the plastic. With high initial tension or with blood of low haemoglobin concentration the exchange can result in errors in Po2 of up to 6% in two minutes and 16% in 30 to 60 minutes. With all-glass syringes the exchange was much slower but, even so, after 24 hours was important in all but a few of 18 interchangeable glass syringes. Therefore unless analysis can be started immediately all-glass syringes are to be preferred, and for prolonged storage even these should be selected. PMID:5565518

  13. Protective coating and hyperthermal atomic oxygen texturing of optical fibers used for blood glucose monitoring

    Science.gov (United States)

    Banks, Bruce A. (Inventor)

    2008-01-01

    Disclosed is a method of producing cones and pillars on polymethylmethacralate (PMMA) optical fibers for glucose monitoring. The method, in one embodiment, consists of using electron beam evaporation to deposit a non-contiguous thin film of aluminum on the distal ends of the PMMA fibers. The partial coverage of aluminum on the fibers is randomly, but rather uniformly distributed across the end of the optical fibers. After the aluminum deposition, the ends of the fibers are then exposed to hyperthermal atomic oxygen, which oxidizes the areas that are not protected by aluminum. The resulting PMMA fibers have a greatly increased surface area and the cones or pillars are sufficiently close together that the cellular components in blood are excluded from passing into the valleys between the cones and pillars. The optical fibers are then coated with appropriated surface chemistry so that they can optically sense the glucose level in the blood sample than that with conventional glucose monitoring.

  14. Evaluation of microcirculation in elderly patients with venous trophic ulcers.

    Science.gov (United States)

    Losev, R Z; Burov, Iu A; Mikul'skaia, Ie G; Iakusheva, Ie A

    2005-01-01

    Altogether 112 patients over 50 years of age suffering from varicosity and chronic trophic ulcers of the distal limb segments were examined. The work was based on an analysis of the microcirculatory flow in lower limb tissues (laser Doppler flowmetry, BLF 21 system, Transonic Systems Inc., USA) and on the evaluation of tissue metabolism by measuring partial oxygen and carbon dioxide tension (percutaneous polarography; TCM-3 system, Radiometry Company, Denmark). The postischemic and orthostatic tests were used to assess the functional microcirculatory reserve. The data obtained indicate local tissue hypoxia in elderly patients with venous trophic ulcers associated with an increase of the basal flow only in the lower third of the leg. Venous trophic ulcers are marked by a significant reduction of partial oxygen tension in the tissues adjacent to the area of trophic ulcers to 4.3+/-0.5 mm Hg on the average in the presence of the low functional microcirculatory reserve. Local tissue hypoxia in the area of trophic ulcers, which develops despite an increase of blood inflow to the microcirculatory bed evidences inhibition of tissue flow and activation of the arterio-venular bypasses. The results obtained in the course of the study allow to optimize the treatment policy in elderly patients suffering from venous trophic ulcers. In addition to the measures lowering venous hypertension, the treatment should include correction of microcirculatory disorders, which is to be carried out in the pre- and postoperative periods.

  15. Blood transfusion improves renal oxygenation and renal function in sepsis-induced acute kidney injury in rats

    NARCIS (Netherlands)

    Zafrani, Lara; Ergin, Bulent; Kapucu, Aysegul; Ince, Can

    2016-01-01

    The effects of blood transfusion on renal microcirculation during sepsis are unknown. This study aimed to investigate the effect of blood transfusion on renal microvascular oxygenation and renal function during sepsis-induced acute kidney injury. Twenty-seven Wistar albino rats were randomized into

  16. Blood transfusion improves renal oxygenation and renal function in sepsis-induced acute kidney injury in rats

    NARCIS (Netherlands)

    L. Zafrani (Lara); B. Ergin (Bulent); Kapucu, A. (Aysegul); C. Ince (Can)

    2016-01-01

    textabstractBackground: The effects of blood transfusion on renal microcirculation during sepsis are unknown. This study aimed to investigate the effect of blood transfusion on renal microvascular oxygenation and renal function during sepsis-induced acute kidney injury. Methods: Twenty-seven Wistar

  17. Diving Related Changes in the Blood Oxygen Stores of Rehabilitating Harbor Seal Pups (Phoca vitulina).

    Science.gov (United States)

    Thomas, Amber; Ono, Kathryn

    2015-01-01

    Harbor seal (Phoca vitulina) pups begin diving within hours of birth, stimulating the development of the blood oxygen (O2) stores necessary to sustain underwater aerobic metabolism. Since harbor seals experience a brief nursing period, the early-life development of these blood O2 stores is necessary for successful post-weaning foraging. If mothers and pups become prematurely separated, the pup may be transported to a wildlife rehabilitation center for care. Previous studies suggest that the shallow pools and lack of diving in rehabilitation facilities may lead to under-developed blood O2 stores, but diving behavior during rehabilitation has not been investigated. This study aimed to simultaneously study the diving behaviors and blood O2 store development of rehabilitating harbor seal pups. Standard hematology measurements (Hct, Hb, RBC, MCV, MCH, MCHC) were taken to investigate O2 storage capacity and pups were equipped with time-depth recorders to investigate natural diving behavior while in rehabilitation. Linear mixed models of the data indicate that all measured blood parameters changed with age; however, when compared to literature values for wild harbor seal pups, rehabilitating pups have smaller red blood cells (RBCs) that can store less hemoglobin (Hb) and subsequently, less O2, potentially limiting their diving capabilities. Wild pups completed longer dives at younger ages (maximum reported dives were observed (maximum during rehabilitation: 13.6 min at 89 days of age). Further, this study suggests that there may be a positive relationship between RBC size and the frequency of long duration dives. Thus, rehabilitating harbor seal pups should be encouraged to make frequent, long duration dives to prepare themselves for post-release foraging.

  18. Diving Related Changes in the Blood Oxygen Stores of Rehabilitating Harbor Seal Pups (Phoca vitulina.

    Directory of Open Access Journals (Sweden)

    Amber Thomas

    Full Text Available Harbor seal (Phoca vitulina pups begin diving within hours of birth, stimulating the development of the blood oxygen (O2 stores necessary to sustain underwater aerobic metabolism. Since harbor seals experience a brief nursing period, the early-life development of these blood O2 stores is necessary for successful post-weaning foraging. If mothers and pups become prematurely separated, the pup may be transported to a wildlife rehabilitation center for care. Previous studies suggest that the shallow pools and lack of diving in rehabilitation facilities may lead to under-developed blood O2 stores, but diving behavior during rehabilitation has not been investigated. This study aimed to simultaneously study the diving behaviors and blood O2 store development of rehabilitating harbor seal pups. Standard hematology measurements (Hct, Hb, RBC, MCV, MCH, MCHC were taken to investigate O2 storage capacity and pups were equipped with time-depth recorders to investigate natural diving behavior while in rehabilitation. Linear mixed models of the data indicate that all measured blood parameters changed with age; however, when compared to literature values for wild harbor seal pups, rehabilitating pups have smaller red blood cells (RBCs that can store less hemoglobin (Hb and subsequently, less O2, potentially limiting their diving capabilities. Wild pups completed longer dives at younger ages (maximum reported <25 days of age: 9 min in previous studies than the captive pups in this study (maximum <25 days of age: 2.86 min. However, captivity may only affect the rate of development, as long duration dives were observed (maximum during rehabilitation: 13.6 min at 89 days of age. Further, this study suggests that there may be a positive relationship between RBC size and the frequency of long duration dives. Thus, rehabilitating harbor seal pups should be encouraged to make frequent, long duration dives to prepare themselves for post-release foraging.

  19. Airborne particulate matter PM2.5 from Mexico City affects the generation of reactive oxygen species by blood neutrophils from asthmatics: an in vitro approach

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    Ceballos Guillermo

    2009-06-01

    Full Text Available Abstract Background The Mexico City Metropolitan Area is densely populated, and toxic air pollutants are generated and concentrated at a higher rate because of its geographic characteristics. It is well known that exposure to particulate matter, especially to fine and ultra-fine particles, enhances the risk of cardio-respiratory diseases, especially in populations susceptible to oxidative stress. The aim of this study was to evaluate the effect of fine particles on the respiratory burst of circulating neutrophils from asthmatic patients living in Mexico City. Methods In total, 6 subjects diagnosed with mild asthma and 11 healthy volunteers were asked to participate. Neutrophils were isolated from peripheral venous blood and incubated with fine particles, and the generation of reactive oxygen species was recorded by chemiluminescence. We also measured plasma lipoperoxidation susceptibility and plasma myeloperoxidase and paraoxonase activities by spectrophotometry. Results Asthmatic patients showed significantly lower plasma paraoxonase activity, higher susceptibility to plasma lipoperoxidation and an increase in myeloperoxidase activity that differed significantly from the control group. In the presence of fine particles, neutrophils from asthmatic patients showed an increased tendency to generate reactive oxygen species after stimulation with fine particles (PM2.5. Conclusion These findings suggest that asthmatic patients have higher oxidation of plasmatic lipids due to reduced antioxidant defense. Furthermore, fine particles tended to increase the respiratory burst of blood human neutrophils from the asthmatic group. On the whole, increased myeloperoxidase activity and susceptibility to lipoperoxidation with a concomitant decrease in paraoxonase activity in asthmatic patients could favor lung infection and hence disrupt the control of asthmatic crises.

  20. Cerebral blood volume and oxygen supply uniformly increase following various intrathoracic pressure strains.

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    Zhang, Zhongxing; Bolz, Nina; Laures, Marco; Oremek, Margit; Schmidt, Christoph; Qi, Ming; Khatami, Ramin

    2017-08-21

    Intrathoracic pressure (ITP) swings challenge many physiological systems. The responses of cerebral hemodynamics to different ITP swings are still less well-known due to the complexity of cerebral circulation and methodological limitation. Using frequency-domain near-infrared spectroscopy and echocardiography, we measured changes in cerebral, muscular and cardiac hemodynamics in five graded respiratory maneuvers (RM), breath holding, moderate and strong Valsalva maneuvers (mVM/sVM) with 20 and 40 cmH2O increments in ITP, moderate and strong Mueller maneuvers (mMM/sMM) with 20 and 40 cmH2O decrements in ITP controlled by esophageal manometry. We found cerebral blood volume (CBV) maintains relative constant during the strains while it increases during the recoveries together with increased oxygen supply. By contrast changes in muscular blood volume (MBV) are mainly controlled by systemic changes. The graded changes of ITP during the maneuvers predict the changes of MBV but not CBV. Changes in left ventricular stroke volume and heart rate correlate to MBV but not to CBV. These results suggest the increased CBV after the ITP strains is brain specific, suggesting cerebral vasodilatation. Within the strains, cerebral oxygen saturation only decreases in sVM, indicating strong increment rather than decrement in ITP may be more challenging for the brain.

  1. Effects of diving and oxygen on autonomic nervous system and cerebral blood flow.

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    Winklewski, Pawel J; Kot, Jacek; Frydrychowski, Andrzej F; Nuckowska, Magdalena K; Tkachenko, Yurii

    2013-09-01

    Recreational scuba diving is a popular leisure activity with the number of divers reaching several millions worldwide. Scuba diving represents a huge challenge for integrative physiology. In mammalian evolution, physiological reflexes developed to deal with lack of oxygen, rather than with an excess, which makes adaptations to scuba diving more difficult to describe and understand than those associated with breath-hold diving. The underwater environment significantly limits the use of equipment to register the organism's functions, so, in most instances, scientific theories are built on experiments that model real diving to some extent, like hyperbaric exposures, dive reflexes or water immersion. The aim of this review is to summarise the current knowledge related to the influence exerted by physiological conditions specific to diving on the autonomic nervous system and cerebral blood flow. The main factors regulating cerebral blood flow during scuba diving are discussed as follows: 1) increased oxygen partial pressure; 2) immersion-related trigemino-cardiac reflexes and 3) exposure to cold, exercise and stress. Also discussed are the potential mechanisms associated with immersion pulmonary oedema.

  2. Widefield in vivo spectral and fluorescence imaging microscopy of microvessel blood supply and oxygenation

    Science.gov (United States)

    Lee, Jennifer; Kozikowski, Raymond; Wankhede, Mamta; Sorg, Brian S.

    2011-02-01

    Abnormal microvascular function and angiogenesis are key components of various diseases that can contribute to the perpetuation of the disease. Several skin diseases and ophthalmic pathologies are characterized by hypervascularity, and in cancer the microvasculature of tumors is structurally and functionally abnormal. Thus, the microvasculature can be an important target for treatment of diseases characterized by abnormal microvasculature. Motivated largely by cancer research, significant effort has been devoted to research on drugs that target the microvasculature. Several vascular targeting drugs for cancer therapy are in clinical trials and approved for clinical use, and several off-label uses of these drugs have been reported for non-cancer diseases. The ability to image and measure parameters related to microvessel function preclinically in laboratory animals can be useful for development and comparison of vascular targeting drugs. For example, blood supply time measurements give information related to microvessel morphology and can be measured with first-pass fluorescence imaging. Hemoglobin saturation measurements give an indication of microvessel oxygen transport and can be measured with spectral imaging. While each measurement individually gives some information regarding microvessel function, the measurements together may yield even more information since theoretically microvessel morphology can influence microvessel oxygenation, especially in metabolically active tissue like tumors. However, these measurements have not yet been combined. In this study, we report the combination of blood supply time imaging and hemoglobin saturation imaging of microvessel networks in tumors using widefield fluorescence and spectral imaging, respectively. The correlation between the measurements in a mouse mammary tumor is analyzed.

  3. Impact of physiological noise correction on detecting blood oxygenation level-dependent contrast in the breast

    Science.gov (United States)

    Wallace, Tess E.; Manavaki, Roido; Graves, Martin J.; Patterson, Andrew J.; Gilbert, Fiona J.

    2017-01-01

    Physiological fluctuations are expected to be a dominant source of noise in blood oxygenation level-dependent (BOLD) magnetic resonance imaging (MRI) experiments to assess tumour oxygenation and angiogenesis. This work investigates the impact of various physiological noise regressors: retrospective image correction (RETROICOR), heart rate (HR) and respiratory volume per unit time (RVT), on signal variance and the detection of BOLD contrast in the breast in response to a modulated respiratory stimulus. BOLD MRI was performed at 3 T in ten volunteers at rest and during cycles of oxygen and carbogen gas breathing. RETROICOR was optimized using F-tests to determine which cardiac and respiratory phase terms accounted for a significant amount of signal variance. A nested regression analysis was performed to assess the effect of RETROICOR, HR and RVT on the model fit residuals, temporal signal-to-noise ratio, and BOLD activation parameters. The optimized RETROICOR model accounted for the largest amount of signal variance ( Δ R\\text{adj}2   =  3.3  ±  2.1%) and improved the detection of BOLD activation (P  =  0.002). Inclusion of HR and RVT regressors explained additional signal variance, but had a negative impact on activation parameter estimation (P  <  0.001). Fluctuations in HR and RVT appeared to be correlated with the stimulus and may contribute to apparent BOLD signal reactivity.

  4. Carboxylated nanodiamond and re-oxygenation process of gamma irradiated red blood cells

    Energy Technology Data Exchange (ETDEWEB)

    Acosta-Elias, M. [Doctorado en Nanotecnologia, Universidad de Sonora (Mexico); Sarabia-Sainz, A.; Silva-Campa, E.; Angulo-Molina, A.; Soto-Puebla, D.; Barboza-Flores, M.; Melendrez, R.; Alvarez-Garcia, S.; Pedroza-Montero, M. [Departamento de Investigacion en Fisica, Universidad de Sonora, Hermosillo (Mexico); Pedroso-Santana, S. [Doctorado en Ciencias (Fisica), Universidad de Sonora, Hermosillo (Mexico); Santacruz-Gomez, K.; Castaneda, B. [Departamento de Fisica, Universidad de Sonora, Hermosillo (Mexico)

    2015-11-15

    Nanodiamonds (NDs) possess exceptional physical, chemical, and biological properties, which make them suitable for potential biomedical applications. They are biocompatible and their usefulness as effective Raman/fluorescence probes for labeling as well as for drug delivery has been demonstrated. Related to their biocompatibility, the interaction between NDs and red blood cells (RBCs) is of great interest. In this work, the influence of carboxylated NDs (cNDs) in the re-oxygenation capability of both γ-irradiated and stored RBCs was studied. The standard 25 Gy γ dose recommended to prevent transfusion associated graft-versus-host disease was used. A 5-day maximum storage time was used to evaluate the ''storage lesion''. The hemoglobin (Hb) oxygenation state was assessed by Raman microspectroscopy and the morphologic changes on cells were tracked by optical imaging. Our results show that irradiated RBCs have a better re-oxygenation capability and morphological recovery when they are in presence of cNDs. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  5. Effect of Change in Portal Venous Blood Flow Rates on the Performance of a 2.45-GHz Microwave Ablation Device.

    Science.gov (United States)

    Dodd, Gerald D; Kreidler, Sarah M; Lanctot, Anthony C; Glueck, Deborah H

    2015-12-01

    To investigate the effect of change in portal venous blood flow rates on the size and shape of ablations created by a 2.45-GHz microwave ablation device. This study was exempt from review by the institutional animal care and use committee. An in vitro bovine liver model perfused with autologous blood via the portal vein at five flow rates (60, 70, 80, 90, and 100 mL/min per 100 g of liver) was used to evaluate the effect of change in flow rates on the size and shape of coagulation created by a 2.45-GHz, 140-W microwave ablation device operated for 5 and 10 minutes. Three ablations per ablation time were conducted in each of 10 livers, with two livers perfused at each flow rate. Short- and long-axis diameters were measured from gross specimens, and volume and sphericity index were calculated. General linear mixed models that accounted for correlations within the liver were used to evaluate the effects of lobe, flow, and ablation time on size and sphericity index of ablations. Flow did not have a significant effect on the size or shape of coagulation created at 5 or 10 minutes (P > .05 for all tests). The mean short- and long-axis diameters and volume were 3.2 cm (95% confidence interval [CI]: 3.1, 3.3), 5.6 cm (95% CI: 5.4, 5.8), and 30.2 cm(3) (95% CI: 28.4, 32.1) for the 5-minute ablations and 3.8 cm (95% CI: 3.7, 3.9), 6.5 cm (95% CI: 6.3, 6.7), and 49.3 cm(3) (95% CI: 47.5, 51.2), for the 10-minute ablations, respectively. The mean sphericity index for both 5- and 10-minute ablations was 34.4% (95% CI: 32%, 36.7%). Change in portal venous blood flow rates did not have an effect on the size and shape of ablations created by a 2.45-GHz microwave ablation device.

  6. The effect of medical clowning on reducing pain, crying, and anxiety in children aged 2-10 years old undergoing venous blood drawing--a randomized controlled study.

    Science.gov (United States)

    Meiri, N; Ankri, A; Hamad-Saied, M; Konopnicki, M; Pillar, G

    2016-03-01

    Recently, the utilization of medical clowns to reduce anxiety, stress, and even pain associated with hospitalization has become popular. However, the scientific basis of this benefit and outcome is scant. Venipuncture and IV cannulation are very common sources of pain in ill children. To reduce pain, one common approach is to apply a local anesthetic prior to the procedure. In the current study, we sought to compare the utilization of medical clowning in this process with two control groups: (1) local anesthetic cream (EMLA®, Astrazeneca, London, UK) applied prior to the procedure (active control) and (2) the procedure performed with neither clown nor EMLA (control group). We hypothesized that a medical clown will reduce pain, crying, and anxiety in children undergoing this procedure.Children aged 2-10 years who required either venous blood sampling or intravenous cannulation were recruited and randomly assigned to one of the three groups. Outcome measures consisted of the duration of the whole procedure (measured objectively by an independent observer), the duration of crying (measured objectively by an independent observer), subjective assessment of pain level (a commonly used validated scale), and anxiety level regarding future blood exams (by questionnaire). Analysis of variance (ANOVA) was used to compare between the groups. p anxiety related to future blood tests as evaluated by telephone the following day revealed that it was significantly lower with clown than in the control group or EMLA (2.6 ± 1.2 vs 3.7 ± 1.3 or 3.8 ± 1.6, p anxiety were lower with a medical clown. These results strongly encourage and support the utilization of medical clowns while drawing blood in children.

  7. Investigating Functional Extension of Optical Coherence Tomography for Spectroscopic Analysis of Blood Oxygen Saturation

    Science.gov (United States)

    Chen, Siyu

    Over the past two decades, optical coherence tomography (OCT) has been successfully applied to various fields of biomedical researching and clinical studies, including cardiology, urology, dermatology, dentistry, oncology, and most successfully, ophthalmology. This dissertation seeks to extend the current OCT practice, which is still largely morphology-based, into a new dimension, functional analysis of metabolic activities in vivo. More specifically, the investigation is focused on retrieving blood oxygen saturation (sO2) using intrinsic hemoglobin optical absorption contrast. Most mammalian cells rely on aerobic respiration to support cellular function, which means they consume oxygen to create adenosine triphosphate (ATP). Metabolic rate of oxygen (MRO2), a key hemodynamic parameter, characterizes how much oxygen is consumed during a given period of time, reflecting the metabolic activity of the target tissue. For example, retinal neurons are highly active and almost entirely rely on the moment-to-moment oxygen supply from retinal circulations. Thus, variation in MRO2 reveals the instantaneous activity of these neurons, shedding light on the physiological and pathophysiological change of cellular functions. Eventually, measuring MRO2 can potentially provide a biomarker for early-stage disease diagnosis, and serve as one benchmark for evaluating effectiveness of medical intervention during disease management. Essential in calculating MRO2, blood sO2 measurements using spectroscopic OCT analysis has been attempted as early as 2003. OCT is intrinsically sensitive to the blood optical absorption spectrum due to its wide-band illumination and detection scheme relying on back-scattered photon. However, accurate retrieval of blood sO2 using conventional near infrared (NIR) OCT systems in vivo has remained challenging. It was not until the development of OCT systems using visible light illumination (vis-OCT) when accurate measurement of blood sO2 was reported in live

  8. The effect of catheter to vein ratio on blood flow rates in a simulated model of peripherally inserted central venous catheters.

    Science.gov (United States)

    Nifong, Thomas P; McDevitt, Timothy J

    2011-07-01

    Catheter-related thrombosis is a common complication in all anatomic sites, especially when smaller veins of the upper extremity are considered. It is presumed that the presence of a catheter within the lumen of a vein will decrease flow and potentially create stasis, and clinical data suggest that the size of the catheter impacts thrombosis rates. We sought to determine, both mathematically and experimentally, the impact of catheters on fluid flow rates. We used fluid mechanics to calculate relative flow rates as a function of the ratio of the catheter to vein diameters. We also measured the flow rate of a blood analyte solution in an annular flow model using diameters that simulate the size of upper extremity veins and commonly used peripherally inserted central catheters (PICCs). We compared each of the derived relative flow rates to the experimentally determined ones for three cylinder sizes and found a correlation of r(2) = 0.90. We also confirmed that the decrease in fluid flow rate with each successive catheter size is statistically significant (P centrally located obstruction. Assuming that blood flow in veins behaves in a similar manner to our models, PICCs, in particular, may substantially decrease venous flow rates by as much as 93%.

  9. Functional imaging of the nonhuman primate Placenta with endogenous blood oxygen level-dependent contrast.

    Science.gov (United States)

    Schabel, M C; Roberts, V H J; Lo, J O; Platt, S; Grant, K A; Frias, A E; Kroenke, C D

    2016-11-01

    To characterize spatial patterns of T2* in the placenta of the rhesus macaque (Macaca mulatta), to correlate these patterns with placental perfusion determined using dynamic contrast-enhanced MRI (DCE-MRI), and to evaluate the potential for using the blood oxygen level-dependent effect to quantify placental perfusion without the use of exogenous contrast reagent. MRI was performed on three pregnant rhesus macaques at gestational day 110. Multiecho spoiled gradient echo measurements were used to compute maps of T2*. Spatial maxima in these maps were compared with foci of early enhancement determined by DCE-MRI. Local maxima in T2* maps were strongly correlated with spiral arteries identified by DCE-MRI, with mean spatial separations ranging from 2.34 to 6.11 mm in the three animals studied. Spatial patterns of R2* ( = 1/ T2*) within individual placental lobules can be quantitatively analyzed using a simple model to estimate fetal arterial oxyhemoglobin concentration [Hbo,f] and a parameter viPS/Φ, reflecting oxygen transport to the fetus. Estimated mean values of [Hbo,f] ranged from 4.25 mM to 4.46 mM, whereas viPS/Φ ranged from 2.80 × 105 cm-3 to 1.61 × 106 cm-3 . Maternal spiral arteries show strong spatial correlation with foci of extended T2* observed in the primate placenta. A simple model of oxygen transport accurately describes the spatial dependence of R2* within placental lobules and enables assessment of placental function and oxygenation without requiring administration of an exogenous contrast reagent. Magn Reson Med 76:1551-1562, 2016. © 2015 International Society for Magnetic Resonance in Medicine. © 2015 International Society for Magnetic Resonance in Medicine.

  10. Global brain blood-oxygen level responses to autonomic challenges in obstructive sleep apnea.

    Directory of Open Access Journals (Sweden)

    Paul M Macey

    Full Text Available Obstructive sleep apnea (OSA is accompanied by brain injury, perhaps resulting from apnea-related hypoxia or periods of impaired cerebral perfusion. Perfusion changes can be determined indirectly by evaluation of cerebral blood volume and oxygenation alterations, which can be measured rapidly and non-invasively with the global blood oxygen level dependent (BOLD signal, a magnetic resonance imaging procedure. We assessed acute BOLD responses in OSA subjects to pressor challenges that elicit cerebral blood flow changes, using a two-group comparative design with healthy subjects as a reference. We separately assessed female and male patterns, since OSA characteristics and brain injury differ between sexes. We studied 94 subjects, 37 with newly-diagnosed, untreated OSA (6 female (age mean ± std: 52.1±8.1 yrs; apnea/hypopnea index [AHI]: 27.7±15.6 events/hr and 31 male 54.3±8.4 yrs; AHI: 37.4±19.6 events/hr, and 20 female (age 50.5±8.1 yrs and 37 male (age 45.6±9.2 yrs healthy control subjects. We measured brain BOLD responses every 2 s while subjects underwent cold pressor, hand grip, and Valsalva maneuver challenges. The global BOLD signal rapidly changed after the first 2 s of each challenge, and differed in magnitude between groups to two challenges (cold pressor, hand grip, but not to the Valsalva maneuver (repeated measures ANOVA, p<0.05. OSA females showed greater differences from males in response magnitude and pattern, relative to healthy counterparts. Cold pressor BOLD signal increases (mean ± adjusted standard error at the 8 s peak were: OSA 0.14±0.08% vs. Control 0.31±0.06%, and hand grip at 6 s were: OSA 0.08±0.03% vs. Control at 0.30±0.02%. These findings, indicative of reduced cerebral blood flow changes to autonomic challenges in OSA, complement earlier reports of altered resting blood flow and reduced cerebral artery responsiveness. Females are more affected than males, an outcome which may contribute to the sex

  11. Blood transfusion improves renal oxygenation and renal function in sepsis-induced acute kidney injury in rats.

    Science.gov (United States)

    Zafrani, Lara; Ergin, Bulent; Kapucu, Aysegul; Ince, Can

    2016-12-20

    The effects of blood transfusion on renal microcirculation during sepsis are unknown. This study aimed to investigate the effect of blood transfusion on renal microvascular oxygenation and renal function during sepsis-induced acute kidney injury. Twenty-seven Wistar albino rats were randomized into four groups: a sham group (n = 6), a lipopolysaccharide (LPS) group (n = 7), a LPS group that received fluid resuscitation (n = 7), and a LPS group that received blood transfusion (n = 7). The mean arterial blood pressure, renal blood flow, and renal microvascular oxygenation within the kidney cortex were recorded. Acute kidney injury was assessed using the serum creatinine levels, metabolic cost, and histopathological lesions. Nitrosative stress (expression of endothelial (eNOS) and inducible nitric oxide synthase (iNOS)) within the kidney was assessed by immunohistochemistry. Hemoglobin levels, pH, serum lactate levels, and liver enzymes were measured. Fluid resuscitation and blood transfusion both significantly improved the mean arterial pressure and renal blood flow after LPS infusion. Renal microvascular oxygenation, serum creatinine levels, and tubular damage significantly improved in the LPS group that received blood transfusion compared to the group that received fluids. Moreover, the renal expression of eNOS was markedly suppressed under endotoxin challenge. Blood transfusion, but not fluid resuscitation, was able to restore the renal expression of eNOS. However, there were no significant differences in lactic acidosis or liver function between the two groups. Blood transfusion significantly improved renal function in endotoxemic rats. The specific beneficial effect of blood transfusion on the kidney could have been mediated in part by the improvements in renal microvascular oxygenation and sepsis-induced endothelial dysfunction via the restoration of eNOS expression within the kidney.

  12. Severe familial hypercholesterolemia impairs the regulation of coronary blood flow and oxygen supply during exercise.

    Science.gov (United States)

    Bender, Shawn B; de Beer, Vincent J; Tharp, Darla L; Bowles, Douglas K; Laughlin, M Harold; Merkus, Daphne; Duncker, Dirk J

    2016-11-01

    Accelerated development of coronary atherosclerosis is a defining characteristic of familial hypercholesterolemia (FH). However, the recent data highlight a significant cardiovascular risk prior to the development of critical coronary stenosis. We, therefore, examined the hypothesis that FH produces coronary microvascular dysfunction and impairs coronary vascular control at rest and during exercise in a swine model of FH. Coronary vascular responses to drug infusions and exercise were examined in chronically instrumented control and FH swine. FH swine exhibited ~tenfold elevation of plasma cholesterol and diffuse coronary atherosclerosis (20-60 % plaque burden). Similar to our recent findings in the systemic vasculature in FH swine, coronary smooth muscle nitric oxide sensitivity was increased in vivo and in vitro with maintained endothelium-dependent vasodilation in vivo in FH. At rest and during exercise, FH swine exhibited increased myocardial O2 extraction resulting in reduced coronary venous SO2 and PO2 versus control. During exercise in FH swine, the transmural distribution of coronary blood flow was unchanged; however, a shift toward anaerobic cardiac metabolism was revealed by increased coronary arteriovenous H(+) concentration gradient. This shift was associated with a worsening of cardiac efficiency (relationship between cardiac work and O2 consumption) in FH during exercise owing, in part, to a generalized reduction in stroke volume which was associated with increased left atrial pressure in FH. Our data highlight a critical role for coronary microvascular dysfunction as a contributor to impaired myocardial O2 balance, cardiac ischemia, and impaired cardiac function prior to the development of critical coronary stenosis in FH.

  13. Blood flow mechanics and oxygen transport and delivery in the retinal microcirculation: multiscale mathematical modeling and numerical simulation.

    Science.gov (United States)

    Causin, Paola; Guidoboni, Giovanna; Malgaroli, Francesca; Sacco, Riccardo; Harris, Alon

    2016-06-01

    The scientific community continues to accrue evidence that blood flow alterations and ischemic conditions in the retina play an important role in the pathogenesis of ocular diseases. Many factors influence retinal hemodynamics and tissue oxygenation, including blood pressure, blood rheology, oxygen arterial permeability and tissue metabolic demand. Since the influence of these factors on the retinal circulation is difficult to isolate in vivo, we propose here a novel mathematical and computational model describing the coupling between blood flow mechanics and oxygen ([Formula: see text]) transport in the retina. Albeit in a simplified manner, the model accounts for the three-dimensional anatomical structure of the retina, consisting in a layered tissue nourished by an arteriolar/venular network laying on the surface proximal to the vitreous. Capillary plexi, originating from terminal arterioles and converging into smaller venules, are embedded in two distinct tissue layers. Arteriolar and venular networks are represented by fractal trees, whereas capillary plexi are represented using a simplified lumped description. In the model, [Formula: see text] is transported along the vasculature and delivered to the tissue at a rate that depends on the metabolic demand of the various tissue layers. First, the model is validated against available experimental results to identify baseline conditions. Then, a sensitivity analysis is performed to quantify the influence of blood pressure, blood rheology, oxygen arterial permeability and tissue oxygen demand on the [Formula: see text] distribution within the blood vessels and in the tissue. This analysis shows that: (1) systemic arterial blood pressure has a strong influence on the [Formula: see text] profiles in both blood and tissue; (2) plasma viscosity and metabolic consumption rates have a strong influence on the [Formula: see text] tension at the level of the retinal ganglion cells; and (3) arterial [Formula: see text

  14. Simultaneous measurements of total hemoglobin concentration and blood oxygenation with laser diode-based optoacoustic system

    Science.gov (United States)

    Petrov, Irene Y.; Prough, Donald S.; Petrov, Yuriy; Henkel, S. Nan; Seeton, Roger; Esenaliev, Rinat O.

    2017-03-01

    Noninvasive, accurate, continuous monitoring of multiple variables, including blood oxygenation, i.e. oxyhemoglobin saturation (SO2) and total hemoglobin concentration (THb) in both high acuity and low acuity environments would greatly facilitate prompt diagnosis and treatment of physiologic derangements. However, most of the existing techniques for patient monitoring are invasive, while noninvasive techniques often fail to provide accurate measurements. We built a compact, multi-wavelength, nanosecond, fiber-coupled laser diode-based optoacoustic system for noninvasive, accurate monitoring of blood SO2 and THb in veins and arteries. We tested the system by probing the radial artery of healthy volunteers. Using blood samples obtained by venipuncture, we also measured a reference THb for each volunteer. Moreover, the optoacoustic data were compared with that obtained from a commercially available noninvasive monitor for measurements of these variables. The optoacoustic system provided rapid, simultaneous, and continuous measurement of THb and SO2 with high precision. The obtained results are promising and we plan to further test the system in clinical studies and at conditions simulating circulatory shock.

  15. Reduction of central venous catheter associated blood stream infections following implementation of a resident oversight and credentialing policy

    Directory of Open Access Journals (Sweden)

    West Cheri E

    2011-06-01

    Full Text Available Abstract Background This study assesses the impact that a resident oversight and credentialing policy for central venous catheter (CVC placement had on institution-wide central line associated bloodstream infections (CLABSI. We therefore investigated the rate of CLABSI per 1,000 line days during the 12 months before and after implementation of the policy. Methods This is a retrospective analysis of prospectively collected data at an academic medical center with four adult ICUs and a pediatric ICU. All patients undergoing non-tunneled CVC placement were included in the study. Data was collected on CLABSI, line days, and serious adverse events in the year prior to and following policy implementation on 9/01/08. Results A total of 813 supervised central lines were self-reported by residents in four departments. Statistical analysis was performed using paired Wilcoxon signed rank tests. There were reductions in median CLABSI rate (3.52 vs. 2.26; p = 0.015, number of CLBSI per month (16.0 to 10.0; p = 0.012, and line days (4495 vs. 4193; p = 0.019. No serious adverse events reported to the Pennsylvania Patient Safety Authority. Conclusions Implementation of a new CVC resident oversight and credentialing policy has been significantly associated with an institution-wide reduction in the rate of CLABSI per 1,000 central line days and total central line days. No serious adverse events were reported. Similar resident oversight policies may benefit other teaching institutions, and support concurrent organizational efforts to reduce hospital acquired infections.

  16. Arterio-venous fistula for automated red blood cells exchange in patients with sickle cell disease: Complications and outcomes.

    Science.gov (United States)

    Delville, Marianne; Manceau, Sandra; Ait Abdallah, Nassim; Stolba, Jan; Awad, Sameh; Damy, Thibaud; Gellen, Barnabas; Sabbah, Laurent; Debbache, Karima; Audard, Vincent; Beaumont, Jean-Louis; Arnaud, Cécile; Chantalat-Auger, Christelle; Driss, Françoise; Lefrère, François; Cavazzana, Marina; Franco, Gilbert; Galacteros, Frederic; Ribeil, Jean-Antoine; Gellen-Dautremer, Justine

    2017-02-01

    Erythrocytapheresis (ER) can improve outcome in patients with sickle cell disease (SCD). A good vascular access is required but frequently it can be difficult to obtain for sickle cell patients. Arterio-venous fistulas (AVFs) have been suggested for ER in SCD supported by limited evidence. We report the largest cohort of ER performed with AVFs from three French SCD reference centers. Data of SCD patients undergoing ER with AVFs in the French SCD reference center were retrospectively collected. The inclusion criteria were: SS or Sβ-Thalassemia and AVF surgery for ER. SCD-related complications, transfusion history, details about AVF surgical procedure, echocardiographic data before and after AVF, AVF-related surgical and hemodynamical complications were collected. Twenty-six patients (mean age 20.5 years, mean follow-up 68 months [11-279]) were included. Twenty-three patients (88.5%) required central vascular access before AVF. Fifteen AVFs (58%) were created on the forearm and 11 (42%) on the arm. Nineteen patients (73%) had stenotic, thrombotic or infectious AVF complications. A total of 0.36 stenosis per 1,000 AVF days, 0.37 thrombosis per 1,000 AVF days and 0.078 infections per 1.000 AVF days were observed. The mean AVF lifespan was 51 months [13-218]. One patient with severe pulmonary hypertension worsened after AVF creation and died. We report the first series of SCD patients with AVF for ER, demonstrating that AVFs could be considered as a potential vascular access for ER. Patients with increased risk for hemodynamic intolerance of AVFs must be carefully identified, so that alternative vascular accesses can be considered. Am. J. Hematol. 92:136-140, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  17. Seasonal variation in blood and muscle oxygen stores attributed to diving behavior, environmental temperature and pregnancy in a marine predator, the California sea lion.

    Science.gov (United States)

    Villegas-Amtmann, Stella; Atkinson, Shannon; Paras-Garcia, Alberto; Costa, Daniel P

    2012-08-01

    Survival depends on an animal's ability to find and acquire prey. In diving vertebrates, this ability is directly related to their physiological capability (e.g. oxygen stores). We studied the seasonal variation in oxygen stores, body temperature and body condition in California sea lions (Zalophus californianus) (CSL) as a function of seasonal variation in temperature, primary productivity, diving behavior and reproductive stage. During summer, blood oxygen stores were significantly greater and muscle oxygen stores were significantly lower than in winter. Total oxygen stores, body condition and body temperature did not change between seasons but variations in body temperature were greater during summer. Changes in oxygen stores are partly attributed to diving behavior, temperature and pregnancy that could increase oxygen consumption. Blood and muscle oxygen stores appear to be influenced by reproductive state. Blood oxygen stores are more likely influenced by diving behavior and temperature than muscle oxygen stores. Copyright © 2012 Elsevier Inc. All rights reserved.

  18. Determination of blood oxygenation in the brain by time-resolved reflectance spectroscopy: influence of the skin, skull, and meninges

    Science.gov (United States)

    Hielscher, Andreas H.; Liu, Hanli; Wang, Lihong; Tittel, Frank K.; Chance, Britton; Jacques, Steven L.

    1994-07-01

    Near infrared light has been used for the determination of blood oxygenation in the brain but little attention has been paid to the fact that the states of blood oxygenation in arteries, veins, and capillaries differ substantially. In this study, Monte Carlo simulations for a heterogeneous system were conducted, and near infrared time-resolved reflectance measurements were performed on a heterogeneous tissue phantom model. The model was made of a solid polyester resin, which simulates the tissue background. A network of tubes was distributed uniformly through the resin to simulate the blood vessels. The time-resolved reflectance spectra were taken with different absorbing solutions filled in the network. Based on the simulation and experimental results, we investigated the dependence of the absorption coefficient obtained from the heterogeneous system on the absorption of the actual absorbing solution filled in the tubes. We show that light absorption by the brain should result from the combination of blood and blood-free tissue background.

  19. Changes in intracranial venous blood flow and pulsatility in Alzheimer's disease: A 4D flow MRI study.

    Science.gov (United States)

    Rivera-Rivera, Leonardo A; Schubert, Tilman; Turski, Patrick; Johnson, Kevin M; Berman, Sara E; Rowley, Howard A; Carlsson, Cynthia M; Johnson, Sterling C; Wieben, Oliver

    2017-06-01

    Cerebral blood flow, arterial pulsation, and vasomotion may be important indicators of cerebrovascular health in aging and diseases of aging such as Alzheimer's disease. Noninvasive markers that assess these characteristics may be helpful in the study of co-occurrence of these diseases and potential additive and interacting effects. In this study, 4D flow MRI was used to measure intra-cranial flow features with cardiac-gated phase contrast MRI in cranial arteries and veins. Mean blood flow and pulsatility index as well as the transit time of the peak flow from the middle cerebral artery to the superior sagittal sinus were measured in a total of 104 subjects comprising of four groups: (a) subjects with Alzheimer's disease, (b) age-matched controls, (c) subjects with mild cognitive impairment, and (d) a group of late middle-aged with parental history of sporadic Alzheimer's disease. The Alzheimer's disease group exhibited: a significant decrease in mean blood flow in the superior sagittal sinus, transverse sinus, middle cerebral artery, and internal carotid arteries; a significant decrease of the peak and end diastolic blood flow in the middle cerebral artery and superior sagittal sinus; a faster transmission of peak flow from the middle cerebral artery to the superior sagittal sinus and increased pulsatility index along the carotid siphon.

  20. Acute and chronic effects of hyperbaric oxygen therapy on blood circulation of human muscle and tendon in vivo.

    Science.gov (United States)

    Kubo, Keitaro; Ikebukuro, Toshihiro

    2012-10-01

    This study aimed to investigate the acute and chronic effects of hyperbaric oxygen therapy on blood circulation of human muscle and tendon in vivo. Using near-infrared spectroscopy and red laser lights, we determined acute changes in blood volume (THb) and oxygen saturation (StO2) of the medial gastrocnemius muscle and Achilles tendon during 60 minutes of hyperbaric oxygen therapy (1.3 atm absolute and 50% O2, experiment 1). In addition, we determined the chronic effects of hyperbaric oxygen therapy (60 minutes, 2 times per week, 6 weeks) on THb and StO2 of muscle and tendon (experiment 2). In experiment 1, THb of the muscle increased gradually from resting level, but StO2 did not change. On the other hand, THb and StO2 of the tendon increased during hyperbaric oxygen therapy. In experiment 2, the pattern of changes in the measured variables during 60 minutes of therapy was similar for both the muscle and tendon between the first and last therapies. During resting, THb and StO2 of the tendon were significantly lower after 6 weeks of therapy, although those of the muscle were not. In conclusion, oxygen saturation of the tendon increased during hyperbaric oxygen therapy, whereas that of the muscle did not. This result would be related to the difference in the treated effects between muscle and tendon. However, oxygen saturation of the tendon, but not the muscle, during resting decreased after 6 weeks of therapy.

  1. Evaluation of venous blood gas levels, blood chemistry and haemocytometric parameters in milk fed veal calves at different periods of livestock cycle.

    Science.gov (United States)

    Giambelluca, S; Fiore, E; Sadocco, A; Gianesella, M; Vazzana, I; Orefice, T; Morgante, M

    2016-12-01

    An evaluation of blood chemistry profile in relation to specific stages of livestock cycle can help better understand variations in physiological conditions in order to adjust management systems to animal needs. In addition to basal hematological investigation, the acid-base balance and blood gases are essential tools in evaluating metabolism in calves. The relationship between blood gas parameters, diet and growth should be further investigated. The aim of this study was to evaluate changes in acid-base status, blood gases, serum chemistry and hematological parameters in veal calves at different periods of livestock cycle. One hundred twenty-eight healthy cross breeding calves were enrolled in a farm in North-East Italy. Blood samplings were carried out from the jugular vein on day 1 (t1), 60 (t2) and 150 (t3) after arrival. Blood gas analysis was performed and hematological parameters were evaluated. One-way ANOVA and Tukey-Kramer post-hoc test were performed to assess differences between blood parameter values at the different periods. The main differences in blood gas parameter levels during the livestock cycle concerned pH, Base Excess and HCO3 with higher values recorded in t3. Urea, creatinine, gamma-glutamyl transpeptidase and bilirubin mean values were significantly higher in t1 than in t2 and t3. Aspartate aminotransferase increased from t1 to t2 and t3. Alkaline Phosphatase was higher in t2. Fe levels severely dropped in t2 and in t3, and the decrease led to a restrained but significant reduction in haemoglobin values. A correspondent decrease in the other haemocytometric parameters was found.

  2. The incidence of low venous oxygen saturation on admission to the intensive care unit : a multi-center observational study in The Netherlands

    NARCIS (Netherlands)

    van Beest, P. A.; Hofstra, J. J.; Schultz, M. J.; Boerma, E. C.; Spronk, P. E.; Kuiper, M. A.

    2008-01-01

    Background Low mixed or central venous saturation (S(c)vO(2)) can reveal global tissue hypoxia and therefore can predict poor prognosis in critically ill patients. Early goal directed therapy (EGDT), aiming at an ScvO(2) >= 70%, has been shown to be a valuable strategy in patients with sepsis or

  3. Remote ischaemic conditioning decreases blood flow and improves oxygen extraction in patients with early complex regional pain syndrome.

    Science.gov (United States)

    Hegelmaier, T; Kumowski, N; Mainka, T; Vollert, J; Goertz, O; Lehnhardt, M; Zahn, P K; Maier, C; Kolbenschlag, J

    2017-09-01

    Remote ischaemic conditioning (RIC) is the cyclic application of non-damaging ischaemia leading to an increased tissue perfusion, among others triggered by NO (monoxide). Complex regional pain syndrome (CRPS) is known to have vascular alterations such as increased blood shunting and decreased NO blood-levels, which in turn lead to decreased tissue perfusion. We therefore hypothesized that RIC could improve tissue perfusion in CRPS. In this proof-of-concept study, RIC was applied in the following groups: in 21 patients with early CRPS with a clinical history less than a year, in 20 age/sex-matched controls and in 12 patients with unilateral nerve lesions via a tourniquet on the unaffected/non-dominant upper limb. Blood flow and tissue oxygen saturation (StO2 ) were assessed before, during and after RIC via laser Doppler and tissue spectroscopy on the affected extremity. The oxygen extraction fraction was calculated. After RIC, blood flow declined in CRPS (p CRPS and healthy controls (p CRPS, the oxygen extraction fraction correlated negatively with the decreasing blood flow (p CRPS, which led to a revised hypothesis: the decrease of blood flow might be due to an anti-inflammatory effect that attenuates vascular disturbances and reduces blood shunting, thus improving oxygen extraction. Further studies could determine whether a repeated application of RIC leads to a reduced hypoxia in chronic CRPS. Remote ischaemic conditioning leads to a decrease of blood flow. This decrease inversely correlates with the oxygen extraction in patients with CRPS. © 2017 European Pain Federation - EFIC®.

  4. EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA); Scientific Opinion on the substantiation of a health claim related to Vitis vinifera L. seeds extract and maintenance of normal venous blood flow pursuant to Article 13(5) of Regulation (EC) No 1924/2006

    DEFF Research Database (Denmark)

    Tetens, Inge

    related to Vitis vinifera L. seeds extract and maintenance of normal venous blood flow. The Panel considers that the food constituent, which is the subject of the health claim, is sufficiently characterised. The claimed effect, maintenance of normal venous blood flow, is a beneficial physiological effect...... and did not measure venous blood flow, the Panel considers that no conclusions can be drawn from these studies for the scientific substantiation of the claim. The Panel concludes that a cause and effect relationship has not been established between the consumption of Vitis vinifera L. seeds extract...

  5. Reduced and reversed temperature dependence of blood oxygenation in an ectothermic scombrid fish: implications for the evolution of regional heterothermy?

    Science.gov (United States)

    Clark, Timothy Darren; Rummer, J L; Sepulveda, C A; Farrell, A P; Brauner, C J

    2010-01-01

    Tunas (family Scombridae) are exceptional among most teleost fishes in that they possess vascular heat exchangers which allow heat retention in specific regions of the body (termed 'regional heterothermy'). Seemingly exclusive to heterothermic fishes is a markedly reduced temperature dependence of blood-oxygen (blood-O(2)) binding, or even a reversed temperature dependence where increasing temperature increases blood-O(2) affinity. These unusual binding properties have been documented in whole blood and in haemoglobin (Hb) solutions, and they are hypothesised to prevent oxygen loss from arteries to veins within the vascular heat exchangers and/or to prevent excessive oxygen unloading to the warm tissues and ensure an adequate supply of oxygen to tissues positioned efferent to the heat exchangers. The temperature sensitivity of blood-O(2) binding has not been characterised in an ectothermic scombrid (mackerels and bonitos), but the existence of the unusual binding properties in these fishes would have clear implications for their proposed association with regional heterothermy. Accordingly, the present study examined oxygenation of whole blood of the chub mackerel (Scomber japonicus) at 10, 20 and 30 degrees C and at 0.5, 1 and 2% CO(2). Oxygen affinity was generally highest at 20 degrees C for all levels of CO(2). Temperature-independent binding was observed at low (0.5%) CO(2), where the PO(2) at 50% blood-O(2) saturation (P (50)) was not statistically different at 10 and 30 degrees C (2.58 vs. 2.78 kPa, respectively) with an apparent heat of oxygenation (H degrees ) close to zero (-6 kJ mol(-1)). The most significant temperature-mediated difference occurred at high (2%) CO(2), where the P (50) at 10 degrees C was twofold higher than that at 20 degrees C with a corresponding H degrees of +43 kJ mol(-1). These results provide clear evidence of independent and reversed open-system temperature effects on blood oxygenation in S. japonicus, and it is therefore

  6. Successful hyperbaric oxygen therapy for refractory BK virus-associated hemorrhagic cystitis after cord blood transplantation.

    Science.gov (United States)

    Hosokawa, K; Yamazaki, H; Nakamura, T; Yoroidaka, T; Imi, T; Shima, Y; Ohata, K; Takamatsu, H; Kotani, T; Kondo, Y; Takami, A; Nakao, S

    2014-10-01

    BK virus-associated hemorrhagic cystitis (BKV-HC) is a common and major cause of morbidity in recipients of allogeneic hematopoietic stem cell transplantation. A 32-year-old woman developed severe BKV-HC on day 24 after cord blood transplantation (CBT). Despite supportive therapies - such as hyperhydration, forced diuresis, and urinary catheterization - macroscopic hematuria and bladder irritation persisted for over a month. Hyperbaric oxygen (HBO) therapy at 2.1 atmospheres for 90 min per day was started on day 64 after CBT. Macroscopic hematuria resolved within a week, and microscopic hematuria was no longer detectable within 2 weeks. Hematuria did not recur after 11 sessions of HBO therapy, and no significant side effects were observed during or after treatment. HBO therapy could thus be useful in controlling refractory BKV-HC after CBT. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  7. Cerebral oxygen metabolism and cerebral blood flow in man during light sleep (stage 2)

    DEFF Research Database (Denmark)

    Madsen, P L; Schmidt, J F; Holm, S

    1991-01-01

    We measured cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO2) during light sleep (stage 2) in 8 young healthy volunteers using the Kety-Schmidt technique with 133Xe as the inert gas. Measurements were performed during wakefulness and light sleep as verified by standard...... polysomnography. Unlike our previous study in man showing a highly significant 25% decrease in CMRO2 during deep sleep (stage 3-4) we found a modest but statistically significant decrease of 5% in CMRO2 during stage 2 sleep. Deep and light sleep are both characterized by an almost complete lack of mental activity....... They differ in respect of arousal threshold as a stronger stimulus is required to awaken a subject from deep sleep as compared to light sleep. Our results suggest that during non-rapid eye movement sleep cerebral metabolism and thereby cerebral synaptic activity is correlated to cerebral readiness rather than...

  8. Acceptance and transfer to a regional severe respiratory failure and veno-venous extracorporeal membrane oxygenation (ECMO) service: predictors and outcomes.

    Science.gov (United States)

    Gillon, S A; Rowland, K; Shankar-Hari, M; Camporota, L; Glover, G W; Wyncoll, D L A; Barrett, N A; Ioannou, N; Meadows, C I S

    2018-02-01

    The use of extracorporeal membrane oxygenation for respiratory failure is high risk and resource intensive. In England, five centres provide this service and patients who are referred have four possible outcomes: declined transfer due to perceived futility; accepted in principle but remain at the referring centre with ongoing surveillance; retrieved using conventional ventilation; or retrieved on extracorporeal support. The decision-making process leading to these outcomes has not previously been examined. We evaluated referrals to one centre and identified factors associated with each decision outcome. Five hundred and sixty-four patients were analysed from January 2012 to October 2015. One hundred and fifty-seven patients were declined; multivariate analysis demonstrated associated factors to be: age (odds ratio (95% confidence interval) 1.05 (1.04-1.07)); immunocompromise (4.95 (2.58-9.67)); lactate (1.11 (1.01-1.22)); duration of ventilation (1.08 (1.04-1.14)); and cardiac failure (3.22 (1.04-10.51)). Factors associated with the decision to retrieve an accepted patient were: plateau pressure (1.05 (1.01-1.10)); ratio of arterial oxygen partial pressure to fractional inspired oxygen (0.89 (0.85-0.93)); partial pressure of carbon dioxide in arterial blood (1.13 (1.03-1.25)); and the absence of non-pulmonary infection (0.31 (0.15-0.61)). Only pH was independently associated with the decision to transfer on extracorporeal support (0.020 (0.002-0.017)). Six-month survival in the declined, non-retrieved, conventionally retrieved and extracorporeal-retrieved groups was 16.6%, 71.1%, 76.7% and 72.1%, respectively, substantially supporting the decision-making model. Survival in the accepted group exceeds that reported previously. However, a proportion of those declined do survive and some remotely managed patients die. This suggests the approach does not account for some important survival-determining factors. © 2017 The Association of Anaesthetists of Great Britain

  9. Effects of Changes in Colored Light on Brain and Calf Muscle Blood Concentration and Oxygenation

    Directory of Open Access Journals (Sweden)

    J. Weinzirl

    2011-01-01

    Full Text Available Color light therapy is a therapeutic method in complementary medicine. In color therapy, light of two contrasting colors is often applied in a sequential order. The aim of this study was to investigate possible physiological effects, i.e., changes in the blood volume and oxygenation in the brain and calf muscle of healthy subjects who were exposed to red and blue light in sequential order. The hypothesis was that if a subject is first exposed to blue and then red light, the effect of the red light will be enhanced due to the contrastingly different characteristics of the two colors. The same was expected for blue light, if first exposing a subject to red and then to blue light. Twelve healthy volunteers (six male, six female were measured twice on two different days by near-infrared spectroscopy during exposure to colored light. Two sequences of colored light were applied in a controlled, randomized, crossover design: first blue, then red, and vice versa. For the brain and muscle, the results showed no significant differences in blood volume and oxygenation between the two sequences, and a high interindividual physiological variability. Thus, the hypothesis had to be rejected. Comparing these data to results from a previous study, where subjects were exposed to blue and red light without sequential color changes, shows that the results of the current study appear to be similar to those of red light exposure. This may indicate that the exposure to red light was preponderant and thus effects of blue light were outweighed.

  10. The Kety-Schmidt Technique for Quantitative Perfusion and Oxygen Metabolism Measurements in the MR Environment

    Science.gov (United States)

    Lee, John J.; Powers, William J.; Faulkner, Chad B.; Boyle, Patrick J.; Derdeyn, Colin P.

    2013-01-01

    The Kety-Schmidt technique provides quantitative measurement of whole brain cerebral blood flow (CBF). CBF is measured as the area between the arterial and venous washout curves of a diffusible tracer. Oxygen extraction and metabolism may be calculated from arterial and venous samples. In this report we present a method for performing these measurements in an MR environment. This technique could be useful for validation of MR methods of hemodynamic and metabolic measurements in humans. PMID:22997166

  11. Role of hemoglobin from blood clam Scapharca kagoshimensis beyond oxygen transport.

    Science.gov (United States)

    Xu, Bin; Zhao, Jun; Jing, Zhao; Zhang, Yanan; Shi, Ying; Fan, Tingjun

    2015-05-01

    The evolutionary race between hosts and pathogens has led to a variety of adaptations. Little is known about the immunological role of hemoglobin (Hb) in antimicrobial immune responses. Results showed that a 31.2 kDa monodimer Hb (skHbI) and a 57.8 kDa heterotetramer Hb (skHbII) from the blood clam, Scapharca kagoshimensis, had phenoloxidase (PO)-like activities and antimicrobial activities. Both were found capable of oxidizing l-DOPA, catechol and hydroquinone. Their PO-like activities were visibly greatly inhibited by oxidase inhibitors, EDTA, and divalent metal ions, and greatly enhanced by isopropanol and Fe(2+), indicating that they have the properties of a metalloenzyme and a catecholase-type PO as well. They also showed obvious anti-bacterial activities against gram-positive bacteria but not against either gram-negative bacteria nor fungi. The anti-bacterial activities levels were a result of the generation of reactive oxygen species (ROS) of superoxide anions. These results indicate that skHbI and skHbII, not only function as iron-containing oxygen carriers, but also exert anti-bacterial activities and catecholase-type oxidizing activities. The fact that skHbII exerts high level of PO-like activity indicates different roles in the innate immunodefense system. These results may improve understanding of the multiple functions of invertebrate Hbs beyond serving as oxygen carriers and may provide insight into how the fundamental and universal mode of the innate immune system has persisted in respiratory proteins throughout the course of evolution. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Reduction of blood oxygen levels enhances postprandial cardiac hypertrophy in Burmese python (Python bivittatus).

    Science.gov (United States)

    Slay, Christopher E; Enok, Sanne; Hicks, James W; Wang, Tobias

    2014-05-15

    Physiological cardiac hypertrophy is characterized by reversible enlargement of cardiomyocytes and changes in chamber architecture, which increase stroke volume and via augmented convective oxygen transport. Cardiac hypertrophy is known to occur in response to repeated elevations of O2 demand and/or reduced O2 supply in several species of vertebrate ectotherms, including postprandial Burmese pythons (Python bivittatus). Recent data suggest postprandial cardiac hypertrophy in P. bivittatus is a facultative rather than obligatory response to digestion, though the triggers of this response are unknown. Here, we hypothesized that an O2 supply-demand mismatch stimulates postprandial cardiac enlargement in Burmese pythons. To test this hypothesis, we rendered animals anemic prior to feeding, essentially halving blood oxygen content during the postprandial period. Fed anemic animals had heart rates 126% higher than those of fasted controls, which, coupled with a 71% increase in mean arterial pressure, suggests fed anemic animals were experiencing significantly elevated cardiac work. We found significant cardiac hypertrophy in fed anemic animals, which exhibited ventricles 39% larger than those of fasted controls and 28% larger than in fed controls. These findings support our hypothesis that those animals with a greater magnitude of O2 supply-demand mismatch exhibit the largest hearts. The 'low O2 signal' stimulating postprandial cardiac hypertrophy is likely mediated by elevated ventricular wall stress associated with postprandial hemodynamics. © 2014. Published by The Company of Biologists Ltd.

  13. The possibility for use of venous flaps in plastic surgery

    Energy Technology Data Exchange (ETDEWEB)

    Baytinger, V. F., E-mail: baitinger@mail.tomsknet.ru; Kurochkina, O. S., E-mail: kurochkinaos@yandex.ru; Selianinov, K. V.; Baytinger, A. V. [Research Institute of Microsurgery, Tomsk (Russian Federation); Dzyuman, A. N. [Siberian State Medical University, Tomsk (Russian Federation)

    2015-11-17

    The use of venous flaps is controversial. The mechanism of perfusion of venous flaps is still not fully understood. The research was conducted on 56 white rats. In our experimental work we studied two different models of venous flaps: pedicled venous flap (PVF) and pedicled arterialized venous flap (PAVF). Our results showed that postoperative congestion was present in all flaps. However 66.7% of all pedicled venous flaps and 100% of all pedicled arterialized venous flaps eventually survived. Histological examination revealed that postoperatively the blood flow in the skin of the pedicled arterialized venous flap became «re-reversed» again; there were no differences between mechanism of survival of venous flaps and other flaps. On the 7-14th day in the skin of all flaps were processes of neoangiogenesis and proliferation. Hence the best scenario for the clinical use of venous flaps unfolds when both revascularization and skin coverage are required.

  14. The possibility for use of venous flaps in plastic surgery

    Science.gov (United States)

    Baytinger, V. F.; Kurochkina, O. S.; Selianinov, K. V.; Baytinger, A. V.; Dzyuman, A. N.

    2015-11-01

    The use of venous flaps is controversial. The mechanism of perfusion of venous flaps is still not fully understood. The research was conducted on 56 white rats. In our experimental work we studied two different models of venous flaps: pedicled venous flap (PVF) and pedicled arterialized venous flap (PAVF). Our results showed that postoperative congestion was present in all flaps. However 66.7% of all pedicled venous flaps and 100% of all pedicled arterialized venous flaps eventually survived. Histological examination revealed that postoperatively the blood flow in the skin of the pedicled arterialized venous flap became «re-reversed» again; there were no differences between mechanism of survival of venous flaps and other flaps. On the 7-14th day in the skin of all flaps were processes of neoangiogenesis and proliferation. Hence the best scenario for the clinical use of venous flaps unfolds when both revascularization and skin coverage are required.

  15. CELL RESPIRATION STUDIES : II. A COMPARATIVE STUDY OF THE OXYGEN CONSUMPTION OF BLOOD FROM NORMAL INDIVIDUALS AND PATIENTS WITH INCREASED LEUCOCYTE COUNTS (SEPSIS; CHRONIC MYELOGENOUS LEUCEMIA).

    Science.gov (United States)

    Daland, G A; Isaacs, R

    1927-06-30

    1. The oxygen consumption of blood of normal individuals, when the hemoglobin is saturated with oxygen, is practically zero within the limits of experimental error of the microspirometer used. 2. The oxygen consumed in a microspirometer by the blood of patients with chronic myelogenous leucemia with a high white blood cell count, and of one with leucocytosis from sepsis, was proportional to the number of adult polymorphonuclear neutrophils in the blood. 3. No correlation could be made between the rate of oxygen absorption and the total number of white blood cells in the blood, or the total number of immature cells, or the number of red blood cells, or the amount of oxyhemoglobin. 4. The blood of patients with chronic myelogenous leucemia continued to use oxygen in the microspirometer longer than that of normal individuals, and the hemoglobin, in the leucemic bloods, became desaturated even though exposed to air. 5. In blood in which the bulk. of the cells were immature and the mature cells few, the oxygen consumption was lower than in blood in which the mature cells predominated. The rate of oxygen consumption of the immature cells was relatively low as compared to the mature. 6. The slower rate of oxygen absorption by the immature leucocytes in chronic myelogenous leucemia as compared to the mature cells, places them, in accord with Warburg's reports, in the class of the malignant tissues in this respect rather than in the group of young or embryonic cells.

  16. Numerical Investigation of Oxygenated and Deoxygenated Blood Flow through a Tapered Stenosed Arteries in Magnetic Field.

    Directory of Open Access Journals (Sweden)

    M Y Abdollahzadeh Jamalabadi

    Full Text Available Current paper is focused on transient modeling of blood flow through a tapered stenosed arteries surrounded a by solenoid under the presence of heat transfer. The oxygenated and deoxygenated blood are considered here by the Newtonian and Non-Newtonian fluid (power law and Carreau-Yasuda models. The governing equations of bio magnetic fluid flow for an incompressible, laminar, homogeneous, non-Newtonian are solved by finite volume method with SIMPLE algorithm for structured grid. Both magnetization and electric current source terms are well thought-out in momentum and energy equations. The effects of fluid viscosity model, Hartmann number, and magnetic number on wall shear stress, shearing stress at the stenosis throat and maximum temperature of the system are investigated and are optimized. The current study results are in agreement with some of the existing findings in the literature and are useful in thermal and mechanical design of spatially varying magnets to control the drug delivery and biomagnetic fluid flows through tapered arteries.

  17. Numerical Investigation of Oxygenated and Deoxygenated Blood Flow through a Tapered Stenosed Arteries in Magnetic Field.

    Science.gov (United States)

    Abdollahzadeh Jamalabadi, M Y; Akbari Bidokhti, Amin Ali; Khak Rah, Hamid; Vaezi, Siavash; Hooshmand, Payam

    2016-01-01

    Current paper is focused on transient modeling of blood flow through a tapered stenosed arteries surrounded a by solenoid under the presence of heat transfer. The oxygenated and deoxygenated blood are considered here by the Newtonian and Non-Newtonian fluid (power law and Carreau-Yasuda) models. The governing equations of bio magnetic fluid flow for an incompressible, laminar, homogeneous, non-Newtonian are solved by finite volume method with SIMPLE algorithm for structured grid. Both magnetization and electric current source terms are well thought-out in momentum and energy equations. The effects of fluid viscosity model, Hartmann number, and magnetic number on wall shear stress, shearing stress at the stenosis throat and maximum temperature of the system are investigated and are optimized. The current study results are in agreement with some of the existing findings in the literature and are useful in thermal and mechanical design of spatially varying magnets to control the drug delivery and biomagnetic fluid flows through tapered arteries.

  18. Does the preference of peripheral versus central venous access in peripheral blood stem cell collection/yield change stem cell kinetics in autologous stem cell transplantation?

    Science.gov (United States)

    Dogu, Mehmet Hilmi; Kaya, Ali Hakan; Berber, Ilhami; Sari, İsmail; Tekgündüz, Emre; Erkurt, Mehmet Ali; Iskender, Dicle; Kayıkçı, Ömur; Kuku, Irfan; Kaya, Emin; Keskin, Ali; Altuntaş, Fevzi

    2016-02-01

    Central venous access is often used during apheresis procedure in stem cell collection. The aim of the present study was to evaluate whether central or peripheral venous access has an effect on stem cell yield and the kinetics of the procedure and the product in patients undergoing ASCT after high dose therapy. A total of 327 patients were retrospectively reviewed. The use of peripheral venous access for stem cell yield was significantly more frequent in males compared to females (p = 0.005). Total volume of the product was significantly lower in central venous access group (p = 0.046). As being a less invasive procedure, peripheral venous access can be used for stem cell yield in eligible selected patients. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Study of fluid dynamics reveals direct communications between lymphatic vessels and venous blood vessels at lymph nodes of mice.

    Science.gov (United States)

    Takeda, Kazu; Mori, Shiro; Kodama, Tetsuya

    2017-06-01

    Cancer cells metastasize to lymph nodes, with distant metastasis resulting in poor prognosis. The role of lymph node metastasis (LNM) in the spread of cancer to distant organs remain incompletely characterized. The visualization of flow dynamics in the lymphatic and blood vessels of MXH10/Mo-lpr/lpr mice, which develop systemic swelling of lymph nodes up to 10mm in diameter, has revealed that lymph nodes have the potential to be a direct source of systemic metastasis. However, it is not known whether these fluid dynamics characteristics are universal phenomena present in other strains of laboratory mice. Here we show that the fluid dynamics observed in MXH10/Mo-lpr/lpr mice are the same as those observed in C57BL/6J, BALB/cAJcl and NOD/ShiJic-scidJcl mice. Furthermore, when fluorescent solution was injected into a tumor-bearing lymph node, the flow dynamics observed in the efferent lymphatic vessels and thoracoepigastric vein depended on the type of tumor cell. Our results indicate that fluid dynamics in the lymphatic and blood vessels of MXH10/Mo-lpr/lpr mice are generalized phenomena seen in conventional laboratory mice. We anticipate our results can facilitate studies of the progression of lymphatic metastasis to hematogenous metastasis via lymph nodes and the early diagnosis and treatment of LNM. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Integrated analysis of halogenated organic pollutants in sub-millilitre volumes of venous and umbilical cord blood sera

    Energy Technology Data Exchange (ETDEWEB)

    Grimalt, Joan O.; Carrizo, Daniel; Otero, Raquel; Vizcaino, Esther [Institute of Environmental Assessment and Water Research (IDAeA-CSIC), Department of Environmental Chemistry, Barcelona, Catalonia (Spain); Howsam, Mike [Universite de Lille 2, Centre Universitaire de Mesure et d' Analyse, Faculte de Pharmacie, Lille (France); Rodrigues de Marchi, Mary Rosa [Institute of Chemistry UNESP, Department of Analytical Chemistry, Araraquara, SP (Brazil)

    2010-03-15

    A rapid, robust and economical method for the analysis of persistent halogenated organic compounds in small volumes of human serum and umbilical cord blood is described. The pollutants studied cover a broad range of molecules of contemporary epidemiological and legislative concern, including polychlorobiphenyls (PCBs), polychlorobenzenes (CBs), hexachlorocyclohexanes (HCHs), DDTs, polychlorostyrenes (PCSs) and polybromodiphenyl ethers (PBDEs). Extraction and clean-up with n-hexane and concentrated sulphuric acid was followed with analysis by gas chromatography coupled to electron capture (GC-ECD) and GC coupled to negative ion chemical ionisation mass spectrometry (GC-NICI-MS). The advantages of this method rest in the broad range of analytes and its simplicity and robustness, while the use of concentrated sulphuric acid extraction/clean-up destroys viruses that may be present in the samples. Small volumes of reference serum between 50 and 1000{mu}L were extracted and the limits of detection/quantification and repeatability were determined. Recoveries of spiked compounds for the extraction of small volumes ({>=}300 {mu}L) of the spiked reference serum were between 90% and 120%. The coefficients of variation of repeatability ranged from 0.1-14%, depending on the compound. Samples of 4-year-old serum and umbilical cord blood (n=73 and 40, respectively) from a population inhabiting a village near a chloro-alkali plant were screened for the above-mentioned halogenated pollutants using this method and the results are briefly described. (orig.)

  1. Age at cancer diagnosis, non-O blood group and asparaginase therapy are independently associated with deep venous thrombosis in pediatric oncology patients: A risk model.

    Science.gov (United States)

    Spavor, Maria; Halton, Jacqueline; Dietrich, Kevin; Israels, Sara; Shereck, Evan; Yong, Jian; Yasui, Yutaka; Mitchell, Lesley Gayle

    2016-08-01

    Pediatric oncology patients are at increased risk for deep venous thrombosis (DVT). Determining the sub-population of children at increased DVT risk is critical for optimum clinical management. Therefore, the aim of the current study was to identify clinical risk factors for DVT which are easily identifiable at cancer diagnosis. A Canadian multicenter case control study in survivors of childhood cancer. Survivors who had DVT (Cases) while being treated for pediatric cancer where matched by center with a minimum of two survivors who did not experience DVT (Controls). Clinical information including age at diagnosis, type of cancer and chemotherapy were collected. Genotyping of blood group was done by single nucleotide polymorphisms analysis. 218 subjects were recruited at 4 Canadian pediatric centers. Multivariable analysis demonstrated 3 significant variables (reported as Odds Ratio (OR), (95% CI), p value): age at diagnosis p2-≤7years, >7≤10years, >10years. A significant association with DVT were seen in children 0-≤2years (OR 3.1 (1.1-8.3) p=0.026) and >10years (OR 3.8, 1.7-8.5 p=0.001). Significant associations with DVT remained for non-O blood group, OR 2.2 (1.2-4.4) p=0.016 and asparaginase treatment, OR 2.1 (1.1-4.0) p=0.027. The value for the clinical risk model receiver operating characteristics curve was 0.67. We have shown 3 independent risk factors for DVT in childhood cancer. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Determinação das glicemias capilar e venosa com glicosímetro versus dosagem laboratorial da glicose plasmática Determination of capillary blood glucose and venous blood glucose with a glucometer versus laboratory determination of venous plasma glucose

    Directory of Open Access Journals (Sweden)

    Caio Mauricio Mendes de Cordova

    2009-10-01

    Full Text Available INTRODUÇÃO E OBJETIVOS: Diabetes mellitus (DM é a mais importante patologia que envolve o pâncreas endócrino, sendo uma das principais causas de morbidade e mortalidade na população geral. O objetivo deste trabalho foi avaliar a determinação da glicemia em diferentes tipos de amostras e metodologias. MÉTODOS: Utilizando um equipamento Accu-Check Advantage (Roche, foi avaliada a glicemia em amostras de sangue capilar (GCG e de sangue venoso (GVG, e a dosagem da glicemia venosa em plasma (GVE foi realizada por método enzimático de rotina. RESULTADOS E CONCLUSÃO: Foi observada boa correlação entre a GCG e a GVG (r = 0,8742. Entretanto, houve diferença significativa entre a GCG e a GVE (r = 0,6543 e entre a GVG e a GVE (r = 0,5038 (p INTRODUCTION AND OBJECTIVES: Diabetes mellitus is the most important pathology that affects the endocrine pancreas and one of the main causes of morbidity and mortality among the general population. The aim of this work was to evaluate the correlation of blood glucose determination in different types of samples and methodologies. METHODS: Using an Accu-Check Advantage glucometer (Roche, it was determined the blood glucose levels in capillary (CBG and venous (VBG samples, and plasma venous glucose was determined by routine enzymatic methodology (EVG. RESULTS AND CONCLUSION: It was observed a good correlation between CBG and VBG (r = 0.8742. However, there was a significant difference between CBG and EVG (r = 0.6543 and between VBG and EVG (r = 0.5038 (p < 0.001. These differences are even more substantial considering only normoglycemic patients. The existence of different studies with inconsistent results does not depend only on the glucometer brand or its specific series, as the same device may present inconsistent results in different studies.

  3. Mechanical indentation improves cerebral blood oxygenation signal quality of functional near-infrared spectroscopy (fNIRS) during breath holding

    Science.gov (United States)

    Vogt, William C.; Romero, Edwin; LaConte, Stephen M.; Rylander, Christopher G.

    2013-03-01

    Functional near-infrared spectroscopy (fNIRS) is a well-known technique for non-invasively measuring cerebral blood oxygenation, and many studies have demonstrated that fNIRS signals can be related to cognitive function. However, the fNIRS signal is attenuated by the skin, while scalp blood content has been reported to influence cerebral oxygenation measurements. Mechanical indentation has been shown to increase light transmission through soft tissues by causing interstitial water and blood flow away from the compressed region. To study the effects of indentation on fNIRS, a commercial fNIRS system with 16 emitter/detector pairs was used to measure cerebral blood oxygenation at 2 Hz. This device used diffuse reflectance at 730 nm and 850 nm to calculate deoxy- and oxy-hemoglobin concentrations. A borosilicate glass hemisphere was epoxied over each sensor to function as both an indenter and a lens. After placing the indenter/sensor assembly on the forehead, a pair of plastic bands was placed on top of the fNIRS headband and strapped to the head to provide uniform pressure and tightened to approx. 15 N per strap. Cerebral blood oxygenation was recorded during a breath holding regime (15 second hold, 15 second rest, 6 cycles) in 4 human subjects both with and without the indenter array. Results showed that indentation increased raw signal intensity by 85 +/- 35%, and that indentation increased amplitude of hemoglobin changes during breath cycles by 313% +/- 105%. These results suggest that indentation improves sensing of cerebral blood oxygenation, and may potentially enable sensing of deeper brain tissues.

  4. Relationship Between Cerebral Oxygenation and Hemodynamic and Oxygen Transport Parameters in Surgery for Acquired Heart Diseases

    Directory of Open Access Journals (Sweden)

    A. I. Lenkin

    2012-01-01

    Full Text Available Objective: to evaluate the relationship between cerebral oxygenation and hemodynamic and oxygen transport parameters in surgical correction of concomitant acquired heart diseases. Subjects and methods. Informed consent was received from 40 patients who required surgery because of concomitant (two or more acquired heart defects. During procedure, perioperative monitoring of oxygen transport and cerebral oxygenation was performed with the aid of PiCCO2 monitor (Pulsion Medical Systems, Germany and a Fore-Sight cerebral oximeter (CASMED, USA. Anesthesia was maintained with propofol and fen-tanyl, by monitoring the depth of anesthesia. Early postoperative intensive therapy was based on the protocol for early targeted correction of hemodynamic disorders. Oxygen transport and cerebral oxygenation parameters were estimated intraopera-tively and within 24 postoperative hours. A statistical analysis including evaluation of Spearman correlations was performed with the aid of SPSS 15.0. Results. During perfusion, there was a relationship between cerebral oximetry values and hemat-ocrit levels, and oxygen partial pressure in the venous blood. Furthermore, a negative correlation between cerebral oximetry values and blood lactate levels was found 30 minutes after initiation of extracorporeal circulation (EC. During the study, there was a positive correlation between cerebral oxygenation and values of cardiac index, central venous saturation, and oxygen delivery index. There was a negative relationship between cerebral oxygenation and extravascular lung water at the beginning of surgery and a correlation between cerebral oximetry values and oxygenation index by the end of the first 24 postoperative hours. Conclusion. The cerebral oxygenation values correlate -with the main determinants of oxygen transport during EC and after cardiac surgical procedures. Cerebral oximetry may be used in early targeted therapy for the surgical correction of acquired combined

  5. Significantly reduced adsorption and activation of blood components in a membrane oxygenator system coated with crosslinkable zwitterionic copolymer.

    Science.gov (United States)

    Wang, Yan-Bing; Shi, Ke-Hui; Jiang, Hong-Li; Gong, Yong-Kuan

    2016-08-01

    A crosslinkable zwitterionic copolymer PMBT was coated onto the surfaces of polypropylene hollow fiber membrane (PP-HFM) oxygenator and its connecting tubes. The PMBT copolymer coating on the oxygenator circuit formed a cell outer membrane mimetic surface with excellent stability. The hemocompatibility of the PMBT copolymer coated PP-HFM oxygenator circuit was evaluated by animal extracorporeal circulation. The concentrations of clotting components fibrinogen and platelet in the blood were almost unchanged during the circulation through the PMBT copolymer coated oxygenator circuits. By contrast, the concentrations of fibrinogen and platelet were significantly reduced to 52% and 56% respectively in the uncoated oxygenator group due to adsorption and thrombogenesis of the blood during 2h circulation. Moreover, concentration of activation marker beta-thromboglobulin for platelet in the blood was remarkably lower in the PMBT group than the uncoated control group (pblood components and eliminate heparin-induced thrombocytopenia, none of them have fabricated stable and densely assembled film, especially with crosslinkable amphiphilic random copolymer described in our manuscript. The novel features of our work include. Copyright © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  6. Relation of mitochondrial oxygen consumption in peripheral blood mononuclear cells to vascular function in type 2 diabetes mellitus.

    Science.gov (United States)

    Hartman, Mor-Li; Shirihai, Orian S; Holbrook, Monika; Xu, Guoquan; Kocherla, Marsha; Shah, Akash; Fetterman, Jessica L; Kluge, Matthew A; Frame, Alissa A; Hamburg, Naomi M; Vita, Joseph A

    2014-02-01

    Recent studies have shown mitochondrial dysfunction and increased production of reactive oxygen species in peripheral blood mononuclear cells (PBMCs) and endothelial cells from patients with diabetes mellitus. Mitochondria oxygen consumption is coupled to adenosine triphosphate (ATP) production and also occurs in an uncoupled fashion during formation of reactive oxygen species by components of the electron transport chain and other enzymatic sites. We therefore hypothesized that diabetes would be associated with higher total and uncoupled oxygen consumption in PBMCs that would correlate with endothelial dysfunction. We developed a method to measure oxygen consumption in freshly isolated PBMCs and applied it to 26 patients with type 2 diabetes mellitus and 28 non-diabetic controls. Basal (192 ± 47 vs 161 ± 44 pmoles/min, p = 0.01), uncoupled (64 ± 16 vs 53 ± 13 pmoles/min, p = 0.007), and maximal (795 ± 87 vs 715 ± 128 pmoles/min, p=0.01) oxygen consumption rates were higher in diabetic patients compared to controls. There were no significant correlations between oxygen consumption rates and endothelium-dependent flow-mediated dilation measured by vascular ultrasound. Non-endothelium-dependent nitroglycerin-mediated dilation was lower in diabetics (10.1 ± 6.6 vs 15.8 ± 4.8%, p = 0.03) and correlated with maximal oxygen consumption (r = -0.64, p=0.001). In summary, we found that diabetes mellitus is associated with a pattern of mitochondrial oxygen consumption consistent with higher production of reactive oxygen species. The correlation between oxygen consumption and nitroglycerin-mediated dilation may suggest a link between mitochondrial dysfunction and vascular smooth muscle cell dysfunction that merits further study. Finally, the described method may have utility for the assessment of mitochondrial function in larger scale observational and interventional studies in humans.

  7. Venous Thromboembolism in Patients With Thrombocytopenia

    DEFF Research Database (Denmark)

    Bælum, Jens Kristian; Ellingsen Moe, Espen; Nybo, Mads

    2017-01-01

    BACKGROUND: Venous thromboembolism (VTE) is a frequent and potentially lethal condition. Venous thrombi are mainly constituted of fibrin and red blood cells, but platelets also play an important role in VTE formation. Information about VTE in patients with thrombocytopenia is, however, missing. O...

  8. Detection of Acute Tubular Necrosis Using Blood Oxygenation Level-Dependent (BOLD MRI

    Directory of Open Access Journals (Sweden)

    Frederic Bauer

    2017-12-01

    Full Text Available Background/Aims: To date, there is no imaging technique to assess tubular function in vivo. Blood oxygen level-dependent magnetic resonance imaging (BOLD MRI measures tissue oxygenation based on the transverse relaxation rate (R2*. The present study investigates whether BOLD MRI can assess tubular function using a tubule-specific pharmacological maneuver. Methods: Cross sectional study with 28 participants including 9 subjects with ATN-induced acute kidney injury (AKI, 9 healthy controls, and 10 subjects with nephron sparing tumor resection (NSS with clamping of the renal artery serving as a model of ischemia/reperfusion (I/R-induced subclinical ATN (median clamping time 15 min, no significant decrease of eGFR, p=0.14. BOLD MRI was performed before and 5, 7, and 10 min after intravenous administration of 40 mg furosemide. Results: Urinary neutrophil gelatinase-associated lipocalin was significantly higher in ATN-induced AKI and NSS subjects than in healthy controls (p=0.03 and p=0.01, respectively. Before administration of furosemide, absolute medullary R2*, cortical R2*, and medullary/cortical R2* ratio did not significantly differ between ATN-induced AKI vs. healthy controls and between NSS-I/R vs. contralateral healthy kidneys (p>0.05 each. Furosemide led to a significant decrease in the medullary and cortical R2* of healthy subjects and NSS contralateral kidneys (p<0.05 each, whereas there was no significant change of R2* in ATN-induced AKI and the NSS-I/R kidneys (p>0.05 each. Conclusion: BOLD-MRI is able to detect even mild tubular injury but necessitates a tubule-specific pharmacological maneuver, e.g. blocking the Na+-K+-2Cl- transporter by furosemide.

  9. Rejuvenation of stored human red blood cells reverses the renal microvascular oxygenation deficit in an isovolemic transfusion model in rats

    NARCIS (Netherlands)

    Raat, Nicolaas J. H.; Hilarius, Petra M.; Johannes, Tanja; de Korte, Dirk; Ince, Can; Verhoeven, Arthur J.

    2009-01-01

    BACKGROUND: Storage of red blood cells (RBCs) results in various biochemical changes, including a decrease in cellular adenosine triphosphate and 2,3-diphosphoglycerate acid. Previously it was shown that stored human RBCs show a deficit in the oxygenation of the microcirculation in the gut of

  10. Effects of zilpaterol hydrochloride on methane production, total body oxygen consumption, and blood metabolites in finishing beef steers

    Science.gov (United States)

    An indirect calorimetry experiment was conducted to determine the effects of feeding zilpaterol hydrochloride (ZH) for 20 d on total body oxygen consumption, respiratory quotient, methane production, and blood metabolites in finishing beef steers. Sixteen Angus steers (initial BW = 555 ± 12.7 kg) w...

  11. Effects of sample storage time, temperature and syringe type on blood gas tensions in samples with high oxygen partial pressures.

    OpenAIRE

    Pretto, J. J.; Rochford, P D

    1994-01-01

    BACKGROUND--Although plastic arterial sampling syringes are now commonly used, the effects of sample storage time and temperature on blood gas tensions are poorly described for samples with a high oxygen partial pressure (PaO2) taken with these high density polypropylene syringes. METHODS--Two ml samples of tonometered whole blood (PaO2 86.7 kPa, PaCO2 4.27 kPa) were placed in glass syringes and in three brands of plastic blood gas syringes. The syringes were placed either at room temperature...

  12. Dehydration affects cerebral blood flow but not its metabolic rate for oxygen during maximal exercise in trained humans

    DEFF Research Database (Denmark)

    Trangmar, Steven J; Chiesa, Scott T; Stock, Christopher G

    2014-01-01

    Intense exercise is associated with a reduction in cerebral blood flow (CBF), but regulation of CBF during strenuous exercise in the heat with dehydration is unclear. We assessed internal (ICA) and common carotid artery (CCA) haemodynamics (indicative of CBF and extra-cranial blood flow), middle.......3 ± 0.1 vs. 36.8 ± 0.1°C), impaired exercise capacity (269 ± 11 vs. 336 ± 14 W), and lowered ICA and MCA Vmean by 12-23% without compromising CCA blood flow. During euhydrated incremental exercise on a separate day, however, exercise capacity and ICA, MCA Vmean and CCA dynamics were preserved. The fast...... venous noradrenaline, and falling arterial carbon dioxide tension (P aCO 2) (R(2) ≥ 0.41, P ≤ 0.01) whereas CCA flow and conductance were related to elevated blood temperature. In conclusion, dehydration accelerated the decline in CBF by decreasing P aCO 2 and enhancing vasoconstrictor activity. However...

  13. Dehydration affects cerebral blood flow but not its metabolic rate for oxygen during maximal exercise in trained humans

    Science.gov (United States)

    Trangmar, Steven J; Chiesa, Scott T; Stock, Christopher G; Kalsi, Kameljit K; Secher, Niels H; González-Alonso, José

    2014-01-01

    Intense exercise is associated with a reduction in cerebral blood flow (CBF), but regulation of CBF during strenuous exercise in the heat with dehydration is unclear. We assessed internal (ICA) and common carotid artery (CCA) haemodynamics (indicative of CBF and extra-cranial blood flow), middle cerebral artery velocity (MCA Vmean), arterial–venous differences and blood temperature in 10 trained males during incremental cycling to exhaustion in the heat (35°C) in control, dehydrated and rehydrated states. Dehydration reduced body mass (75.8 ± 3 vs. 78.2 ± 3 kg), increased internal temperature (38.3 ± 0.1 vs. 36.8 ± 0.1°C), impaired exercise capacity (269 ± 11 vs. 336 ± 14 W), and lowered ICA and MCA Vmean by 12–23% without compromising CCA blood flow. During euhydrated incremental exercise on a separate day, however, exercise capacity and ICA, MCA Vmean and CCA dynamics were preserved. The fast decline in cerebral perfusion with dehydration was accompanied by increased O2 extraction (P dehydration accelerated the decline in CBF by decreasing and enhancing vasoconstrictor activity. However, the circulatory strain on the human brain during maximal exercise does not compromise CMRO2 because of compensatory increases in O2 extraction. PMID:24835170

  14. The role of tissue oxygen tension in the control of local blood flow in the microcirculation of skeletal muscles

    DEFF Research Database (Denmark)

    Ngo, Thuc Anh

    2010-01-01

    (inhibitor of KATP channels) in the superfusate abolished both vasodilatation and constriction to low and high oxygen superfusate, indicating that KATP channels are involved in both hypoxic vasodilatation and hyperoxic vasoconstriction. Red blood cells (RBCs) have been proposed to release ATP and......In the microcirculation blood flow is highly regulated dependent on the metabolic activity of the tissues. Among several mechanisms, mechanisms involved in the coupling of changes in tissue oxygen tension due to changes in the metabolic activity of the tissue play an important role. In the systemic...... as in the intact blood-perfused arteriole. This indicates that RBCs are not essential for hypoxic vasodilatation. In addition several potential pathways were evaluated. Application of DPCPX (inhibitor of adenosine A1 and A2 receptors) and L-NAME (inhibitor of NO-synthase) did not affect vasomotor responses to low...

  15. Effects of Walking with Blood Flow Restriction on Excess Post-exercise Oxygen Consumption.

    Science.gov (United States)

    Mendonca, G V; Vaz, J R; Pezarat-Correia, P; Fernhall, B

    2015-02-09

    This study determined the influence of walking with blood flow restriction (BFR) on the excess post-exercise oxygen consumption (EPOC) of healthy young men. 17 healthy young men (22.1±2.9 years) performed graded treadmill exercise to assess VO2peak. In a randomized fashion, each participant performed 5 sets of 3-min treadmill exercise at their optimal walking speed with 1-min interval either with or without BFR. Participants were then seated in a chair and remained there for 30 min of recovery. Expired gases were continuously monitored during exercise and recovery. BFR increased the O2 cost of walking as well as its relative intensity and cumulative O2 deficit (pEPOC magnitude after walking with BFR was greater than in the non-BFR condition (pEPOC. The EPOC magnitude was no longer different between conditions after controlling for the differences in relative intensity and in the cumulative O2 deficit (p>0.05). These data indicate that walking with BFR increases the magnitude of EPOC. Moreover, they also demonstrate that such increment in EPOC is likely explained by the effects of BFR on walking relative intensity and cumulative O2 deficit. © Georg Thieme Verlag KG Stuttgart · New York.

  16. [Application of near infrared spectroscopy in monitoring blood oxygen saturation of fibula flaps].

    Science.gov (United States)

    Shan, Xiao-feng; Cai, Zhi-gang; Yu, Guang-yan; Li, Yue; Ding, Hai-shu

    2008-07-01

    To study the change of tissue oxygen index (TOI) by non-invasive near infrared spectroscopy (NIRS) and to investigate the blood flow variety of fibula flaps after operation. Thirty-six patients who accepted fibula flap reconstruction were chosen as subjects. Authors measured the TOI of the fibula flaps and the control side every four hours in the first twenty-four hours, and measured these positions with the intermittence of twelve hours from second to eighth day after operation. Thirty-five flaps were successful and one failed. The TOI of fibula flaps shortly after operation was significantly lower than that before the operation( P<0.05). In the successful cases the TOI of fibula flaps and the control sides was fluctuated from 50.0% to 72.0%. The TOI of fibula flaps was significantly lower than that of the control sides within 144 hours after operation(P<0.05). After 144 hours the TOI was equal to that of the control side. TOI of the failed case decreased dramatically. NIRS can reliably indicate the change of TOI in buried flaps and detect ischemia at the early stage. The TOI of the fibula flaps depress at the early stage and returns to normal at 144 hours after operation.

  17. Implementation of spin-echo blood oxygen level-dependent (BOLD) functional MRI in birds.

    Science.gov (United States)

    Poirier, Colline; Verhoye, Marleen; Boumans, Tiny; Van der Linden, Annemie

    2010-11-01

    The advent of high-field MRI systems has allowed the implementation of blood oxygen level-dependent functional MRI (BOLD fMRI) on small animals. An increased magnetic field improves the signal-to-noise ratio and thus allows an improvement in the spatial resolution. However, it also increases susceptibility artefacts in the commonly acquired gradient-echo images. This problem is particularly prominent in songbird MRI because of the presence of numerous air cavities in the skull of birds. These T(2)*-related image artefacts can be circumvented using spin-echo BOLD fMRI. In this article, we describe the implementation of spin-echo BOLD fMRI in zebra finches, a small songbird of 15-25 g, extensively studied in the behavioural neurosciences of birdsong. Because the main topics in this research domain are song perception and song learning, the protocol implemented used auditory stimuli. Despite the auditory nature of the stimuli and the weak contrast-to-noise ratio of spin-echo BOLD fMRI compared with gradient-echo BOLD fMRI, we succeeded in detecting statistically significant differences in BOLD responses triggered by different stimuli. This study shows that spin-echo BOLD fMRI is a viable approach for the investigation of auditory processing in the whole brain of small songbirds. It can also be applied to study auditory processing in other small animals, as well as other sensory modalities.

  18. Blood oxygen-level dependent functional assessment of cerebrovascular reactivity: Feasibility for intraoperative 3 Tesla MRI.

    Science.gov (United States)

    Fierstra, Jorn; Burkhardt, Jan-Karl; van Niftrik, Christiaan Hendrik Bas; Piccirelli, Marco; Pangalu, Athina; Kocian, Roman; Neidert, Marian Christoph; Valavanis, Antonios; Regli, Luca; Bozinov, Oliver

    2017-02-01

    To assess the feasibility of functional blood oxygen-level dependent (BOLD) MRI to evaluate intraoperative cerebrovascular reactivity (CVR) at 3 Tesla field strength. Ten consecutive neurosurgical subjects scheduled for a clinical intraoperative MRI examination were enrolled in this study. In addition to the clinical protocol a BOLD sequence was implemented with three cycles of 44 s apnea to calculate CVR values on a voxel-by-voxel basis throughout the brain. The CVR range was then color-coded and superimposed on an anatomical volume to create high spatial resolution CVR maps. Ten subjects (mean age 34.8 ± 13.4; 2 females) uneventfully underwent the intraoperative BOLD protocol, with no complications occurring. Whole-brain CVR for all subjects was (mean ± SD) 0.69 ± 0.42, whereas CVR was markedly higher for tumor subjects as compared to vascular subjects, 0.81 ± 0.44 versus 0.33 ± 0.10, respectively. Furthermore, color-coded functional maps could be robustly interpreted for a whole-brain assessment of CVR. We demonstrate that intraoperative BOLD MRI is feasible in creating functional maps to assess cerebrovascular reactivity throughout the brain in subjects undergoing a neurosurgical procedure. Magn Reson Med 77:806-813, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

  19. New principle for measuring arterial blood oxygenation, enabling motion-robust remote monitoring.

    Science.gov (United States)

    van Gastel, Mark; Stuijk, Sander; de Haan, Gerard

    2016-12-07

    Finger-oximeters are ubiquitously used for patient monitoring in hospitals worldwide. Recently, remote measurement of arterial blood oxygenation (SpO2) with a camera has been demonstrated. Both contact and remote measurements, however, require the subject to remain static for accurate SpO2 values. This is due to the use of the common ratio-of-ratios measurement principle that measures the relative pulsatility at different wavelengths. Since the amplitudes are small, they are easily corrupted by motion-induced variations. We introduce a new principle that allows accurate remote measurements even during significant subject motion. We demonstrate the main advantage of the principle, i.e. that the optimal signature remains the same even when the SNR of the PPG signal drops significantly due to motion or limited measurement area. The evaluation uses recordings with breath-holding events, which induce hypoxemia in healthy moving subjects. The events lead to clinically relevant SpO2 levels in the range 80-100%. The new principle is shown to greatly outperform current remote ratio-of-ratios based methods. The mean-absolute SpO2-error (MAE) is about 2 percentage-points during head movements, where the benchmark method shows a MAE of 24 percentage-points. Consequently, we claim ours to be the first method to reliably measure SpO2 remotely during significant subject motion.

  20. Effects of Handgrip Training With Venous Restriction on Brachial Artery Vasodilation

    OpenAIRE

    Credeur, Daniel P.; Hollis, Brandon C.; Welsch, Michael A.

    2010-01-01

    Previous studies have shown that resistance training with restricted venous blood flow (Kaatsu) results in significant strength gains and muscle hypertrophy. However, few studies have examined the concurrent vascular responses following restrictive venous blood flow training protocols.

  1. Red blood cells in sports: effects of exercise and training on oxygen supply by red blood cells

    National Research Council Canada - National Science Library

    Mairbäurl, Heimo

    2013-01-01

    .... These functions require adequate amounts of red blood cells in circulation. Trained athletes, particularly in endurance sports, have a decreased hematocrit, which is sometimes called "sports anemia...

  2. [Band 3 protein as a metabolic sensor--CO2 regulates the amount of oxygen delivered to tissues from red blood cells].

    Science.gov (United States)

    Hamasaki, Naotaka

    2006-03-01

    Oxygen is essential for most forms of life, but too much oxygen is harmful and can induce tissue damage. Living creatures therefore have a tightly regulated system to deliver the necessary amount of oxygen to specific tissues at the right time. CO2 is not simply waste matter from tissues, but regulates the amount of oxygen delivered to tissues from red blood cells, utilizing the synergistic effects of hemoglobin, carbonic anhydrase and the anion exchange activity of band 3 protein. Red blood cells play an important role in this system and provide an ideal vehicle for delivering oxygen to tissues, depending on their metabolic activity.

  3. High-frequency photoacoustic imaging of erythrocyte aggregation and oxygen saturation: probing hemodynamic relations under pulsatile blood flow

    Science.gov (United States)

    Bok, Tae-Hoon; Hysi, Eno; Kolios, Michael C.

    2015-03-01

    In this paper, we investigate the feasibility of high-frequency photoacoustic (PA) imaging to study the shear rate dependent relationship between red blood cell (RBC) aggregation and oxygen saturation (SO2) in a simulated blood flow system. The PA signal amplitude increased during the formation of aggregates and cyclically varied at intervals corresponding to the beat rate (30, 60, 120, 180 and 240 bpm) for all optical wavelengths of illumination (750 and 850 nm).The SO2 also cyclically varied in phase with the PA signal amplitude for all beat rates. In addition, the mean blood flow velocity cyclically varied at the same interval of beat rate, and the shear rate (i.e. the radial gradient of flow velocity) also cyclically varied. On the other hand, the phase of the cyclic variation in the shear rate was reversed compared to that in the PA signal amplitude. This study indicates that RBC aggregation induced by periodic changes in the shear rate can be correlated with the SO2 under pulsatile blood flow. Furthermore, PA imaging of flowing blood may be capable of providing a new biomarker for the clinical application in terms of monitoring blood viscosity, oxygen delivery and their correlation.

  4. Umbilical cord blood gas analysis.

    Science.gov (United States)

    Thorp, J A; Rushing, R S

    1999-12-01

    Umbilical cord blood gas and pH values should always be obtained in the high-risk delivery and whenever newborn depression occurs. This practice is important because umbilical cord blood gas analysis may assist with clinical management and excludes the diagnosis of birth asphyxia in approximately 80% of depressed newborns at term. The most useful umbilical cord blood parameter is arterial pH. Sampling umbilical venous blood alone is not recommended because arterial blood is more representative of the fetal metabolic condition and because arterial acidemia may occur with a normal venous pH. A complete blood gas analysis may provide important information regarding the type and cause of acidemia and sampling the artery and vein may provide a more clear assessment. The sampling technique is simple and easily mastered by any treatment person in the delivery room. Preheparinized syringes ensure a consistent dose and amount of heparin. Depending on how normality is defined and on the population studied, normal ranges for umbilical cord blood gas values vary (see Table 1). In general, the lower range for normal arterial pH extends to at least 7.10 and that for venous pH to at least 7.20. Many different factors during pregnancy, labor, and delivery can affect cord blood gases. Umbilical blood sampling for acid-base status at all deliveries cannot be universally recommended because many facilities do not have the capabilities to support such a practice and in doing so may impose an excessive financial burden. Considering the costs, the accumulated published data, and the nonspecificity of electronic fetal monitoring in the evaluation of fetal oxygenation, it may be more rational to implement universal cord blood gas analysis. Care providers and institutions with the logistical capabilities in place should consider the cost efficacy of routine cord blood gas analysis because it is the gold standard assessment of uteroplacental function and fetal oxygenation/acid-base status

  5. [Effect of sodium nitroprusside on hemoglobin oxygen binding properties of the blood during hepatic ischemia-reperfusion in rabbits].

    Science.gov (United States)

    Khodosovskiĭ, M N; Zinchuk, V V

    2012-05-01

    The parameters of blood oxygen transport were determined in rabbits during the hepatic ischemia/reperfusion (HIR) with or without sodium nitroprusside (SNP) administration. Hepatic ischemia was induced for 30 min by a. hepatica propria clamping, reperfusion lasted 120 min. Indices of blood oxygen transport (hemoglobin-oxygen affinity index (p50), pO2, pH, pCO2, HCO3-, TCO2, ABE, etc.) and nitrite/nitrate (NO(x)) amounts were measured in blood during HIR. Animals were subdivided into two groups: 1st group--HIR; 2nd--HIR plus SNP infusion (SNP, Sigma, i.v. 10 mcmol/kg). The experiments had shown that HIR led to significant acidic changes in the acid-base balance and high blood p50. The SNP infusion in the 2nd group led to less changing in the p50 values during HIR which were accompanied with high NO(x) levels. We conclude that oxyhemoglobin dissociation curve shift leftwards after SNP administration promotes the maintenance liver during ischemia-reperfusion.

  6. Total Anomalous Pulmonary Venous Connection: Preoperative Anatomy, Physiology, Imaging, and Interventional Management of Postoperative Pulmonary Venous Obstruction.

    Science.gov (United States)

    Files, Matthew D; Morray, Brian

    2017-06-01

    Total anomalous pulmonary venous connection refers to a spectrum of cardiac anomalies where the pulmonary veins fail to return to the left atrium and the pulmonary venous blood returns through a systemic vein or directly to the right atrium. There is a wide anatomical variety of venous connections and degrees of pulmonary venous obstruction that affect the presentation, surgical repair, and outcomes. In this review, we explore the preoperative physiology, echocardiographic diagnosis, and approach to postoperative complications.

  7. Automatic Control of Veno-Venous Extracorporeal Lung Assist.

    Science.gov (United States)

    Kopp, Ruedger; Bensberg, Ralf; Stollenwerk, Andre; Arens, Jutta; Grottke, Oliver; Walter, Marian; Rossaint, Rolf

    2016-10-01

    Veno-venous extracorporeal lung assist (ECLA) can provide sufficient gas exchange even in most severe cases of acute respiratory distress syndrome. Commercially available systems are manually controlled, although an automatically controlled ECLA could allow individualized and continuous adaption to clinical requirements. Therefore, we developed a demonstrator with an integrated control algorithm to keep continuously measured peripheral oxygen saturation and partial pressure of carbon dioxide constant by automatically adjusting extracorporeal blood and gas flow. The "SmartECLA" system was tested in six animal experiments with increasing pulmonary hypoventilation and hypoxic inspiratory gas mixture to simulate progressive acute respiratory failure. During a cumulative evaluation time of 32 h for all experiments, automatic ECLA control resulted in a peripheral oxygen saturation ≥90% for 98% of the time with the lowest value of 82% for 15 s. Partial pressure of venous carbon dioxide was between 40 and 49 mm Hg for 97% of the time with no value 49 mm Hg. With decreasing inspiratory oxygen concentration, extracorporeal oxygen uptake increased from 68 ± 25 to 154 ± 34 mL/min (P respiratory rate resulted in increasing extracorporeal carbon dioxide elimination from 71 ± 37 to 92 ± 37 mL/min (P concept could be demonstrated for this novel automatically controlled veno-venous ECLA circuit. Copyright © 2015 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  8. Functional neuroanatomy in depressed patients with sexual dysfunction: blood oxygenation level dependent functional MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jong Chul [Chonnam National Univ. Hospital, Kwangju (Korea, Republic of)

    2004-06-15

    To demonstrate the functional neuroanatomy associated with sexual arousal visually evoked in depressed males who have underlying sexual dysfunction using Blood Oxygenation Level Dependent-based fMRI. Ten healthy volunteers (age range 21-55: mean 32.5 years), and 10 depressed subjects (age range 23-51: mean 34.4 years, mean Beck Depression Inventory score of 39.6 {+-} 5.9, mean Hamilton Rating Scale Depression (HAMD)-17 score of 33.5 {+-} 6.0) with sexual arousal dysfunction viewed erotic and neutral video films during functional magnetic resonance imaging (fMRI) with 1.5 T MR scanner (GE Signa Horizon). The fMRI data were obtained from 7 oblique planes using gradient-echo EPI (flip angle/TR/TE=90 .deg. /6000 ms/50 ms). The visual stimulation paradigm began with 60 sec of black screen, 150 sec of neutral stimulation with a documentary video film, 30 sec of black screen, 150 sec of sexual stimulation with an erotic video film followed by 30 sec of black screen. The brain activation maps and their quantification were analyzed by SPM99 program. There was a significant difference of brain activation between two groups during visual sexual stimulation. In depressed subjects, the level of activation during the visually evoked sexual arousal was significantly less than that of healthy volunteers, especially in the cerebrocortical areas of the hypothalamus, thalamus, caudate nucleus, and inferior and superior temporal gyri. On the other hand, the cerebral activation patterns during the neutral condition in both groups showed no significant differences ({rho} < 0.01). This study is the first demonstration of the functional neuroanatomy of the brain associated with sexual dysfunction in depressed patients using fMRI. In order to validate our physiological neuroscience results, further studies that would include patients with other disorders and sexual dysfunction, and depressed patients without sexual dysfunction and their treatment response are needed.

  9. Measurement of retinal oxygen saturation in patients with chronic obstructive pulmonary disease.

    Science.gov (United States)

    Palkovits, Stefan; Lasta, Michael; Boltz, Agnes; Schmidl, Doreen; Kaya, Semira; Hammer, Martin; Marzluf, Beatrice; Popa-Cherecheanu, Alina; Frantal, Sophie; Schmetterer, Leopold; Garhöfer, Gerhard

    2013-02-05

    There is growing evidence that disturbances in retinal oxygenation may trigger ocular diseases. New instruments allow for the noninvasive measurement of retinal oxygen saturation in humans. The present study was designed to investigate the retinal oxygen saturation in patients with chronic obstructive pulmonary disease (COPD). This was also done in an effort to test the validity of retinal oxygenation measurements with a retinal vessel analyzer. In all, 16 patients with severe COPD grade 4 who were on long-term oxygen treatment were included in the study. For each patient two identical study days were scheduled. Measurements of retinal arterial and venous oxygen saturation were done using a commercially available instrument for retinal oxygen analysis. Peripheral arterial oxygen saturation values were analyzed with pulse oximetry and via a capillary blood sample drawn from the earlobe. Measurements were performed during oxygen treatment and during a period without oxygen supplementation. Analysis of all images for retinal oxygen saturation quantification was done by a masked investigator. Analysis was done using Pearson's correlation and a multivariate regression model. Arterial and venous retinal oxygen saturation decreased significantly after the cessation of the oxygen therapy. The arteriovenous oxygen difference was unchanged while breathing ambient air or pure oxygen-enriched air. With both Pearson's correlation and the multivariate model, we found significant positive correlation coefficients between retinal arterial and peripheral arterial oxygen saturation as assessed with pulse oximetry as well as between retinal arterial and peripheral arterial oxygen saturation measured in blood samples. The change of oxygen saturation after discontinuation of oxygen supplementation showed a good correlation between retinal arterial oxygen saturation and peripheral arterial oxygen saturation (r = 0.53, P arterial and peripheral arterial oxygen saturation indicating good

  10. Fingertip Reconstruction Using Free Toe Tissue Transfer Without Venous Anastomosis

    Directory of Open Access Journals (Sweden)

    Won Young Yoon

    2012-09-01

    Full Text Available BackgroundThis study was designed to introduce the feasibility of toe tissue transfer without venous outflow for fingertip reconstruction.MethodsFive cases of fingertip defects were treated successfully with this method. Four cases were traumatic fingertip defects, and one case was a hook-nail deformity. The lateral pulp of a great toe or medioinferior portion of a second toe was used as the donor site. An arterial pedicle was dissected only within the digit and anastomosis was performed within 2 cm around the defect margin. The digital nerve was repaired simultaneously. No additional dissection of the dorsal or volar pulp vein was performed in either the donor or recipient sites. Other surgical procedures were performed following conventional techniques. Postoperative venous congestion was monitored with pulp temperature, color, and degree of tissue oxygen saturation. Venous congestion was decompressed with a needle-puncture method intermittently, but did not require continuous external bleeding for salvage.ResultsVenous congestion was observed in all the flaps, but improved within 3 or 4 days postoperatively. The flap size was from 1.5×1.5 cm2 to 2.0×3.0 cm2. The mean surgical time was 2 hours and 20 minutes. A needle puncture was carried out every 2 hours during the first postoperative day, and then every 4 hours thereafter. The amount of blood loss during each puncture procedure was less than 0.2 mL. In the long-term follow-up, no flap atrophy was observed.ConclusionsWhen used properly, the free toe tissue transfer without venous anastomosis method can be a treatment option for small defects on the fingertip area.

  11. The Bohr effect is not a likely promoter of renal preglomerular oxygen shunting

    Directory of Open Access Journals (Sweden)

    Ufuk Olgac

    2016-10-01

    Full Text Available The aim of this study was to evaluate whether possible preglomerular arterial-to-venous oxygen shunting is affected by the interaction between renal preglomerular carbon dioxide and oxygen transport. We hypothesized that a reverse (venous-to-arterial shunting of carbon dioxide will increase partial pressure of carbon dioxide and decrease pH in the arteries and thereby lead to increased oxygen offloading and consequent oxygen shunting. To test this hypothesis, we employed a segment-wise three-dimensional computational model of coupled renal oxygen and carbon dioxide transport, wherein coupling is achieved by shifting the oxygen-hemoglobin dissociation curve in dependence of local changes in partial pressure of carbon dioxide and pH. The model suggests that primarily due to the high buffering capacity of blood, there is only marginally increased acidity in the preglomerular vasculature compared to systemic arterial blood caused by carbon dioxide shunting. Furthermore, effects of carbon dioxide transport do not promote but rather impair preglomerular oxygen shunting, as the increase in acidity is higher in the veins compared to that in the arteries. We conclude that while substantial arterial-to-venous oxygen shunting might take place in the postglomerular vasculature, the net amount of oxygen shunted at the preglomerular vasculature appears to be marginal.

  12. Effects of Cortical Spreading Depression on Synaptic Activity, Blood Flow and Oxygen Consumption in Rat Cerebral Cortex

    DEFF Research Database (Denmark)

    Hansen, Henning Piilgaard

    2010-01-01

    two different sets of interneurons. Our data imply that for a given cortical area the amplitude of vascular signals will depend critically on the type of input and hence on the type of neurons activated. In the second study I investigated the effect of cortical spreading depression (CSD) on the evoked...... Laser-Doppler Flowmetry for measurements of cerebral blood flow, glass microelectrodes for recording of synaptic activity – local field potentials – and ongoing cortical electrical activity and a Clark type electrode for measurements of tissue partial pressure of oxygen (tpO2). Offline calculations......As the title of this thesis indicates I have during my PhD studied the effects of cortical spreading depression (CSD) on synaptic activity, blood flow and oxygen consumption in rat cerebral cortex. This was performed in vivo using an open cranial window approach in anesthetized rats. I applied...

  13. Effects of acetazolamide on cerebral blood flow and brain tissue oxygenation

    DEFF Research Database (Denmark)

    Lassen, N A; Friberg, L; Kastrup, J

    1987-01-01

    decreased gradually to 70% of the control value, indicating hyperventilation. At sea level hyperventilation will not increase brain oxygenation significantly in normal man, as the arterial oxygen content only increases minimally, while CBF is unchanged. At high altitude the beneficial effects...... of acetazolamide on the symptoms of acute mountain sickness may well be due to an improved oxygen supply to the brain, as hyperventilation will, at the low ambient PO2, cause a significant increase of the arterial oxygen content, while CBF presumably is unaffected by the drug. During hypoxia at high altitude...

  14. Cortical Venous Redness Represents Tissue Circulation Status in Patients With Moyamoya Disease.

    Science.gov (United States)

    Machida, Toshio; Higuchi, Yoshinori; Nakano, Shigeki; Ishige, Satoshi; Fujikawa, Atsushi; Akaogi, Yuichi; Shimada, Junichiro; Yoshida, Yoichi; Maru, Sigenori; Ono, Junichi

    2017-06-01

    Venous oxygen saturation (SO2) is measured in medical fields to assess tissue circulation insufficiency. This study aimed to elucidate the use of a cortical venous redness measurement to evaluate hemodynamic changes during revascularization surgery for patients with moyamoya disease. In this retrospective case-series analysis, we first quantitatively measured and correlated SO2 and R intensity of 24-bit color digital red-green-blue pictures of blood samples from 3 volunteers. Subsequently, based on intraoperative digital pictures of 29 patients with moyamoya disease, we measured the R intensities of a cortical vein near the anastomosis site before and after anastomosis. Cerebral blood flow (CBF) at the site was measured using a single-photon emission computed tomography before and 1 to 3 days after surgery. Venous R intensity and CBF were measured twice by 4 raters, and their correlations were examined using generalized linear mixed effect model and linear regression analysis. A strong linear correlation was found between blood R intensity and its SO2 (coefficients, 0.522; 95% confidence interval, 0.364-0.680, using generalized linear mixed effect model). Venous R intensity before the anastomosis was not correlated with preoperative CBF (coefficients, 0.000352; 95% confidence interval, -0.000369 to 0.00107, by generalized linear mixed effect); however, the increases in venous R intensity after anastomosis were correlated with postoperative increases in CBF (R(2), 0.367; 95% confidence interval, 0.116-0.618 to 0.548; 95% confidence interval, 0.331-0.764, by linear regression analysis). Cortical venous redness represented impaired CBF and could be a useful parameter for assessing hemodynamic changes during revascularization surgery. © 2017 American Heart Association, Inc.

  15. A neural measure of behavioral engagement: Task-residual low frequency blood oxygenation level dependent activity in the precuneus

    OpenAIRE

    Zhang, Sheng; Li, Chiang-shan Ray

    2009-01-01

    Brain imaging has provided a useful tool to examine the neural processes underlying human cognition. A critical question is whether and how task engagement influences the observed regional brain activations. Here we highlighted this issue and derived a neural measure of task engagement from the task-residual low frequency blood oxygenation level dependent (BOLD) activity in the precuneus. Using independent component analysis, we identified brain regions in the default circuit – including the ...

  16. The Effects of Postoperative Activity on Subcuranious Tissue Oxygen Tension and Blood Flow in Orthopedic Surgical Patients

    Science.gov (United States)

    1993-06-01

    synthesis and deposition of collagen depends on construction of new vessels to supply required metabolic materials (Hunt, 1988). 10 Neoangiogenesis...measure PscO2 a sterile Silastic catheter is placed into subcutaneous tissue and a polarographic oxygen electrode or fluorescent optical probe is introduced...Thereafter, as body temperature rises, skin blood flow increases. The increased temperature is sensed by thermosensitive neurons in the hypothalmus and the

  17. Mapping of cerebral metabolic rate of oxygen using dynamic susceptibility contrast and blood oxygen level dependent MR imaging in acute ischemic stroke

    Energy Technology Data Exchange (ETDEWEB)

    Gersing, Alexandra S.; Schwaiger, Benedikt J. [Technical University Munich, Klinikum rechts der Isar, Department of Neuroradiology, Munich (Germany); University of California, Department of Radiology and Biomedical Imaging, San Francisco, CA (United States); Ankenbrank, Monika; Toth, Vivien; Bauer, Jan S.; Zimmer, Claus [Technical University Munich, Klinikum rechts der Isar, Department of Neuroradiology, Munich (Germany); Janssen, Insa [Technical University Munich, Department of Neurosurgery, Munich (Germany); Kooijman, Hendrik [Philips Healthcare, Hamburg (Germany); Wunderlich, Silke [Technical University Munich, Department of Neurology, Munich (Germany); Preibisch, Christine [Technical University Munich, Klinikum rechts der Isar, Department of Neuroradiology, Munich (Germany); Technical University Munich, Department of Neurology, Munich (Germany)

    2015-12-15

    MR-derived cerebral metabolic rate of oxygen utilization (CMRO{sub 2}) has been suggested to be analogous to PET-derived CMRO{sub 2} and therefore may be used for detection of viable tissue at risk for infarction. The purpose of this study was to evaluate MR-derived CMRO{sub 2} mapping in acute ischemic stroke in relation to established diffusion- and perfusion-weighted imaging. In 23 patients (mean age 63 ± 18.7 years, 11 women) with imaging findings for acute ischemic stroke, relative oxygen extraction fraction was calculated from quantitative transverse relaxation times (T2, T2*) and relative cerebral blood volume using a quantitative blood oxygenation level dependent (BOLD) approach in order to detect a local increase of deoxyhemoglobin. Relative CMRO{sub 2} (rCMRO{sub 2}) maps were calculated by multiplying relative oxygen extraction fraction (rOEF) by cerebral blood flow, derived from PWI. After co-registration, rCMRO{sub 2} maps were evaluated in comparison with apparent diffusion coefficient (ADC) and time-to-peak (TTP) maps. Mean rCMRO{sub 2} values in areas with diffusion-restriction or TTP/ADC mismatch were compared with rCMRO{sub 2} values in the contralateral tissue. In tissue with diffusion restriction, mean rCMRO{sub 2} values were significantly decreased compared to perfusion-impaired (17.9 [95 % confidence interval 10.3, 25.0] vs. 58.1 [95 % confidence interval 50.1, 70.3]; P < 0.001) and tissue in the contralateral hemisphere (68.2 [95 % confidence interval 61.4, 75.0]; P < 0.001). rCMRO{sub 2} in perfusion-impaired tissue showed no significant change compared to tissue in the contralateral hemisphere (58.1 [95 % confidence interval 50.1, 70.3] vs. 66.7 [95 % confidence interval 53.4, 73.4]; P = 0.34). MR-derived CMRO{sub 2} was decreased within diffusion-restricted tissue and stable within perfusion-impaired tissue, suggesting that this technique may be adequate to reveal different pathophysiological stages in acute stroke. (orig.)

  18. A meta-analysis on the utility of peripheral venous blood gas analyses in exacerbations of chronic obstructive pulmonary disease in the emergency department.

    Science.gov (United States)

    Lim, Beng Leong; Kelly, Anne-Maree

    2010-10-01

    The objective of this case-based review is to identify and summarize the relevant evidence for the clinical utility of peripheral venous blood gas (pVBG) analyses in patients with acute exacerbations of chronic obstructive pulmonary disease (COPD) treated in the emergency department. Relevant studies were identified using the Cochrane Library, Medline, Embase, and CINAHL databases and by hand searching of references of published articles. Included studies were prospective trials comparing arterial and pVBG results in patients with COPD or respiratory distress that reported at least average differences and/or limits of agreement between the two results in English. Outcomes of interest were agreement between arterial and pVBG values for pH, pCO2, pO2, and HCO3. Eighty-nine studies were identified of which six were relevant. The weighted average difference for pCO2 was 5.92 mmHg, whereas those for pH, pO2, and HCO3 were 0.028, 18.65 mmHg, and 1.34 mEq/l, respectively. Using Bland-Altman analysis, the 95% limits of agreement were in the range of -0.10 to 0.08, -17 to 26 mmHg and, -3.5 to 3.5 mEq/l for pH, pCO2, and HCO3, respectively. Reported cutoff pVBG pCO2 values for screening of arterial hypercarbia ranged from 30 to 46 mmHg. No studies investigated the role of pVBG analysis in treatment alteration or clinical outcomes. Available evidence suggests that there is good agreement for pH and HCO3 values between arterial and pVBG results in patients with COPD, but not for pO2 or pCO2. Widespread clinical use is limited because of the lack of validation studies on clinical outcomes.

  19. White blood cell count measured prior to cancer development is associated with future risk of venous thromboembolism--the Tromsø study.

    Directory of Open Access Journals (Sweden)

    Kristine Blix

    Full Text Available BACKGROUND: Elevated white blood cell (WBC count is associated with risk of venous thromboembolism (VTE in cancer patients initiating chemotherapy. It is not known whether the risk of VTE by WBC count in cancer patients is causal or merely a consequence of the malignant disease. To address this question, we studied the association between WBC count, measured prior to cancer development, and risk of VTE in subjects who did and did not develop cancer during follow-up in a prospective population-based study. METHODS: Baseline characteristics, including WBC and neutrophil counts, were measured in 24304 initially cancer-free subjects who participated in the Tromsø Study in 1994-1995. Incident cancer diagnosis and VTE events were registered up to September 1, 2007. In the cancer cohort, WBC and neutrophil counts were measured in average 7.1 years before cancer development. Cox-regression models were used to calculate hazard ratios (HRs for VTE by WBC and neutrophil counts as categorized variables (80(th percentile with 95% confidence intervals (CIs. RESULTS: During follow-up, 1720 subjects developed cancer and there were 388 VTE events, of which 116 occurred in the cancer-group (6.9 per 1000 person-years and 272 in the cancer-free group (1.1 per 1000 person-years. In those who developed cancer, WBC count above the 80(th percentile (≥ 8.6 x 10(9 cells/L was associated with a 2.4-fold higher risk (HR 2.36, 95% CI: 1.44-3.87 of VTE compared to WBC count below the 40(th percentile (<6.4 x 10(9 cells/L. No association was found between WBC count and VTE in those who stayed cancer-free (HR 0.94, 95% CI 0.65-1.36. Similar findings were observed for neutrophils. COMMENT: Pre-cancer WBC count was associated with risk of VTE in cancer patients, but not in cancer-free subjects. Our findings suggest that leukocytes may play a causal role in cancer-related VTE rather than only reflecting the low-grade inflammation associated with cancer.

  20. Use of venous-to-arterial carbon dioxide tension difference to guide resuscitation therapy in septic shock

    Science.gov (United States)

    Mallat, Jihad; Lemyze, Malcolm; Tronchon, Laurent; Vallet, Benoît; Thevenin, Didier

    2016-01-01

    The mixed venous-to-arterial carbon dioxide (CO2) tension difference [P (v-a) CO2] is the difference between carbon dioxide tension (PCO2) in mixed venous blood (sampled from a pulmonary artery catheter) and the PCO2 in arterial blood. P (v-a) CO2 depends on the cardiac output and the global CO2 production, and on the complex relationship between PCO2 and CO2 content. Experimental and clinical studies support the evidence that P (v-a) CO2 cannot serve as an indicator of tissue hypoxia, and should be regarded as an indicator of the adequacy of venous blood to wash out the total CO2 generated by the peripheral tissues. P (v-a) CO2 can be replaced by the central venous-to-arterial CO2 difference (ΔPCO2), which is calculated from simultaneous sampling of central venous blood from a central vein catheter and arterial blood and, therefore, more easy to obtain at the bedside. Determining the ΔPCO2 during the resuscitation of septic shock patients might be useful when deciding when to continue resuscitation despite a central venous oxygen saturation (ScvO2) > 70% associated with elevated blood lactate levels. Because high blood lactate levels is not a discriminatory factor in determining the source of that stress, an increased ΔPCO2 (> 6 mmHg) could be used to identify patients who still remain inadequately resuscitated. Monitoring the ΔPCO2 from the beginning of the reanimation of septic shock patients might be a valuable means to evaluate the adequacy of cardiac output in tissue perfusion and, thus, guiding the therapy. In this respect, it can aid to titrate inotropes to adjust oxygen delivery to CO2 production, or to choose between hemoglobin correction or fluid/inotrope infusion in patients with a too low ScvO2 related to metabolic demand. The combination of P (v-a) CO2 or ΔPCO2 with oxygen-derived parameters through the calculation of the P (v-a) CO2 or ΔPCO2/arteriovenous oxygen content difference ratio can detect the presence of global anaerobic metabolism

  1. Cardiac contractility, central haemodynamics and blood pressure regulation during semistarvation

    DEFF Research Database (Denmark)

    Stokholm, K H; Breum, L; Astrup, A

    1991-01-01

    Eight obese patients were studied before and after 2 weeks of treatment by a very-low-calorie diet (VLCD). Cardiac output and central blood volume (pulmonary blood volume and left atrial volume) were determined by indicator dilution (125I-albumin) and radionuclide angiocardiography (first pass...... increased capacitance of the venous bed was the main operator of a reduced venous return. Thus, the haemodynamic alterations in obese patients during short-term semistarvation may be caused by the fall in oxygen uptake and produced mainly by changes in the sympathetic tone....

  2. Elevated global cerebral blood flow, oxygen extraction fraction and unchanged metabolic rate of oxygen in young adults with end-stage renal disease: an MRI study

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Gang; Lou, Yaxian; Pan, Zhiying; Liu, Ya [Medical School of Nanjing University, Department of Medical Imaging, Jinling Hospital, Nanjing, Jiangsu (China); Nanjing University of Aeronautics and Astronautics, College of Aivil Aviation, Nanjing, Jiangsu (China); Wen, Jiqiu; Li, Xue; Zhang, Zhe [Medical School of Nanjing University, National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing, Jiangsu (China); Lu, Hanzhang [University of Texas Southwestern Medical Center, Advanced Imaging Research Center, Dallas, TX (United States); Liu, Wei [Siemens Shenzhen Magnetic Resonance Ltd., Shenzhen, Guangdong (China); Liu, Hui [Siemens MR NEA Collaboration, Siemens Ltd., Shanghai (China); Chen, Huijuan; Kong, Xiang; Luo, Song; Jiang, Xiaolu; Zhang, Zongjun; Zhang, Long Jiang; Lu, Guang Ming [Medical School of Nanjing University, Department of Medical Imaging, Jinling Hospital, Nanjing, Jiangsu (China)

    2016-06-15

    To noninvasively assess global cerebral blood flow (CBF), oxygen extraction fraction (OEF) and cerebral metabolic rate of oxygen (CMRO{sub 2}) in young adults with end-stage renal disease (ESRD). Thirty-six patients and 38 healthy volunteers were included and took part in MR examinations, blood and neuropsychological tests. CBF and OEF were measured by phase-contrast and T2-relaxation-under-spin-tagging MRI techniques, respectively. CMRO{sub 2} was computed from CBF, OEF and hematocrit according to Fick's principle. Correlations were performed between MR measurements, blood biochemistry measurements and neuropsychological test scores. Compared with controls, ESRD patients had elevated CBF (72.9 ± 12.5 vs. 63.8 ± 8.5 ml min{sup -1} 100 g{sup -1}, P < 0.001), elevated OEF (47.2 ± 10.2 vs. 35.8 ± 5.4 %, P < 0.001), but unaffected CMRO{sub 2} (199.5 ± 36.4 vs. 193.8 ± 28.6 μmol O{sub 2} min{sup -1} 100 g{sup -1}, P = 0.879). Hematocrit negatively correlated with CBF (r = -0.640, P < 0.001) and OEF (r = -0.701, P < 0.001), but not with CMRO{sub 2}. Altered neuropsychological test scores of ESRD patients were associated with OEF and CBF, but not with CMRO{sub 2}. There were weak relationships between eGFR and hematocrit (r = 0.308, P = 0.068) or CBF (r = 0.318, P = 0.059). Our findings suggested that anaemic young adults with ESRD may afford higher CBF and OEF to maintain a normal CMRO{sub 2}. Despite this compensatory process, however, cognitive function was still impaired and its severity was correlated with their CBF and OEF abnormality. (orig.)

  3. High-resolution ultrasound imaging and noninvasive optoacoustic monitoring of blood variables in peripheral blood vessels

    Science.gov (United States)

    Petrov, Irene Y.; Petrov, Yuriy; Prough, Donald S.; Esenaliev, Rinat O.

    2011-03-01

    Ultrasound imaging is being widely used in clinics to obtain diagnostic information non-invasively and in real time. A high-resolution ultrasound imaging platform, Vevo (VisualSonics, Inc.) provides in vivo, real-time images with exceptional resolution (up to 30 microns) using high-frequency transducers (up to 80 MHz). Recently, we built optoacoustic systems for probing radial artery and peripheral veins that can be used for noninvasive monitoring of total hemoglobin concentration, oxyhemoglobin saturation, and concentration of important endogenous and exogenous chromophores (such as ICG). In this work we used the high-resolution ultrasound imaging system Vevo 770 for visualization of the radial artery and peripheral veins and acquired corresponding optoacoustic signals from them using the optoacoustic systems. Analysis of the optoacoustic data with a specially developed algorithm allowed for measurement of blood oxygenation in the blood vessels as well as for continuous, real-time monitoring of arterial and venous blood oxygenation. Our results indicate that: 1) the optoacoustic technique (unlike pure optical approaches and other noninvasive techniques) is capable of accurate peripheral venous oxygenation measurement; and 2) peripheral venous oxygenation is dependent on skin temperature and local hemodynamics. Moreover, we performed for the first time (to the best of our knowledge) a comparative study of optoacoustic arterial oximetry and a standard pulse oximeter in humans and demonstrated superior performance of the optoacoustic arterial oximeter, in particular at low blood flow.

  4. Investigation of source-detector separation optimization for an implantable perfusion and oxygenation sensor for liver blood vessels

    Energy Technology Data Exchange (ETDEWEB)

    Baba, Justin S [ORNL; Akl, Tony [Texas A& M University; Cote, Gerard L. [Texas A& M University; Wilson, Mark A. [University of Pittsburgh School of Medicine, Pittsburgh PA; Ericson, Milton Nance [ORNL

    2011-01-01

    An implanted system is being developed to monitor transplanted liver health during the critical 7-10 day period posttransplantation. The unit will monitor organ perfusion and oxygen consumption using optically-based probes placed on both the inflow and outflow blood vessels, and on the liver parenchymal surface. Sensing probes are based on a 3- wavelength LED source and a photodiode detector. Sample diffuse reflectance is measured at 735, 805, and 940 nm. To ascertain optimal source-to-photodetector spacing for perfusion measurement in blood vessels, an ex vivo study was conducted. In this work, a dye mixture simulating 80% blood oxygen saturation was developed and perfused through excised porcine arteries while collecting data for various preset probe source-to-photodetector spacings. The results from this study demonstrate a decrease in the optical signal with decreasing LED drive current and a reduction in perfusion index signal with increasing probe spacing. They also reveal a 2- to 4-mm optimal range for blood vessel perfusion probe source-to-photodetector spacing that allows for sufficient perfusion signal modulation depth with maximized signal to noise ratio (SNR). These findings are currently being applied to guide electronic configuration and probe placement for in vivo liver perfusion porcine model studies.

  5. Acute effects of nicotine and smoking on blood flow, tissue oxygen, and aerobe metabolism of the skin and subcutis

    DEFF Research Database (Denmark)

    Sørensen, Lars Tue; Jørgensen, Stig; Petersen, Lars J

    2009-01-01

    BACKGROUND: Nicotine released from tobacco smoke causing reduction in blood flow has been suggested as causative for postoperative wound complications in smokers, but the mechanism remains unknown. MATERIALS AND METHODS: In eight healthy male smokers and eight ex-smokers, the cutaneous and subcut......BACKGROUND: Nicotine released from tobacco smoke causing reduction in blood flow has been suggested as causative for postoperative wound complications in smokers, but the mechanism remains unknown. MATERIALS AND METHODS: In eight healthy male smokers and eight ex-smokers, the cutaneous...... and subcutaneous blood flow (QBF, SqBF) was assessed by Laser Doppler and 133Xe clearance. Tissue oxygen tension (TO(2)) was measured by a LICOX O(2)-electrode. Tissue glucose and lactate (Tgluc, Tlact) were assessed by microdialysis. The parameters were studied after intravenous infusion of 1.0 mg nicotine...

  6. Relationship between heart rate variability, blood pressure and arterial wall properties during air and oxygen breathing in healthy subjects.

    Science.gov (United States)

    Graff, Beata; Szyndler, Anna; Czechowicz, Krzysztof; Kucharska, Wiesława; Graff, Grzegorz; Boutouyrie, Pierre; Laurent, Stephane; Narkiewicz, Krzysztof

    2013-11-01

    Previous studies reported that normobaric hyperoxia influences heart rate, arterial pressure, cardiac output and systemic vascular resistance, but the mechanisms underlying these changes are still not fully understood. Several factors are considered including degeneration of endothelium-derived nitric oxide by reactive oxygen species, the impact of oxygen-free radicals on tissues and alterations of autonomic nervous system function. Recently, new devices for the detailed non-invasive assessment of large and small arteries have been developed. Therefore, the aim of our study was to assess heart rate variability (HRV) as a potential indicator of autonomic balance and its relation to blood pressure and vascular properties during medical air (MAB) and 100% oxygen breathing (OXB) in healthy volunteers. In 12 healthy subjects we assessed heart rate and blood pressure variability, baroreflex sensitivity, respiratory frequency, common carotid artery diameter and its wall distensibility, as well as changes in the digital artery pulse waveform, stroke index and systemic vascular resistance during MAB and OXB. Mean and systolic blood pressure have increased significantly while digital pulse amplitude and carotid artery diameter were significantly lower during hyperoxia. Heart rate variability measures did not differ during MAB and OXB. However, the correlations between spectral HRV components and those hemodynamic parameters which have changed due to hyperoxia varied substantially during MAB (correlated significantly) and OXB (no significant correlations were noted). Our findings suggest that autonomic nervous system might not be the main mediator of the cardiovascular changes during 100% oxygen breathing in healthy subjects. It seems that the direct vascular responses are initial consequences of hyperoxia and other cardiovascular parameter alterations are secondary to them. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. The effects of graded changes in oxygen and carbon dioxide tension on coronary blood velocity independent of myocardial energy demand.

    Science.gov (United States)

    Boulet, Lindsey M; Stembridge, Mike; Tymko, Michael M; Tremblay, Joshua C; Foster, Glen E

    2016-08-01

    In humans, coronary blood flow is tightly regulated by microvessels within the myocardium to match myocardial energy demand. However, evidence regarding inherent sensitivity of the microvessels to changes in arterial partial pressure of carbon dioxide and oxygen is conflicting because of the accompanied changes in myocardial energy requirements. This study aimed to investigate the changes in coronary blood velocity while manipulating partial pressures of end-tidal CO2 (Petco2) and O2 (Peto2). It was hypothesized that an increase in Petco2 (hypercapnia) or decrease in Peto2 (hypoxia) would result in a significant increase in mean blood velocity in the left anterior descending artery (LADVmean) due to an increase in both blood gases and energy demand associated with the concomitant cardiovascular response. Cardiac energy demand was assessed through noninvasive measurement of the total left ventricular mechanical energy. Healthy subjects (n = 13) underwent a euoxic CO2 test (Petco2 = -8, -4, 0, +4, and +8 mmHg from baseline) and an isocapnic hypoxia test (Peto2 = 64, 52, and 45 mmHg). LADVmean was assessed using transthoracic Doppler echocardiography. Hypercapnia evoked a 34.6 ± 8.5% (mean ± SE; P changes in arterial blood gases are important contributors to the observed changes in LADVmean (P metabolic changes within the heart and an inherent sensitivity to arterial blood gases. Copyright © 2016 the American Physiological Society.

  8. Relating oxygen partial pressure, saturation and content: the haemoglobin–oxygen dissociation curve

    Directory of Open Access Journals (Sweden)

    Julie-Ann Collins

    2015-09-01

    The delivery of oxygen by arterial blood to the tissues of the body has a number of critical determinants including blood oxygen concentration (content, saturation (SO2 and partial pressure, haemoglobin concentration and cardiac output, including its distribution. The haemoglobin–oxygen dissociation curve, a graphical representation of the relationship between oxygen satur­ation and oxygen partial pressure helps us to understand some of the principles underpinning this process. Historically this curve was derived from very limited data based on blood samples from small numbers of healthy subjects which were manipulated in vitro and ultimately determined by equations such as those described by Severinghaus in 1979. In a study of 3524 clinical specimens, we found that this equation estimated the SO2 in blood from patients with normal pH and SO2 >70% with remarkable accuracy and, to our knowledge, this is the first large-scale validation of this equation using clinical samples. Oxygen saturation by pulse oximetry (SpO2 is nowadays the standard clinical method for assessing arterial oxygen saturation, providing a convenient, pain-free means of continuously assessing oxygenation, provided the interpreting clinician is aware of important limitations. The use of pulse oximetry reduces the need for arterial blood gas analysis (SaO2 as many patients who are not at risk of hypercapnic respiratory failure or metabolic acidosis and have acceptable SpO2 do not necessarily require blood gas analysis. While arterial sampling remains the gold-standard method of assessing ventilation and oxygenation, in those patients in whom blood gas analysis is indicated, arterialised capillary samples also have a valuable role in patient care. The clinical role of venous blood gases however remains less well defined.

  9. Role of blood-oxygen transport in thermal tolerance of the cuttlefish, Sepia officinalis

    OpenAIRE

    Melzner, Frank; Mark, Felix Christopher; Pörtner, Hans-Otto

    2007-01-01

    Mechanisms that affect thermal tolerance of ectothermic organisms have recently received much interest,mainly due to global warming and climate-change debates in both the public and in the scientific community.In physiological terms, thermal tolerance of several marine ectothermic taxa can be linked to oxygen availability,with capacity limitations in ventilatory and circulatory systems contributing to oxygen limitation at extremetemperatures. The present review briefly summarizes the processe...

  10. Multimodal ultrasound-photoacoustic imaging of tissue engineering scaffolds and blood oxygen saturation in and around the scaffolds.

    Science.gov (United States)

    Talukdar, Yahfi; Avti, Pramod; Sun, John; Sitharaman, Balaji

    2014-05-01

    Preclinical, noninvasive imaging of tissue engineering polymeric scaffold structure and/or the physiological processes such as blood oxygenation remains a challenge. In vitro or ex vivo, the widely used scaffold characterization modalities such as porosimetry, electron or optical microscopy, and X-ray microcomputed tomography have limitations or disadvantages-some are invasive or destructive, others have limited tissue penetration (few hundred micrometers) and/or show poor contrast under physiological conditions. Postmortem histological analysis, the most robust technique for the evaluation of neovascularization is obviously not appropriate for acquiring physiological or longitudinal data. In this study, we have explored the potential of ultrasound (US)-coregistered photoacoustic (PA) imaging as a noninvasive multimodal imaging modality to overcome some of the above challenges and/or provide complementary information. US-PA imaging was employed to characterize poly(lactic-co-glycolic acid) (PLGA) polymer scaffolds or single-walled carbon nanotube (SWCNT)-incorporated PLGA (SWCNT-PLGA) polymer scaffolds as well as blood oxygen saturation within and around the scaffolds. Ex vivo, PLGA and SWCNT-PLGA scaffolds were placed at 0.5, 2, and 6 mm depths in chicken breast tissues. PLGA scaffolds could be localized with US imaging, but generate no PA signal (excitation wavelengths 680 and 780 nm). SWCNT-PLGA scaffolds generated strong PA signals at both wavelengths due to the presence of the SWCNTs and could be localized with both US and PA imaging depths between 0.5-6 mm (lateral resolution = 90 μm, axial resolution = 40 μm). In vivo, PLGA and SWCNT-PLGA scaffolds were implanted in subcutaneous pockets at 2 mm depth in rats, and imaged at 7 and 14 days postsurgery. The anatomical position of both the scaffolds could be determined from the US images. Only SWCNT-PLGA scaffolds could be easily detected in the US-PA images. SWCNT-PLGA scaffolds had significant four times

  11. Quantification of myocardial oxygenation in heart failure using blood-oxygen-level-dependent T2* magnetic resonance imaging: Comparison with cardiopulmonary exercise test.

    Science.gov (United States)

    Nagao, Michinobu; Yamasaki, Yuzo; Kawanami, Satoshi; Kamitani, Takeshi; Sagiyama, Koji; Higo, Taiki; Ide, Tomomi; Takemura, Atsushi; Ishizaki, Umiko; Fukushima, Kenji; Watanabe, Yuji; Honda, Hiroshi

    2017-06-01

    Quantification of myocardial oxygenation (MO) in heart failure (HF) has been less than satisfactory. This has necessitated the use of invasive techniques to measure MO directly or to determine the oxygen demand during exercise using the cardiopulmonary exercise (CPX) test. We propose a new quantification method for MO using blood-oxygen-level-dependent (BOLD) myocardial T2* magnetic resonance imaging (M-T2* MRI), and investigate its correlation with CPX results. Thirty patients with refractory HF who underwent cardiac MRI and CPX test for heart transplantation, and 24 healthy, age-matched volunteers as controls were enrolled. M-T2* imaging was performed using a 3-Tesla and multi-echo gradient-echo sequence. M-T2* was calculated by fitting the signal intensity data for the mid-left ventricular septum to a decay curve. M-T2* was measured under room-air (T2*-air) and after inhalation of oxygen for 10min at a flow rate of 10L/min (T2*-oxy). MO was defined as the difference between the two values (ΔT2*). Changes in M-T2* at the two conditions and ΔT2* between the two groups were compared. Correlation between ΔT2* and CPX results was analyzed using the Pearson coefficient. T2*-oxy was significantly greater than T2*-air in patients with HF (29.9±7.3ms vs. 26.7±6.0ms, p<0.001), whereas no such difference was observed in controls (25.5±4.0ms vs. 25.4±4.4ms). ΔT2* was significantly greater for patients with HF than for controls (3.2±4.5ms vs. -0.1±1.3ms, p<0.001). A significant correlation between ΔT2* and CPX results (peak VO2, r=-0.46, p<0.05; O2 pulse, r=-0.54, p<0.005) was observed. ΔT2* is increased T2*-oxy is greater in patients with HF, and is correlated with oxygen metabolism during exercise as measured by the CPX test. Hence, ΔT2* can be used as a surrogate marker of MO instead of CPX test. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Correlation between single-trial visual evoked potentials and the blood oxygenation level dependent response in simultaneously recorded electroencephalography-functional magnetic resonance imaging

    DEFF Research Database (Denmark)

    Fuglø, Dan; Pedersen, Henrik; Rostrup, Egill

    2012-01-01

    To compare different electroencephalography (EEG)-based regressors and their ability to predict the simultaneously recorded blood oxygenation level dependent response during blocked visual stimulation, simultaneous EEG-functional magnetic resonance imaging in 10 healthy volunteers was performed...

  13. [Local tissue hypoxia consequence in the trophic venous ulceration in elderly patients].

    Science.gov (United States)

    Losev, R Z; Zakharova, N B; Burov, Iu A; Iakusheva, E A; Nikitina, V V; Stepanova, T V; Mikul'skaia, E G

    2007-01-01

    This paper analyzes the data of examination and the results of the treatment of 25 patients aged over 80 years (mean age 68.5+/-7 years) suffering from varicosity with long nonhealing trophic ulcers of the distal limb segments (CVI CMP C6) and 20 patients of the same age groups with CVI CEAP stages 3-5. All patients with CVI underwent either full-scope phlebectomy (64.4%) or partial truncal phlebectomy (35.6%), in which the trunk of the greater saphenous vein was stripped up to the upper third of the leg. A TCM-3 outfit (RADIOmeter, Denmark) was employed to measure oxygen tension in limb tissues. Parameters of lipid peroxidation and antioxidant tissue defence were measured intraoperatively in the capillary blood of the fingers as well as in the venous blood withdrawn from the cubital vein and the greater saphenous vein in the lower third of the leg near ulcer). The data obtained evidenced that lipid peroxidation activity was most pronounced in the soft tissues of the lower third of the leg in the group of patients with remarkable chronic venous insufficiency without trophic venous ulcers (GVI CEAP C3-5) and was significantly depleted after formation of varicose ulcers (CVI CEAP C6) associated with remarkable tissue hypoxia (TepO2 1.7-7.0 mm Hg). In all patients with CVI, the syndrome of lipid peroxidation was associated with the lowering of antioxidant defence activity. Patients with trophic venous ulcers had the signs of active inflammation in the soft tissues of the leg. The data obtained in the course of the study made it possible to optimize the treatment policy for elderly patients with trophic venous ulcers. In addition to the lowering of venous hypertension, the treatment included correction of microcirculatory disorders related to local hypoxia. Of special importance was reperfusion attenuation in the postoperative period.

  14. High impact of uranyl ions on carrying-releasing oxygen capability of hemoglobin-based blood substitutes

    Energy Technology Data Exchange (ETDEWEB)

    Duan, Li; Du, Lili; Liu, Wenyuan; Liu, Zhichao [Northwest Institute of Nuclear Technology, Xi' an, Shaanxi (China); Jia, Yi; Li, Junbai [Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Colloid Interface and Chemical Thermodynamics, Institute of Chemistry, Chinese Academy of Sciences, Beijing (China)

    2015-01-07

    The effect of radioactive UO{sub 2}{sup 2+} on the oxygen-transporting capability of hemoglobin-based oxygen carriers has been investigated in vitro. The hemoglobin (Hb) microspheres fabricated by the porous template covalent layer-by-layer (LbL) assembly were utilized as artificial oxygen carriers and blood substitutes. Magnetic nanoparticles of iron oxide (Fe{sub 3}O{sub 4}) were loaded in porous CaCO{sub 3} particles for magnetically assisted chemical separation (MACS). Through the adsorption spectrum of magnetic Hb microspheres after adsorbing UO{sub 2}{sup 2+}, it was found that UO{sub 2}{sup 2+} was highly loaded in the magnetic Hb microspheres, and it shows that the presence of UO{sub 2}{sup 2+} in vivo destroys the structure and oxygen-transporting capability of Hb microspheres. In view of the high adsorption capacity of UO{sub 2}{sup 2+}, the as-assembled magnetic Hb microspheres can be considered as a novel, highly effective adsorbent for removing metal toxins from radiation-contaminated bodies, or from nuclear-power reactor effluent before discharge into the environment. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  15. Venous Sampling

    Science.gov (United States)

    ... neck to help locate abnormally functioning glands or pituitary adenoma . This test is most often used after an unsuccessful neck exploration. Inferior petrosal sinus sampling , in which blood samples are taken from veins that drain the pituitary gland to study disorders related to pituitary hormone ...