Using Willie's Acid-Base Box for Blood Gas Analysis

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Dietz, John R.

2011-01-01

In this article, the author describes a method developed by Dr. William T. Lipscomb for teaching blood gas analysis of acid-base status and provides three examples using Willie's acid-base box. Willie's acid-base box is constructed using three of the parameters of standard arterial blood gas analysis: (1) pH; (2) bicarbonate; and (3) CO[subscript…

Long-term facial artery catheter implantation for serial arterial blood sampling and invasive arterial blood pressure measurement in horses.

Science.gov (United States)

Dias, Deborah Penteado Martins; Teixeira, Luisa Gouvêa; Canola, Paulo Aléscio; Albernaz, Raquel Mincarelli; Marques, José Antônio; Neto, José Corrêa de Lacerda

2012-06-01

The purpose of this investigation was to evaluate surgical catheter implantation in the facial artery of horses and the long-term maintenance of such arteries using heparin and ascorbic acid as filling solution. Nine horses were implanted with a polyurethane catheter. The catheters were flushed with a heparin/ascorbic acid solution every 8h and remained patent for 25 days. Arterial blood samples were collected twice a day, and one exercise test that included serial blood samples and arterial pressure recordings was performed on a treadmill. Polyurethane catheters surgically implanted in the facial artery can be kept patent by filling with a heparin/ascorbic acid solution and provide convenient invasive arterial access in horses which is suitable for use for serial blood sampling and blood pressure recordings, even during exercise on treadmill. Copyright © 2011 Elsevier Ltd. All rights reserved.

Neonatal oxidative stress depends on oxygen blood pressure in umbilical artery.

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Proietti, F; De Bernardo, G; Longini, M; Sordino, D; Scaramuzzini, G; Tataranno, M L; Belvisi, E; Bazzini, F; Perrone, S; Buonocore, G

2016-01-01

With advancing gestation, partial pressure of oxygen (pO2) and pH fall significantly. Hypoxia is a main factor inducing free radical generation and thereby oxidative stress (OS). Placental and fetal tissue response when oxygen becomes restricted is complex and partially known. We tested the hypothesis that changes in umbilical artery and vein blood gas concentrations modulate OS occurrence in the newborn. Seventy umbilical artery and vein plasma samples were collected from healthy term newborns immediately after delivery. F2 Isoprostanes (F2-Isop) were measured in all samples as reliable markers of lipid peroxidation. Significantly lower pCO2 and higher pO2 and pH were found in umbilical vein than in artery, as expected. A positive correlation was detected between pH and pO2 only in umbilical artery (p=0.019). F2-Isop levels were no different between artery and vein in cord blood. Significant correlations were found between F2-Isop and pCO2 (p=0.025) as well as between F2-Isop and pH in umbilical vein (p=0.027). F2-Isop correlated with pCO2 (p=0.007) as well as with pO2 values (p=0.005) in umbilical artery blood. Oxidative stress (OS) in newborns depends on oxygen concentrations in umbilical artery. OS biomarkers significantly correlate with pO2 and in umbilical artery but not in umbilical vein. In normoxic conditions fetal-maternal gas exchanges occurring in placenta re-establish normal higher oxygen levels in umbilical vein than artery, with a normal production of free radicals without any deleterious effects.

Effects of xylazine on acid-base balance and arterial blood-gas tensions in goats under different environmental temperature and humidity conditions

Directory of Open Access Journals (Sweden)

E.G.M. Mogoa

2000-07-01

Full Text Available The effects of acute exposure to 3 different temperature and humidity conditions on arterial blood-gas and acid-base balance in goats were investigated after intravenous bolus administration of xylazine at a dose of 0.1 mg/kg. Significant (P < 0.05 changes in the variables occurred under all 3 environmental conditions. Decreases in pH, partial pressure of oxygen and oxyhaemoglobin saturation were observed, and the minimum values for oxygen tension and oxyhaemoglobin saturation were observed within 5 min of xylazine administration. The pH decreased to its minimum values between 5 and 15 min. Thereafter, the variables started to return towards baseline, but did not reach baseline values at the end of the 60 min observation period. Increases in the partial pressure of carbon dioxide, total carbon dioxide content, bicarbonate ion concentration, and the actual base excess were observed. The maximum increase in the carbon dioxide tension occurred within 5 min of xylazine administration. The increase in the actual base excess only became significant after 30 min in all 3 environments, and maximal increases were observed at 60 min. There were no significant differences between the variables in the 3 different environments. It was concluded that intravenous xylazine administration in goats resulted in significant changes in arterial blood-gas and acid-base balance that were associated with hypoxaemia and respiratory acidosis, followed by metabolic alkalosis that continued for the duration of the observation period. Acute exposure to different environmental temperature and humidity conditions after xylazine administration did not influence the changes in arterial blood-gas and acid-base balance.

[Smartphone application for blood gas interpretation].

Science.gov (United States)

Obiols, Julien; Bardo, Pascale; Garnier, Jean-Pierre; Brouard, Benoît

2013-01-01

Ninety four per cent of health professionals use their smartphone for business purposes and more than 50% has medical applications. The «Blood Gas» application was created to be part of this dynamic and participate to e-health development in France. The «Blood Gas» application facilitates interpretation of the results of blood gas analysis using an algorithm developed with reference to a medical bibliography. It can detect some complex or intricate acid-base disorders in evaluating the effectiveness of the secondary response. The application also studied the respiratory status of the patient by calculating the PaO2/FiO2 ratio and the alveol-arterial gradient. It also indicates the presence of a shunt effect. Finally, a specific module to calculate the SID (strong ion difference) depending on the model of Stewart can detect complex acid-base disorders.

Influence of myocardial oxygen demand on the coronary vascular response to arterial blood gas changes in humans.

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Vermeulen, Tyler Dennis; Boulet, Lindsey M; Stembridge, Mike; Williams, Alexandra Mackenzie; Anholm, James D; Subedi, Prajan; Gasho, Chris; Ainslie, Philip N; Feigl, Eric O; Foster, Glen Edward

2018-03-30

It remains unclear if the human coronary vasculature is inherently sensitive to changes in arterial PO 2 and PCO 2 or if coronary vascular responses are the result of concomitant increases in myocardial O 2 consumption/demand (MVO 2 ). We hypothesized that the coronary vascular response to PO 2 and PCO 2 would be attenuated in healthy men when MVO 2 was attenuated with β 1 -adrenergic receptor blockade. Healthy men (n=11; age: 25 {plus minus} 1 years) received intravenous esmolol (β 1 -adrenergic receptor antagonist) or volume-matched saline in a double-blind, randomized, crossover study, and were exposed to poikilocapnic hypoxia, isocapnic hypoxia, and hypercapnic hypoxia. Measurements made at baseline and following 5-min of steady state at each gas manipulation included left anterior descending coronary blood velocity (LAD V ; Doppler echocardiography), heart rate and arterial blood pressure. LAD V values at the end of each hypoxic condition were compared between esmolol and placebo. Rate pressure product (RPP) and left-ventricular mechanical energy (ME LV ) were calculated as indices of MVO 2 . All gas manipulations augmented RPP, ME LV , and LAD V but only RPP and ME LV were attenuated (4-18%) following β 1 -adrenergic receptor blockade (P<0.05). Despite attenuated RPP and MELV responses, β 1 -adrenergic receptor blockade did not attenuate the mean LADV vasodilatory response when compared to placebo during poikilocapnic hypoxia (29.4{plus minus}2.2 vs. 27.3{plus minus}1.6 cm/s) and isocapnic hypoxia (29.5{plus minus}1.5 vs. 30.3{plus minus}2.2 cm/s). Hypercapnic hypoxia elicited a feed-forward coronary dilation that was blocked by β 1 -adrenergic receptor blockade. These results indicate a direct influence of arterial PO 2 on coronary vascular regulation that is independent of MVO 2 .

Can we Replace Arterial Blood Gas Analysis by Pulse Oximetry in Neonates with Respiratory Distress Syndrome, who are Treated According to INSURE Protocol?

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Pedram Niknafs

2015-05-01

Full Text Available Neonates with respiratory distress syndrome (RDS, who are treated according to INSURE protocol; require arterial blood gas (ABG analysis to decide on appropriate management. We conducted this study to investigate the validity of pulse oximetry instead of frequent ABG analysis in the evaluation of these patients. From a total of 193 blood samples obtained from 30 neonates <1500 grams with RDS, 7.2% were found to have one or more of the followings: acidosis, hypercapnia, or hypoxemia. We found that pulse oximetry in the detection of hyperoxemia had a good validity to appropriately manage patients without blood gas analysis. However, the validity of pulse oximetry was not good enough to detect acidosis, hypercapnia, and hypoxemia.

[Application of continuous intra-arterial blood gas monitoring system "Paratrend 7" for pulmonary lavage of a patient with alveolar proteinosis].

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Harigae, M; Hirose, Y; Gamo, M; Hirose, M; Fujiwara, C; Matsuo, K

1999-03-01

We applied a continuous intra-arterial blood gas monitoring system (Paratrend 7) to a patient with pulmonary alveolar proteinosis during pulmonary lavage. Lavage was performed under general anesthesia with one lung ventilation. We inserted the sensor of Patatrend 7 through a 20 G catheter into the radial artery, and monitored pH, PaCO2 and PaO2 continuously throughout the procedure. SpO2 and EtCO2 were also monitored. Saline 1000-1500 ml was instilled and drained repeatedly by volume limited methods. PaO2 values by Paratrend 7 increased during instillation and decreased during drainage of the irrigating fluid. In contrast, PaCO2 value by Paratrend 7 decreased slightly during instillation and increased during drainage. The change of SpO2 was almost the same as that by Paratrend 7, but the response time of pulse oxymetry was a little quicker than Paratrend 7. During the lavage procedure, respiratory and circulatory condition changed very rapidly, and it is necessary to monitor blood gas change intensively. Paratrend 7 is useful as a perioperative monitoring system, but pulse oxymetry might be sufficient during pulmonary lavage considering its cost.

Changes in electrolytes and blood gas after transfusion of irradiated MAP

International Nuclear Information System (INIS)

Miyao, Hideki; Katayama, Akinori; Okamoto, Yumi; Koyama, Kaoru; Kawasaki, Jun; Kawazoe, Taro

2001-01-01

This study was undertaken to investigate the changes in recipient serum electrolytes and arterial blood gas after irradiated blood transfusion. We measured electrolytes and arterial blood gas before and after the transfusion during elective surgery in 55 patients. The mean blood loss was 1,477 g and the mean transfused blood unit of irradiated Mannitol-Adenine-Phosphate (MAP) was 5.9 units. Potassium concentration increased from 3.8 to 4.2 mEq·l -1 . A total of 187 units, which had been stored for 12.3±3.5 days after donation and for 5.1±3.8 days after irradiation, was used. There was a significant correlation between the storage period from the day of irradiation and the potassium concentration of the supernatant (r=0.56, p<0.0001). This study recommends that a safe transfusion rate of irradiated blood should be determined because the high potassium concentration of irradiated blood may lead to lethal complications in case of rapid transfusion. (author)

Utilization of arterial blood gas measurements in a large tertiary care hospital.

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Melanson, Stacy E F; Szymanski, Trevor; Rogers, Selwyn O; Jarolim, Petr; Frendl, Gyorgy; Rawn, James D; Cooper, Zara; Ferrigno, Massimo

2007-04-01

We describe the patterns of utilization of arterial blood gas (ABG) tests in a large tertiary care hospital. To our knowledge, no hospital-wide analysis of ABG test utilization has been published. We analyzed 491 ABG tests performed during 24 two-hour intervals, representative of different staff shifts throughout the 7-day week. The clinician ordering each ABG test was asked to fill out a utilization survey. The most common reasons for requesting an ABG test were changes in ventilator settings (27.6%), respiratory events (26.4%), and routine (25.7%). Of the results, approximately 79% were expected, and a change in patient management (eg, a change in ventilator settings) occurred in 42% of cases. Many ABG tests were ordered as part of a clinical routine or to monitor parameters that can be assessed clinically or through less invasive testing. Implementation of practice guidelines may prove useful in controlling test utilization and in decreasing costs.

Weaning mechanical ventilation after off-pump coronary artery bypass graft procedures directed by noninvasive gas measurements.

Science.gov (United States)

Chakravarthy, Murali; Narayan, Sandeep; Govindarajan, Raghav; Jawali, Vivek; Rajeev, Subramanyam

2010-06-01

Partial pressure of carbon dioxide and oxygen were transcutaneously measured in adults after off-pump coronary artery bypass (OPCAB) surgery. The clinical use of such measurements and interchangeability with arterial blood gas measurements for weaning patients from postoperative mechanical ventilation were assessed. This was a prospective observational study. Tertiary referral heart hospital. Postoperative OPCAB surgical patients. Transcutaneous oxygen and carbon dioxide measurements. In this prospective observational study, 32 consecutive adult patients in a tertiary care medical center underwent OPCAB surgery. Noninvasive measurement of respiratory gases was performed during the postoperative period and compared with arterial blood gases. The investigator was blinded to the reports of arterial blood gas studies and weaned patients using a "weaning protocol" based on transcutaneous gas measurement. The number of patients successfully weaned based on transcutaneous measurements and the number of times the weaning process was held up were noted. A total of 212 samples (pairs of arterial and transcutaneous values of oxygen and carbon dioxide) were obtained from 32 patients. Bland-Altman plots and mountain plots were used to analyze the interchangeability of the data. Twenty-five (79%) of the patients were weaned from the ventilator based on transcutaneous gas measurements alone. Transcutaneous carbon dioxide measurements were found to be interchangeable with arterial carbon dioxide during 96% of measurements, versus 79% for oxygen measurements. More than three fourths of the patients were weaned from mechanical ventilation and extubated based on transcutaneous gas values alone after OPCAB surgery. The noninvasive transcutaneous carbon dioxide measurement can be used as a surrogate for arterial carbon dioxide measurement to manage postoperative OPCAB patients. Copyright 2010 Elsevier Inc. All rights reserved.

Effect of Sample Storage Temperature and Time Delay on Blood Gases, Bicarbonate and pH in Human Arterial Blood Samples.

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Mohammadhoseini, Elham; Safavi, Enayat; Seifi, Sepideh; Seifirad, Soroush; Firoozbakhsh, Shahram; Peiman, Soheil

2015-03-01

Results of arterial blood gas analysis can be biased by pre-analytical factors, such as time interval before analysis, temperature during storage and syringe type. To investigate the effects of samples storage temperature and time delay on blood gases, bicarbonate and PH results in human arterial blood samples. 2.5 mL arterial blood samples were drawn from 45 patients via an indwelling Intraarterial catheter. Each sample was divided into five equal samples and stored in multipurpose tuberculin plastic syringes. Blood gas analysis was performed on one of five samples as soon as possible. Four other samples were divided into two groups stored at 22°C and 0°C. Blood gas analyses were repeated at 30 and 60 minutes after sampling. PaO2 of the samples stored at 0°C was increased significantly after 60 minutes (P = 0.007). The PaCO2 of the samples kept for 30 and 60 minutes at 22°C was significantly higher than primary result (P = 0.04, P samples stored at 22°C, pH decreased significantly after 30 and 60 minutes (P = 0.017, P = 0.001). There were no significant differences in other results of samples stored at 0°C or 22°C after 30 or 60 minutes. In samples stored in plastic syringes, overestimation of PaO2 levels should be noted if samples cooled before analysis. In samples stored in plastic syringes, it is not necessary to store samples in iced water when analysis delayed up to one hour.

21 CFR 868.1100 - Arterial blood sampling kit.

Science.gov (United States)

2010-04-01

...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1100 Arterial blood sampling kit. (a) Identification. An arterial blood sampling kit is a device, in kit form, used to obtain arterial blood samples... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Arterial blood sampling kit. 868.1100 Section 868...

The quantitative regional cerebral blood flow measurement with autoradiography method using 123I-IMP SPECT. Evaluation of arterialized venous blood sampling as a substitute for arterial blood sampling

International Nuclear Information System (INIS)

Ohnishi, Takashi; Yano, Takao; Nakano, Shinichi; Jinnouchi, Seishi; Nagamachi, Shigeki; Flores, L. II; Nakahara, Hiroshi; Watanabe, Katsushi.

1996-01-01

The purpose of this study is validation of calibrating a standard input function in autoradiography (ARG) method by one point venous blood sampling as a substitute for that by one point arterial blood sampling. Ten and 20 minutes after intravenous constant infusion of 123 I-IMP, arterialized venous blood sampling from a dorsal vein were performed on 15 patients having ischemic cerebrovascular disease. And arterial blood sampling from radial artery was performed 10 min after 123 I-IMP infusion. The mean difference rates of integrated input function between calibrated standard input function by arterial blood sampling at 10 min and that by venous blood sampling were 4.1±3% and 9.3±5.4% at 10 and 20 min after 123 I-IMP infusion, respectively. The ratio of venous blood radioactivity to arterial blood radioactivity at 10 min after 123 I-IMP infusion was 0.96±0.02. There was an excellent correlation between ARG method CBF values obtained by arterial blood sampling at 10 min and those obtained by arterialized venous blood sampling at 10 min. In conclusion, a substitution by arterialized venous blood sampling from dorsal hand vein for artery can be possible. The optimized time for arterialized venous blood sampling was 10 min after 123 I-IMP infusion. (author)

Effects of feeding on arterial blood gases in the American alligator Alligator mississippiensis.

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Busk, M; Overgaard, J; Hicks, J W; Bennett, A F; Wang, T

2000-10-01

Reptiles habitually ingest large meals at infrequent intervals, leading to changes in acid-base status as the net secretion of acid to the stomach causes a metabolic alkalosis (the alkaline tide). In chronically cannulated and undisturbed amphibians and reptiles, the pH changes in arterial blood are, nevertheless, reduced by a concomitant respiratory acidosis (increased P(CO2) caused by a relative hypoventilation). Alligators (Alligator mississippiensis) have been reported to exhibit exceptionally large increases in plasma [HCO3(-)] following feeding, but these studies were based on blood samples obtained by cardiac puncture, so stress and disturbance may have affected the blood gas levels. Furthermore, crocodilian haemoglobin is characterised by a unique binding of HCO3(-) that act to reduce blood oxygen-affinity, and it has been proposed that this feature safeguards oxygen offloading by counteracting pH effects on blood oxygen-affinity. Therefore, to study acid-base regulation and the interaction between the alkaline tide and oxygen transport in more detail, we describe the arterial blood gas composition of chronically cannulated and undisturbed alligators before and after voluntary feeding (meal size 7.5+/-1% of body mass). Digestion was associated with an approximately fourfold increase in metabolic rate (from 0.63+/-0.04 to 2.32+/-0.24 ml O(2) min(-1)kg(-1)) and was accompanied by a small increase in the respiratory gas exchange ratio. The arterial P(O2) of fasting alligators was 60.3+/-6.8 mmHg (1 mmHg = 0.133 kPa) and reached a maximum of 81.3+/-2.7 mmHg at 96 h following feeding; there was only a small increase in lactate levels, so the increased metabolic rate seems to be entirely aerobic. Plasma [HCO3(-)] increased from 24.4+/-1.1 to 36.9+/-1.7 mmol l(-1) (at 24 h), but since arterial P(CO2) increased from 29.0+/-1.1 to 36.8+/-1.3 mmHg, arterial pH remained virtually unaffected (changing from 7.51+/-0.01 to 7.58+/-0.01 at 24 h). The changes in plasma [HCO

Arterial blood oxygen saturation during blood pressure cuff-induced hypoperfusion

International Nuclear Information System (INIS)

Kyriacou, P A; Shafqat, K; Pal, S K

2007-01-01

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 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 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 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. Both pulse

Arterial blood oxygen saturation during blood pressure cuff-induced hypoperfusion

Science.gov (United States)

Kyriacou, P. A.; Shafqat, K.; Pal, S. K.

2007-10-01

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 (SpO2) 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 (SpO2) 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/SpO2 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. Both pulse

Maternal Body Mass Index Does Not Affect Neonatal Umbilical Artery Blood Gas Parameters

Directory of Open Access Journals (Sweden)

Salam E. Chalouhi

2013-01-01

Full Text Available This study was undertaken to assess the impact of obesity on fetal well-being in glucose-tolerant and nonhypertensive women. Medical charts of all patients admitted to the labor and delivery department at our institution between January, 2011 and July, 2011 were retrospectively reviewed. Patients with diabetes/impaired glucose tolerance or hypertension were excluded. A total of 100 women, 50 lean and 50 obese, were included. Umbilical artery blood gas parameters (BGPs were compared in lean (<25 kg/m2 and obese (≥30 kg/m2 women. Obese and lean women were comparable with respect to all baseline characteristics. There was no difference in any of the BGP or Apgar scores between obese and lean patients. Pearson’s correlation coefficient found no significant correlation between BMI and BGP/Apgar scores. Maternal obesity does not seem to affect BGP and fetal well-being in glucose-tolerant and nonhypertensive women.

Effect of body weight loss on cardiopulmonary function assessed by 6-minute walk test and arterial blood gas analysis in obese dogs.

Science.gov (United States)

Manens, J; Ricci, R; Damoiseaux, C; Gault, S; Contiero, B; Diez, M; Clercx, C

2014-01-01

Few studies show the detrimental effect of canine obesity on cardiopulmonary function (CPF). The 6-Minute Walk Test (6MWT) is a noninvasive exercise test easy to perform in clinical settings. The aim of this study was to investigate the effect of obesity and body weight loss (BWL) on CPF assessed by the 6MWT and arterial blood gas analysis. Six experimental Beagles and 9 privately owned obese dogs were enrolled in a diet-induced BWL program. Arterial blood gas analysis and 6MWT were repeated in obese subjects (BCS 8-9/9), in the middle of BWL (overweight, BCS 6-7/9), and in lean dogs (BCS 5/9). Heart rate (HRp) and oxygen saturation (SpO2 ) were measured by pulse oximetry before the 6MWT, at midtest, and during a 5-minute recovery period. Twelve dogs completed the BWL program (initial BW, 27.3 ± 2.9 kg; final BW, 20.85 ± 2.9, lsmeans ± SE, P ≤ .001). BWL caused a significant increase in 6MWT walked distance (WD; obese: 509 ± 35 m; overweight: 575 ± 36 m; lean: 589 ± 36 m; P ≤ .05). Resting arterial blood gas results were not influenced by BWL. Including all time points, obese dogs showed higher HRp and lower SpO2 compared to overweight and lean dogs. SpO2 at the end of the walk was significantly lower in obese dogs. Obesity negatively affects 6MWT performances in dogs. The 6MWT may be used to demonstrate the efficacy of BWL to improve CPF and quality of life in obese dogs. Although BWL induced significant improvement of cardiopulmonary parameters before ideal BW, WD improved until the end of the BWL program. Copyright © 2013 by the American College of Veterinary Internal Medicine.

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

Improved arterial blood oxygenation following intravenous infusion of cold supersaturated dissolved oxygen solution.

Science.gov (United States)

Grady, Daniel J; Gentile, Michael A; Riggs, John H; Cheifetz, Ira M

2014-01-01

One of the primary goals of critical care medicine is to support adequate gas exchange without iatrogenic sequelae. An emerging method of delivering supplemental oxygen is intravenously rather than via the traditional inhalation route. The objective of this study was to evaluate the gas-exchange effects of infusing cold intravenous (IV) fluids containing very high partial pressures of dissolved oxygen (>760 mm Hg) in a porcine model. Juvenile swines were anesthetized and mechanically ventilated. Each animal received an infusion of cold (13 °C) Ringer's lactate solution (30 mL/kg/hour), which had been supersaturated with dissolved oxygen gas (39.7 mg/L dissolved oxygen, 992 mm Hg, 30.5 mL/L). Arterial blood gases and physiologic measurements were repeated at 15-minute intervals during a 60-minute IV infusion of the supersaturated dissolved oxygen solution. Each animal served as its own control. Five swines (12.9 ± 0.9 kg) were studied. Following the 60-minute infusion, there were significant increases in PaO2 and SaO2 (P < 0.05) and a significant decrease in PaCO2 (P < 0.05), with a corresponding normalization in arterial blood pH. Additionally, there was a significant decrease in core body temperature (P < 0.05) when compared to the baseline preinfusion state. A cold, supersaturated dissolved oxygen solution may be intravenously administered to improve arterial blood oxygenation and ventilation parameters and induce a mild therapeutic hypothermia in a porcine model.

The effect of CPAP treatment on venous lactate and arterial blood gas among obstructive sleep apnea syndrome patients.

Science.gov (United States)

Lin, Ting; Huang, Jie-Feng; Lin, Qi-Chang; Chen, Gong-Ping; Wang, Bi-Ying; Zhao, Jian-Ming; Qi, Jia-Chao

2017-05-01

The aim of this observational study was to investigate the influence of continuous positive airway pressure (CPAP) on arterial blood gas and venous lactate, markers of tissue hypoxia, among obstructive sleep apnea syndrome (OSAS) patients, and determine the risk factor of serum lactate and hydrogen ion concentration (PH) in OSAS patients. One-hundred and nine patients with newly diagnosed OSAS were enrolled in the study. All individuals were treated with CPAP for one night. Venous lactate and arterial blood gas were gathered from all subjects in the morning at the end of polysomnography and the next morning after CPAP treatment. Of the 109 selected subjects, the average lactate level was 2.23 ± 0.59 mmol/L, and the mean PH, PaO 2 , and PaCO 2 were 7.380 ± 0.23, 88.14 ± 17.83 mmHg, and 38.70 ± 4.28 mmHg, respectively. Compared to baseline, lactic acid significantly decreased (2.10 ± 0.50 mmol/L, p = 0.03), while PH increased (7.388 ± 0.27, p treatment. In addition, neck circumference and the polysomnographic parameters, including apnea-hypopnea index, oxygen desaturation index (ODI), mean oxygen saturation (SpO 2 ), and the percentage of sleep time with SpO 2 treatment could reduce serum lactate and increase PH in OSAS patients and might alleviate acid-base balance disorders in OSAS. Furthermore, TS90 % was a risk factor for elevated lactate, and age was independently associated with PH.

Role of central and peripheral opiate receptors in the effects of fentanyl on analgesia, ventilation and arterial blood-gas chemistry in conscious rats

Science.gov (United States)

Henderson, Fraser; May, Walter J.; Gruber, Ryan B.; Discala, Joseph F.; Puscovic, Veljko; Young, Alex P.; Baby, Santhosh M.; Lewis, Stephen J.

2015-01-01

This study determined the effects of the peripherally restricted µ-opiate receptor (µ-OR) antagonist, naloxone methiodide (NLXmi) on fentanyl (25 µg/kg, i.v.)-induced changes in (1) analgesia, (2) arterial blood gas chemistry (ABG) and alveolar-arterial gradient (A-a gradient), and (3) ventilatory parameters, in conscious rats. The fentanyl-induced increase in analgesia was minimally affected by a 1.5 mg/kg of NLXmi but was attenuated by a 5.0 mg/kg dose. Fentanyl decreased arterial blood pH, pO2 and sO2 and increased pCO2 and A-a gradient. These responses were markedly diminished in NLXmi (1.5 mg/kg)-pretreated rats. Fentanyl caused ventilatory depression (e.g., decreases in tidal volume and peak inspiratory flow). Pretreatment with NLXmi (1.5 mg/kg, i.v.) antagonized the fentanyl decrease in tidal volume but minimally affected the other responses. These findings suggest that (1) the analgesia and ventilatory depression caused by fentanyl involve peripheral µ-ORs and (2) NLXmi prevents the fentanyl effects on ABG by blocking the negative actions of the opioid on tidal volume and A-a gradient. PMID:24284037

Uso de sangue arterial e venoso no exame do equilíbrio ácido-básico de novilhos normais ou com acidose metabólica Arterial and venous blood in the assessment of blood gas and acid-base status in healthy steers or steers with metabolic acidosis

Directory of Open Access Journals (Sweden)

Maria Claudia Araripe Sucupira

2003-10-01

Full Text Available Doze novilhos foram utilizados para comparar os resultados hemogasométricos de sangue arterial e venoso. Esses animais foram divididos em três grupos idênticos, recebendo: 1- dieta balanceada, proporcionando ganho de peso de 600g/d; 2- dieta de mantença em proteína e energia e 3- dieta com teores 20% abaixo da mantença. Amostras de sangue arterial (artéria auricular caudal e venoso (veia jugular foram colhidas por 11 quinzenas consecutivas, num total de 132 amostras. Ao término do experimento, os animais dos grupos 2 e principalmente 3 apresentaram acidose metabólica moderada. Maiores valores de pH e de pO2 foram constatados no sangue arterial enquanto os teores de bicarbonato, TCO2, BE e pCO2 foram superiores no sangue venoso. Existiram altas correlações entre os valores do sangue arterial e venoso para o pH (r = 0,81, bicarbonato e TCO2 (r = 0,94, sendo esta correlação média, mas significativa, no caso da pCO2 (r = 0,56 e inexistente na pO2 (r= -0,06. Quanto maiores foram os valores de pCO2 maiores foram os teores de bicarbonato (r = 0,54 e TCO2 (r =0,56. Apesar das discrepâncias de pH, das concentrações de bicarbonato, TCO2, e mesmo de pCO2 obtidos no sangue venoso e arterial, é possível estimar, adequadamente, a partir do primeiro esses valores nas amostras arteriais em novilhos normais e com moderado grau de acidose metabólica. Nos casos de alterações respiratórias, amostras de sangue arterial devem ser colhidas para determinação de pO2. A colheita de sangue venoso foi mais facilmente realizada que do sangue arterial.Twelve steers were used to compare the blood gas and acid-base status. The animals were randomly divided in three equal groups according to the following diets: 1- adequate, for gaining 600g/head/d ; 2- protein and energy levels to meet the maintenence; 3- protein and energy 20% below the maintenance levels. One hundred thirty-two arterial blood (caudal auricular artery or venous blood (jugular vein

Parameters of Blood Flow in Great Arteries in Hypertensive ISIAH Rats with Stress-Dependent Arterial Hypertension.

Science.gov (United States)

Seryapina, A A; Shevelev, O B; Moshkin, M P; Markel', A L

2016-08-01

Magnetic resonance angiography was used to examine blood flow in great arteries of hypertensive ISIAH and normotensive Wistar rats. In hypertensive ISIAH rats, increased vascular resistance in the basin of the abdominal aorta and renal arteries as well as reduced fraction of total renal blood flow were found. In contrast, blood flow through both carotid arteries in ISIAH rats was enhanced, which in suggests more intensive blood supply to brain regulatory centers providing enhanced stress reactivity of these rats characterized by stress-dependent arterial hypertension.

Animal models of cerebral arterial gas embolism

NARCIS (Netherlands)

Weenink, Robert P.; Hollmann, Markus W.; van Hulst, Robert A.

2012-01-01

Cerebral arterial gas embolism is a dreaded complication of diving and invasive medical procedures. Many different animal models have been used in research on cerebral arterial gas embolism. This review provides an overview of the most important characteristics of these animal models. The properties

The relationship between total arterial revascularization and blood transfusion following coronary artery bypass grafting.

Science.gov (United States)

Djordjevic, Jasmina; Ngaage, Dumbor L

2015-05-01

Blood transfusion adversely affects the outcome of coronary artery bypass grafting (CABG), yet blood transfusion after CABG is still common. Total arterial revascularisation (TAR) is increasingly used in current practice but its impact on postoperative blood transfusion is not known. We reviewed the cardiothoracic and blood bank databases and collected data for isolated primary CABG patients from July 2007 to June 2012, excluding patients who had a single graft (n = 148). Perioperative variables of TAR patients (n = 745) were compared with patients who had one or more venous grafts (SVG, n = 1,761) for first-time isolated CABG. The conduits used in TAR patients were predominantly left internal thoracic and radial arteries. Matched group comparison of TAR and SVG patients was performed. The association of TAR with blood transfusion was investigated using multivariate and matched analysis. Of 2,506 patients, the 745 (29.7 %) that had TAR were generally younger, with less complex coronary artery disease and less often diabetic. After correcting for these by 1:1 matching, the mean chest tube drainage and rates of blood transfusion remained significantly lower (p transfused in TAR patients. By multivariate analysis, TAR had an independent effect on reducing blood transfusion after CABG [odds ratio (OR) 0.67, 95 % confidence interval (CI) 0.47-0.97, p = .03]. TAR achieved predominantly with left internal thoracic and radial arteries substantially reduced blood transfusion rates after primary CABG. Further studies are warranted.

DETERMINATION OF AMMONIA IN EAR-LOBE CAPILLARY BLOOD IS AN ALTERNATIVE TO ARTERIAL BLOOD AMMONIA

NARCIS (Netherlands)

HUIZENGA, [No Value; GIPS, CH; CONN, HO; JANSEN, PLM

1995-01-01

Blood ammonia determination is a laboratory test to diagnose hepatic encephalopathy. Arterial blood is superior to peripheral venous blood ammonia because of ammonia metabolism in muscle. We have compared capillary with arterial whole blood ammonia as capillary sampling is an attractive alternative.

Determination of ammonia in ear-lobe capillary blood is an alternative to arterial blood ammonia

NARCIS (Netherlands)

Huizenga, J. R.; Gips, C. H.; Conn, H. O.; Jansen, P. L.

1995-01-01

Blood ammonia determination is a laboratory test to diagnose hepatic encephalopathy. Arterial blood is superior to peripheral venous blood ammonia because of ammonia metabolism in muscle. We have compared capillary with arterial whole blood ammonia as capillary sampling is an attractive alternative.

[Ultrasonographic study of blood flow in the renal arteries of patients with arterial hypertension].

Science.gov (United States)

Makarenko, E S; Dombrovskiĭ, V I; Nelasov, N Iu

2012-01-01

Vascular duplex ultrasound duplex with simultaneous ECG registration was made to estimate the quantitative and time parameters of blood flow in the renal arteries with grade 1-2 arterial hypertension. There were increases in vascular resistance indices and acceleration phase index and a reduction in systolic phase index. There were correlations of the time parameters of blood flow in the renal arteries with age and lipidogram values.

Left coronary arterial blood flow: Noninvasive detection by Doppler US

International Nuclear Information System (INIS)

Gramiak, R.; Holen, J.; Moss, A.J.; Gutierrez, O.H.; Picone, A.L.; Roe, S.A.

1986-01-01

Continuous wave (CW) and pulsed Doppler ultrasound studies with spectral analysis were used to detect the left coronary arterial blood flow in patients who were undergoing routine echocardiography. The pulmonary artery is a stable ultrasonic landmark from which detection of the blood flow can be effected. The left coronary artery can be distinguished by its blood flow toward the cardiac apex and by specific, functional flow features. Flow patterns vary among the left main, circumflex, and anterior descending arteries; patterns also vary with respiration cycles. In the present study, coronary arterial blood flow was detected in 58 of 70 patients (83%). Findings were validated by selectively injecting an agitated saline contrast medium into the left coronary artery and, in another study, by comparing human Doppler phasic flow waveforms with electromagnetic flowmeter recordings obtained in dogs

Quantitative changes in the arterial blood gases of mice following localized irradiation of the lungs

International Nuclear Information System (INIS)

Siemann, D.W.; Hill, R.P.

1983-01-01

The arterial pH and partial pressures of oxygen (PaO 2 ) and carbon dioxide (PaCO 2 ) were evaluated in LAF1 mice 15 and 38 weeks after localized irradiation of the animals' thoraxes. Graded radiation doses of 900 to 1200 rad were administered. These doses resulted in 0 to 100% lethality by 26 weeks (180 days) after irradiation. At 15 weeks after treatment mice receiving radiation doses which would subsequently result in lethality (by 180 days) exhibited significant reductions in their PaO 2 and elevations in their PaCO 2 values, respectively. However, there was no clear dose-response relationship between blood gas values and radiation dose, which may reflect the animals' ability to compensate for their poor blood gas exchange by an increased breathing frequency. At 38 weeks after irradiation the blood gas values were abnormal in mice from groups which had normal blood gas values at Week 15 (and no fatalities by Week 26) but in which animal deaths had occurred between Weeks 26 and 38. These data therfore indicated (i) that abnormal blood gas values occurred in the mice prior to fatalities resulting from the acute radiation pneumonitis syndrome and (ii) that mice surviving the initial radiation pneumonitis phase could still succumb to progressive pulmonary toxicity which was reflected by the increasing levels of animal lethality and altered blood gas tensions at the later times

Accuracy of Transcutaneous CO2 Values Compared With Arterial and Capillary Blood Gases.

Science.gov (United States)

Lambert, Laura L; Baldwin, Melissa B; Gonzalez, Cruz Velasco; Lowe, Gary R; Willis, J Randy

2018-05-08

Transcutaneous monitors are utilized to monitor a patient's respiratory status. Some patients have similar values when comparing transcutaneous carbon dioxide ( P tcCO 2 ) values with blood gas analysis, whereas others show extreme variability. A retrospective review of data was performed to determine how accurately P tcCO 2 correlated with CO 2 values obtained by arterial blood gas (ABG) or capillary blood gas. To determine whether P tcCO 2 values correlated with ABG or capillary blood gas values, subjects' records were retrospectively reviewed. Data collected included the P tcCO 2 value at the time of blood gas procurement and the ABG or capillary blood gas P CO 2 value. Agreement of pairs of methods (ABG vs P tcCO 2 and capillary blood gas vs P tcCO 2 ) was assessed with the Bland-Altman approach with limits of agreement estimated with a mixed model to account for serial measurements per subject. A total of 912 pairs of ABG/ P tcCO 2 values on 54 subjects and 307 pairs of capillary blood gas/ P tcCO 2 values on 34 subjects were analyzed. The P CO 2 range for ABG was 24-106 mm Hg, and P tcCO 2 values were 27-133 mm Hg. The P CO 2 range for capillary blood gas was 29-108 mm Hg, and P tcCO 2 values were 30-103 mm Hg. For ABG/ P tcCO 2 comparisons, the Pearson correlation coefficient was 0.82, 95% CI was 0.80-0.84, and P was <.001. For capillary blood gas/ P tcCO 2 comparisons, the Pearson correlation coefficient was 0.77, 95% CI was 0.72-0.81, and P was <.001. For ABG/ P tcCO 2 , the estimated difference ± SD was -6.79 t± 7.62 mm Hg, and limits of agreement were -22.03 to 8.45. For capillary blood gas/ P tcCO 2 , the estimated difference ± SD was -1.61 ± 7.64 mm Hg, and limits of agreement were -16.88 to 13.66. The repeatability coefficient was about 30 mm Hg. Based on these data, capillary blood gas comparisons showed less variation and a slightly lower correlation with P tcCO 2 than did ABG comparisons. After accounting for serial measurements per patient

Regional blood flow analysis and its relationship with arterial branch lengths and lumen volume in the coronary arterial tree

International Nuclear Information System (INIS)

Molloi, Sabee; Wong, Jerry T

2007-01-01

The limitations of visually assessing coronary artery disease are well known. These limitations are particularly important in intermediate coronary lesions (30-70% diameter stenosis) where it is difficult to determine whether a particular lesion is the cause of ischaemia. Therefore, a functional measure of stenosis severity is needed. The purpose of this study is to determine whether the expected maximum coronary blood flow in an arterial tree is predictable from its sum of arterial branch lengths or lumen volume. Using a computer model of a porcine coronary artery tree, an analysis of blood flow distribution was conducted through a network of millions of vessels that included the entire coronary artery tree down to the first capillary branch. The flow simulation results show that there is a linear relationship between coronary blood flow and the sum of its arterial branch lengths. This relationship holds over the entire arterial tree. The flow simulation results also indicate that there is a 3/4 er relation between coronary blood flow (Q) and the sum of its arterial lumen volume (V). Moreover, there is a linear relationship between normalized Q and normalized V raised to a power of 3/4 over the entire arterial tree. These results indicate that measured arterial branch lengths or lumen volumes can be used to predict the expected maximum blood flow in an arterial tree. This theoretical maximum blood flow, in conjunction with an angiographically measured blood flow, can potentially be used to calculate fractional flow reserve based entirely on angiographic data

Regulation of acid-base status in ectothermic vertebrates: the consequences for oxygen pressures in lung gas and arterial blood.

Science.gov (United States)

Glass, M L; Soncini, R

1995-01-01

Extensive literature reports a negative delta pHa/delta t in ectothermic vertebrates, but data are scarce as to its consequences for O2 transport. In reptiles, the negative delta pHa/delta t results from an elevated lung gas PCO2 (PACO2) at higher temperatures, implying a corresponding fall of PAO2. In parallel, arterial PO2 rises with temperature, due to a combination of central vascular shunt and decreasing Hb.O2 affinity. As a result, the PO2 gradient between lung gas and blood (PA-aO2) becomes reduced at higher temperatures. In amphibians, the negative delta pHa/delta t results from combined cutaneous and pulmonary CO2 elimination. We propose that this leads to a rather temperature-independent lung gas PO2. Moreover, our calculations suggest that resting reptiles and amphibians maintain a relatively large PA-aO2 also at high temperatures. The negative delta pHa/delta t in teleost fish is generally considered to be a result of modulated plasma [HCO3-]. Recent data from our laboratory suggest that acute pH adjustments at high temperatures may involve alterations of PaCO2 through gill ventilation, leading to a decrease of PaO2 with rising temperature.

Dopexamine increases internal mammary artery blood flow following coronary artery bypass grafting.

LENUS (Irish Health Repository)

Flynn, Michael J

2012-02-03

OBJECTIVE: Vasoactive agents and inotropes influence conduit-coronary blood flow following coronary artery bypass grafting (CABG). It was hypothesized that dopexamine hydrochloride, a dopamine A-1 (DA-1) and beta(2) agonist would increase conduit-coronary blood flow. A prospective randomized double blind clinical trial was carried out to test this hypothesis. DA-1 receptors have previously been localized to human left ventricle. METHODS: Twenty-six American Society of Anaesthesiology class 2-3 elective coronary artery bypass graft patients who did not require inotropic support on separation from cardiopulmonary bypass (CPB) were studied. According to a randomized allocation patients received either dopexamine (1 microg\\/kg per min) or placebo (saline) by intravenous infusion for 15 min. Immediately prior to and at 5,10 and 15 min of infusion, blood flow through the internal mammary and vein grafts (Transit time flow probes, Transonic Ltd.), heart rate, cardiac index, mean arterial pressure and pulmonary haemodynamics were noted. The data were analysed using multivariate analysis of variance. RESULTS: Low-dose dopexamine (1 microg\\/kg per min) caused a significant increase in mammary graft blood flow compared to placebo at 15 min of infusion (P=0.028, dopexamine group left internal mammary artery (LIMA) flow of 43.3+\\/-14.2 ml\\/min, placebo group LIMA flow at 26.1+\\/-16.3 ml\\/min). Dopexamine recipients demonstrated a non-significant trend to increased saphenous vein graft flow (P=0.059). Increased heart rate was the only haemodynamic change induced by dopexamine (P=0.004, dopexamine group at 85.2+\\/-9.6 beats\\/min and placebo group at 71.1+\\/-7.6 beats\\/min after 15 min of infusion). CONCLUSION: This study demonstrates that administration of dopexamine (1 microg\\/kg per min) was associated with a significant increase in internal mammary artery graft blood flow with mild increase in heart rate being the only haemodynamic change. Low-dose dopexamine may

Middle cerebral artery blood velocity during running

DEFF Research Database (Denmark)

Lyngeraa, Tobias; Pedersen, Lars Møller; Mantoni, T

2013-01-01

for eight subjects, respectively, were excluded from analysis because of insufficient signal quality. Running increased mean arterial pressure and mean MCA velocity and induced rhythmic oscillations in BP and in MCA velocity corresponding to the difference between step rate and heart rate (HR) frequencies....... During running, rhythmic oscillations in arterial BP induced by interference between HR and step frequency impact on cerebral blood velocity. For the exercise as a whole, average MCA velocity becomes elevated. These results suggest that running not only induces an increase in regional cerebral blood flow...

Evaluation of Blood Hemodynamics in Vascular Grafts after Total Arterial Coronary Revascularization

Directory of Open Access Journals (Sweden)

Ahmad Ali Amirghofran

2016-07-01

Full Text Available Arterial grafting has increasingly been advocated for the treatment of coronary artery disease in an attempt to improve the long-term results. In the quest to perform routine total arterial revascularization, composite Y graft methods are gaining popularity. The aim of our study was to evaluate whether blood flow in the left internal thoracic artery can provide sufficient perfusion to the entire cardiac muscle per se. Twenty patients with severe coronary artery stenosis who underwent complete arterial coronary revascularization using a composite graft entered our study. Blood flow in thoracic trunk was evaluated in three phases: cross-clamp on, cross-clamp off, and after weaning the patient from cardiopulmonary bypass. Mean arterial blood pressure in the thoracic trunk in these various positions was 62.7±3.7. left internal thora cic artery can provide sufficient blood flow to the cardiac muscles for both rest and exercise conditions.

[Prognostic Doppler ultrasound examination of fetal arteries blood flow].

Science.gov (United States)

Sieroszewski, Piotr; Sabatowska, Małgorzata; Karowicz-Bilińska, Agata; Suzin, Jacek

2002-08-01

Early detection of fetal risk is one of the main issues in today obstetrics. Ultrasound diagnostics plays a significant role, as the introduction of Doppler imaging method in the evaluation of blood flow has enabled non-invasive assessment of uteroplacental circulation. Therefore, we have analysed foetal three arteries: umbilical artery, middle cerebral artery and renal artery after determining the normal range for the analysed parameters. 1. Comparison of the obtained blood flow indices (S/D, RI, PI) in the umbilical artery, middle cerebral artery and renal artery of foetuses from normal and complicated full-term pregnancies. 2. Determination of indices: umbilical-cerebral and renal-cerebral in normal and pathological pregnancy. 3. Evaluation of feasibility of the analysed flow parameters for the detection of intrauterine foetal hypoxia. We have examined 151 women, who were divided into control group--101 pregnant women with normal pregnancy and study group--50 pregnant women with complicated pregnancy. All pregnant women underwent ultrasound examination using the Hitachi EUB 515 C (Japan) scanner with 3.5 MHz convex probe, connected to the colour pulsed Doppler. The study consisted of the biometric measurements and evaluation of the spectrum of blood flow in the umbilical artery, middle cerebral artery and renal artery. We have determined following indices: a) systolic-diastolic ratio S/D, resistance index RI, pulsatility index PI, b) umbilical-cerebral ratio P/M. (PI ua/PI mca), renal--cerebral ratio N/M (PI ra/PI mca). Statistically significant difference was found between the study and control groups for all the flow indices assessed (S/D, RI, PI) for the middle cerebral artery, for the indices P/M and N/M. (p < 0.001) and pulsatility index in the renal artery (p < 0.01). Similar, although slightly smaller difference (p < 0.05) was seen for the values of flow parameters in the umbilical artery. 1) Evaluation of blood flow in the middle cerebral artery, and in

Blood-conservation techniques for coronary-artery bypass surgery at a private hospital.

Science.gov (United States)

Davies, M J; Picken, J; Buxton, B F; Fuller, J A

1988-11-21

The utilization of homologous blood and blood products was recorded in 100 consecutive patients who underwent primary coronary-artery bypass surgery. Nine patients underwent saphenous-vein grafts only, 55 patients underwent a single internal-mammary-artery graft that was supplemented by vein grafts and 36 patients underwent bilateral internal-mammary-artery grafts and vein grafts. All patients underwent normovolaemic haemodilution, and autologous blood was collected before bypass surgery. Residual blood was collected from the cardiopulmonary bypass machine and was washed and concentrated in a cell processor, and blood also was scavenged postoperatively from the mediastinal drainage tubes as methods to conserve blood. The mean (+/- SD) utilization of homologous blood was 1.3 +/- 1.5 units with 0.2 +/- 0.7 units of fresh-frozen plasma being used, and 0.8 +/- 2.1 units of platelets being used. The utilization of homologous blood was not different among the three different methods of coronary-artery bypass surgery, but patients who underwent bilateral internal-mammary-artery grafts suffered a greater postoperative loss of blood than did those patients who underwent saphenous-vein grafts or single internal-mammary-artery grafts. A comparison of patients who were taking aspirin or a non-steroidal anti-inflammatory drug preoperatively with those patients who were not showed no difference in the utilization of homologous blood but a statistically-significant difference was found in the loss of blood postoperatively.

Middle cerebral artery blood velocity during running

NARCIS (Netherlands)

Lyngeraa, T. S.; Pedersen, L. M.; Mantoni, T.; Belhage, B.; Rasmussen, L. S.; van Lieshout, J. J.; Pott, F. C.

2013-01-01

Running induces characteristic fluctuations in blood pressure (BP) of unknown consequence for organ blood flow. We hypothesized that running-induced BP oscillations are transferred to the cerebral vasculature. In 15 healthy volunteers, transcranial Doppler-determined middle cerebral artery (MCA)

Erythrocyte 2,3-diphosphoglycerate depletion associated with hypophosphatemia detected by routine arterial blood gas analysis.

Science.gov (United States)

Larsen, V H; Waldau, T; Gravesen, H; Siggaard-Andersen, O

1996-01-01

To describe a clinical case where an extremely low erythrocyte 2,3-diphosphoglycerate concentration (2,3-DPG) was discovered by routine blood gas analysis supplemented by computer calculation of derived quantities. The finding of a low 2,3-DPG revealed a severe hypophosphatemia. Open uncontrolled study of a patient case. Intensive care observation during 41 days. A 44 year old woman with an abdominal abscess. Surgical drainage, antibiotics and parenteral nutrition. daily routine blood gas analyses with computer calculation of the hemoglobin oxygen affinity and estimation of the 2,3-DPG. An abrupt decline of 2,3-DPG was observed late in the course coincident with a pronounced hypophosphatemia. The fall in 2,3-DPG was verified by enzymatic analysis. 2,3-DPG may be estimated by computer calculation of routine blood gas data. A low 2,3-DPG which may be associated with hypophosphatemia causes an unfavorable increase in hemoglobin oxygen affinity which reduces the oxygen release to the tissues.

ABO Blood Group and Risk of Thromboembolic and Arterial Disease

DEFF Research Database (Denmark)

Vasan, Senthil K; Rostgaard, Klaus; Majeed, Ammar

2016-01-01

BACKGROUND: ABO blood groups have been shown to be associated with increased risks of venous thromboembolic and arterial disease. However, the reported magnitude of this association is inconsistent and is based on evidence from small-scale studies. METHODS AND RESULTS: We used the SCANDAT2...... (Scandinavian Donations and Transfusions) database of blood donors linked with other nationwide health data registers to investigate the association between ABO blood groups and the incidence of first and recurrent venous thromboembolic and arterial events. Blood donors in Denmark and Sweden between 1987......-up. Compared with blood group O, non-O blood groups were associated with higher incidence of both venous and arterial thromboembolic events. The highest rate ratios were observed for pregnancy-related venous thromboembolism (incidence rate ratio, 2.22; 95% confidence interval, 1.77-2.79), deep vein thrombosis...

Autologous Transfusion of Stored Red Blood Cells Increases Pulmonary Artery Pressure

Science.gov (United States)

Pinciroli, Riccardo; Stowell, Christopher P.; Wang, Lin; Yu, Binglan; Fernandez, Bernadette O.; Feelisch, Martin; Mietto, Cristina; Hod, Eldad A.; Chipman, Daniel; Scherrer-Crosbie, Marielle; Bloch, Kenneth D.; Zapol, Warren M.

2014-01-01

Rationale: Transfusion of erythrocytes stored for prolonged periods is associated with increased mortality. Erythrocytes undergo hemolysis during storage and after transfusion. Plasma hemoglobin scavenges endogenous nitric oxide leading to systemic and pulmonary vasoconstriction. Objectives: We hypothesized that transfusion of autologous blood stored for 40 days would increase the pulmonary artery pressure in volunteers with endothelial dysfunction (impaired endothelial production of nitric oxide). We also tested whether breathing nitric oxide before and during transfusion could prevent the increase of pulmonary artery pressure. Methods: Fourteen obese adults with endothelial dysfunction were enrolled in a randomized crossover study of transfusing autologous, leukoreduced blood stored for either 3 or 40 days. Volunteers were transfused with 3-day blood, 40-day blood, and 40-day blood while breathing 80 ppm nitric oxide. Measurements and Main Results: The age of volunteers was 41 ± 4 years (mean ± SEM), and their body mass index was 33.4 ± 1.3 kg/m2. Plasma hemoglobin concentrations increased after transfusion with 40-day and 40-day plus nitric oxide blood but not after transfusing 3-day blood. Mean pulmonary artery pressure, estimated by transthoracic echocardiography, increased after transfusing 40-day blood (18 ± 2 to 23 ± 2 mm Hg; P transfusing 3-day blood (17 ± 2 to 18 ± 2 mm Hg; P = 0.5). Breathing nitric oxide decreased pulmonary artery pressure in volunteers transfused with 40-day blood (17 ± 2 to 12 ± 1 mm Hg; P Transfusion of autologous leukoreduced blood stored for 40 days was associated with increased plasma hemoglobin levels and increased pulmonary artery pressure. Breathing nitric oxide prevents the increase of pulmonary artery pressure produced by transfusing stored blood. Clinical trial registered with www.clinicaltrials.gov (NCT 01529502). PMID:25162920

PREDICTION OF BLOOD PATTERN IN S-SHAPED MODEL OF ARTERY UNDER NORMAL BLOOD PRESSURE

Directory of Open Access Journals (Sweden)

Mohd Azrul Hisham Mohd Adib

2013-06-01

Full Text Available Athletes are susceptible to a wide variety of traumatic and non-traumatic vascular injuries to the lower limb. This paper aims to predict the three-dimensional flow pattern of blood through an S-shaped geometrical artery model. This model has created by using Fluid Structure Interaction (FSI software. The modeling of the geometrical S-shaped artery is suitable for understanding the pattern of blood flow under constant normal blood pressure. In this study, a numerical method is used that works on the assumption that the blood is incompressible and Newtonian; thus, a laminar type of flow can be considered. The authors have compared the results with a previous study with FSI validation simulation. The validation and verification of the simulation studies is performed by comparing the maximum velocity at t = 0.4 s, because at this time, the blood accelerates rapidly. In addition, the resulting blood flow at various times, under the same boundary conditions in the S-shaped geometrical artery model, is presented. The graph shows that velocity increases linearly with time. Thus, it can be concluded that the flow of blood increases with respect to the pressure inside the body.

Neonatal blood gas sampling methods

African Journals Online (AJOL)

You work in a regional neonatal intensive care unit. An 8-day-old ... The baby was born at 28 weeks' gestation with a birth weight of 1. 100 g. ... and arterial blood taken from indwelling arterial lines.2-4 However, even ... tal age of 48 - 72 hours.

Respiratory properties of blood and arterial blood gases in the tegu lizard: effects of temperature and hypercapnia.

Science.gov (United States)

Wood, S C; Glass, M L; Andersen, N A; Heisler, N

1987-01-01

The effects of body temperature and hypercapnia (7% inspired CO2) on arterial blood gases, plasma pH, and the characteristics of the blood oxygen dissociation curve were determined in Tegu lizards (Tupinambis nigropunctatus). Arterial pH fell from 7.59 to 7.50 when body temperature was increased from 25 to 35 degrees C. The pH/temperature coefficient (delta pH/delta t = -0.009 U/degrees C) was half of that predicted on the basis of 'constant relative alkalinity' and the alphastat hypothesis. The fall in plasma pH resulted from a decrease in plasma [HCO3-], and a rise in plasma Pco2. The O2 affinity of Tegu blood, expressed by the partial pressure at half saturation (P50), decreased with temperature in vitro from 42.3 to 49.6 torr at pH 7.4. The apparent enthalpy (delta H = -3.1 kcal/mol) is about 1/4 of that of human blood. In vivo, the arterial blood oxygen saturation decreased from 89% at 25 degrees to 82% at 35 degrees C. Arterial Po2 increased from 61 to 71 torr as expected from the right-shift of the oxygen dissociation curve. During environmental hypercapnia (7% CO2, 21% O2, 72% N2 inspired concentrations), arterial pH decreased to 7.28. Arterial O2 saturation remained constant and arterial Po2 increased from 61 to 85 torr due to the right-shift of the oxygen dissociation curve. The comparatively small effect of changes in temperature on the oxygen affinity of Tegu blood (directly according to the delta H value, and indirectly via changes in blood pH) results in a relatively small right shift of the oxygen dissociation curve, and accordingly in relatively high arterial and tissue Po2 values also at higher temperatures.

[Basic laws of blood screw motion in human common carotid arteries].

Science.gov (United States)

Kulikov, V P; Kirsanov, R I

2008-08-01

The basic laws of blood screw motion in common carotid arteries in people were determined by means of modern ultrasound techniques for the first time. 92 healthy adults, aged 18-30, were examined. The blood flow in the middle one-third of common carotid arteries was registered by means of Color Doppler Imaging and impulse Doppler with the help of ultrasound Medison 8000EX scanner by linear transducer of 5-9 MHz. The steady registration of blood screw motion in both common carotid arteries in Color Doppler Imaging regimen was observed in 54.3 % of cases. The direction of screw stream rotation in most cases (54%) was multi-directed: in the right common carotid artery it was right, in the left common carotid artery--left (48%), and in 6% of cases it was reverse. For 46% of cases blood rotation in both common carotid arteries was one-directed (26%--right, 20%--left). The velocity parameters of rotation component of blood motion were determined, maximum velocity being 19.68 +/- 5.84 cm/sec, minimum--4.57 +/- 2.89 cm/sec, average--7.48 +/- 2.49 cm/sec, angular--10.7 +/- 2.49 sec(-1). The rated velocity of blood cells motion in screw motion with regard of screw current lines to the vessel vertical axis makes up from 158.67 +/- 32.79 to 224.39 +/- 46.37 cm/sec.

Improved calculation of the equilibrium magnetization of arterial blood in arterial spin labeling

DEFF Research Database (Denmark)

Ahlgren, André; Wirestam, Ronnie; Knutsson, Linda

2018-01-01

PURPOSE: To propose and assess an improved method for calculating the equilibrium magnetization of arterial blood ( M0a), used for calibration of perfusion estimates in arterial spin labeling. METHODS: Whereas standard M0a calculation is based on dividing a proton density-weighted image by an ave...

Distribution of ABO Blood Groups and Coronary Artery Calcium.

Science.gov (United States)

Wang, Yao; Zhou, Bing-Yang; Zhu, Cheng-Gang; Guo, Yuan-Lin; Wu, Na-Qiong; Qing, Ping; Gao, Ying; Liu, Geng; Dong, Qian; Li, Jian-Jun

2017-06-01

ABO blood groups have been confirmed to be associated with cardiovascular diseases such as coronary artery disease. However, whether ABO blood group is correlated with coronary artery calcium (CAC) is still unknown. 301 patients with coronary artery calcium score (CACS) assessed by computed tomography were consecutively enrolled and divided into two groups: with calcium group (CACS>0, n=104) and without calcium group (CACS=0, n=197). Distribution of ABO blood groups was evaluated between the two groups. The percentage of A blood type was significantly higher (p=0.008) and O blood type was significantly lower (p=0.037) in the calcium group. Univariate regression analysis showed that age, total cholesterol, low density lipoprotein cholesterol, high-sensitivity C-reactive protein, A blood type were positively correlated with CAC, and O blood type was inversely associated with CAC. Multivariate regression analysis showed that A blood type was independently associated with CAC (odds ratio: 2.217, 95% confidence interval: 1.260-3.900, p=0.006) even after further adjustment for variables that were clearly different between the two groups. Our data has suggested for the first time that A blood type was an independent risk marker for CAC. Copyright © 2016 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

MR measurement of coronary arterial blood flow velocity. Evaluation of age, stenosis and drugs as factors affecting coronary blood flow

International Nuclear Information System (INIS)

Taoka, Yoshiaki; Harada, Masafumi; Nishitani, Hiromu; Yukinaka, Michiko; Nomura, Masahiro

1998-01-01

Coronary arterial blood flow velocity was measured using MRI. Two types of phase contrast methods were used for the measurements, one of which exhibited good resolving power whereas the other provided more distinct images acquired while the subject patients held their breath. Before measuring coronary arterial blood flow velocity, accuracy of the two phase contrast methods was evaluated using a phantom. The results obtained with both methods largely agreed with the values obtained using the phantom. Using both methods, the patterns of coronary arterial blood flow over one cardiac cycle were essentially identical. A peak was noted in late systole or in early diastole in the right coronary artery, whereas in the left coronary artery, a peak was noted somewhat later in diastole. In healthy volunteers, no significant difference in the maximal flow velocity in the coronary arteries was found from one age group to another. Among patients with coronary arterial stenosis, coronary arterial blood flow velocity central to the area of stenosis was lower than that observed in the healthy volunteers. Coronary arterial blood flow velocity was observed to decrease after administration of isosorbide dinitrate and increased following administration of nifedipine. (author)

The origin of extrarenal arterial blood supply of renal malignancy and its clinical value

International Nuclear Information System (INIS)

Du Duanming; Tong Xiaoqiang; Song Li; Zou Yinghua

2007-01-01

Objective: To study the mechanisms of extrarenal arterial blood supply of renal malignancy for its interventional therapy. Methods: Routine abdominal aortography and selective questionable feeding arteriography were performed in 141 patients with renal malignancy. The characteristics and formation mechanisms of extrarenal arterial blood supply for renal malignancy were analyzed. Results: Of the 141 patients, extrarenal arterial blood supply of renal malignancy were found in 51 patients and there were 87 branchs. The breakthrough of renal capsule with malignancy were found in those 51 patients. No extrarenal arterial blood supply of renal malignancy was found in 90 patients, including 50 patients with and 40 patients without the renal capsule breakthrough with malignancy. The emerge of extrarenal arterial blood supply of renal malignancy were significantly different (χ 2 =31.64, P<0.01) between the patients with and without the breakthrough of renal capsule with malignancy. The origin of extrarenal arterial blood supply were correlated with the location of the tumor. Conclusions: It is important to determine the origin of the extrarenal arterial blood supply in renal malignancy for its interventional therapy. (authors)

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....... Arterialization was generated by 10 min heating of the contralateral hand. Concentrations of albumin, C-reactive protein (CRP), tissue-type plasminogen activator (t-PA), plasminogen activator inhibitor type 1 (PAI-1), and von Willebrand factor (vWF) were measured by validated assays. Concentrations of albumin......, CRP, and vWF were significantly lower in arterialized than in venous blood (albumin: 43.8 g/l and 44.8 g/l, P = 0.02). Differences in CRP and vWF became insignificant after adjusting for albumin. The endogenous thrombin potential (ETP) was significantly higher in arterialized than in venous blood...

A common humoral background of intraocular and arterial blood pressure dysregulation.

Science.gov (United States)

Skrzypecki, Janusz; Grabska-Liberek, Iwona; Przybek, Joanna; Ufnal, Marcin

2018-03-01

It has been postulated that intraocular pressure, an important glaucoma risk factor, correlates positively with arterial blood pressure (blood pressure). However, results of experimental and clinical studies are often contradictory. It is hypothesized that, in some hypertensive patients, disturbances in intraocular pressure regulation may depend on biological effects of blood borne hormones underlying a particular type of hypertension, rather than on blood pressure level itself. This review compares the effects of hormones on blood pressure and intraocular pressure, in order to identify a hormonal profile of hypertensive patients with an increased risk of intraocular pressure surge. The PUBMED database was searched to identify pre-clinical and clinical studies investigating the role of angiotensin II, vasopressin, adrenaline, noradrenaline, prostaglandins, and gaseous transmitters in the regulation of blood pressure and intraocular pressure. Studies included in the review suggest that intraocular and blood pressures often follow a different pattern of response to the same hormone. For example, vasopressin increases blood pressure, but decreases intraocular pressure. In contrast, high level of nitric oxide decreases blood pressure, but increases intraocular pressure. Arterial hypertension is associated with altered levels of blood borne hormones. Contradicting results of studies on the relationship between arterial hypertension and intraocular pressure might be partially explained by diverse effects of hormones on arterial and intraocular pressures. Further studies are needed to evaluate if hormonal profiling may help to identify glaucoma-prone patients.

Straight versus tortuous retinal arteries in relation to blood pressure and genetics

DEFF Research Database (Denmark)

Taarnhøj, N C B B; Munch, I C; Sander, B

2008-01-01

dizygotic same-sex healthy twin pairs, aged 20 to 46 years, who were characterised by determination of retinal vessel diameters, arterial blood pressure, blood glucose, body mass index, smoking habits and retinal arterial tortuosity, using a three-level grading scale (straight, wavy, tortuous). Heritability......BACKGROUND/AIMS: To assess the relative influence of genetic and environmental factors on retinal arterial tortuosity and the association between tortuosity and various health indices in healthy young to middle-aged persons. METHODS: This cross-sectional study included 57 monozygotic and 52...... accounting for the remaining 18% (CI(95 )8, 36%). Increasing values of mean arterial blood pressure and body mass index were both associated with decreasing levels of retinal arterial tortuosity. CONCLUSION: There was a large variation in tortuosity of retinal arteries in these healthy subjects...

Predicting Electrocardiogram and Arterial Blood Pressure Waveforms with Different Echo State Network Architectures

Science.gov (United States)

2014-11-01

Predicting Electrocardiogram and Arterial Blood Pressure Waveforms with Different Echo State Network Architectures Allan Fong, MS1,3, Ranjeev...the medical staff in Intensive Care Units. The ability to predict electrocardiogram and arterial blood pressure waveforms can potentially help the...type of neural network for mining, understanding, and predicting electrocardiogram and arterial blood pressure waveforms. Several network

Ammonia concentrations in arterial blood, venous blood, and cerebrospinal fluid of dogs with and without congenital extrahepatic portosystemic shunts.

Science.gov (United States)

Or, Matan; Devriendt, Nausikaa; Kitshoff, Adriaan M; Peremans, Kathelijne; Vandermeulen, Eva; Paepe, Dominique; Polis, Ingeborgh; Martlé, Valentine; de Rooster, Hilde

2017-11-01

OBJECTIVE To compare ammonia concentrations in arterial blood, venous blood, and CSF samples of dogs with and without extrahepatic portosystemic shunts (EHPSS). ANIMALS 19 dogs with congenital EHPSS and 6 healthy control dogs. PROCEDURES All dogs underwent a physical examination and then were anesthetized for transsplenic portal scintigraphy to confirm the presence or absence of EHPSS. While dogs were anesthetized, arterial and venous blood samples and a CSF sample were simultaneously collected for determination of ammonia concentration, which was measured by use of a portable blood ammonia analyzer (device A) and a nonportable biochemical analyzer (device B). Results were compared between dogs with EHPSS and control dogs. RESULTS Arterial, venous, and CSF ammonia concentrations for dogs with EHPSS were significantly greater than those for control dogs. For dogs with EHPSS, ammonia concentrations in both arterial and venous blood samples were markedly increased from the reference range. There was a strong positive correlation between arterial and venous ammonia concentrations and between blood (arterial or venous) and CSF ammonia concentrations. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that blood and CSF ammonia concentrations in dogs with EHPSS were greater than those for healthy dogs and were strongly and positively correlated, albeit in a nonlinear manner. This suggested that the permeability of the blood-brain barrier to ammonia may be abnormally increased in dogs with EHPSS, but further investigation of the relationship between blood or CSF ammonia concentration and clinical signs of hepatic encephalopathy or the surgical outcome for dogs with EHPSS is warranted.

SU-G-IeP1-12: Size Selective Arterial Cerebral Blood Volume Mapping Using Multiple Inversion Time Arterial Spin Labeling

Energy Technology Data Exchange (ETDEWEB)

Jung, Y; Johnston, M; Whitlow, C [Wake Forest School of Medicine, Winston-salem, NC (United States); Liu, H [UT MD Anderson Cancer Center, Houston, TX (United States)

2016-06-15

Purpose: To demonstrate the feasibility of a novel method for size specific arterial cerebral blood volume (aCBV) mapping using pseudo-continuous arterial spin labeling (PCASL), with multiple TI. Methods: Multiple PCASL images were obtained from a subject with TI of [300, 400, 500, 600, 700, 800, 900, 1000, 1500, 2000, 2500, 3000, 3500, 4000] ms. Each TI pair was averaged six times. Two scans were performed: one without a flow crusher gradient and the other with a crusher gradient (10cm/s in three directions) to remove signals from large arteries. Scan times were 5min. without a crusher gradient and 5.5 min with a crusher gradient. Non-linear fitting algorithm finds the minimum mean squared solution of per-voxel based aCBV, cerebral blood flow, and arterial transit time, and fits the data into a hemodynamic model that represents superposition of blood volume and flow components within a single voxel. Results: aCBV maps with a crusher gradient represent signals from medium and small sized arteries, while those without a crusher gradient represent signals from all sized arteries, indicating that flow crusher gradients can be effectively employed to achieve size-specific aCBV mapping. Regardless of flow crusher, the CBF and ATT maps are very similar in appearance. Conclusion: Quantitative size selective blood volume mapping controlled by a flow crusher is feasible without additional information because the ASL quantification process doesn’t require an arterial input function measured from a large artery. The size specific blood volume mapping is not interfered by sSignals from large arteries do not interfere with size specific aCBV mapping in the applications of interest in for applications in which only medium or small arteries are of interest.

Can flavonoid-rich chocolate modulate arterial elasticity and pathological uterine artery Doppler blood flow in pregnant women? A pilot study.

Science.gov (United States)

von Wowern, Emma; Olofsson, Per

2018-09-01

Dark chocolate has shown beneficial effects on cardiovascular health and might also modulate hypertensive complications in pregnancy and uteroplacental blood flow. Increased uteroplacental resistance is associated with systemic arterial stiffness. We aimed to investigate the short-term effect of flavonoid-rich chocolate on arterial stiffness and Doppler blood flow velocimetry indexes in pregnant women with compromised uteroplacental blood flow. Doppler blood flow velocimetry and digital pulse wave analysis (DPA) were performed in 25 women pregnant in the second and third trimesters with uterine artery (UtA) score (UAS) 3-4, before and after 3 days of ingestion of chocolate with high flavonoid and antioxidant contents. UtA pulsatility index (PI), UtA diastolic notching, UAS (semiquantitative measure of PI and notching combined), and umbilical artery PI were calculated, and DPA variables representing central and peripheral maternal arteries were recorded. Mean UtA PI (p = .049) and UAS (p = .025) significantly decreased after chocolate consumption. There were no significant changes in UtA diastolic notching or any DPA indexes of arterial stiffness/vascular tone. Chocolate may have beneficial effects on the uteroplacental circulation, but in this pilot study, we could not demonstrate effects on arterial vascular tone as assessed by DPA.

Biochemical characterization of blood plasma of coronary artery ...

Indian Academy of Sciences (India)

This study aimed to investigate the biochemical profile of blood plasma of patients with coronary artery disease (CAD) and angiographically normal subjects (controls) to determine biomarkers for their differentiation. In this double blind study, 5 mL venous blood was drawn before angiography from CAD patients (n=60) and ...

[Conjunct changes in the resistance and engorgement of the cerebral vessels in shifts in the blood gas composition].

Science.gov (United States)

Krasil'nikov, V G; Artem'eva, A I

1982-08-01

In anesthetized cats, under perfusion and with constant volume of the hemodynamically isolated brain, hypercapnia and hypoxia led to a decrease of cerebral vessels resistance and to a reduction of the brain blood flow, whereas a decrease in the PCO2 and an increase in the PO2 in the blood exerted on opposite effect. The different responses of the vessels had some similar features in respect to threshold changes of the PCO2 and PO2, to potentiation of effects of both parts of the brain vascular system on increased shifts of the blood gas tension, to greater sensitivity of both parts to PCO2 changes, to effect of the blood gas tension on reactivity of both parts to noradrenaline. The authors suggest a possibility of alterations of the filter-absorption interrelationships in the brain due to different responses of arterial and venous vessels to changes of the blood gas tension.

Time course and recovery of arterial blood gases during exacerbations in adults with Cystic Fibrosis.

LENUS (Irish Health Repository)

Waterhouse, D F

2012-02-01

INTRODUCTION: Hypoxia and hypercapnia are closely linked to morbidity and mortality in patients with Cystic Fibrosis (CF). The aims of this study were to describe the changes in blood gases during and following an acute pulmonary exacerbation in adults with CF. METHODS: We performed a prospective observational study of patients with CF admitted for management of an acute exacerbation. Blood gas and spirometric analysis was performed on admission, throughout the treatment period, and 31 days after discharge (day 45). RESULTS: At presentation, eight of nineteen patients had evidence of either hypoxia (PaO(2)<8 kPa) and\\/or hypercapnia (PaCO(2)>6.6 kPa). Blood gas parameters stabilized following two weeks of intravenous antibiotic therapy, with little difference evident in between treatment completion and subsequent review following discharge. Hypercapnia reversed in three patients, with persistent hypercapnia evident in two patients. CONCLUSION: In our study group, hypoxemia and hypercapnia were frequently observed at presentation of the acute exacerbation. Blood gases stabilized following two weeks of intravenous antibiotic therapy, with arterial PCO(2) one month following hospital discharge generally similar to that at time of discharge.

Noninvasive 24-hour ambulatory arterial blood pressure monitoring in cirrhosis

DEFF Research Database (Denmark)

Møller, Søren; Wiinberg, N; Henriksen, Jens Henrik

1995-01-01

Cirrhotic patients have disturbed systemic hemodynamics with reduced arterial blood pressure, but this has not been investigated during daily activity and sleep. Systolic (SBP), diastolic (DBP), and mean arterial blood pressure (MAP), and heart rate (HR) were measured by an automatic ambulant...... device for monitoring blood pressure in 35 patients with cirrhosis and 35 healthy matched controls. During the daytime, SBP, DBP, and MAP were significantly lower in the patients than in the controls (median 118 vs. 127; 70 vs. 78; 86 vs. 94 mm Hg, P blood pressures...... were almost similar in the two groups (108 vs. 110; 65 vs. 67; 78 vs. 82 mm Hg, NS). Conversely, HR was significantly higher in the patients both in the daytime (86 vs. 72/min, P blood pressure and HR from daytime...

Investigation of spiral blood flow in a model of arterial stenosis

OpenAIRE

Paul, M.C.; Larman, A.

2009-01-01

The spiral component of blood flow has both beneficial and detrimental effects in human circulatory system [Stonebridge PA, Brophy CM. Spiral laminar flow in arteries? Lancet 1991; 338: 1360–1]. We investigate the effects of the spiral blood flow in a model of three-dimensional arterial stenosis with a 75% cross-sectional area reduction at the centre by means of computational fluid dynamics (CFD) techniques. The standard κ–ω model is employed for simulation of the blood flow for the...

Relationship of daily arterial blood pressure monitoring readings and arterial stiffness profile in male patients with chronic obstructive pulmonary disease combined with arterial hypertension

Directory of Open Access Journals (Sweden)

Karoli N.A.

2013-06-01

Full Text Available The aim of the study was to determine correlation between arterial blood pressure daily rhythm and daily profile of arterial stiffness in male patients with chronic obstructive pulmonary disease (COPD and arterial hypertension. Materials et methods: Prospective investigation comprised 45 male patients with COPD and arterial hypertension. Individuals of 40 years younger and 80 years elder, patients with diabetes, stroke, angina pectoris, or heart infarction, vascular diseases, and exacerbation of chronic disease, bronchial and pulmonary diseases of other etiology were excluded from the analyses. Comparison group included 47 patients with essential arterial hypertension and without chronic respiratory diseases closely similar on general parameters with patients from main clinical series. Twenty-four-hour arterial blood pressure monitoring (ABPM and daily arterial stiffness monitoring were performed using BPLab® MnSDP-2 apparatus (Petr Telegin, Russian Federation. Results: Patients with COPD combined with arterial hypertension with raised arterial stiffness measures prevail over individuals in essential hypertension group. There is pathological alteration of the ABPM circadian rhythm and raised «Pressure load» values in raised arterial stiffness group. Conclusion: We found ABPM raised parameters in patients with COPD and arterial hypertension. It confirms necessity of ABPM in daily arterial stiffness assessment in patients with COPD.

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

A new method for noninvasive measurement of pulmonary gas exchange using expired gas.

Science.gov (United States)

West, John B; Prisk, G Kim

2018-01-01

Measurement of the gas exchange efficiency of the lung is often required in the practice of pulmonary medicine and in other settings. The traditional standard is the values of the PO2, PCO2, and pH of arterial blood. However arterial puncture requires technical expertise, is invasive, uncomfortable for the patient, and expensive. Here we describe how the composition of expired gas can be used in conjunction with pulse oximetry to obtain useful measures of gas exchange efficiency. The new procedure is noninvasive, well tolerated by the patient, and takes only a few minutes. It could be particularly useful when repeated measurements of pulmonary gas exchange are required. One product of the procedure is the difference between the PO2 of end-tidal alveolar gas and the calculated PO2 of arterial blood. This measurement is related to the classical alveolar-arterial PO2 difference based on ideal alveolar gas. However that traditional index is heavily influenced by lung units with low ventilation-perfusion ratios, whereas the new index has a broader physiological basis because it includes contributions from the whole lung. Copyright © 2017 Elsevier B.V. All rights reserved.

Relationship between vertebral artery blood flow in different head positions and vertigo.

Science.gov (United States)

Araz Server, Ela; Edizer, Deniz Tuna; Yiğit, Özgür; Yasak, Ahmet Görkem; Erdim, Çağrı

2018-01-01

To identify the vertebral artery blood flow in different head positions in patients with positional vertigo with no specific diagnosis. Patients with history of vestibular symptoms associated with changes in head position were enrolled into the study. Healthy volunteers were evaluated as control group. Doppler ultrasonography examination of the cervical segment of the vertebral arteries was performed under three different head positions: (i) supine position, (ii) head hyperextended and rotated to the right side and (iii) head hyperextended and rotated to the left side. In the study group, right and left vertebral artery blood flow was significantly lower in the ipsilateral hyperextended position compared to standard supine position (respectively p = .014; p = .001), but did not differ significantly when compared between the standard supine and contralateral hyperextended positions (respectively = .959; p = .669). In the control group, left and right vertebral artery blood flow did not differ significantly when the head was hyperextended to the right or left sides compared to standard supine position (p > .05). Our data demonstrated that the etiology of vestibular complaints in patients with undiagnosed positional vertigo might be related to impairment in vertebral artery blood flow according to head positions.

Arterial cord blood lactate at birth correlates with duration of pushing efforts.

Science.gov (United States)

Dessolle, Lionel; Lebrec, Jeremie; Daraï, Emile

2010-01-01

To evaluate the impact of the duration of pushing efforts on arterial cord blood lactate values. This was a prospective observational study of 124 consecutive normal vaginal deliveries in a tertiary teaching hospital. Arterial cord blood lactate was determined immediately at birth with a test strip method. Univariate and multivariate analyses were performed to check for clinical determinants of lactate levels. The main measure was lactate according to the duration of pushing efforts. Arterial cord lactates increased significantly and were strongly correlated with the duration of pushing efforts, independent of gestational age and birthweight. Women pushing for more than 20 min had higher arterial cord blood lactates (4.9 +/- 1.4 vs. 3.3 +/- 1.16 mM, respectively) and a higher rate of lactates >6 mM (18 vs. 3%) than those pushing for less than 20 min. At normal delivery, arterial cord blood lactates increase significantly with the duration of pushing efforts. Pushing for more than 20 min is associated with an increased risk of metabolic acidosis in the neonate. Further studies are required to evaluate the clinical significance of these observations. 2009 S. Karger AG, Basel.

Blood flows in the maxillocarotid anastomoses and internal carotid artery of conscious dogs.

Science.gov (United States)

Lee, M C; Reid, I A; Ramsay, D J

1986-06-01

Although the external carotid artery is known to contribute to the cerebral blood flow in anesthetized dogs, quantitative information on the anastomoses and their role in conscious dogs is lacking. This study was carried out to determine blood flows in these anastomoses and the internal carotid artery, and also to examine the functional significance of the anastomoses in conscious dogs. Fifteen-micron radioactive microspheres were injected into common and external carotid arteries of four conscious dogs through chronically implanted catheters. Blood flows were determined by the reference sample method and by comparing microsphere distributions in the brain and the masseter muscle. Blood flows were estimated to be 140 +/- 32, 7.7 +/- 1.4, and 3.3 +/- 1.1 ml/minute (mean +/- SD) in the common carotid artery, internal carotid artery, and anastomoses on each side, respectively. Additional evidence indicated that the anastomotic flow so determined was primarily the flow in the anastomotic artery. Humoral responses to angiotensin II infusions were also studied in conscious dogs. External carotid angiotensin increased plasma 11-hydroxycorticosteroid concentration (used as an index of ACTH secretion) but did not increase plasma vasopressin concentration to the same extent as common carotid infusion. Therefore, the external carotid artery is functionally important in perfusing the brain in conscious dogs.

Differential increases in blood flow velocity in the middle cerebral artery after tourniquet deflation during sevoflurane, isoflurane or propofol anaesthesia.

Science.gov (United States)

Kadoi, Y; Kawauchi, C H; Ide, M; Saito, S; Mizutani, A

2009-07-01

The purpose of this study was to examine the comparative effects of sevoflurane, isoflurane or propofol on cerebral blood flow velocity after tourniquet deflation during orthopaedic surgery. Thirty patients undergoing elective orthopaedic surgery were randomly divided into sevoflurane, isoflurane and propofol groups. Anaesthesia was maintained with sevoflurane, isoflurane or propofol infusion in 33% oxygen and 67% nitrous oxide, in whatever concentrations were necessary to keep bispectral index values between 45 and 50. Ventilatory rate or tidal volume was adjusted to target PaCO2 of 35 mmHg. A 2.0 MHz transcranial Doppler probe was attached to the patient's head at the temporal window and mean blood flow velocity in the middle cerebral artery was continuously measured. The extremity was exsanguinated with an Esmarch bandage and the pneumatic tourniquet was inflated to a pressure of 450 mmHg. Arterial blood pressure, heart rate, velocity in the middle cerebral artery and arterial blood gas analysis were measured every minute for 10 minutes after release of the tourniquet in all three groups. Velocity in the middle cerebral artery in the three groups increased for five minutes after tourniquet deflation. Because of the different cerebrovascular effects of the three agents, the degree of increase in flow velocity in the isoflurane group was greater than in the other two groups, the change in flow velocity in the propofol group being the lowest (at three minutes after deflation 40 +/- 7%, 32 +/- 6% and 28 +/- 10% in the isoflurane, sevoflurane and propofol groups respectively, P < 0.05).

Clinical observations on the effect of carotid artery occlusion on cerebral blood flow mapped by xenon computed tomography and its correlation with carotid artery back pressure

International Nuclear Information System (INIS)

Steed, D.L.; Webster, M.W.; DeVries, E.J.; Jungreis, C.A.; Horton, J.A.; Sehkar, L.; Yonas, H.

1990-01-01

Xenon computed tomographic cerebral blood flow mapping was correlated with internal carotid artery stump pressures and clinical neurologic assessment during temporary internal carotid artery occlusion. One hundred fourteen patients with skull base tumors or intracranial aneurysms potentially requiring carotid resection or ligation underwent angiography, xenon CT cerebral blood flow mapping, and internal carotid artery blood pressure monitoring. The internal carotid artery was then temporarily occluded with a balloon catheter, stump pressure was measured through the catheter, and the xenon CT cerebral blood flow mapping was repeated. Adequate xenon CT cerebral blood flow was defined as greater than 30 cc/100 gm/min. All patients had normal xenon CT cerebral blood flow before internal carotid artery occlusion. During internal carotid artery occlusion, xenon CT cerebral blood flow was found to be normal (group I, 40 patients), globally reduced but still within the normal range (group II, 50 patients), or low in the distribution of the ipsilateral middle cerebral artery (group III, 13 patients). With balloon occlusion, an immediate neurologic deficit developed in 11 patients (9%) requiring deflation of the balloon preceding xenon CT cerebral blood flow measurement (group IV). In group I internal carotid artery blood pressure was 128 mm Hg. (range 85 to 171 mm Hg) with stump pressure 86 mm Hg (range 46 to 125 mm Hg). In group II internal carotid artery blood pressure was 130 mm Hg. (range 78 to 199 mm Hg), with stump pressure 86 mm Hg (range 31 to 150 mm Hg)

CT perfusion of the liver during selective hepatic arteriography. Pure arterial blood perfusion of liver tumor and parenchyma

International Nuclear Information System (INIS)

Komemushi, Atsushi; Tanigawa, Noboru; Kojima, Hiroyuki; Kariya, Shuji; Sawada, Satoshi

2003-01-01

The purpose of this study was to quantify pure arterial blood perfusion of liver tumor and parenchyma by using CT perfusion during selective hepatic arteriography. A total of 44 patients underwent liver CT perfusion study by injection of contrast medium via the hepatic artery. CT-perfusion parameters including arterial blood flow, arterial blood volume, and arterial mean transit time in the liver parenchyma and liver tumor were calculated using the deconvolution method. The CT-perfusion parameters and vascularity of the tumor were compared. A complete analysis could be performed in 36 of the 44 patients. For liver tumor and liver parenchyma, respectively, arterial blood flow was 184.6±132.7 and 41.0±27.0 ml/min/100 g, arterial blood volume was 19.4±14.6 and 4.8±4.2 ml/100 g, and arterial mean transit time was 8.9±4.2 and 10.2±5.3 sec. Arterial blood flow and arterial blood volume correlated significantly with the vascularity of the tumor; however no correlation was detected between arterial mean transit time and the vascularity of the tumor. This technique could be used to quantify pure hepatic arterial blood perfusion. (author)

[Umbilical blood-gas status at cesarean section for breech presentation: a comparison with vertex presentation].

Science.gov (United States)

Haruta, M; Saeki, N; Naka, Y; Funato, T; Ohtsuki, Y

1989-10-01

Umbilical blood-gas status at elective cesarean section with oxygen inhalation for breech presentation (25 cases) was compared with that for vertex presentation (25 cases), so as to confirm the security of full-term breech fetuses delivered by cesarean section under spinal anesthesia. Umbilical arterial oxygen levels were significantly lower in the breech group (Mean PO2:18.9 mmHg; SO2:37.3%; Oxygen content:7.6 ml/dl). The number of hypoxemic fetuses was significantly higher in the breech group (the breech: 7; the vertex; 0). The other umbilical blood-gas values revealed no significant differences between the breech and vertex groups, and were within normal limits in both groups. Oxygen extraction in the breech (Mean: 49.0%) was higher than that in the vertex (32.9%). Therefore decreased umbilical blood flow in the breech was suggested. The incidence of depression at 1 minute after delivery in the breech infants (24%) was significantly higher than that in the vertex infants (0%). It became obvious in the breech that as the interval between the uterine incision and delivery increased, umbilical arterial blood tended to acidosis and the 1 minute Apgar score decreased. Cesarean section for breech presentation requires sufficient and optimal incisions of the abdominal wall and uterus as well as a skillful manual delivery technique, because the fetus or neonate should be protected against asphyxia resulting from umbilical compression and prolonged delivery interval.

Usefulness of Clinical Prediction Rules, D-dimer, and Arterial Blood Gas Analysis to Predict Pulmonary Embolism in Cancer Patients

Directory of Open Access Journals (Sweden)

Shazia Awan

2017-03-01

Full Text Available Objectives: Pulmonary embolism (PE is seven times more common in cancer patients than non-cancer patients. Since the existing clinical prediction rules (CPRs were validated predominantly in a non-cancer population, we decided to look at the utility of arterial blood gas (ABG analysis and D-dimer in predicting PE in cancer patients. Methods: Electronic medical records were reviewed between December 2005 and November 2010. A total of 177 computed tomography pulmonary angiograms (CTPAs were performed. We selected 104 individuals based on completeness of laboratory and clinical data. Patients were divided into two groups, CTPA positive (patients with PE and CTPA negative (PE excluded. Wells score, Geneva score, and modified Geneva score were calculated for each patient. Primary outcomes of interest were the sensitivities, specificities, positive, and negative predictive values for all three CPRs. Results: Of the total of 104 individuals who had CTPAs, 33 (31.7% were positive for PE and 71 (68.3% were negative. There was no difference in basic demographics between the two groups. Laboratory parameters were compared and partial pressure of oxygen was significantly lower in patients with PE (68.1 mmHg vs. 71 mmHg, p = 0.030. Clinical prediction rules showed good sensitivities (88−100% and negative predictive values (93−100%. An alveolar-arterial (A-a gradient > 20 had 100% sensitivity and negative predictive values. Conclusions: CPRs and a low A-a gradient were useful in excluding PE in cancer patients. There is a need for prospective trials to validate these results.

Functional dilatation and medial remodeling of the renal artery in response to chronic increased blood flow.

Science.gov (United States)

Roan, Jun-Neng; Yeh, Chin-Yi; Chiu, Wen-Cheng; Lee, Chou-Hwei; Chang, Shih-Wei; Jiangshieh, Ya-Fen; Tsai, Yu-Chuan; Lam, Chen-Fuh

2011-01-01

Renal blood flow (RBF) is tightly regulated by several intrinsic pathways in maintaining optimal kidney blood supply. Using a rat model of aortocaval (AC) fistula, we investigated remodeling of the renal artery following prolonged increased blood flow. An AC fistula was created in the infrarenal aorta of anesthetized rats, and changes of blood flow in the renal artery were assessed using an ultrasonic flow probe. Morphological changes and expression of endothelial nitric oxide synthase and matrix metalloproteinase-2 in the remodeled renal artery were analyzed. Blood flow in the renal artery increased immediately after creation of AC fistula, but normal RBF was restored 8 weeks later. The renal artery dilated significantly 8 weeks after operation. Expression of endothelial nitric oxide synthase and matrix metalloproteinase-2 was upregulated shortly after blood flow increase, and returned to baseline levels after 3 weeks. Histological sections showed luminal dilatation with medial thickening and endothelial cell-to-smooth muscle cell attachments in the remodeled renal artery. Increased RBF was accommodated by functional dilatation and remodeling in the medial layer of the renal artery in order to restore normal blood flow. Our results provide important mechanistic insight into the intrinsic regulation of the renal artery in response to increased RBF. Copyright © 2011 S. Karger AG, Basel.

Accuracy of Capillary and Arterial Whole Blood Glucose Measurements Using a Glucose Meter in Patients under General Anesthesia in the Operating Room.

Science.gov (United States)

Karon, Brad S; Donato, Leslie J; Larsen, Chelsie M; Siebenaler, Lindsay K; Wells, Amy E; Wood-Wentz, Christina M; Shirk-Marienau, Mary E; Curry, Timothy B

2017-09-01

The aim of this study was to evaluate the use of a glucose meter with surgical patients under general anesthesia in the operating room. Glucose measurements were performed intraoperatively on 368 paired capillary and arterial whole blood samples using a Nova StatStrip (Nova Biomedical, USA) glucose meter and compared with 368 reference arterial whole blood glucose measurements by blood gas analyzer in 196 patients. Primary outcomes were median bias (meter minus reference), percentage of glucose meter samples meeting accuracy criteria for subcutaneous insulin dosing as defined by Parkes error grid analysis for type 1 diabetes mellitus, and accuracy criteria for intravenous insulin infusion as defined by Clinical and Laboratory Standards Institute guidelines. Time under anesthesia, patient position, diabetes status, and other variables were studied to determine whether any affected glucose meter bias. Median bias (interquartile range) was -4 mg/dl (-9 to 0 mg/dl), which did not differ from median arterial meter bias of -5 mg/dl (-9 to -1 mg/dl; P = 0.32). All of the capillary and arterial glucose meter values met acceptability criteria for subcutaneous insulin dosing, whereas only 89% (327 of 368) of capillary and 93% (344 of 368) arterial glucose meter values met accuracy criteria for intravenous insulin infusion. Time, patient position, and diabetes status were not associated with meter bias. Capillary and arterial blood glucose measured using the glucose meter are acceptable for intraoperative subcutaneous insulin dosing. Whole blood glucose on the meter did not meet accuracy guidelines established specifically for more intensive (e.g., intravenous insulin) glycemic control in the acute care environment.

Effect of volume expansion on systemic hemodynamics and central and arterial blood volume in cirrhosis

DEFF Research Database (Denmark)

Møller, S; Bendtsen, F; Henriksen, Jens Henrik Sahl

1995-01-01

, and arterial pressure were determined before and during a volume expansion induced by infusion of a hyperosmotic galactose solution. RESULTS: During volume expansion, the central and arterial blood volume increased significantly in patients with class A and controls, whereas no significant change was found...... in patients with either class B or class C. Conversely, the noncentral blood volume increased in patients with class B and C. In both patients and controls, the cardiac output increased and the systemic vascular resistance decreased, whereas the mean arterial blood pressure did not change significantly......BACKGROUND & AIMS: Systemic vasodilatation in cirrhosis may lead to hemodynamic alterations with reduced effective blood volume and decreased arterial blood pressure. This study investigates the response of acute volume expansion on hemodynamics and regional blood volumes in patients with cirrhosis...

Respiratory sinus arrhythmia stabilizes mean arterial blood pressure at high-frequency interval in healthy humans.

Science.gov (United States)

Elstad, Maja; Walløe, Lars; Holme, Nathalie L A; Maes, Elke; Thoresen, Marianne

2015-03-01

Arterial blood pressure variations are an independent risk factor for end organ failure. Respiratory sinus arrhythmia (RSA) is a sign of a healthy cardiovascular system. However, whether RSA counteracts arterial blood pressure variations during the respiratory cycle remains controversial. We restricted normal RSA with non-invasive intermittent positive pressure ventilation (IPPV) to test the hypothesis that RSA normally functions to stabilize mean arterial blood pressure. Ten young volunteers were investigated during metronome-paced breathing and IPPV. Heart rate (ECG), mean arterial blood pressure and left stroke volume (finger arterial pressure curve) and right stroke volume (pulsed ultrasound Doppler) were recorded, while systemic and pulmonary blood flow were calculated beat-by-beat. Respiratory variations (high-frequency power, 0.15-0.40 Hz) in cardiovascular variables were estimated by spectral analysis. Phase angles and correlation were calculated by cross-spectral analysis. The magnitude of RSA was reduced from 4.9 bpm(2) (95% CI 3.0, 6.2) during metronome breathing to 2.8 bpm(2) (95% CI 1.1, 5.0) during IPPV (p = 0.03). Variations in mean arterial blood pressure were greater (2.3 mmHg(2) (95% CI 1.4, 3.9) during IPPV than during metronome breathing (1.0 mmHg(2) [95% CI 0.7, 1.3]) (p = 0.014). Respiratory variations in right and left stroke volumes were inversely related in the respiratory cycle during both metronome breathing and IPPV. RSA magnitude is lower and mean arterial blood pressure variability is greater during IPPV than during metronome breathing. We conclude that in healthy humans, RSA stabilizes mean arterial blood pressure at respiratory frequency.

Implantable blood pressure sensor for analyzing elasticity in arteries

Science.gov (United States)

Franco-Ayala, Marco; Martínez-Piñón, Fernando; Reyes-Barranca, Alfredo; Sánchez de la Peña, Salvador; Álvarez-Chavez, José A.

2009-03-01

MEMS technology could be an option for the development of a pressure sensor which allows the monitoring of several electronic signals in humans. In this work, a comparison is made between the typical elasticity curves of several arteries in the human body and the elasticity obtained for MEMS silicon microstructures such as membranes and cantilevers employing Finite Element analysis tools. The purpose is to identify which types of microstructures are mechanically compatible with human arteries. The goal is to integrate a blood pressure sensor which can be implanted in proximity with an artery. The expected benefits for this type of sensor are mainly to reduce the problems associated with the use of bulk devices through the day and during several days. Such a sensor could give precise blood pressure readings in a continuous or periodic form, i.e. information that is especially important for some critical cases of hypertension patients.

The influence of the non-Newtonian properties of blood on blood-hammer through the posterior cerebral artery.

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Tazraei, Pedram; Riasi, Alireza; Takabi, Behrouz

2015-06-01

This work investigates a two dimensional numerical analysis of blood hammer through the posterior cerebral artery. The non-Newtonian and usual Newtonian blood models are compared in the case of blood hammer through the posterior cerebral artery to quantify the differences between the models. In this way, a validated CFD simulation is used to study non-Newtonian shear-thinning effects of blood. The governing equations for the modeling of two-dimensional transient flow are solved using a combination of characteristics and central finite difference methods, respectively for the hyperbolic and parabolic parts. Herein, the non-Newtonian viscosity characteristic of blood is incorporated by using the Carreau model. To convert the nonlinear terms available in the characteristics equation into the linear ones, the Newton-Kantorovich method is implemented. The verification and validation of the numerical results are carried out in detail. Hemodynamic characteristics of blood hammer through the posterior cerebral artery are derived with both the Newtonian and non-Newtonian models, and the results are meticulously compared and discussed. The results show that when blood hammer occurs, the non-Newtonian properties greatly influence the velocity and shear stress profiles. At the early stages of blood hammer, there is a 64% difference between magnitudes of wall shear stress in these two models, and the magnitude of the wall shear stress for the shear-thinning blood flow is lower than the Newtonian one. Copyright © 2015 Elsevier Inc. All rights reserved.

A simple method for measurement of cerebral blood flow using 123I-IMP SPECT with calibrated standard input function by one point blood sampling. Validation of calibration by one point venous blood sampling as a substitute for arterial blood sampling

International Nuclear Information System (INIS)

Ito, Hiroshi; Akaizawa, Takashi; Goto, Ryoui

1994-01-01

In a simplified method for measurement of cerebral blood flow using one 123 I-IMP SPECT scan and one point arterial blood sampling (Autoradiography method), input function is obtained by calibrating a standard input function by one point arterial blood sampling. A purpose of this study is validation of calibration by one point venous blood sampling as a substitute for one point arterial blood sampling. After intravenous infusion of 123 I-IMP, frequent arterial and venous blood sampling were simultaneously performed on 12 patients of CNS disease without any heart and lung disease and 5 normal volunteers. The radioactivity ratio of venous whole blood which obtained from cutaneous cubital vein to arterial whole blood were 0.76±0.08, 0.80±0.05, 0.81±0.06, 0.83±0.11 at 10, 20, 30, 50 min after 123 I-IMP infusion, respectively. The venous blood radioactivities were always 20% lower than those of arterial blood radioactivity during 50 min. However, the ratio which obtained from cutaneous dorsal hand vein to artery were 0.93±0.02, 0.94±0.05, 0.98±0.04, 0.98±0.03, at 10, 20, 30, 50 min after 123 I-IMP infusion, respectively. The venous blood radioactivity was consistent with artery. These indicate that arterio-venous difference of radioactivity in a peripheral cutaneous vein like a dorsal hand vein is minimal due to arteriovenous shunt in palm. Therefore, a substitution by blood sampling from cutaneous dorsal hand vein for artery will be possible. Optimized time for venous blood sampling evaluated by error analysis was 20 min after 123 I-IMP infusion, which is 10 min later than that of arterial blood sampling. (author)

Measurement of Blood Flow in an Intracranial Artery Bypass From the Internal Maxillary Artery by Intraoperative Duplex Sonography.

Science.gov (United States)

Yu, Zaitao; Shi, Xiang'en; Brohi, Shams Raza; Qian, Hai; Liu, Fangjun; Yang, Yang

2017-02-01

This study explored the hemodynamic characteristics of a subcranial-intracranial bypass from the internal maxillary artery by measuring blood flow on intraoperative duplex sonography. The hemodynamic parameters of the internal maxillary artery (n = 20), radial artery (n = 20), internal maxillary artery-middle cerebral artery bypass (n = 42), and internal maxillary artery-posterior cerebral artery bypass (n = 9) were measured by intraoperative duplex sonography. There was no significant difference in the internal diameters of the internal maxillary and radial arteries (mean ± SD, 2.51 ± 0.34 versus 2.56 ± 0.22 mm; P = .648). The mean radial artery graft length for subcranial-intracranial bypasses was 88.5 ± 12.78 mm (95% confidence interval [CI], 80.8-90.2 mm). Internal maxillary artery-middle cerebral artery bypasses required a shorter radial artery graft than internal maxillary artery-posterior cerebral artery bypasses (77.8 ± 2.47 versus 104.8 ± 4.77 mm; P = .001). The mean flow volumes were 85.3 ± 18.5 mL/min (95% CI, 76.6-93.9 mL/min) for the internal maxillary artery, 72.6 ± 26.4 mL/min (95% CI, 64.3-80.9 mL/min) for internal maxillary artery-middle cerebral artery bypasses, and 45.4 ± 6.7 mL/min (95% CI, 40.7-50.0 mL/min) for internal maxillary artery-posterior cerebral artery bypasses. All grafts were opened after the success of the salvage procedures had been established, and the early patency rates (1 month after the operation) were 95% for internal maxillary artery-middle cerebral artery bypasses and 100% the internal maxillary artery-posterior cerebral artery bypasses. Measurement of blood flow by intraoperative sonography can be helpful in decision making and predicting graft patency and success after neurosurgical bypass procedures. © 2016 by the American Institute of Ultrasound in Medicine.

PX-18 Protects Human Saphenous Vein Endothelial Cells under Arterial Blood Pressure.

Science.gov (United States)

Kupreishvili, Koba; Stooker, Wim; Emmens, Reindert W; Vonk, Alexander B A; Sipkens, Jessica A; van Dijk, Annemieke; Eijsman, Leon; Quax, Paul H; van Hinsbergh, Victor W M; Krijnen, Paul A J; Niessen, Hans W M

2017-07-01

Arterial blood pressure-induced shear stress causes endothelial cell apoptosis and inflammation in vein grafts after coronary artery bypass grafting. As the inflammatory protein type IIA secretory phospholipase A 2 (sPLA 2 -IIA) has been shown to progress atherosclerosis, we hypothesized a role for sPLA 2 -IIA herein. The effects of PX-18, an inhibitor of both sPLA 2 -IIA and apoptosis, on residual endothelium and the presence of sPLA 2 -IIA were studied in human saphenous vein segments (n = 6) perfused at arterial blood pressure with autologous blood for 6 hrs. The presence of PX-18 in the perfusion blood induced a significant 20% reduction in endothelial cell loss compared to veins perfused without PX18, coinciding with significantly reduced sPLA 2 -IIA levels in the media of the vein graft wall. In addition, PX-18 significantly attenuated caspase-3 activation in human umbilical vein endothelial cells subjected to shear stress via mechanical stretch independent of sPLA 2 -IIA. In conclusion, PX-18 protects saphenous vein endothelial cells from arterial blood pressure-induced death, possibly also independent of sPLA 2 -IIA inhibition. Copyright © 2017 Elsevier Inc. All rights reserved.

The conundrum of arterial stiffness, elevated blood pressure, and aging.

Science.gov (United States)

AlGhatrif, Majd; Lakatta, Edward G

2015-02-01

Isolated systolic hypertension is a major health burden that is expanding with the aging of our population. There is evidence that central arterial stiffness contributes to the rise in systolic blood pressure (SBP); at the same time, central arterial stiffening is accelerated in patients with increased SBP. This bidirectional relationship created a controversy in the field on whether arterial stiffness leads to hypertension or vice versa. Given the profound interdependency of arterial stiffness and blood pressure, this question seems intrinsically challenging, or probably naïve. The aorta's function of dampening the pulsatile flow generated by the left ventricle is optimal within a physiological range of distending pressure that secures the required distal flow, keeps the aorta in an optimal mechanical conformation, and minimizes cardiac work. This homeostasis is disturbed by age-associated, minute alterations in aortic hemodynamic and mechanical properties that induce short- and long-term alterations in each other. Hence, it is impossible to detect an "initial insult" at an epidemiological level. Earlier manifestations of these alterations are observed in young adulthood with a sharp decline in aortic strain and distensibility accompanied by an increase in diastolic blood pressure. Subsequently, aortic mechanical reserve is exhausted, and aortic remodeling with wall stiffening and dilatation ensue. These two phenomena affect pulse pressure in opposite directions and different magnitudes. With early remodeling, there is an increase in pulse pressure, due to the dominance of arterial wall stiffness, which in turn accelerates aortic wall stiffness and dilation. With advanced remodeling, which appears to be greater in men, the effect of diameter becomes more pronounced and partially offsets the effect of wall stiffness leading to plateauing in pulse pressure in men and slower increase in pulse pressure (PP) than that of wall stiffness in women. The complex nature of

Plasma volume changes during hypoglycaemia: the effect of arterial blood sampling

DEFF Research Database (Denmark)

Hilsted, J; Bendtsen, Flemming; Christensen, N J

1990-01-01

To investigate whether previously reported changes in venous blood volume and composition induced by acute hypoglycaemia in humans are representative for the entire body we measured erythrocyte 51Cr content, haematocrit, plasma volume, intravascular albumin content and transcapillary escape rate...... hypoglycaemia. The magnitude of the changes in arterial and venous blood were not significantly different. These results indicate that the above changes in blood volume and composition are whole-body phenomena: furthermore, the major part of the changes are likely to occur in tissues other than upper extremity...... of albumin in arterial and venous blood in seven healthy subjects before and during insulin-induced hypoglycaemia. In both vascular sites blood 51Cr content and the haematocrit increased, plasma volume and intravascular albumin content decreased and the transcapillary escape rate of albumin increased during...

Allergic rhinitis and arterial blood pressure: a population-based study.

Science.gov (United States)

Sakallioglu, O; Polat, C; Akyigit, A; Cetiner, H; Duzer, S

2018-05-01

To investigate the likelihood of allergic rhinitis and potential co-morbidities, and to assess whether allergic rhinitis is associated with arterial blood pressure and hypertension. In this population-based study, 369 adults with allergic rhinitis and asthma were assessed via a questionnaire and immunoglobulin E levels. There were four groups: control (n = 90), allergic rhinitis (n = 99), asthma (n = 87) and hypertension (n = 93). Arterial blood pressure was measured in all groups. There were no significant differences in systolic or diastolic blood pressure between males and females in any group. Pairwise comparisons revealed no significant differences between: the control and allergic rhinitis groups, the control and asthma groups, or the allergic rhinitis and asthma groups. The systolic and diastolic blood pressure values of males and females were significantly higher in the hypertension group than the allergic rhinitis group. There were no significant differences in systolic blood pressure or diastolic blood pressure for seasonal and perennial allergic rhinitis patients. Rhinitis was not associated with increased blood pressure. Allergic rhinitis can coincide with asthma and hypertension. The findings do not support the need for blood pressure follow up in allergic rhinitis patients.

Measurement of regional cerebral blood flow using one-point arterial blood sampling and microsphere model with 123I-IMP. Correction of one-point arterial sampling count by whole brain count ratio

International Nuclear Information System (INIS)

Makino, Kenichi; Masuda, Yasuhiko; Gotoh, Satoshi

1998-01-01

The experimental subjects were 189 patients with cerebrovascular disorders. 123 I-IMP, 222 MBq, was administered by intravenous infusion. Continuous arterial blood sampling was carried out for 5 minutes, and arterial blood was also sampled once at 5 minutes after 123 I-IMP administration. Then the whole blood count of the one-point arterial sampling was compared with the octanol-extracted count of the continuous arterial sampling. A positive correlation was found between the two values. The ratio of the continuous sampling octanol-extracted count (OC) to the one-point sampling whole blood count (TC5) was compared with the whole brain count ratio (5:29 ratio, Cn) using 1-minute planar SPECT images, centering on 5 and 29 minutes after 123 I-IMP administration. Correlation was found between the two values. The following relationship was shown from the correlation equation. OC/TC5=0.390969 x Cn-0.08924. Based on this correlation equation, we calculated the theoretical continuous arterial sampling octanol-extracted count (COC). COC=TC5 x (0.390969 x Cn-0.08924). There was good correlation between the value calculated with this equation and the actually measured value. The coefficient improved to r=0.94 from the r=0.87 obtained before using the 5:29 ratio for correction. For 23 of these 189 cases, another one-point arterial sampling was carried out at 6, 7, 8, 9 and 10 minutes after the administration of 123 I-IMP. The correlation coefficient was also improved for these other point samplings when this correction method using the 5:29 ratio was applied. It was concluded that it is possible to obtain highly accurate input functions, i.e., calculated continuous arterial sampling octanol-extracted counts, using one-point arterial sampling whole blood counts by performing correction using the 5:29 ratio. (K.H.)

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.

Effect of cage vs. floor litter environments on the pulmonary hypertensive response to intravenous endotoxin and on blood-gas values in broilers.

Science.gov (United States)

Wang, W; Erf, G F; Wideman, R F

2002-11-01

Intravenous endotoxin has been shown to trigger a delayed pulmonary hypertensive response that varies widely in magnitude and duration among individual broilers. It was proposed that this individual variability may reflect immunological differences acquired during previous respiratory challenges that might have subsequently altered the endotoxin-initiated biochemical cascade. In Experiment 1, we tested the hypothesis that, when compared with broilers reared in clean stainless steel cages (Cage group), broilers reared on floor litter (Floor group) should experience a greater respiratory challenge and therefore may consistently exhibit a more enhanced pulmonary hypertensive response to intravenous endotoxin. Birds in the Cage group were grown in stainless steel cages at a low density (72 birds/8 m2 chamber), and fecal and dander materials were removed daily. Birds in the Floor group were reared on wood-shavings litter at a higher density (110 birds/8 m2 chamber). Pulmonary and systemic mean arterial pressures and blood-gas values were evaluated prior to and following the intravenous administration of 1 mg Salmonella typhimurium endotoxin. Broilers in the Floor and Cage groups exhibited pulmonary hypertensive responses to endotoxin that were very similar in terms of time of onset, duration, and magnitude, as well as variability in the response among individuals. Systemic hypotension also developed similarly in both groups following endotoxin injection. Blood-gas values indicated that the partial pressure of CO2 and the HCO3- concentration in arterial blood were higher (P broilers, and confirmed the negative impact of floor rearing on blood-gas values. We conclude that broilers reared on the floor inhaled litter dust and noxious fumes, which impaired pulmonary gas exchange and increased the arterial partial pressure of CO2 when compared with broilers reared in clean stainless steel cages. Nevertheless, the pulmonary hypertensive response to endotoxin did not differ

Relocation of blood gas laboratory to the emergency department helps decrease lactic acid values.

Science.gov (United States)

Brazg, Jared; Huang, Phyllis; Weiner, Corey; Singh, Guneet; Likourezos, Antonios; Salem, Linda; Dickman, Eitan; Marshall, John

2018-03-12

Emergency Physicians often rely on Lactic Acid (LA) values to make important clinical decisions. Accuracy of LA values improve when blood gas analysis is performed in the emergency department (ED) as opposed to a satellite laboratory (SL). To investigate an association between blood gas laboratory location and accuracy of ED lactic acid samples. The study team evaluated lactic acid values from venous and arterial blood gas samples drawn between June 1, 2015 and September 30, 2016. The study was exempt from institutional review board approval. Samples were separated into two groups: those which were drawn prior to and after relocation of the blood gas laboratory to the ED. The data, including patient demographic characteristics, acute illness severity indices, and blood gas results were compared within and between each group using t-test for continuous variables and chi-square test for categorical variables. The primary outcome was the mean lactate value measured in the SL group in 2015 compared to the ED group in 2016. Potassium and creatinine values were measured between the two groups as secondary outcomes. Of the 21,595 consecutive samples drawn, 10,363 samples were from the SL group and 11,232 from the ED group. The SL group included 5458 (52.7%) women; mean (SD) age was 61.8 (21.0). The ED group contained 5860 (52.2%) women; mean (SD) age was 61.7 (20.5). Mean Emergency Severity Index (ESI) were the same in each group at 2.31 and rates of Systemic Inflammatory Response Syndrome (SIRS) were also equivalent in each group at 22.2%. Significant differences were found between LA values in the SL group (mean 2.21mmol/L) and in the ED group (mean 1.99mmol/L) with a p value of values in the SL group (mean 3.98meq/L) compared to the ED Group (mean 3.96meq/L) with a p value of 0.022. No significant difference was found between the creatinine values. These results suggest that mean lactate values decreased when measured in an ED blood gas laboratory and may provide more

Relocation of blood gas laboratory to the emergency department helps decrease lactic acid values.

Science.gov (United States)

Brazg, Jared; Huang, Phyllis; Weiner, Corey; Singh, Guneet; Likourezos, Antonios; Salem, Linda; Dickman, Eitan; Marshall, John

2018-03-20

Emergency physicians often rely on Lactic Acid (LA) values to make important clinical decisions. Accuracy of LA values improve when blood gas analysis is performed in the emergency department (ED) as opposed to a satellite laboratory (SL). To investigate an association between blood gas laboratory location and accuracy of ED lactic acid samples. The study team evaluated lactic acid values from venous and arterial blood gas samples drawn between June 1, 2015 and September 30, 2016. The study was exempt from institutional review board approval. Samples were separated into two groups: those which were drawn prior to and after relocation of the blood gas laboratory to the ED. The data, including patient demographic characteristics, acute illness severity indices, and blood gas results were compared within and between each group using t-test for continuous variables and chi-square test for categorical variables. The primary outcome was the mean lactate value measured in the SL group in 2015 compared to the ED group in 2016. Potassium and creatinine values were measured between the two groups as secondary outcomes. Of the 21,595 consecutive samples drawn, 10,363 samples were from the SL group and 11,232 from the ED group. The SL group included 5458 (52.7%) women; mean (SD) age was 61.8 (21.0). The ED group contained 5860 (52.2%) women; mean (SD) age was 61.7 (20.5). Mean Emergency Severity Index (ESI) were the same in each group at 2.31 and rates of Systemic Inflammatory Response Syndrome (SIRS) were also equivalent in each group at 22.2%. Significant differences were found between LA values in the SL group (mean 2.21mmol/L) and in the ED group (mean 1.99mmol/L) with a p value of values in the SL group (mean 3.98meq/L) compared to the ED Group (mean 3.96meq/L) with a p value of 0.022. No significant difference was found between the creatinine values. These results suggest that mean lactate values decreased when measured in an ED blood gas laboratory and may provide more

A femoral arteriovenous shunt facilitates arterial whole blood sampling in animals

International Nuclear Information System (INIS)

Weber, Bruno; Burger, Cyrill; Buck, Alfred; Biro, Peter

2002-01-01

In this study we evaluated on-line continuous blood sampling in a femoral arteriovenous (a-v) shunt for use in quantitative tracer studies using gamma-emitting radionuclides in animals. The shunt consisted of 40 cm polyethylene tubing (PE-50) guided through a coincidence probe. Two three-way valves allowed blood pressure measurements and tracer injection. Blood flow in the shunt and the impulse response function (IRF) were assessed using heparinized human blood mixed with fluorine-18 fluorodeoxyglucose (FDG). In vivo experiments were performed in eight male rats (300-350 g) anaesthetized with halothane. In three rats, manual blood sampling was performed in parallel with on-line sampling. In another five animals, the arterial whole blood activity was recorded on-line for 40 min. For the experiments 150-180 MBq FDG was injected over 35 s. Blood flow in the shunt was 23.6, 29.2 and 42.8 ml/h at 100, 120 and 160 mmHg, respectively. The IRF was characterized by minimal dispersion (1-2 s FWHM). Deconvolution of the measured arterial input curves with the IRF changed the measured curve only minimally. Whole blood radioactivity concentration derived from manual and on-line sampling were in excellent agreement. The curves derived from on-line sampling were of high statistical quality. In conclusion, a femoral a-v shunt allows multiple manipulations such as measurement of the arterial whole blood activity, continuous blood pressure monitoring, injection of the tracer and collection of blood samples if necessary. It is not associated with blood loss if the collection of blood samples is not required. It is more convenient to use than manual sampling, the peak of the input curve is never missed and the input curves are of high statistical quality. (orig.)

The pulmonary artery does not participate in the blood supply of lung cancer: experimental and DSA study

International Nuclear Information System (INIS)

Han Mingjun; Feng Gansheng; Yang Jianyong; Su Hongying; Zhao Zhongchun

2000-01-01

Objective: To investigate whether or not the pulmonary artery participates in the blood supply of lung cancer and its change of morphology and blood flow in lung cancer. Methods: Two different colors of silicone were injected separately into the bronchial and pulmonary arteries of 33 rat models with squamous cell carcinoma of lung. The origin of blood supply of lung cancer and the morphologic change of pulmonary artery were observed under a stereo-microscope. The DSA of bronchial and pulmonary artery were performed simultaneously in 28 patients with lung cancer. Results: The pulmonary branch of rat and patients were reduced,thinned and occluded in the affected lung. The pulmonary artery did not form tumor vessel,and pulmonary blood flow and perfusion were reduced or absent in the affected area. Conclusion: The pulmonary artery did not participate in the blood supply of lung cancer. It is unreasonable to perform transcatheter chemo-embolization for lung cancer via pulmonary artery

Circadian rhythm of arterial blood pressure and albuminuria in diabetic nephropathy

DEFF Research Database (Denmark)

Hansen, H P; Rossing, P; Tarnow, L

1996-01-01

The aim of our study was to evaluate the diurnal relationship between arterial blood pressure and albuminuria, and some potential mechanisms responsible for impaired nocturnal blood pressure reduction (non-dippers, groups I and II) in diabetic nephropathy (DN). Twenty-four-hour ambulatory blood p...

Blood gas testing and related measurements: National recommendations on behalf of the Croatian Society of Medical Biochemistry and Laboratory Medicine.

Science.gov (United States)

Dukić, Lora; Kopčinović, Lara Milevoj; Dorotić, Adrijana; Baršić, Ivana

2016-10-15

Blood gas analysis (BGA) is exposed to risks of errors caused by improper sampling, transport and storage conditions. The Clinical and Laboratory Standards Institute (CLSI) generated documents with recommendations for avoidance of potential errors caused by sample mishandling. Two main documents related to BGA issued by the CLSI are GP43-A4 (former H11-A4) Procedures for the collection of arterial blood specimens; approved standard - fourth edition, and C46-A2 Blood gas and pH analysis and related measurements; approved guideline - second edition. Practices related to processing of blood gas samples are not standardized in the Republic of Croatia. Each institution has its own protocol for ordering, collection and analysis of blood gases. Although many laboratories use state of the art analyzers, still many preanalytical procedures remain unchanged. The objective of the Croatian Society of Medical Biochemistry and Laboratory Medicine (CSMBLM) is to standardize the procedures for BGA based on CLSI recommendations. The Working Group for Blood Gas Testing as part of the Committee for the Scientific Professional Development of the CSMBLM prepared a set of recommended protocols for sampling, transport, storage and processing of blood gas samples based on relevant CLSI documents, relevant literature search and on the results of Croatian survey study on practices and policies in acid-base testing. Recommendations are intended for laboratory professionals and all healthcare workers involved in blood gas processing.

Relationship between the Direction of Ophthalmic Artery Blood Flow and Ocular Microcirculation before and after Carotid Artery Stenting.

Science.gov (United States)

Ishii, Masashi; Hayashi, Morito; Yagi, Fumihiko; Sato, Kenichiro; Tomita, Goji; Iwabuchi, Satoshi

2016-01-01

When internal carotid artery stenosis is accompanied by ocular ischemic syndrome, intervention is recommended to prevent irreversible visual loss. In this study, we used laser speckle flowgraphy to measure the ocular microcirculation in the optic nerve head before and after carotid artery stenting (CAS) of 40 advanced internal carotid stenosis lesions from 37 patients. The aim was to investigate the relationship between ocular microcirculation and the direction of ophthalmic artery blood flow obtained by angiography. We found that there was a significant increase in blood flow after CAS ( P = 0.003). Peak systolic velocity as an indicator of the rate of stenosis was also significantly higher in the group with retrograde/undetected flow of the ophthalmic artery than in the group with antegrade flow ( P = 0.002). In all cases where retrograde flow of the ophthalmic artery was observed before stenting, the flow changed to antegrade after stenting. Through the use of laser speckle flowgraphy, this study found that CAS can improve ocular microcirculation. Furthermore, while patients displaying retrograde flow of the ophthalmic artery before stenting have a poor prognosis, CAS corrected the flow to antegrade, suggesting that visual loss can be prevented by improving the ocular microcirculation.

Pulmonary hemodynamics and gas exchange in off pump coronary artery bypass grafting.

Science.gov (United States)

Vedin, Jenny; Jensen, Ulf; Ericsson, Anders; Samuelsson, Sten; Vaage, Jarle

2005-10-01

To investigate the influence of cardiopulmonary bypass on pulmonary hemodynamics and gas exchange. Low risk patients admitted for elective coronary artery bypass grafting were randomized to either on (n=25) or off pump (n=25) surgery. Central hemodynamics, gas exchange, and venous admixture were studied during and up to 20 h after surgery. There was no difference in pulmonary vascular resistance index (P=0.16), right ventricular stroke work index (P>0.2), mean pulmonary artery pressure (P>0.2) or pulmonary capillary wedge pressure (P>0.2) between groups. Soon after surgery there was a tendency towards higher cardiac index (P=0.07) in the off pump group. Arterial oxygen tension (P>0.2), hematocrit (P>0.2), venous admixture (P>0.2), and arterial-venous oxygen content difference (P=0.12) did not differ between groups. This prospective, randomized study showed no difference in pulmonary hemodynamics, pulmonary gas exchange, and venous admixture, in low risk patients undergoing off pump compared to on pump coronary artery bypass surgery.

Effect of Ginkgo biloba extract in combined with prednisone on the arterial blood gas and pulmonary function in patients with idiopathic pulmonary fibrosis

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Zhen-Chun Shi

2016-09-01

Full Text Available Objective: To explore the effect of Ginkgo biloba extract (EGb in combined with prednisone on the arterial blood gas and pulmonary function in patients with idiopathic pulmonary fibrosis (IPF. Methods: A total of 76 patients with IPF who were admitted in our hospital from March, 2015 to March, 2016 were included in the study and randomized into the observation group and the control group. The patients in the two groups were given oxygen inhalation, bronchodilator agents, phlegm dissipating and asthma relieving, anti-infection, and other supporting treatments. The patients in the control group were orally given prednisone (0.5 mg/ kg.d, continuously for 4 weeks, then in a dose of 0.25 mg/kg.d, continuously for 8 weeks, and finally the dosage was reduced to 0.125 mg/kg.d. On this basis, the patients in the observation group were given additional EGb, i.e. Ginkgo leaf capsule, 1 g/time, 3 times/d, continuously for 12 weeks. The efficacy was evaluated after 12-week treatment. PaO2, PaCO2, P(A-aO2, and SaO2 before and after treatment were detected. FVC, FEV1/FVC, MVV, TLC, and DLCO before and after treatment were determined. Results: PaO2, PaCO2, and SaO2 after treatment were significantly elevated, while P(A-aO2 was significantly reduced when compared with before treatment. The comparison of PaO2 and P(A-aO2 between the two groups was statistically significant, while the comparison of PaCO2 and SaO2 between the two groups was not statistically significant. After treatment, FVC, FEV1/FVC, MVV, TLC, and DLCO in the two groups were significantly elevated when compared with before treatment, and those in the observation group were significantly superior to those in the control group. Conclusions: EGb in combined with prednisone in the treatment of IPF can effectively improve the arterial blood gas indicators and pulmonary function, and enhance the patients’ living qualities; therefore, it deserves to be widely recommended.

Measurement of blood flow in the carotid arteries using color doppler in healthy Korean adults

International Nuclear Information System (INIS)

Moon, Ki Ho; Jeon, Do Ig; Choi, Chang Ho; Ro, Young Jin; Kim, Hak Jin; Lee, Suck Hong; Kim, Byung Soo

1994-01-01

To evaluate the blood flow patterns and velocities of the carotid arteries in healthy Korean adults. We evaluated the blood flow patterns and measured the peak systolic and end-diastolic velocities of the common, internal and external carotid arteries in 48 healthy adults who did not have cardiovascular disorders and neck lesions. The velocity difference was analyzed according to different age groups. In addition, peak systolic and end-diastolic velocity ratio of the internal to common carotid artery was estimated, and our data were compared with values reported by other authors. Generally, the velocity in the younger age group tends be to higher than in older group. The peak systolic and end diastolic velocities of the internal carotid artery were 84.5 cm/sec and 30.5 cm/sec. The peak systolic and end diastolic velocity ratio of the internal to common carotid artery were 0.715 and 0.966. The internal carotid artery was less resistant in blood flow than the external carotid artery. Our data were lower than the values which were reported by Bluth et al. The blood flow velocities of the internal carotid artery in healthy adults were lower than those of previous reported foreign values, but the patterns were similar

WE-FG-206-05: New Arterial Spin Labeling Method for Simultaneous Estimation of Arterial Cerebral Blood Volume, Cerebral Blood Flow and Arterial Transit Time

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Johnston, M; Whitlow, C; Jung, Y [Wake Forest School of Medicine, Winston-Salem, NC (United States); Liu, H [UT MD Anderson Cancer Center, Houston, TX (United States)

2016-06-15

Purpose: To demonstrate the feasibility of a novel Arterial Spin Labeling (ASL) method for simultaneously measuring cerebral blood flow (CBF), arterial transit time (ATT), and arterial cerebral blood volume (aCBV) without the use of a contrast agent. Methods: A series of multi-TI ASL images were acquired from one healthy subject on a 3T Siemens Skyra, with the following parameters: PCASL labeling with variable TI [300, 400, 500, 600, 700, 800, 900, 1000, 1500, 2000, 2500, 3000, 3500, 4000] ms, labeling bolus 1400 ms when TI allows, otherwise 100 ms less than TI, TR was minimized for each TI, two sinc shaped pre-saturation pulses were applied in the imaging plane immediately before 2D EPI acquisition. 64×64×24 voxels, 5 mm slice thickness, 1 mm gap, full brain coverage, 6 averages per TI, no crusher gradients, 11 ms TE, scan time of 4:56. The perfusion weighted time-series was created for each voxel and fit to a novel model. The model has two components: 1) the traditional model developed by Buxton et al., accounting for CBF and ATT, and 2) a box car function characterizing the width of the labeling bolus, with variable timing and height in proportion to the aCBV. All three parameters were fit using a nonlinear fitting routine that constrained all parameters to be positive. The main purpose of the high-temporal resolution TI sampling for the first second of data acquisition was to precisely estimate the blood volume component for better detection of arrival time and magnitude of signal. Results: Whole brain maps of CBF, ATT, and aCBV were produced, and all three parameters maps are consistent with similar maps described in the literature. Conclusion: Simultaneous mapping of CBF, ATT, and aCBV is feasible with a clinically tractable scan time (under 5 minutes).

Downstream Hepatic Arterial Blood Pressure Changes Caused by Deployment of the Surefire AntiReflux Expandable Tip

International Nuclear Information System (INIS)

Rose, Steven C.; Kikolski, Steven G.; Chomas, James E.

2013-01-01

Purpose: The purpose of this work was to evaluate blood pressure changes caused by deployment of the Surefire antireflux expandable tip. The pressure measurements are relevant because they imply changes in hepatoenteric arterial blood flow within this liver compartment during hepatic artery delivery of cytotoxic agents. Methods: After positioning the Surefire antireflux system in the targeted hepatic artery, blood pressure was obtained initially with the tip collapsed (or through a femoral artery sheath), then again after the tip was expanded before chemoembolization or yttrium 90 ( 90 Y) radioembolization. Results: Eighteen patients with liver malignancy underwent 29 procedures in 29 hepatic arteries (3 common hepatic, 22 lobar, 4 segmental). Systolic, diastolic, and mean blood pressure were all decreased by a mean of 29 mm Hg (p = 0.000004), 14 mm Hg (p = 0.0000004), and 22 mm Hg (p = 0.00000001), respectively. Conclusion: When the Surefire expandable tip is deployed to prevent retrograde reflux of agents, it also results in a significant decrease in blood pressure in the antegrade distribution, potentially resulting in hepatopedal blood flow in vessels that are difficult to embolize, such as the supraduodenal arteries

Arterial blood pressure measurement and pulse wave analysis—their role in enhancing cardiovascular assessment

International Nuclear Information System (INIS)

Avolio, Alberto P; Butlin, Mark; Walsh, Andrew

2010-01-01

The most common method of clinical measurement of arterial blood pressure is by means of the cuff sphygmomanometer. This instrument has provided fundamental quantitative information on arterial pressure in individual subjects and in populations and facilitated estimation of cardiovascular risk related to levels of blood pressure obtained from the brachial cuff. Although the measurement is taken in a peripheral limb, the values are generally assumed to reflect the pressure throughout the arterial tree in large conduit arteries. Since the arterial pressure pulse becomes modified as it travels away from the heart towards the periphery, this is generally true for mean and diastolic pressure, but not for systolic pressure, and so pulse pressure. The relationship between central and peripheral pulse pressure depends on propagation characteristics of arteries. Hence, while the sphygmomanometer gives values of two single points on the pressure wave (systolic and diastolic pressure), there is additional information that can be obtained from the time-varying pulse waveform that enables an improved quantification of the systolic load on the heart and other central organs. This topical review will assess techniques of pressure measurement that relate to the use of the cuff sphygmomanometer and to the non-invasive registration and analysis of the peripheral and central arterial pressure waveform. Improved assessment of cardiovascular function in relation to treatment and management of high blood pressure will result from future developments in the indirect measurement of arterial blood pressure that involve the conventional cuff sphygmomanometer with the addition of information derived from the peripheral arterial pulse. (topical review)

Strength training reduces arterial blood pressure but not sympathetic neural activity in young normotensive subjects

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Carter, Jason R.; Ray, Chester A.; Downs, Emily M.; Cooke, William H.

2003-01-01

The effects of resistance training on arterial blood pressure and muscle sympathetic nerve activity (MSNA) at rest have not been established. Although endurance training is commonly recommended to lower arterial blood pressure, it is not known whether similar adaptations occur with resistance training. Therefore, we tested the hypothesis that whole body resistance training reduces arterial blood pressure at rest, with concomitant reductions in MSNA. Twelve young [21 +/- 0.3 (SE) yr] subjects underwent a program of whole body resistance training 3 days/wk for 8 wk. Resting arterial blood pressure (n = 12; automated sphygmomanometer) and MSNA (n = 8; peroneal nerve microneurography) were measured during a 5-min period of supine rest before and after exercise training. Thirteen additional young (21 +/- 0.8 yr) subjects served as controls. Resistance training significantly increased one-repetition maximum values in all trained muscle groups (P < 0.001), and it significantly decreased systolic (130 +/- 3 to 121 +/- 2 mmHg; P = 0.01), diastolic (69 +/- 3 to 61 +/- 2 mmHg; P = 0.04), and mean (89 +/- 2 to 81 +/- 2 mmHg; P = 0.01) arterial blood pressures at rest. Resistance training did not affect MSNA or heart rate. Arterial blood pressures and MSNA were unchanged, but heart rate increased after 8 wk of relative inactivity for subjects in the control group (61 +/- 2 to 67 +/- 3 beats/min; P = 0.01). These results indicate that whole body resistance exercise training might decrease the risk for development of cardiovascular disease by lowering arterial blood pressure but that reductions of pressure are not coupled to resistance exercise-induced decreases of sympathetic tone.

Intraosseous blood samples for point-of-care analysis: agreement between intraosseous and arterial analyses.

Science.gov (United States)

Jousi, Milla; Saikko, Simo; Nurmi, Jouni

2017-09-11

Point-of-care (POC) testing is highly useful when treating critically ill patients. In case of difficult vascular access, the intraosseous (IO) route is commonly used, and blood is aspirated to confirm the correct position of the IO-needle. Thus, IO blood samples could be easily accessed for POC analyses in emergency situations. The aim of this study was to determine whether IO values agree sufficiently with arterial values to be used for clinical decision making. Two samples of IO blood were drawn from 31 healthy volunteers and compared with arterial samples. The samples were analysed for sodium, potassium, ionized calcium, glucose, haemoglobin, haematocrit, pH, blood gases, base excess, bicarbonate, and lactate using the i-STAT® POC device. Agreement and reliability were estimated by using the Bland-Altman method and intraclass correlation coefficient calculations. Good agreement was evident between the IO and arterial samples for pH, glucose, and lactate. Potassium levels were clearly higher in the IO samples than those from arterial blood. Base excess and bicarbonate were slightly higher, and sodium and ionised calcium values were slightly lower, in the IO samples compared with the arterial values. The blood gases in the IO samples were between arterial and venous values. Haemoglobin and haematocrit showed remarkable variation in agreement. POC diagnostics of IO blood can be a useful tool to guide treatment in critical emergency care. Seeking out the reversible causes of cardiac arrest or assessing the severity of shock are examples of situations in which obtaining vascular access and blood samples can be difficult, though information about the electrolytes, acid-base balance, and lactate could guide clinical decision making. The analysis of IO samples should though be limited to situations in which no other option is available, and the results should be interpreted with caution, because there is not yet enough scientific evidence regarding the agreement of IO

Queixa de vertigem e hipertensão arterial Vertigo complaint and blood hypertension

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Luciana Lozza de Moraes Marchiori

2007-03-01

Full Text Available OBJETIVO: investigar a presença de queixa de vertigem em pacientes de meia idade com hipertensão arterial. MÉTODOS: estudo do tipo prospectivo, transversal. Composto por 154 indivíduos de ambos os gêneros com idade de 45 a 64 anos. A hipertensão foi verificada por meio de medição da pressão arterial e de questionário sistematizado sobre hipertensão e uso de medicamentos para pressão arterial. A queixa de vertigem foi verificada por meio de anamnese audiológica. RESULTADOS: pode-se verificar que existe associação significante entre hipertensão arterial e queixa de vertigem. CONCLUSÃO: os resultados da presente pesquisa, por meio da constatação da associação entre hipertensão arterial e queixa de vertigem, servirão de base a profissionais da área de saúde que estão envolvidos com sintomas provenientes da hipertensão arterial.PURPOSE: to investigate the presence of vertigo complaint in middle-aged hypertension patients. METHODS: a transversal study. Composed by 154 patients of both genders, aged from 45 to 64 years, included in the research after sample estimation. Hypertension was verified through blood pressure readings and by a systematized questionnaire about hypertension and the use of medication for blood pressure. Vertigo was assessed through audiological anamneses. RESULTS: there is a significant association between blood hypertension and vertigo. CONCLUSION: the results in this research, through evidence of association between blood hypertension and vertigo complaint, can be a base for health professionals concerned with alterations caused by blood hypertension.

Comparative study of Newtonian physiological blood flow through normal and stenosed carotid artery

Science.gov (United States)

Rahman, Mohammad Matiur; Hossain, Md. Anwar; Mamun, Khairuzzaman; Akhter, Most. Nasrin

2017-06-01

A numerical simulation is performed to investigate Newtonian physiological flows behavior on three dimensional idealized carotid artery (CA) and single stenosed (75% by area) carotid artery(SCA). The wall vessel is set as rigid during simulation. Bifurcated blood vessel are simulated by using three-dimensional flow analysis. Physiological and parabolic velocity profiles are set out to fix the conditions of inlet boundaries of artery. In other hand, physiological waveform is an important part of compilation and it is successfully done by utilization of Fourier series having sixteen harmonics. The investigation has a Reynolds number range of 94 to 1120. Low Reynolds number k — ω model has been used as governing equation. The investigation has been carried out to characterize the flow behavior of blood in two geometry, namely, (i) Normal carotid artery (CA) and (ii) Stenosed carotid artery (SCA). The Newtonian model has been used to study the physics of fluid. The findings of the two models are thoroughly compared in order to observe there behavioral sequence of flows. The numerical results were presented in terms of velocity, pressure, wall shear stress distributions and cross sectional velocities as well as the streamlines contour. Stenosis disturbs the normal pattern of blood flow through the artery as reduced area. At stenosis region velocity and peak Reynolds number rapidly increase and Reynolds number reach transitional and turbulent region. These flow fluctuation and turbulence have bad effect to the blood vessel which makes to accelerate the progress of stenosis.

Techniques for Non-Invasive Monitoring of Arterial Blood Pressure

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Agnes S. Meidert

2018-01-01

Full Text Available Since both, hypotension and hypertension, can potentially impair the function of vital organs such as heart, brain, or kidneys, monitoring of arterial blood pressure (BP is a mainstay of hemodynamic monitoring in acutely or critically ill patients. Arterial BP can either be obtained invasively via an arterial catheter or non-invasively. Non-invasive BP measurement provides either intermittent or continuous readings. Most commonly, an occluding upper arm cuff is used for intermittent non-invasive monitoring. BP values are then obtained either manually (by auscultation of Korotkoff sounds or palpation or automatically (e.g., by oscillometry. For continuous non-invasive BP monitoring, the volume clamp method or arterial applanation tonometry can be used. Both techniques enable the arterial waveform and BP values to be obtained continuously. This article describes the different techniques for non-invasive BP measurement, their advantages and limitations, and their clinical applicability.

Cerebral blood flow response to changes in arterial carbon dioxide tension during hypothermic cardiopulmonary bypass in children

International Nuclear Information System (INIS)

Kern, F.H.; Ungerleider, R.M.; Quill, T.J.; Baldwin, B.; White, W.D.; Reves, J.G.; Greeley, W.J.

1991-01-01

We examined the relationship of changes in partial pressure of carbon dioxide on cerebral blood flow responsiveness in 20 pediatric patients undergoing hypothermic cardiopulmonary bypass. Cerebral blood flow was measured during steady-state hypothermic cardiopulmonary bypass with the use of xenon 133 clearance methodology at two different arterial carbon dioxide tensions. During these measurements there was no significant change in mean arterial pressure, nasopharyngeal temperature, pump flow rate, or hematocrit value. Cerebral blood flow was found to be significantly greater at higher arterial carbon dioxide tensions (p less than 0.01), so that for every millimeter of mercury rise in arterial carbon dioxide tension there was a 1.2 ml.100 gm-1.min-1 increase in cerebral blood flow. Two factors, deep hypothermia (18 degrees to 22 degrees C) and reduced age (less than 1 year), diminished the effect carbon dioxide had on cerebral blood flow responsiveness but did not eliminate it. We conclude that cerebral blood flow remains responsive to changes in arterial carbon dioxide tension during hypothermic cardiopulmonary bypass in infants and children; that is, increasing arterial carbon dioxide tension will independently increase cerebral blood flow

Feasibility of arterial blood bypass using microcatheter in intraarterial thrombolysis for acute cerebral ischemic stroke

International Nuclear Information System (INIS)

Wang Wei; Li Cheng; Liu Zhensheng; Zhang Xinjiang; Zhou Longjiang; Yin Haiyan

2010-01-01

Objective: To assess the feasibility of arterial blood bypass using microcatheter in intraarterial thrombolysis for acute cerebral ischemic stroke. Methods: Six patients with acute cerebral infarction within 6 hours underwent intraarterial thrombolysis, in which arterial blood bypass was used. A 2.3 F microcatheter was advanced through the clot and two milliliters of contrast was injected beyond the clot that remained stagnant in the major branches. At this point, 20 ml of oxygenated blood from femoral artery was injected for 2 minutes through the microcatheter past the occluding clot. Then, conventional intraarterial thrombolysis, including fibrinolytic agents infusion and mechanical disruption, was performed. Intraarterial thrombolysis and oxygenated blood infusion alternated every 30 minutes. Results: Every patient received arterial blood bypass with average three times (from 1 to 5 times) in the process of the intraarterial thrombolysis, which cost (8.0 ± 3.2) min. Recanalization was achieved in all 6 patients, but minor subarachnoid hemorrhage developed in one patient. All the patients got favorable clinical outcome. The life conditions is excellent in 4 cases and good in 2 cases. Conclusions: Arterial blood bypass using microcatheter in intraarterial thrombolysis for acute cerebral ischemic stroke might be feasible, which did not interfere with conventional intraarterial thrombolysis and prolong the operation time significantly but could protect ischemic penumbra. (authors)

Numerical investigation of MHD flow of blood and heat transfer in a stenosed arterial segment

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Majee, Sreeparna; Shit, G.C., E-mail: gcs@math.jdvu.ac.in

2017-02-15

A numerical investigation of unsteady flow of blood and heat transfer has been performed with an aim to provide better understanding of blood flow through arteries under stenotic condition. The blood is treated as Newtonian fluid and the arterial wall is considered to be rigid having deposition of plaque in its lumen. The heat transfer characteristic has been analyzed by taking into consideration of the dissipation of energy due to applied magnetic field and the viscosity of blood. The vorticity-stream function formulation has been adopted to solve the problem using implicit finite difference method by developing well known Peaceman–Rachford Alternating Direction Implicit (ADI) scheme. The quantitative profile analysis of velocity, temperature and wall shear stress as well as Nusselt number is carried out over the entire arterial segment. The streamline and temperature contours have been plotted to understand the flow pattern in the diseased artery, which alters significantly in the downstream of the stenosis in the presence of magnetic field. Both the wall shear stress and Nusselt number increases with increasing magnetic field strength. However, wall shear stress decreases and Nusselt number enhances with Reynolds number. The results show that with an increase in the magnetic field strength upto 8 T, does not causes any damage to the arterial wall, but the study is significant for assessing temperature rise during hyperthermic treatment. - Highlights: • Fully numerical simulation is carried out for MHD blood flow in stenosed artery. • Dissipation of energy due to both magnetic field and blood viscosity is considered. • Strong Vortices are observed at the downstream of the stenosis in the arterial wall. • Flow reversal of blood is reduced by applying sufficient magnetic field strength. • Isothermal lines are strongly distorted in the presence of magnetic field strength.

Effect of adjuvant noninvasive positive pressure ventilation on blood gas parameters, cardiac function and inflammatory state in patients with COPD and type II respiratory failure

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You-Ming Zhu1

2017-03-01

Full Text Available Objective: T o analyze the effect of adjuvant noninvasive positive pressure ventilation on blood gas parameters, cardiac function and inflammatory state in patients with chronic obstructive pulmonary disease (COPD and type II respiratory failure. Methods: 90 patients with COPD and type II respiratory failure were randomly divided into observation group and control group (n=45. Control group received conventional therapy, observation group received conventional therapy + adjuvant noninvasive positive pressure ventilation, and differences in blood gas parameters, cardiac function, inflammatory state, etc., were compared between two groups of patients 2 weeks after treatment. Results: Arterial blood gas parameters pH and alveolar-arterial partial pressure of oxygen [P(A-aO2] levels of observation group were higher than those of control group while, potassium ion (K+, chloride ion (Cl﹣ and carbon dioxide combining power (CO2CP levels were lower than those of control group 2 weeks after treatment; echocardiography parameters Doppler-derived tricuspid lateral annular systolic velocity (DTIS and pulmonary arterial velocity (PAV levels were lower than those of control group (P＜0.05 while pulmonary artery accelerating time (PAACT, left ventricular enddiastolic dimension (LVDd and right atrioventricular tricuspid annular plane systolic excursion (TAPSE levels were higher than those of control group (P＜0.05; serum cardiac function indexes adiponectin (APN, Copeptin, N-terminal pro-B-type natriuretic peptide (NT-proBNP, cystatin C (CysC, growth differentiation factor-15 (GDF-15 and heart type fatty acid binding protein (H-FABP content were lower than those of control group (P＜0.05; serum inflammatory factors hypersensitive C-reactive protein (hs-CRP, tumor necrosis factor-α (TNF-α, interleukin-1β (IL-1β, IL-8, IL-10, and transforming growth factor-β1 (TGF-β1 content were lower than those of control group (P＜0.05. Conclusions: Adjuvant

Evaluation of arterial digital blood flow using Doppler ultrasonography in healthy dairy cows.

Science.gov (United States)

Müller, H; Heinrich, M; Mielenz, N; Reese, S; Steiner, A; Starke, A

2017-06-06

Local circulatory disturbances have been implicated in the development of foot disorders in cattle. The goals of this study were to evaluate the suitability of the interdigital artery in the pastern region in both hind limbs using pulsed-wave (PW) Doppler ultrasonography and to investigate quantitative arterial blood flow variables at that site in dairy cows. An Esaote MyLabOne ultrasound machine with a 10-MHz linear transducer was used to assess blood flow in the interdigital artery in the pastern region in both hind limbs of 22 healthy German Holstein cows. The cows originated from three commercial farms and were restrained in a standing hoof trimming chute without sedation. A PW Doppler signal suitable for analysis was obtained in 17 of 22 cows. The blood flow profiles were categorised into four curve types, and the following quantitative variables were measured in three uniform cardiac cycles: vessel diameter, pulse rate, maximum systolic velocity, maximum diastolic velocity, end-diastolic velocity, reverse velocity, maximum time-averaged mean velocity, blood flow rate, resistance index and persistence index. The measurements did not differ among cows from the three farms. Maximum systolic velocity, vessel diameter and pulse rate did not differ but other variables differed significantly among blood flow profiles. Differences in weight-bearing are thought to be responsible for the normal variability of blood flow profiles in healthy cows. The scanning technique used in this report for evaluation of blood flow in the interdigital artery appears suitable for further investigations in healthy and in lame cows.

Investigation Of Arterial Blood Pressure Level And Metabolic Indices In Patients With Arterial Hypertension At Pharmacotherapy With Antihypertensive Medicines Of Various Chemical Structure

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G.Kh. Glybochko

2009-12-01

Full Text Available The research goal is to carry on the comparative analysis of medicines of various chemical structure, Telmisar-tan and Bisoprolol, and to reveal their effect on the arterial blood pressure level and the indices of various metabolic processes in patients with arterial hypertension. 60 out-patients with arterial hypertension (stage II risk III both males and females aged 33-55 have been under study taking Telmisartan and Bisoprolol for 3 months. While treating the patients the arterial blood pressure level control and biochemical investigations for determination the indices of metabolic processes have been carried out. The investigated medications have provided the decrease of systolic and diastolic arterial pressure parameters, the increase of concentration of total and ionized calcium, chlorine ions, urea and total bilirubin in blood plasma. Therapy with Telmisartan has shown more significant increase of potassium level in erythro-cytes, decrease of levels of natrium, glucose, glycolized hemoglobin and triglycerides and increased contents of alani-naminotransferase and aspartataminotransferase. The course of therapy with Bisoprolol has restored the normal level of magnesium in blood plasma, has not have any influence on carbohydrate and lipid metabolism, increased the level of alaninaminotransferase and significantly increased the contents of total and ionized calcium, urea and creatinine. 3-months therapy with Telmisartan and Bisoprolol has proved the decrease of systolic and diastolic arterial pressure in patients with arterial hypertension. The medications under study have had active and variable effects on metabolic indices

Clinical study of color Doppler sonography in Graves' disease blood flow changes after thyroid arteries embolization

International Nuclear Information System (INIS)

Zhuang Wenquan; Li Weiduo; Yang Jianyong; Chen Wei; Huang Yonghui; Guo Wenbo; Li Jiaping

2003-01-01

Objective: To study the color doppler image characteristics of thyroid arteries pre- and post-interventional procedure and to assess the clinical efficacy in Gnaves' disease. Methods: 11 from 31 patients diagnosed as Graves' disease undertaken thyroid arteries embolization, were analyzed. Color Doppler sonography was applied to monitor the pre-and post- procedure thyroid size and diameters of thyroid arteries. Power Doppler was used to detect the Vmax, Vmin, RI and blood flow. Results: After thyroid arteries embolization, the size and vascularity of thyroids were reduced. The thyroid arteries showed shrinkage and stoppage blood flow at the embolized site. The changes of RI, blood parameters of Vmax, Vmin and diameters of the thyroid arteries pre- and post-procedure turned out to be statistically significant for clinical restriction. Conclusion: The color Doppler sonography plays an important role for preoperative diagnosis and predicting the prognosis

Oscillometric blood pressure measurements: differences between measured and calculated mean arterial pressure.

NARCIS (Netherlands)

Kiers, H.D.; Hofstra, J.M.; Wetzels, J.F.M.

2008-01-01

Mean arterial pressure (MAP) is often used as an index of overall blood pressure. In recent years, the use of automated oscillometric blood pressure measurement devices is increasing. These devices directly measure and display MAP; however, MAP is often calculated from systolic blood pressure (SBP)

Longitudinal fasting blood glucose patterns and arterial stiffness risk in a population without diabetes.

Science.gov (United States)

Wu, Yuntao; Yu, Junxing; Jin, Cheng; Li, Yun; Su, Jinmei; Wei, Guoqing; Zheng, Xiaoming; Gao, Jingsheng; Gao, Wenyuan; Wu, Shouling

2017-01-01

To identify long-term fasting blood glucose trajectories and to assess the association between the trajectories and the risk of arterial stiffness in individuals without diabetes. We enrolled 16,454 non-diabetic participants from Kailuan cohort. Fasting blood glucose concentrations were measured in 2006, 2008, and 2010 survey. Brachial-ankle pulse wave velocities were measured during 2011 to 2016. Multivariate regression model was used to estimate the difference of brachial-ankle pulse wave velocity levels and logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (95%CIs) of arterial stiffness risk, according to the fasting blood glucose trajectories. We identified five distinct fasting blood glucose trajectories and each of the trajectories was labeled according to its range and change over 2006-2010 survey: elevated-stable pattern (5.0% of participants), elevated-decreasing pattern (6.6%), moderate-increasing pattern (10.9%), moderate-stable pattern (59.3%), and low-stable pattern (18.2%). After adjustment for potential confounders, individuals with elevated-stable pattern had a 42.6 cm/s (95%CI: 24.7 to 60.6 cm/s) higher brachial-ankle pulse wave velocity level and a 37% (OR 1.37, 95%CI: 1.14 to 1.66) higher arterial stiffness risk, and individuals with moderate-increasing pattern had a 19.6 cm/s (95%CI: 6.9 to 32.3 cm/s) higher brachial-ankle pulse wave velocity level and a 17% (OR 1.17, 95%CI: 1.03 to 1.33) higher arterial stiffness risk, related to individuals with moderate-stable pattern. We did not find significant associations of the elevated-decreasing or low-stable patterns with arterial stiffness. Consistently, the cumulative average, variability, and increased rate of fasting blood glucose during 2006-2010 survey were significantly associated with the arterial stiffness risk. Discrete fasting blood glucose trajectories were associated with the arterial stiffness risk in non-diabetic individuals.

Characterization of a Gas-Purge Method to Access 11C-Carbon-Dioxide Radioactivity in Blood

International Nuclear Information System (INIS)

Ng, Y.; Green, M.A.

2014-01-01

Carbon-11 (t 1/2 : 20 minutes) labeled radiotracers, such as 11 C-acetate and 11 C-palmitate are widely used in positron emission tomography (PET) for noninvasive evaluation of myocardial metabolism under varied physiological conditions. These tracers are attractive probes of tissue physiology, because they are simply radiolabeled versions of the native biochemical substrates. One of the major metabolites generated by these tracers upon the administration is 11 CO 2 produced via the citric acid cycle. In quantitative modeling of 11 C-acetate and 11 C-palmitate PET data, the fraction of blood 11 C radioactivity present as 11 CO 2 needs to be measured to obtain a correct radiotracer arterial input function. Accordingly, the literature describes a method whereby the total blood 11 C-activity is counted in blood samples treated with base solution, while the fraction of 11 CO 2 is measured after the blood is treated with acid followed by a 10 minutes gas-purge. However, a detailed description of the experimental validation of this method was not provided. The goal of this study was to test the reliability of a 10-minute gas purging method used to assay 11 CO 2 radioactivity in blood. (author)

Assessing the blood pressure waveform of the carotid artery using an ultrasound image processing method

Energy Technology Data Exchange (ETDEWEB)

Soleimani, Effat; Mokhtari-Dizaji, Manijhe [Dept. of Medical Physics, Tarbiat Modares University, Tehran (Iran, Islamic Republic of); Fatouraee, Nasser [Dept. of Medical Engineering, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Saben, Hazhir [Dept. Radiology, Imaging Center of Imam Khomaini Hospital, Tehran Medical Sciences University, Tehran (Iran, Islamic Republic of)

2017-04-15

The aim of this study was to introduce and implement a noninvasive method to derive the carotid artery pressure waveform directly by processing diagnostic sonograms of the carotid artery. Ultrasound image sequences of 20 healthy male subjects (age, 36±9 years) were recorded during three cardiac cycles. The internal diameter and blood velocity waveforms were extracted from consecutive sonograms over the cardiac cycles by using custom analysis programs written in MATLAB. Finally, the application of a mathematical equation resulted in time changes of the arterial pressure. The resulting pressures were calibrated using the mean and the diastolic pressure of the radial artery. A good correlation was found between the mean carotid blood pressure obtained from the ultrasound image processing and the mean radial blood pressure obtained using a standard digital sphygmomanometer (R=0.91). The mean absolute difference between the carotid calibrated pulse pressures and those measured clinically was -1.333±6.548 mm Hg. The results of this study suggest that consecutive sonograms of the carotid artery can be used for estimating a blood pressure waveform. We believe that our results promote a noninvasive technique for clinical applications that overcomes the reproducibility problems of common carotid artery tonometry with technical and anatomical causes.

Assessing the blood pressure waveform of the carotid artery using an ultrasound image processing method

International Nuclear Information System (INIS)

Soleimani, Effat; Mokhtari-Dizaji, Manijhe; Fatouraee, Nasser; Saben, Hazhir

2017-01-01

The aim of this study was to introduce and implement a noninvasive method to derive the carotid artery pressure waveform directly by processing diagnostic sonograms of the carotid artery. Ultrasound image sequences of 20 healthy male subjects (age, 36±9 years) were recorded during three cardiac cycles. The internal diameter and blood velocity waveforms were extracted from consecutive sonograms over the cardiac cycles by using custom analysis programs written in MATLAB. Finally, the application of a mathematical equation resulted in time changes of the arterial pressure. The resulting pressures were calibrated using the mean and the diastolic pressure of the radial artery. A good correlation was found between the mean carotid blood pressure obtained from the ultrasound image processing and the mean radial blood pressure obtained using a standard digital sphygmomanometer (R=0.91). The mean absolute difference between the carotid calibrated pulse pressures and those measured clinically was -1.333±6.548 mm Hg. The results of this study suggest that consecutive sonograms of the carotid artery can be used for estimating a blood pressure waveform. We believe that our results promote a noninvasive technique for clinical applications that overcomes the reproducibility problems of common carotid artery tonometry with technical and anatomical causes

Assessment of a continuous blood gas monitoring system in animals during circulatory stress

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Renzulli Attilio

2011-01-01

Full Text Available Abstract Background The study was aimed to determine the measurement accuracy of The CDI™ blood parameter monitoring system 500 (Terumo Cardiovascular Systems Corporation, Ann Arbor MI in the real-time continuous measurement of arterial blood gases under different cardiocirculatory stress conditions Methods Inotropic stimulation (Dobutamine 2.5 and 5 μg/kg/min, vasoconstriction (Arginine-vasopressin 4, 8 and 16 IU/h, hemorrhage (-10%, -20%, -35%, and -50% of the theoretical volemia, and volume resuscitation were induced in ten swine (57.4 ± 10.7 Kg.Intermittent blood gas assessments were carried out using a routine gas analyzer at any experimental phase and compared with values obtained at the same time settings during continuous monitoring with CDI™ 500 system. The Bland-Altman analysis was employed. Results Bias and precision for pO2 were - 0.06 kPa and 0.22 kPa, respectively (r2 = 0.96; pCO2 - 0.02 kPa and 0.15 kPa, respectively; pH -0.001 and 0.01 units, respectively ( r2 = 0.96. The analysis showed very good agreement for SO2 (bias 0.04,precision 0.33, r2 = 0.95, Base excess (bias 0.04,precision 0.28, r2 = 0.98, HCO3 (bias 0.05,precision 0.62, r2 = 0.92,hemoglobin (bias 0.02,precision 0.23, r2 = 0.96 and K+ (bias 0.02, precision 0.27, r2 = 0.93. The sensor was reliable throughout the experiment during hemodynamic variations. Conclusions Continuous blood gas analysis with the CDI™ 500 system was reliable and it might represent a new useful tool to accurately and timely monitor gas exchange in critically ill patients. Nonetheless, our findings need to be confirmed by larger studies to prove its reliability in the clinical setting.

Prognosis in Acute Cerebrovascular Accidents in Relation to Respiratory Pattern and Blood—gas Tensions

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Rout, M. W.; Lane, D. J.; Wollner, L.

1971-01-01

Respiratory pattern and arterial blood gas tensions were assessed in patients with acute cerebrovascular accidents. Hyperventilation, low Pco2, and high arterial pH were associated with a poor prognosis, whereas patients with normal respiratory pattern and blood gas tensions survived. Periodic and Cheyne-Stokes breathing carried an intermediate prognosis. PMID:5091916

Scintigraphic study of blood perfusion of the pulmonary artery in pulmonary tuberculosis

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Certain, D.A.; Brolio, R.; Salomon, G.C.; Carvalho, N.; Barbosa, Z.L.M.

1972-01-01

Blood perfusion in the pulmonary artery is studied by pulmonary scintigraphy with macroaggregated albumin 131 I, in 74 cases of pulmonary tuberculosis. Results shown by scintigraphy are compared to those observed in roentgenography and also correlated with the extension and degree of the lesions, and with the presence of associated tuberculosis, considered capable of changing the scintigraphic picture. The reduction of blood flow in the pulmonary artery are observed in cases of infiltrative, fibrotic of caseous lesions, as well as in cases of minor lesions [pt

Scintigraphic study of blood perfusion of the pulmonary artery in pulmonary tuberculosis

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Certain, D A; Brolio, R; Salomon, G C [Sao Paulo Univ. (Brazil). Faculdade de Saude Publica; Carvalho, N [Sao Paulo Univ. (Brazil). Centro de Medicina Nuclear; Barbosa, Z L.M. [Associacao dos Sanatorios Populares de Campos do Jordao, Brazil

1972-10-01

Blood perfusion in the pulmonary artery is studied by pulmonary scintigraphy with macroaggregated albumin /sup 131/I, in 74 cases of pulmonary tuberculosis. Results shown by scintigraphy are compared to those observed in roentgenography and also correlated with the extension and degree of the lesions, and with the presence of associated tuberculosis, considered capable of changing the scintigraphic picture. The reduction of blood flow in the pulmonary artery are observed in cases of infiltrative, fibrotic of caseous lesions, as well as in cases of minor lesions.

The effect of altering pulmonary blood flow on pulmonary gas exchange in the turtle Trachemys (Pseudemys) scripta.

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Hopkins, S R; Wang, T; Hicks, J W

1996-10-01

In resting reptiles, the PO2 of pulmonary venous return (PLAO2; left atrial blood) may be 20 mmHg (1 mmHg = 0.1333 kPa) lower than the PO2 of gas in the lung. This level of PO2 is considerably higher than that observed in resting mammals and birds and results from ventilation-perfusion (V/Q) heterogeneity, pulmonary diffusion limitation and intrapulmonary shunting. However, the relative contribution of each of these factors is unknown. Many reptiles, particularly chelonians, exhibit an intermittent ventilation pattern where pulmonary blood flow (QL) increases during the ventilatory periods and, therefore, we hypothesized that V/Q matching would improve with increasing QL. We applied the multiple inert gas elimination technique in anaesthetized turtles at 22 degrees C. Turtles were continuously ventilated at a rate of 140 ml kg-1 min-1, equivalent to the rate of ventilation within a ventilatory period. Trace amounts of six inert gases were infused through the jugular vein. Blood samples from the pulmonary artery and the left atrium and mixed expired gases were collected for analysis. QL was reduced by a factor of six (low flow) using a vascular occluder placed around the common pulmonary artery or increased by a factor of two (high flow) through bolus injection of adrenaline. V/Q heterogeneity was significantly reduced with increasing pulmonary blood flow (P means +/- S.E.M.) and PLAO2 increased significantly (P < 0.05) from 88 +/- 17 mmHg (low flow) to 120 +/- 14 mmHg (high flow). There was evidence of pulmonary diffusion limitation under all conditions, which was unchanged with increasing blood flow. These findings suggest that increased pulmonary blood flow during a ventilatory period results in both temporal and spatial matching of ventilation and perfusion, without altering pulmonary diffusion limitation.

[Evaluation of the arterial blood flow parameters in the eye of myopic patients].

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Mrugacz, Małgorzata; Bryl, Anna

2013-04-01

Myopia is a common refractive defect. Has a good vision from near and deterioration of vision with increasing distance. The main reason for its occurrence is too long axis of the eyeball. The consequence of elongation of the eyeball is the development of degenerative changes in the retina. Despite much research has failed to clearly identify the causes of degenerative changes in those short-sighted. The aim of the study was to evaluate the maximum and minimum speed in arterial blood vessels of the eye in people with myopia. The study included 70 patients (138 eyes), 53 women and 17 men, aged from 18 to 79 years, with myopia of -0.25 to -18.0 Dsph and length of the eyeball from 22.61 to 33.36 mm. Depending on the kind and the degree of the progress of degenerative changes, patients were divided in 4 groups: I - without degenerative changes on the fundus (n=32; K-23, M-9); II- with the short-sighted sickle (n=20; K-14, M-6); Ill - with the structure thinned down of the retina, accompanying the short-sighted sickle (n = 8; K-6, M-2); IV - with extensive choroidal-retina disappearances in the fundus (n = 10; K-7, M-3). In all individuals enrolled underwent Color Doppler ultrasound with apparatus SSA 770A Toshiba Aplio with linear probe frequency 12 MHz, judging maximum (Vmax) and minimum (Vmin) speed in the arteries of the eye: ophthalmic artery (OA), central retinal artery (CRA) and short posterior ciliary arteries (SPCA) located on the nasal and temporal side of the optic disc. The results were statistically analyzed. No statistically significant relationship between the nature of degenerative changes of the eye, and blood velocity in the OA. There was a increase in Vmax and Vmin blood in OA in Group IV, but these changes were not statistically significant. Statistically significant correlation was observed while in the CRA. With a decrease in Vmax and Vmin of blood flowing through a vessel exacerbation of retinal degeneration. Vmax and Vmin changes in the blood did

Metabolic liver function measured in vivo by dynamic (18)F-FDGal PET/CT without arterial blood sampling.

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Horsager, Jacob; Munk, Ole Lajord; Sørensen, Michael

2015-01-01

Metabolic liver function can be measured by dynamic PET/CT with the radio-labelled galactose-analogue 2-[(18)F]fluoro-2-deoxy-D-galactose ((18)F-FDGal) in terms of hepatic systemic clearance of (18)F-FDGal (K, ml blood/ml liver tissue/min). The method requires arterial blood sampling from a radial artery (arterial input function), and the aim of this study was to develop a method for extracting an image-derived, non-invasive input function from a volume of interest (VOI). Dynamic (18)F-FDGal PET/CT data from 16 subjects without liver disease (healthy subjects) and 16 patients with liver cirrhosis were included in the study. Five different input VOIs were tested: four in the abdominal aorta and one in the left ventricle of the heart. Arterial input function from manual blood sampling was available for all subjects. K*-values were calculated using time-activity curves (TACs) from each VOI as input and compared to the K-value calculated using arterial blood samples as input. Each input VOI was tested on PET data reconstructed with and without resolution modelling. All five image-derived input VOIs yielded K*-values that correlated significantly with K calculated using arterial blood samples. Furthermore, TACs from two different VOIs yielded K*-values that did not statistically deviate from K calculated using arterial blood samples. A semicircle drawn in the posterior part of the abdominal aorta was the only VOI that was successful for both healthy subjects and patients as well as for PET data reconstructed with and without resolution modelling. Metabolic liver function using (18)F-FDGal PET/CT can be measured without arterial blood samples by using input data from a semicircle VOI drawn in the posterior part of the abdominal aorta.

[Influence of Sympathetic Denervation of the Renal Artery on the Level of Arterial Blood Pressure, Cerebral Blood Flow and Cognitive Function In Patients With Resistant Arterial Hypertension].

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Efimova, Y N; Lichikaki, A V; Lishmanov, B Y

2017-07-01

To study the effect of radiofrequency ablation of renal arteries on regional cerebral blood flow and cognitive function in patients with resistant arterial hypertension (AH). Transcatheter renal denervation (TRD) was performed in 17 patients with resistant AH. Examination before and after TRD included SPECT with mTc-HMPAO, 24-hours blood pressure (BP) monitoring, and comprehensive neuropsychological testing. Fifteen patients without angiographic signs of carotid atherosclerosis, coronary artery disease and AH, neurological and psychiatric disorders were investigated as control group. Compared with control group patients with AH had decreases of regional cerebral blood flow (rCBF) in right (by 13.5%, p=0.00002) and left (by 15.5%, p=0.0006) inferior frontal lobes, in right temporal brain region (by 11.5%, p=0.008); in right and left occipital lobes (by 8.2%, p=0.04). In 6 months after TRD we observed significant improvement of cognitive function, parameters of 24-hour BP monitoring, and rCBF. We also noted definite close interdependence between changes of rCBF, indices of 24-hours BP monitoring, and dynamics of cognitive function. Improvement of long-term verbal memory correlated with increases of rCBF in left superior frontal and right occipital regions while dynamics of mentation and attention correlated positively with augmentation of rCBF in right posterior parietal region. Changes of perfusion in inferior parts of left frontal lobe and in right occipital region correlated with dynamics of index of diurnal diastolic hypertension time (R2=0.64, p=0.001, and R2=0.60, p=0.03, respectively). Our results suggest, that in patients with resistant AH positive effect of TRD on levels of 24-hour mean BP as well as on indices of BP load leads to in augmentation of rCBF and improvement of cognitive function.

Energy harvesting from arterial blood pressure for powering embedded brain sensors

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Nanda, Aditya; Karami, M. Amin

2016-04-01

This paper investigates energy harvesting from arterial blood pressure via the piezoelectric effect by using a novel streaked cylinder geometry for the purpose of powering embedded micro-sensors in the brain. Initially, we look at the energy harvested by a piezoelectric cylinder placed inside an artery acted upon by blood pressure. Such an arrangement would be tantamount to constructing a stent out of piezoelectric materials. A stent is a cylinder placed in veins and arteries to prevent obstruction in blood flow. The governing equations of a conductor coated piezoelectric cylinder are obtained using Hamilton's principle. Pressure acting in arteries is radially directed and this is used to simplify the modal analysis and obtain the transfer function relating pressure to the induced voltage across the surface of the harvester. The power harvested by the cylindrical harvester is obtained for different shunt resistances. Radially directed pressure occurs elsewhere and we also look at harvesting energy from oil flow in pipelines. Although the energy harvested by the cylindrical energy harvester is significant at resonance, the natural frequency of the system is found to be very high. To decrease the natural frequency, we propose a novel streaked stent design by cutting it along the length, transforming it to a curved plate and decreasing the natural frequency. The governing equations corresponding to the new geometry are derived using Hamilton's principle and modal analysis is used to obtain the transfer function.

Blood Pressure and Arterial Load After Transcatheter Aortic Valve Replacement for Aortic Stenosis.

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Lindman, Brian R; Otto, Catherine M; Douglas, Pamela S; Hahn, Rebecca T; Elmariah, Sammy; Weissman, Neil J; Stewart, William J; Ayele, Girma M; Zhang, Feifan; Zajarias, Alan; Maniar, Hersh S; Jilaihawi, Hasan; Blackstone, Eugene; Chinnakondepalli, Khaja M; Tuzcu, E Murat; Leon, Martin B; Pibarot, Philippe

2017-07-01

After aortic valve replacement, left ventricular afterload is often characterized by the residual valve obstruction. Our objective was to determine whether higher systemic arterial afterload-as reflected in blood pressure, pulsatile and resistive load-is associated with adverse clinical outcomes after transcatheter aortic valve replacement (TAVR). Total, pulsatile, and resistive arterial load were measured in 2141 patients with severe aortic stenosis treated with TAVR in the PARTNER I trial (Placement of Aortic Transcatheter Valve) who had systolic blood pressure (SBP) and an echocardiogram obtained 30 days after TAVR. The primary end point was 30-day to 1-year all-cause mortality. Lower SBP at 30 days after TAVR was associated with higher mortality (20.0% for SBP 100-129 mm Hg versus 12.0% for SBP 130-170 mm Hg; P <0.001). This association remained significant after adjustment, was consistent across subgroups, and confirmed in sensitivity analyses. In adjusted models that included SBP, higher total and pulsatile arterial load were associated with increased mortality ( P <0.001 for all), but resistive load was not. Patients with low 30-day SBP and high pulsatile load had a 3-fold higher mortality than those with high 30-day SBP and low pulsatile load (26.1% versus 8.1%; hazard ratio, 3.62; 95% confidence interval, 2.36-5.55). Even after relief of valve obstruction in patients with aortic stenosis, there is an independent association between post-TAVR blood pressure, systemic arterial load, and mortality. Blood pressure goals in patients with a history of aortic stenosis may need to be redefined. Increased pulsatile arterial load, rather than blood pressure, may be a target for adjunctive medical therapy to improve outcomes after TAVR. URL: http://www.clinicaltrials.gov. Unique identifier: NCT00530894. © 2017 American Heart Association, Inc.

Corrections of arterial input function for dynamic H215O PET to assess perfusion of pelvic tumours: arterial blood sampling versus image extraction

International Nuclear Information System (INIS)

Luedemann, L; Sreenivasa, G; Michel, R; Rosner, C; Plotkin, M; Felix, R; Wust, P; Amthauer, H

2006-01-01

Assessment of perfusion with 15 O-labelled water (H 2 15 O) requires measurement of the arterial input function (AIF). The arterial time activity curve (TAC) measured using the peripheral sampling scheme requires corrections for delay and dispersion. In this study, parametrizations with and without arterial spillover correction for fitting of the tissue curve are evaluated. Additionally, a completely noninvasive method for generation of the AIF from a dynamic positron emission tomography (PET) acquisition is applied to assess perfusion of pelvic tumours. This method uses a volume of interest (VOI) to extract the TAC from the femoral artery. The VOI TAC is corrected for spillover using a separate tissue TAC and for recovery by determining the recovery coefficient on a coregistered CT data set. The techniques were applied in five patients with pelvic tumours who underwent a total of 11 examinations. Delay and dispersion correction of the blood TAC without arterial spillover correction yielded in seven examinations solutions inconsistent with physiology. Correction of arterial spillover increased the fitting accuracy and yielded consistent results in all patients. Generation of an AIF from PET image data was investigated as an alternative to arterial blood sampling and was shown to have an intrinsic potential to determine the AIF noninvasively and reproducibly. The AIF extracted from a VOI in a dynamic PET scan was similar in shape to the blood AIF but yielded significantly higher tissue perfusion values (mean of 104.0 ± 52.0%) and lower partition coefficients (-31.6 ± 24.2%). The perfusion values and partition coefficients determined with the VOI technique have to be corrected in order to compare the results with those of studies using a blood AIF

Analysis of bias in measurements of potassium, sodium and hemoglobin by an emergency department-based blood gas analyzer relative to hospital laboratory autoanalyzer results.

Directory of Open Access Journals (Sweden)

Jian Bo Zhang

Full Text Available The emergency departments (EDs of Chinese hospitals are gradually being equipped with blood gas machines. These machines, along with the measurement of biochemical markers by the hospital laboratory, facilitate the care of patients with severe conditions who present to the ED. However, discrepancies have been noted between the Arterial Blood Gas (ABG analyzers in the ED and the hospital laboratory autoanalyzer in relation to electrolyte and hemoglobin measurements. The present study was performed to determine whether the ABG and laboratory measurements of potassium, sodium, and hemoglobin levels are equivalent, and whether ABG analyzer results can be used to guide clinical care before the laboratory results become available.Study power analyses revealed that 200 consecutive patients who presented to our ED would allow this prospective single-center cohort study to detect significant differences between ABG- and laboratory-measured potassium, sodium, and hemoglobin levels. Paired arterial and venous blood samples were collected within 30 minutes. Arterial blood samples were measured in the ED by an ABL 90 FLEX blood gas analyzer. The biochemistry and blood cell counts of the venous samples were measured in the hospital laboratory. The potassium, sodium, and hemoglobin concentrations obtained by both methods were compared by using paired Student's t-test, Spearman's correlation, Bland-Altman plots, and Deming regression.The mean ABG and laboratory potassium values were 3.77±0.44 and 4.2±0.55, respectively (P<0.0001. The mean ABG and laboratory sodium values were 137.89±5.44 and 140.93±5.50, respectively (P<0.0001. The mean ABG and laboratory Hemoglobin values were 12.28±2.62 and 12.35±2.60, respectively (P = 0.24.Although there are the statistical difference and acceptable biases between ABG- and laboratory-measured potassium and sodium, the biases do not exceed USCLIA-determined limits. In parallel, there are no statistical differences and

A 2D nonlinear multiring model for blood flow in large elastic arteries

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Ghigo, Arthur R.; Fullana, Jose-Maria; Lagrée, Pierre-Yves

2017-12-01

In this paper, we propose a two-dimensional nonlinear ;multiring; model to compute blood flow in axisymmetric elastic arteries. This model is designed to overcome the numerical difficulties of three-dimensional fluid-structure interaction simulations of blood flow without using the over-simplifications necessary to obtain one-dimensional blood flow models. This multiring model is derived by integrating over concentric rings of fluid the simplified long-wave Navier-Stokes equations coupled to an elastic model of the arterial wall. The resulting system of balance laws provides a unified framework in which both the motion of the fluid and the displacement of the wall are dealt with simultaneously. The mathematical structure of the multiring model allows us to use a finite volume method that guarantees the conservation of mass and the positivity of the numerical solution and can deal with nonlinear flows and large deformations of the arterial wall. We show that the finite volume numerical solution of the multiring model provides at a reasonable computational cost an asymptotically valid description of blood flow velocity profiles and other averaged quantities (wall shear stress, flow rate, ...) in large elastic and quasi-rigid arteries. In particular, we validate the multiring model against well-known solutions such as the Womersley or the Poiseuille solutions as well as against steady boundary layer solutions in quasi-rigid constricted and expanded tubes.

Evaluation of arterial blood gases and arterial blood pressures in brachycephalic dogs.

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Hoareau, G L; Jourdan, G; Mellema, M; Verwaerde, P

2012-01-01

Brachycephalic dogs (BD) are prone to congenital upper airway obstruction (brachycephalic syndrome, BS). In humans suffering from sleep apnea, upper airway obstruction is known to cause hypertension. There is no information regarding the influence of BS in dogs on cardiorespiratory physiology. BD are prone to lower P(a) O(2), higher P(a) CO (2), and hypertension compared with meso- or dolicocephalic dogs (MDD). Eleven BD and 11 MDD. After a questionnaire was completed by the owner, a physical examination was performed. Height and thoracic circumferences were measured. Arterial blood gases, electrolyte concentrations, and packed cell volume (PCV) were measured. Systolic (SAP), mean (MAP), and diastolic (DAP) arterial blood pressure recordings were performed. A total of 7 French and 4 English bulldogs met the inclusion criteria. The control group consisted in 6 Beagles, 2 mixed breed dogs, 1 Staffordshire Bull Terrier, 1 Parson Russell Terrier, and 1 Australian Cattle Dog. Statistically, BD had lower P(a) O(2), higher P(a) CO2, and higher PCV when compared with controls (86.2 ± 15.9 versus 100.2 ± 12.6 mmHg, P = .017; 36.3 ± 4.6 versus 32.7 ± 2.6 mmHg, P = .019; 48.2 ± 3.5 versus 44.2 ± 5.4%, P = .026, respectively). Also, they had significantly higher SAP (177.6 ± 25.0 versus 153.5 ± 21.7 mmHg, P = .013), MAP (123.3 ± 17.1 versus 108.3 ± 12.2 mmHg, P = .014), and DAP (95.3 ± 19.2 versus 83.0 ± 11.5 mmHg, P = .042). BD with a P(a) CO (2) >35 mmHg were significantly older than those with a P(a) CO (2) ≤35 mmHg (58 ± 16 and 30 ± 11 months, P = .004). Results of this study suggest that some BD are prone to lower P(a) O(2), higher P(a) CO (2), and hypertension when compared with MDD. Age may be a contributing factor. Copyright © 2012 by the American College of Veterinary Internal Medicine.

Use of paravascular admittance waveforms to monitor relative change in arterial blood pressure

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Zielinski, Todd M.; Hettrick, Doug; Cho, Yong

2010-04-01

Non-invasive methods to monitor ambulatory blood pressure often have limitations that can affect measurement accuracy and patient adherence [1]. Minimally invasive measurement of a relative blood pressure surrogate with an implantable device may provide a useful chronic diagnostic and monitoring tool. We assessed a technique that uses electrocardiogram and paravascular admittance waveform morphology analysis to one, measure a time duration (vascular tone index, VTI in milliseconds) change from the electrocardiogram R-wave to admittance waveform peak and two, measure the admittance waveform minimum, maximum and magnitude as indicators of change in arterial compliance/distensibility or pulse pressure secondary to change in afterload. Methods: Five anesthetized domestic pigs (32 ± 4.2 kg) were used to study the effects of phenylephrine (1-5 ug/kg/min) on femoral artery pressure and admittance waveform morphology measured with a quadrapolar electrode array catheter placed next to the femoral artery to assess the relative change in arterial compliance due to change in peripheral vascular tone. Results: Statistical difference was observed (p blood pressure may be suitable for implantable devices to detect progression of cardiovascular disease such as hypertension.

[Baroreflexes originated in vertebral artery zones upon peripheral vein tonus, systemic arterial blood pressure, and external respiration].

Science.gov (United States)

Agadzhanian, N A; Kupriianov, S V

2008-06-01

The investigation was intended to study the role ofbaroreceptors ofhemodynamically isolated zone of vertebral arteries in regulation of peripheral veins tonus, arterial pressure and external respiration. Pressure decrease in this vascular reflexogenic zone led to reflex responses of increase in femoral vein tonus, elevation of blood pressure level and stimulation of external respiration. The opposite reflex responses of cardio-respiratory functional system to initial pressure activation of vertebral arteries baroreceptors are observed. Basing on generalization of our own findings and similar physiological and morphological researches of other authors, it is established that afferentation from the vertebral artery zone is a reflexogenic factor of somatic muscles' veins tonus regulation. These reflexes of capacity vessels tonic activity changes are part of cardio-respiratory responses of maintaining the tissue gaseous exchange.

Investigation of spiral blood flow in a model of arterial stenosis.

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Paul, Manosh C; Larman, Arkaitz

2009-11-01

The spiral component of blood flow has both beneficial and detrimental effects in human circulatory system [Stonebridge PA, Brophy CM. Spiral laminar flow in arteries? Lancet 1991; 338: 1360-1]. We investigate the effects of the spiral blood flow in a model of three-dimensional arterial stenosis with a 75% cross-sectional area reduction at the centre by means of computational fluid dynamics (CFD) techniques. The standard k-omega model is employed for simulation of the blood flow for the Reynolds number of 500 and 1000. We find that for Re=500 the spiral component of the blood flow increases both the total pressure and velocity of the blood, and some significant differences are found between the wall shear stresses of the spiral and non-spiral induced flow downstream of the stenosis. The turbulent kinetic energy is reduced by the spiral flow as it induces the rotational stabilities in the forward flow. For Re=1000 the tangential component of the blood velocity is most influenced by the spiral speed, but the effect of the spiral flow on the centreline turbulent kinetic energy and shear stress is mild. The results of the effects of the spiral flow are discussed in the paper along with the relevant pathological issues.

Sympathoadrenal, cardiovascular and blood gas responses to highly selective mu and delta opioid peptides.

Science.gov (United States)

Kiritsy-Roy, J A; Marson, L; Van Loon, G R

1989-12-01

The relative importance of mu and delta opioid receptors in brain regulation of sympathoadrenal, cardiovascular and respiratory function was investigated using highly selective mu and delta opioid peptide analogs. Groups of conscious rats received i.c.v. injections of either the mu-selective agonist, [D-Ala2, MePhe4, Gly-ol5]enkephalin (DAMGO) or the delta-selective agonist, [D-Pen2, D-Pen5]enkephalin (DPDPE). Blood pressure and heart rate were recorded continuously via a chronic catheter in the carotid artery, and arterial blood samples were taken at intervals through the same catheter for determination of blood pH, pCO2, pO2 and plasma catecholamine concentrations. Both DAMGO and DPDPE increased plasma catecholamine levels and blood pressure in a dose-related manner. The slopes of the dose-response lines were parallel, but the delta compound was about 250 times less potent than DAMGO. Only the highest dose of 5 nmol of DAMGO caused a significant bradycardia, mediated by parasympathetic (vagal) activation. DAMGO and DPDPE also induced dose-dependent acidosis, with DAMGO again being much more potent than DPDPE. The effects of both DAMGO and DPDPE on plasma catecholamines, blood pressure and blood gases were antagonized by a mu-selective dose of naloxone (0.4 mg/kg i.a.). Intracerebroventricular administration of the delta-selective antagonist, ICI 174,864, only partially attenuated sympathoadrenal and blood gas responses to DAMGO or DPDPE. The pressor responses to DAMGO or DPDPE were resistant to antagonism by ICI 174,864. These results indicate that brain opioid receptors regulating autonomic outflow, cardiovascular and respiratory function are mainly of the mu type, although a delta opioid system may contribute to sympathoadrenal and respiratory effects of opioids.

[Interpretation and use of routine pulmonary function tests: Spirometry, static lung volumes, lung diffusion, arterial blood gas, methacholine challenge test and 6-minute walk test].

Science.gov (United States)

Bokov, P; Delclaux, C

2016-02-01

Resting pulmonary function tests (PFT) include the assessment of ventilatory capacity: spirometry (forced expiratory flows and mobilisable volumes) and static volume assessment, notably using body plethysmography. Spirometry allows the potential definition of obstructive defect, while static volume assessment allows the potential definition of restrictive defect (decrease in total lung capacity) and thoracic hyperinflation (increase in static volumes). It must be kept in mind that this evaluation is incomplete and that an assessment of ventilatory demand is often warranted, especially when facing dyspnoea: evaluation of arterial blood gas (searching for respiratory insufficiency) and measurement of the transfer coefficient of the lung, allowing with the measurement of alveolar volume to calculate the diffusing capacity of the lung for CO (DLCO: assessment of alveolar-capillary wall and capillary blood volume). All these pulmonary function tests have been the subject of an Americano-European Task force (standardisation of lung function testing) published in 2005, and translated in French in 2007. Interpretative strategies for lung function tests have been recommended, which define abnormal lung function tests using the 5th and 95th percentiles of predicted values (lower and upper limits of normal values). Thus, these recommendations need to be implemented in all pulmonary function test units. A methacholine challenge test will only be performed in the presence of an intermediate pre-test probability for asthma (diagnostic uncertainty), which is an infrequent setting. The most convenient exertional test is the 6-minute walk test that allows the assessment of walking performance, the search for arterial desaturation and the quantification of dyspnoea complaint. Copyright © 2015 Société nationale française de médecine interne (SNFMI). Published by Elsevier SAS. All rights reserved.

Changes in Hepatic Blood Flow During Transcatheter Arterial Infusion with Heated Saline in Hepatic VX2 Tumor

International Nuclear Information System (INIS)

Cao Wei; Li Jing; Wu Zhiqun; Zhou Changxi; Liu Xi; Wan Yi; Duan Yunyou

2013-01-01

Purpose. This study evaluates the influence of transcatheter arterial infusion with heated saline on hepatic arterial and portal venous blood flows to tumor and normal hepatic tissues in a rabbit VX2 tumor model. Methods. All animal experiments were approved by the institutional animal care and use committee. Twenty rabbits with VX2 liver tumors were divided into the following two groups: (a) the treated group (n = 10), which received a 60 mL transarterial injection of 60 °C saline via the hepatic artery; (b) the control group (n = 10), which received a 60 mL injection of 37 °C saline via the hepatic artery. Using ultrasonography, the blood flows in both the portal vein and hepatic artery were measured, and the changes in the hemodynamic indices were recorded before and immediately after the injection. The changes in the tumor and normal liver tissues of the two groups were histopathologically examined by hematoxylin and eosin staining after the injection. Results. After the transcatheter arterial heated infusion, there was a decrease in the hepatic arterial blood flow to the tumor tissue, a significant decrease in the hepatic artery mean velocity (P < 0.05), and a significant increase in the resistance index (P < 0.05). On hematoxylin and eosin staining, there were no obvious signs of tissue destruction in the normal liver tissue or the tumor tissue after heated perfusion, and coagulated blood plasma was observed in the cavities of intratumoral blood vessels in the treated group. Conclusions. The changes in tumor blood flow in the rabbit VX2 tumor model were presumably caused by microthrombi in the tumor vessels, and the portal vein likely mediated the heat loss in normal liver tissue during the transarterial heated infusion.

Changes in Hepatic Blood Flow During Transcatheter Arterial Infusion with Heated Saline in Hepatic VX2 Tumor

Energy Technology Data Exchange (ETDEWEB)

Cao Wei, E-mail: cawe-001@163.com [Tangdu Hospital, The Fourth Military Medical University, Department of Interventional Radiology (China); Li Jing, E-mail: lijing02@fmmu.edu.cn [Tangdu Hospital, The Fourth Military Medical University, Department of Burn and Plastic Surgery (China); Wu Zhiqun, E-mail: zhiqunwu@fmmu.edu.cn [Tangdu Hospital, The Fourth Military Medical University, Department of Interventional Radiology (China); Zhou Changxi, E-mail: changxizhou@163.com [Chinese PLA General Hospital, Department of Respiratory Disease (China); Liu Xi, E-mail: xiliu@fmmu.edu.cn [Tangdu Hospital, The Fourth Military Medical University, Department of Ultrasound Diagnostics (China); Wan Yi, E-mail: yiwan@163.com [The Fourth Military Medical University, Department of Health Statistics, Institute for Health Informatics (China); Duan Yunyou, E-mail: yunyouduan@fmmu.edu.cn [Tangdu Hospital, The Fourth Military Medical University, Department of Ultrasound Diagnostics (China)

2013-06-15

Purpose. This study evaluates the influence of transcatheter arterial infusion with heated saline on hepatic arterial and portal venous blood flows to tumor and normal hepatic tissues in a rabbit VX2 tumor model. Methods. All animal experiments were approved by the institutional animal care and use committee. Twenty rabbits with VX2 liver tumors were divided into the following two groups: (a) the treated group (n = 10), which received a 60 mL transarterial injection of 60 Degree-Sign C saline via the hepatic artery; (b) the control group (n = 10), which received a 60 mL injection of 37 Degree-Sign C saline via the hepatic artery. Using ultrasonography, the blood flows in both the portal vein and hepatic artery were measured, and the changes in the hemodynamic indices were recorded before and immediately after the injection. The changes in the tumor and normal liver tissues of the two groups were histopathologically examined by hematoxylin and eosin staining after the injection. Results. After the transcatheter arterial heated infusion, there was a decrease in the hepatic arterial blood flow to the tumor tissue, a significant decrease in the hepatic artery mean velocity (P < 0.05), and a significant increase in the resistance index (P < 0.05). On hematoxylin and eosin staining, there were no obvious signs of tissue destruction in the normal liver tissue or the tumor tissue after heated perfusion, and coagulated blood plasma was observed in the cavities of intratumoral blood vessels in the treated group. Conclusions. The changes in tumor blood flow in the rabbit VX2 tumor model were presumably caused by microthrombi in the tumor vessels, and the portal vein likely mediated the heat loss in normal liver tissue during the transarterial heated infusion.

Dual-modality arterial pulse monitoring system for continuous blood pressure measurement.

Science.gov (United States)

Wen-Xuan Dai; Yuan-Ting Zhang; Jing Liu; Xiao-Rong Ding; Ni Zhao

2016-08-01

Accurate and ambulatory measurement of blood pressure (BP) is essential for efficient diagnosis, management and prevention of cardiovascular diseases (CVDs). However, traditional cuff-based BP measurement methods provide only intermittent BP readings and can cause discomfort with the occlusive cuff. Although pulse transit time (PTT) method is promising for cuffless and continuous BP measurement, its pervasive use is restricted by its limited accuracy and requirement of placing sensors on multiple body sites. To tackle these issues, we propose a novel dual-modality arterial pulse monitoring system for continuous blood pressure measurement, which simultaneously records the pressure and photoplethysmography (PPG) signals of radial artery. The obtained signals can be used to generate a pressure-volume curve, from which the elasticity index (EI) and viscosity index (VI) can be extracted. Experiments were carried out among 7 healthy subjects with their PPG, ECG, arterial pressure wave and reference BP collected to examine the effectiveness of the proposed indexes. The results of this study demonstrate that a linear regression model combining EI and VI has significantly higher BP tracking correlation coefficient as compared to the PTT method. This suggests that the proposed system and method can potentially be used for convenient and continuous blood pressure estimation with higher accuracy.

Tulathromycin disturbs blood oxidative and coagulation status | Er ...

African Journals Online (AJOL)

... (white and red blood cells) and arterial blood gas parameters (packed cell volume, ... excess in vitro, oxygen saturation, sodium and potassium) were also determined. Tulathromycin increased (P < 0.05) the levels of malondialdehyde, nitric ...

Intravenous digital subtraction angiography for the evaluation of renal artery blood flow following the removal of a neuroblastoma

International Nuclear Information System (INIS)

Yamagiwa, Iwao; Obata, Kazuya; Saito, Hiroyuki; Washio, Masahiko

1994-01-01

There have been several reports of acute renal failure following the resection of an abdominal neuroblastoma combined with ipsilateral nephrectomy as well as the atrophy or disappearance of an unresected kidney after tumor resection. Spasms or thrombosis of the renal artery during tumor excision are considered to be the major cause. Since 1989, intravenous digital subtraction angiography (IVDSA) has been used to evaluate the renal artery blood flow immediately following surgery in seven patients with abdominal neuroblastomas. IVDSA was performed using a central venous catheter inserted prior to surgery. In all seven patients, IVDSA provided clear images for the evaluation of renal artery blood flow. In one of the two patients whose kidneys briefly became cyanosed during tumor excision, IVDSA demonstrated an occlusion of the renal artery and prompt measures could be taken to reestablish the blood flow. No complications of IVDSA occurred in any of the seven patients. IVDSA using a central venous catheter was thus considered to be useful for evaluating the renal artery blood flow in patients with a suspected renal artery blood flow disturbance without any risk of complications, and this modality obviated the need for intraarterial angiography. (author)

Relationship of 133Xe cerebral blood flow to middle cerebral arterial flow velocity in men at rest

Science.gov (United States)

Clark, J. M.; Skolnick, B. E.; Gelfand, R.; Farber, R. E.; Stierheim, M.; Stevens, W. C.; Beck, G. Jr; Lambertsen, C. J.

1996-01-01

Cerebral blood flow (CBF) was measured by 133Xe clearance simultaneously with the velocity of blood flow through the left middle cerebral artery (MCA) over a wide range of arterial PCO2 in eight normal men. Average arterial PCO2, which was varied by giving 4% and 6% CO2 in O2 and by controlled hyperventilation on O2, ranged from 25.3 to 49.9 mm Hg. Corresponding average values of global CBF15 were 27.2 and 65.0 ml 100 g min-1, respectively, whereas MCA blood-flow velocity ranged from 42.8 to 94.2 cm/s. The relationship of CBF to MCA blood-flow velocity over the imposed range of arterial PCO2 was described analytically by a parabola with the equation: CBF = 22.8 - 0.17 x velocity + 0.006 x velocity2 The observed data indicate that MCA blood-flow velocity is a useful index of CBF response to change in arterial PCO2 during O2 breathing at rest. With respect to baseline values measured while breathing 100% O2 spontaneously, percent changes in velocity were significantly smaller than corresponding percent changes in CBF at increased levels of arterial PCO2 and larger than CBF changes at the lower arterial PCO2. These observed relative changes are consistent with MCA vasodilation at the site of measurement during exposure to progressive hypercapnia and also during extreme hyperventilation hypocapnia.

Changes in myocardial blood flow and S-T segment elevation following coronary artery occlusion in dogs

International Nuclear Information System (INIS)

Smith, H.J.; Singh, B.N.; Norris, R.M.; John, M.B.; Hurley, P.J.

1975-01-01

The relationship between regional blood flow and epicardial S-T segment elevation was studied in 26 open-chest anesthetized dogs with left anterior coronary artery ligations. Changes in myocardial blood flow, measured with 15 +- 5 μ (diameter) microspheres labeled with 141 Ce, 85 Sr, and 169 Yb, were correlated with summated S-T segment elevations 15 minutes, 1 hour, and 2 hours after coronary artery occlusion. In normal areas, myocardial blood flow was 113 +- 5 ml/min 100 g -1 and summated S-T segment elevation was 0.3 +- 0.2 mv. Fifteen minutes after coronary artery occlusion in 26 dogs, S-T segment elevation was 5.7 +- 0.7 mv over the center of the infarct and myocardial blood flow was 10 +- 1 ml/min 100 g -1 ; over the border zone, myocardial blood flow was 63 +- 4 ml/min 100 g -1 and S-T segment elevation was 3.1 +- 0.1 mv. One third of the areas with a myocardial blood flow of 10 ml/min 100 g -1 or less had no S-T segment elevation. In the center and border zones of the infarct in 9 dogs, myocardial blood flow increased from 11 +- 2 and 67 +- 8 ml/min 100 g -1 15 minutes after occlusion to 20 +- 4 and 84 +- 12 ml/min 100 g -1 , respectively, 2 hours after coronary artery occlusion. These increases were not associated with a significant reduction in summated S-T segment elevation. The results do not suggest a simple quantitative relationship between epicardial S-T segment elevation and myocardial blood flow following acute coronary artery occlusion

Nocturnal foot blood flow in patients with arterial insufficiency

DEFF Research Database (Denmark)

Jelnes, Rolf; Tønnesen, K H

1984-01-01

Twenty-four hour continuous recording of xenon (133Xe) wash-out from the forefoot was performed on patients with normal circulations (n = 10) and on patients with different degrees of arterial insufficiency (n = 36). During day hours the calculated subcutaneous blood flow in the forefoot was on a...

Non Newtonian Behavior of Blood in Presence of Arterial Occlusion

OpenAIRE

Dr.Arun Kumar Maiti

2016-01-01

The objective of the present numerical model is to investigate the effect of shape of stenosis on blood flow through an artery using Bingham plastic fluid model. Blood is modeled as Bingham plastic fluid in a uniform circular tube with an axially symmetric but radially non symmetric stenosis. The expressions for flux, dimensionless resistance to flow with stenosis shape parameter, stenosis length and stenosis size have been shown graphically

Distribution of the blood flow supplied by the vertebral artery in humans as assessed by emission CT

International Nuclear Information System (INIS)

Taki, W.; Handa, H.; Higa, T.; Tanada, S.; Fukuyama, H.; Fujita, T.; Yonekawa, Y.; Kameyama, M.; Torizuka, K.

1984-01-01

Though unilateral blood distribution of the vertebral artery has not been studied in humans, it is significant when considering the ischemic events especially embolic occlusion in vertebrobasilar system. To clarify the blood distribution, Krypton-81m was continuously infused into the vertebral arteries of 10 patients. Radioactivity was recorded by a rotating gamma camera. The perfusion images, reconstructed by computer in the transaxial plane, were classified according to whether the distribution was equal, or predominantly unilateral. Overlapping of blood supply from each vertebral artery was studied. In addition, the perfusion from one of the vertebral arteries revealed four distribution patterns with respect to laterality. A) ipsilateral; B) contralateral; C) bilateral; D) mosaic. Images obtained following perfusion of the vertebral artery show less uniformity compared to that of the internal carotid artery, suggesting a complicated vascular supply of the vertebral basilar territory. This complex distribution can be classified by the use of continuous infusion of Krypton-81m

Measurement of cerebral blood flow the blood sampling method using 99mTc-ECD. Simultaneous scintigram scanning of arterial blood samples and the brain with a gamma camera

International Nuclear Information System (INIS)

Hachiya, Takenori; Inugami, Atsushi; Iida, Hidehiro; Mizuta, Yoshihiko; Kawakami, Takeshi; Inoue, Minoru

1999-01-01

To measure regional cerebral blood flow (rCBF) by blood sampling using 99m Tc-ECD we devised a method of measuring the radioactive concentration in arterial blood sample with a gamma camera. In this method the head and a blood sample are placed within the same visual field to record the SPECT data of both specimens simultaneously. The results of an evaluation of the counting rate performance, applying the 30 hours decaying method using 99m Tc solution showed that this method is not comparable to the well-type scintillation counter and in clinical cases the active concentration in arterial blood sample remained well within the dynamic range. In addition, examination of the influence of scattered radiation from the brain by the dilution method showed that it was negligible at a distance of more than 7.5 cm between the brain and the arterial blood sample. In the present study we placed a head-shaped phantom next to the sample. The results of the examinations suggested that this method is suitable for clinical application, and because it does not require a well-type scintillation counter, it is expected to find wide application. (author)

Hemoglobin, hematocrit, and changes in cerebral blood flow : The Second Manifestations of ARTerial disease-Magnetic Resonance study

NARCIS (Netherlands)

van der Veen, Pieternella H.; Muller, Majon; Vincken, Koen L.; Westerink, Jan; Mali, Willem P. T. M.; van der Graaf, Yolanda; Geerlings, Mirjam I.; Doevendans, PAFM

Hemoglobin and hematocrit are important determinants of blood viscosity and arterial oxygen content and may therefore influence cerebral blood flow (CBF). We examined cross-sectional and prospective associations of hemoglobin and hematocrit with CBF in 569 patients with manifest arterial disease

Arterial Blood Pressure Induces Transient C4b-Binding Protein in Human Saphenous Vein Grafts.

Science.gov (United States)

Kupreishvili, Koba; Meischl, Christof; Vonk, Alexander B A; Stooker, Wim; Eijsman, Leon; Blom, Anna M; Quax, Paul H A; van Hinsbergh, Victor W M; Niessen, Hans W M; Krijnen, Paul A J

2017-05-01

Complement is an important mediator in arterial blood pressure-induced vein graft failure. Previously, we noted activation of cell protective mechanisms in human saphenous veins too. Here we have analyzed whether C4b-binding protein (C4bp), an endogenous complement inhibitor, is present in the vein wall. Human saphenous vein segments obtained from patients undergoing coronary artery bypass grafting (n = 55) were perfused in vitro at arterial blood pressure with either autologous blood for 1, 2, 4, or 6 hr or with autologous blood supplemented with reactive oxygen species scavenger N-acetylcysteine. The segments were subsequently analyzed quantitatively for presence of C4bp and complement activation product C3d using immunohistochemistry. Perfusion induced deposition of C3d and C4bp within the media of the vessel wall, which increased reproducibly and significantly over a period of 4 hr up to 3.8% for C3d and 81% for C4bp of the total vessel area. Remarkably after 6 hr of perfusion, the C3d-positive area decreased significantly to 1.3% and the C4bp-positive area to 19% of the total area of the vein. The areas positive for both C4bp and C3d were increased in the presence of N-acetylcysteine. Exposure to arterial blood pressure leads to a transient presence of C4bp in the vein wall. This may be part of a cell-protective mechanism to counteract arterial blood pressure-induced cellular stress and inflammation in grafted veins. Copyright © 2017 Elsevier Inc. All rights reserved.

A Comparison of Po2, Pco2, Ph and Bicarbonate in Blood from the Carotid and Coccygeal Arteries of Calves

OpenAIRE

Gustin, Pascal; de Groote, A.; Dhem, A. R.; Bakima, M.; Lomba; Lekeux, Pierre

1988-01-01

A technique is described for the subcutaneous deviation of the carotid artery into the jugular groove of calves weighing between 90 and 200 kg. This makes sampling arterial blood or chronic cannulation for further experimentation very easy. Values of oxygen tension, carbon dioxide tension, pH and bicarbonate concentration in blood sampled from the ventral coccygeal artery were compared with the values obtained in blood from carotid artery puncture. The high correlations observed indicate that...

Involvement of placental/umbilical cord blood acid-base status and gas values on the radiosensitivity of human fetal/neonatal hematopoietic stem/progenitor cells

International Nuclear Information System (INIS)

Yamaguchi, Masaru; Ebina, Satoko; Kashiwakura, Ikuo

2013-01-01

Arterial cord blood (CB) acid-base status and gas values, such as pH, PCO 2 , PO 2 , HCO 3 - and base excess, provide useful information on the fetal and neonatal condition. However, it remains unknown whether these values affect the radiosensitivity of fetal/neonatal hematopoiesis. The present study evaluated the relationship between arterial CB acid-base status, gas values, and the radiosensitivity of CB hematopoietic stem/progenitor cells (HSPCs). A total of 25 CB units were collected. The arterial CB acid-base status and gas values were measured within 30 min of delivery. The CD34 + HSPCs obtained from CB were exposed to 2 Gy X-irradiation, and then assayed for colony-forming unit-granulocyte-macrophage, burst-forming unit-erythroid (BFU-E), and colony-forming unit-granulocyte erythroid, macrophage and megakaryocyte cells. Acid-base status and gas values for PCO 2 and HCO 3 - showed a statistically significant negative correlation with the surviving fraction of BFU-E. In addition, a significant positive correlation was observed between gestational age and PCO 2 . Moreover, the surviving fraction of BFU-E showed a significant negative correlation with gestational age. Thus, HSPCs obtained from CB with high PCO 2 /HCO 3 - levels were sensitive to X-irradiation, which suggests that the status of arterial PCO 2 /HCO 3 - influences the radiosensitivity of fetal/neonatal hematopoiesis, especially erythropoiesis. (author)

Gene expression patterns in peripheral blood correlate with the extent of coronary artery disease.

Directory of Open Access Journals (Sweden)

Peter R Sinnaeve

Full Text Available Systemic and local inflammation plays a prominent role in the pathogenesis of atherosclerotic coronary artery disease, but the relationship of whole blood gene expression changes with coronary disease remains unclear. We have investigated whether gene expression patterns in peripheral blood correlate with the severity of coronary disease and whether these patterns correlate with the extent of atherosclerosis in the vascular wall. Patients were selected according to their coronary artery disease index (CADi, a validated angiographical measure of the extent of coronary atherosclerosis that correlates with outcome. RNA was extracted from blood of 120 patients with at least a stenosis greater than 50% (CADi > or = 23 and from 121 controls without evidence of coronary stenosis (CADi = 0. 160 individual genes were found to correlate with CADi (rho > 0.2, P<0.003. Prominent differential expression was observed especially in genes involved in cell growth, apoptosis and inflammation. Using these 160 genes, a partial least squares multivariate regression model resulted in a highly predictive model (r(2 = 0.776, P<0.0001. The expression pattern of these 160 genes in aortic tissue also predicted the severity of atherosclerosis in human aortas, showing that peripheral blood gene expression associated with coronary atherosclerosis mirrors gene expression changes in atherosclerotic arteries. In conclusion, the simultaneous expression pattern of 160 genes in whole blood correlates with the severity of coronary artery disease and mirrors expression changes in the atherosclerotic vascular wall.

The impact of renal artery stent revascularization on blood pressure: 1-year follow-up of 110 cases

International Nuclear Information System (INIS)

Wang Chao; Zou Yinghua; Yang Min; Wang Jian; Tong Xiaoqiang; Song Li

2007-01-01

Objective: To investigate the effect of renal artery revascularization through renal artery stenting(PTRAS)on blood pressure in patients with renal artery stenosis. Methods: During April 2000 through May 2005 110 cases of renal artery stenosis received PTRAS and followed up for at least 1 year with blood pressure measurements pre-and 1 year post-PTRAS. Results: The technical success rate was 100% for all 110 cases. The renal artery stenosis were decreased from 60%-100% before PTRAS to 0%-15% after the stent placement. There was significant difference between blood pressure pre-and 1 year post PTRAS. Systolic pressures decreased from(153 ± 32) mmHg to(131 ± 27) mmHg and diastolic pressures from(87 ± 19) mmHg to(75 ± 19) mmHg. The administration of antihypertensive diugs reduced from(2.6 ± 0.9 ) sorts to(1.9 ± 0.9) sorts. Conclusions: PTRAS revascularization is an effective procedure for blood pressure control in renal vascular hypertension during one year follow up. (authors)

Cerebral arterial gas embolism from attempted mechanical thrombectomy: recovery following hyperbaric oxygen therapy.

Science.gov (United States)

Segan, Louise; Permezel, Fiona; Ch'ng, Wei; Millar, Ian; Brooks, Mark; Lee-Archer, Matt; Cloud, Geoffrey

2018-04-01

Cerebral arterial gas embolism is a recognised complication of endovascular intervention with an estimated incidence of 0.08%. Its diagnosis is predominantly clinical, supported by neuroimaging. The treatment relies on alleviating mechanical obstruction and reversing the proinflammatory processes that contribute to tissue ischaemia. Hyperbaric oxygen therapy is an effective treatment and has multiple mechanisms to reverse the pathological processes involved in cerebral arterial gas embolism. Symptomatic cerebral arterial gas embolism is a rare complication of endovascular intervention for acute ischaemic stroke. Although there are no previous descriptions of its successful treatment with hyperbaric oxygen therapy following mechanical thrombectomy, this is likely to become more common as mechanical thrombectomy is increasingly used worldwide to treat acute ischaemic stroke. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Measurement of regional cerebral blood flow using one-point venous blood sampling and causality model. Evaluation by comparing with conventional continuous arterial blood sampling method

International Nuclear Information System (INIS)

Mimura, Hiroaki; Sone, Teruki; Takahashi, Yoshitake

2008-01-01

Optimal setting of the input function is essential for the measurement of regional cerebral blood flow (rCBF) based on the microsphere model using N-isopropyl-4-[ 123 I]iodoamphetamine ( 123 I-IMP), and usually the arterial 123 I-IMP concentration (integral value) in the initial 5 min is used for this purpose. We have developed a new convenient method in which 123 I-IMP concentration in arterial blood sample is estimated from that in venous blood sample. Brain perfusion single photon emission computed tomography (SPECT) with 123 I-IMP was performed in 110 cases of central nervous system disorders. The causality was analyzed between the various parameters of SPECT data and the ratio of octanol-extracted arterial radioactivity concentration during the first 5 min (Caoct) to octanol-extracted venous radioactivity concentration at 27 min after intravenous injection of 123 I-IMP (Cvoct). A high correlation was observed between the measured and estimated values of Caoct/Cvoct (r=0.856) when the following five parameters were included in the regression formula: radioactivity concentration in venous blood sampled at 27 min (Cv), Cvoct, Cvoct/Cv, and total brain radioactivity counts that were measured by a four-head gamma camera 5 min and 28 min after 123 I-IMP injection. Furthermore, the rCBF values obtained using the input parameters estimated by this method were also highly correlated with the rCBF values measured using the continuous arterial blood sampling method (r=0.912). These results suggest that this method would serve as the new, convenient and less invasive method of rCBF measurement in clinical setting. (author)

Numerical investigation of MHD flow of blood and heat transfer in a stenosed arterial segment

Science.gov (United States)

Majee, Sreeparna; Shit, G. C.

2017-02-01

A numerical investigation of unsteady flow of blood and heat transfer has been performed with an aim to provide better understanding of blood flow through arteries under stenotic condition. The blood is treated as Newtonian fluid and the arterial wall is considered to be rigid having deposition of plaque in its lumen. The heat transfer characteristic has been analyzed by taking into consideration of the dissipation of energy due to applied magnetic field and the viscosity of blood. The vorticity-stream function formulation has been adopted to solve the problem using implicit finite difference method by developing well known Peaceman-Rachford Alternating Direction Implicit (ADI) scheme. The quantitative profile analysis of velocity, temperature and wall shear stress as well as Nusselt number is carried out over the entire arterial segment. The streamline and temperature contours have been plotted to understand the flow pattern in the diseased artery, which alters significantly in the downstream of the stenosis in the presence of magnetic field. Both the wall shear stress and Nusselt number increases with increasing magnetic field strength. However, wall shear stress decreases and Nusselt number enhances with Reynolds number. The results show that with an increase in the magnetic field strength upto 8 T, does not causes any damage to the arterial wall, but the study is significant for assessing temperature rise during hyperthermic treatment.

Simple Radiowave-Based Method For Measuring Peripheral Blood Flow Project

Science.gov (United States)

Oliva-Buisson, Yvette J.

2014-01-01

Project objective is to design small radio frequency based flow probes for the measurement of blood flow velocity in peripheral arteries such as the femoral artery and middle cerebral artery. The result will be the technological capability to measure peripheral blood flow rates and flow changes during various environmental stressors such as microgravity without contact to the individual being monitored. This technology may also lead to an easier method of detecting venous gas emboli during extravehicular activities.

[Invasive arterial blood pressure measurement using an aneroid pressure system in cattle].

Science.gov (United States)

Mosing, M; Franz, S; Iff, I; Schwendenwein, I

2009-06-01

The aim of this study was to compare the results of invasive arterial blood pressure measurement using an electronic pressure transducer (EPT) or an aneroid pressure system (APS) in cattle. A catheter was placed in the auricular artery of 11 adult cattle and connected to a pressure transducer via pressure line. The aneroid system was connected to the same catheter using a three-way stop-cock in the pressure line. On five occasions three consecutive measurements were performed with the APS. The mean blood pressure values of the EPT were recorded before each individual measurement. Values from each device were compared using Passing and Bablok regression of agreement and a Bland and Altman difference plot. One hundred and forty-seven paired measurements were analysed. The average bias between the two methods (EPT vs. APS) was -1.6 mmHg (95 % confidence interval [CI]: -3.0 to -0.2 mmHg). The coefficient of correlation was 1.0084. The aneroid system showed an almost perfect agreement with the EPT. This study shows that it can be used in a clinical setting as well as under field conditions to measure arterial blood pressure in cattle.

Tale of two sites: capillary versus arterial blood glucose testing in the operating room.

Science.gov (United States)

Akinbami, Felix; Segal, Scott; Schnipper, Jeffrey L; Stopfkuchen-Evans, Matthias; Mills, Jonathan; Rogers, Selwyn O

2012-04-01

Pre- and intraoperative glycemic control has been identified as a putative target to improve outcomes of surgical patients. Glycemic control requires frequent monitoring of blood glucose levels with appropriate adjustments. However, monitoring standards have been called into question, especially in cases in which capillary samples are used. Point-of-care testing (POCT) using capillary samples and glucometers has been noted to give relatively accurate results for critically ill patients. However, the package inserts of most glucometers warn that they should not be used for patients in shock. This has led clinicians to doubt their accuracy in the operating room. The accuracy of capillary samples when tested in patients undergoing surgical procedures has not been proven. This study aims to determine the accuracy of intraoperative blood glucose values using capillary samples relative to arterial samples. A prospective study was conducted by collecting paired capillary and arterial samples of patients undergoing major operations at a tertiary medical center from August 2009 to May 2011. Subjects were a convenience sample of patients who had arterial lines and needed glucose testing while undergoing the procedure. Precision Xceed Pro (Abbott) handheld glucometers were used to obtain the blood glucose values. Our primary outcome of interest was the degree of correlation between capillary and arterial blood glucose values or the degree to which arterial glucose levels can be predicted by capillary glucose samples. We used linear regression and the Student t tests for statistical analyses. Seventy-two-paired samples were collected. Of the cases, 54% were major abdominal operations, whereas 24% were vascular operations. The mean values ± standard deviation for glucose levels were 146 ± 35 mg/dL (capillary) and 147 ± 36 mg/dL (arterial). The mean time ± standard deviation between the collection of both samples was 3.5 ± 1.3 minutes. The regression coefficient showed a

Evaluation and investigation of regional cerebral blood flow by 1 point arterial blood collection method using 99mTc-ECD. Intravenous injection for 4 minutes with constant speed

International Nuclear Information System (INIS)

Itoh, Takeo; Shibata, Kazuhiro; Sudoh, Hideaki; Tanaka, Masato; Itoh, Kenjiro; Ueno, Yasushi

1998-01-01

Regional cerebral blood flow (rCBF) was measured using a 99m Tc-ECD through the 4-min constant intravenous infusion/one point arterial blood sampling method, proposed by Nakagawara et al. of Nakamura Memorial Hospital, and 133Xenon ( 133 Xe)-SPECT was performed on the same subjects to investigate the reproducibility of this method. We also determined whether cerebral blood flow (CBF) could be measured on the day of blood sampling through dilution of the obtained blood because it was difficult to measure the radioactivity in the blood on the day of blood sampling by this method. More, we investigated fixation of an octanol extraction rate and the substitution of venous blood for arterial blood in this method. The results revealed that CBF measured by this method with a 99m Tc-ECD were closely correlated to those measured by 133 Xe-SPECT, indicating the reliability as a method of measuring CBF. rCBF could be measured on the day of blood sampling through appropriate dilution of the obtained arterial blood. Octanol extraction rates were almost constant, indicating possible omission of cumbersome extraction procedure by fixation. However, the substitution of venous blood for arterial blood showed no correlation under the study system examined. (author)

The stability of arterial blood gases during transportation of patients using the RespirTech PRO.

Science.gov (United States)

Romano, M; Raabe, O G; Walby, W; Albertson, T E

2000-05-01

The transportation of critically ill patients requiring mechanical ventilation is recognized as a high-risk and expensive procedure. Approaches have included using manual bag-type valve resuscitators and expensive portable transport ventilators. This study evaluated the effectiveness of the inexpensive portable RespirTech PRO (RTP) gas-powered automatic resuscitator during intrahospital transport of critically ill mechanically ventilated patients. Twenty medical intensive care patients on stable mechanical ventilator settings had arterial blood gas and vital sign determination before routine transport out of the intensive care unit (ICU). Repeat measurements were made during transport approximately 30 minutes after being placed on the RTP portable pressure-cycled automatic resuscitator using an FiO2 of 100%. During use of the RTP for transport, there were no statistically significant variations observed in mean arterial blood pressure [82 +/- 11 SD (range 65 to 112) mm Hg before transport versus 85 +/- 14 SD (range 59 to 110) mm Hg during transport], heart rate [94 +/- 16 SD (range 74 to 127) beats/min) before versus 96 +/- 17 SD (range 69 to 132) beats/min during], arterial pH [7.41 +/- 0.07 SD (range 7.31 to 7.58) before versus 7.42 +/- 0.05 SD (range 7.37 to 7.52) during], and PaCO2 [43 +/- 10 SD (range 26 to 65) mm Hg before versus 43 +/- 10 SD (range 27 to 61 mm Hg) during]. Because the FiO2 before transport was 63 +/- 26 SD (range 30% to 100%) versus 100% during transport using the RTP, the mean PaO2 was significantly increased from 124 +/- 86 SD (range 57 to 367) mm Hg before transport to 297 +/- 168 SD (range 65 to 537) mm Hg during (P< .001). No transportation associated clinical adverse events were noted. Several previous investigations have shown that portable ventilators are safe and effective in intrahospital transport of mechanically ventilated patients. This study showed that the portable pressure-cycled RTP also allows safe transportation of

Prediction of blood pressure and blood flow in stenosed renal arteries using CFD

Science.gov (United States)

Jhunjhunwala, Pooja; Padole, P. M.; Thombre, S. B.; Sane, Atul

2018-04-01

In the present work an attempt is made to develop a diagnostive tool for renal artery stenosis (RAS) which is inexpensive and in-vitro. To analyse the effects of increase in the degree of severity of stenosis on hypertension and blood flow, haemodynamic parameters are studied by performing numerical simulations. A total of 16 stenosed models with varying degree of stenosis severity from 0-97.11% are assessed numerically. Blood is modelled as a shear-thinning, non-Newtonian fluid using the Carreau model. Computational Fluid Dynamics (CFD) analysis is carried out to compute the values of flow parameters like maximum velocity and maximum pressure attained by blood due to stenosis under pulsatile flow. These values are further used to compute the increase in blood pressure and decrease in available blood flow to kidney. The computed available blood flow and secondary hypertension for varying extent of stenosis are mapped by curve fitting technique using MATLAB and a mathematical model is developed. Based on these mathematical models, a quantification tool is developed for tentative prediction of probable availability of blood flow to the kidney and severity of stenosis if secondary hypertension is known.

Effects of iodinated contrast media on common carotid and brachial artery blood flow and wall shear stress

International Nuclear Information System (INIS)

Irace, C.; Tamburini, S.; Bertucci, B.; Franceschi, M.S. de; Gnasso, A.

2006-01-01

The aim of our study was to evaluate the effect of the intravenous contrast media iomeprol on wall shear stress, blood flow and vascular parameters in the common carotid and brachial artery. Thirty outpatients undergoing thoracic or abdominal spiral CT scans were studied. The internal diameter and flow velocity of the common carotid and brachial artery were evaluated by ultrasound, and blood viscosity was measured before and after low osmolality iomeprol (Iomeron 350) injection. The wall shear stress, blood flow and pulsatility index were calculated. To test the differences between groups, the Wilcoxon rank test and Mann Whitney U test were applied. Blood viscosity decreased slightly, but significantly after contrast media (4.6±0.7 vs. 4.5±0.7 mPa.s, P=0.02). Contrarily, blood flow and wall shear stress did not change in the common carotid artery, but significantly decreased in the brachial artery (0.9±0.4 vs. 0.6±0.3 ml/s, P<0.0001, and 41.5±13.9 vs. 35.3±11.0 dynes/cm2, P<0.002, respectively), whereas the pulsatility index significantly increased in the brachial artery (5.0±3.3 vs. 7.5±5.3, P<0.001). Iomeprol injection causes blood flow and wall shear stress reduction of the brachial artery; the rise in the pulsatility index suggests an increase in peripheral vascular resistance. Further investigation is needed to evaluate whether these modifications can be clinically relevant. (orig.)

Measurements of pulmonary gas exchange efficiency using expired gas and oximetry: results in normal subjects.

Science.gov (United States)

West, John B; Wang, Daniel L; Prisk, G Kim

2018-04-01

We are developing a novel, noninvasive method for measuring the efficiency of pulmonary gas exchange in patients with lung disease. The patient wears an oximeter, and we measure the partial pressures of oxygen and carbon dioxide in inspired and expired gas using miniature analyzers. The arterial Po 2 is then calculated from the oximeter reading and the oxygen dissociation curve, using the end-tidal Pco 2 to allow for the Bohr effect. This calculation is only accurate when the oxygen saturation is ideal alveolar Po 2 minus the measured arterial Po 2 . That measurement requires an arterial blood sample. The present study suggests that this noninvasive procedure will be valuable in assessing the degree of impaired gas exchange in patients with lung disease.

The phosphodiesterase 3 inhibitor cilostazol dilates large cerebral arteries in humans without affecting regional cerebral blood flow

DEFF Research Database (Denmark)

Birk, Steffen; Kruuse, Christina Rostrup; Petersen, Kenneth A

2004-01-01

in the middle cerebral arteries (VMCA) was measured with transcranial Doppler, and the superficial temporal and radial arteries diameters were measured with ultrasonography. During the 4-hour observation period, there was no effect on systolic blood pressure (P = 0.28), but diastolic blood pressure decreased...

Changes in pulmonary blood flow do not affect gas exchange during intermittent ventilation in resting turtles

DEFF Research Database (Denmark)

Wang, Tobias; Hicks, James W.

2008-01-01

The breathing pattern of many different air-breathing vertebrates, including lungfish, anuran amphibians, turtles, crocodiles and snakes, is characterized by brief periods of lung ventilation interspersed among apnoeas of variable duration. These intermittent ventilatory cycles are associated...... experimentally. The present study measured pulmonary gas exchange in fully recovered, freely diving turtles, where changes in pulmonary blood flow were prevented by partial occlusion of the pulmonary artery. Prevention of L-R shunt during ventilation did not impair CO2 excretion and overall, oxygen uptake and CO...

Choice of marker for assessment of RV dysfunction in acute pulmonary embolism : NT-proBNP, pulmonary artery systolic pressure, mean arterial pressure, or blood pressure index.

Science.gov (United States)

Ates, H; Ates, I; Kundi, H; Yilmaz, F M

2017-12-01

We aimed to examine the value of NT-proBNP, pulmonary artery systolic pressure (PASP), blood pressure index (BPI), and mean arterial pressure (MAP) in the determination of right ventricular dysfunction (RVD) in patients with acute pulmonary embolism (APE). A total of 547 patients diagnosed with APE were included in the study. Demographic characteristics and comorbid conditions of patients were recorded in patient files. For blood pressure measurement, a calibrated digital blood pressure monitor was used at regular intervals. Blood samples were taken from patients at the time of admission for hemogram, biochemical, and hemostasis blood tests. Echocardiography was performed on all patients to detect RVD and evaluate pulmonary artery pressure. PASP (p blood pressure (p blood cell (p AUC ± SE = 0.975 ± 0.006; p < 0.001) was found to be the best predictor of RVD with a higher sensitivity (92.8%) and specificity (100%). We found that BPI had a better diagnostic discrimination for RVD compared with PASP and NT-proBNP.

Magnetization Transfer Effects on the Efficiency of Flow-driven Adiabatic Fast Passage Inversion of Arterial Blood

OpenAIRE

Hernandez-Garcia, Luis; Lewis, David P.; Moffat, Bradford; Branch, Craig A.

2007-01-01

Continuous arterial spin labeling experiments typically use flow-driven adiabatic fast passage (AFP) inversion of the arterial blood water protons. In this article, we measure the effect of magnetization transfer in blood and how it affects the inversion label. We use modified Bloch equations to model flow-driven adiabatic inversion in the presence of magnetization transfer in blood flowing at velocities from 1 to 30 cm/s in order to explain our findings. Magnetization transfer results in a r...

Arterial versus venous lactate: a measure of sepsis in children.

Science.gov (United States)

Samaraweera, Sahan Asela; Gibbons, Berwyck; Gour, Anami; Sedgwick, Philip

2017-08-01

This study assessed the agreement between arterial and venous blood lactate and pH levels in children with sepsis. This retrospective, three-year study involved 60 PICU patients, with data collected from electronic or paper patient records. The inclusion criteria comprised of children (≤17 years old) with sepsis and those who had a venous blood gas taken first with an arterial blood gas taken after within one hour. The lactate and pH values measured through each method were analysed. There is close agreement between venous and arterial lactate up to 2 mmol/L. As this value increases, this agreement becomes poor. The limits of agreement (LOA) are too large (±1.90 mmol/L) to allow venous and arterial lactate to be used interchangeably. The mean difference and LOA between both methods would be much smaller if derived using lactate values under 2.0 mmol/L. There is close agreement between arterial and venous pH (MD = -0.056, LOA ± 0.121). However, due to extreme variations in pH readings during sepsis, pH alone is an inadequate marker. A venous lactate ≤2 mmol/L can be used as a surrogate for arterial lactate during early management of sepsis in children. However, if the value exceeds 2 mmol/L, an arterial sample must confirm the venous result. What is known: • In children with septic shock, a blood gas is an important test to show the presence of acidosis and high lactic acid. Hyperlactataemia on admission is an early predictor of outcome and is associated with a greater mortality risk. • An arterial sample is the standard for lactate measurement, however getting a sample may be challenging in the emergency department or a general paediatric ward. Venous samples are quicker and easier to obtain. Adult studies generally advise caution in replacing venous lactate values for the arterial standard, whilst paediatric studies are limited in this area. What is new: • This is the first study assessing the agreement between arterial and peripheral venous

Radioimmunoassay for determination of blood aldosterone and renin in the diagnosis of some forms of arterial hypertension

International Nuclear Information System (INIS)

Khamidov, R.I.; Khalmuratova, R.A.; Sattarova, F.K.

1987-01-01

Aldosterone concentration and renin activity in the blood from the ulnar, inferior cava veins at the level of the 12th thoracic vertebra, the left and right renal veins were studied in 60 patients with arterial hypertension by means of a radioimmunoassay kits (France). The patients were divided into 4 groups: with primary and idiopathic hyperaldosteronism, renal-parenchymatous and essential arterial hypertension. The diagnosis of primary and idiopathic hyperaldosteronism was also confirmed by low blood renin activity. Renin activity in the peripheral venous blood was considerably elevated in renal-parenchymatous arterial hypertension and was normal in essential hypertension. Aldosterone concentration in the blood from the vena cava inferior and renal veins was 1.6-2-fold as high on the affected side as on the contralateral one

Blood gas sample spiking with total parenteral nutrition, lipid emulsion, and concentrated dextrose solutions as a model for predicting sample contamination based on glucose result.

Science.gov (United States)

Jara-Aguirre, Jose C; Smeets, Steven W; Wockenfus, Amy M; Karon, Brad S

2018-05-01

Evaluate the effects of blood gas sample contamination with total parenteral nutrition (TPN)/lipid emulsion and dextrose 50% (D50) solutions on blood gas and electrolyte measurement; and determine whether glucose concentration can predict blood gas sample contamination with TPN/lipid emulsion or D50. Residual lithium heparin arterial blood gas samples were spiked with TPN/lipid emulsion (0 to 15%) and D50 solutions (0 to 2.5%). Blood gas (pH, pCO2, pO2), electrolytes (Na+, K+ ionized calcium) and hemoglobin were measured with a Radiometer ABL90. Glucose concentration was measured in separated plasma by Roche Cobas c501. Chart review of neonatal blood gas results with glucose >300 mg/dL (>16.65 mmol/L) over a seven month period was performed to determine whether repeat (within 4 h) blood gas results suggested pre-analytical errors in blood gas results. Results were used to determine whether a glucose threshold could predict contamination resulting in blood gas and electrolyte results with greater than laboratory-defined allowable error. Samples spiked with 5% or more TPN/lipid emulsion solution or 1% D50 showed glucose concentration >500 mg/dL (>27.75 mmol/L) and produced blood gas (pH, pO 2 , pCO 2 ) results with greater than laboratory-defined allowable error. TPN/lipid emulsion, but not D50, produced greater than allowable error in electrolyte (Na + ,K + ,Ca ++ ,Hb) results at these concentrations. Based on chart review of 144 neonatal blood gas results with glucose >250 mg/dL received over seven months, four of ten neonatal intensive care unit (NICU) patients with glucose results >500 mg/dL and repeat blood gas results within 4 h had results highly suggestive of pre-analytical error. Only 3 of 36 NICU patients with glucose results 300-500 mg/dL and repeat blood gas results within 4 h had clear pre-analytical errors in blood gas results. Glucose concentration can be used as an indicator of significant blood sample contamination with either TPN

Arterial stiffness, cardiovagal baroreflex sensitivity and postural blood pressure changes in older adults: the Rotterdam Study

NARCIS (Netherlands)

Mattace-Raso, Francesco U. S.; van den Meiracker, Anton H.; Bos, Willem Jan; van der Cammen, Tischa J. M.; Westerhof, Berend E.; Elias-Smale, Suzette; Reneman, Robert S.; Hoeks, Arnold P. G.; Hofman, Albert; Witteman, Jacqueline C. M.

2007-01-01

Arterial stiffness may be involved in the impairment of the arterial baroreflex. In the present study the associations between arterial stiffness and cardiovagal baroreflex sensitivity (BRS) and between BRS and postural blood pressure (BP) changes were investigated within the framework of the

Study on blood supply of lung metastasis with trans-pulmonary arterial lipiodol infusion

International Nuclear Information System (INIS)

Zhou Jianqin; Dong Weihua; Dong Weihua; Ouyang Chang; Chang Heng; Xiao Xiangsheng

2008-01-01

Objective: To evaluate the blood supply of pulmonary metastases using small volume of lipiodol through pulmonary arterial infusion. Methods: 10 cases of lung metastasis were enroled including the primary tumors of liver cancer (n=5), renal carcinoma (n=3), chordoma (n=1) and malignant neurofibroma (n=1). Plain CT scan was performed to exclude calcification or ossification within metastasis and then pulmonary arterial DSA was undertaken to evaluate tumor vessels or staining. After pulmonary arteriovenous fistula or other anomalous circulation was excluded by lobar arterial DSA, small volume of lipiodol was infused under fluoroscopy (0.5-1.5 ml for each lobar artery, total volume less than 3.0 ml). CT scan was immediately performed. Blood supply of the pulmonary metastases was assessed according to the accumulation of lipiodol on CT scans. Results: No cases but one experienced cough, expectoration, suffocating or dyspnea. No complication of cerebral or visceral embolism occurred. Totally 27 nodules were studied including 6 nodules with cloudy lipiodol accumulation and 6 nodules with tiny granules of lipiodol accumulation. No enlarged tumor vessel or tumor stain was observed within all 27 nodules on pulmonary arterial DSA. Conclusions: Pulmonary artery supplys only parts of pulmonary metastases, especially those sited at the peripheral region of the lung. Infusion of small volume of lipiodol through pulmonary artery is safe, and the increased density of lung field could return normal after several days. (authors)

Prognostic value of renal fractional flow reserve in blood pressure response after renal artery stenting (PREFER study).

Science.gov (United States)

Kądziela, Jacek; Januszewicz, Andrzej; Prejbisz, Aleksander; Michałowska, Ilona; Januszewicz, Magdalena; Florczak, Elżbieta; Kalińczuk, Łukasz; Norwa-Otto, Bożena; Warchoł, Ewa; Witkowski, Adam

2013-01-01

The aim of our study was to determine a potential relationship between resting translesional pressures ratio (Pd/Pa ratio), renal fractional flow reserve (rFFR) and blood pressure response after renal artery stenting. Thirty five hypertensive patients (49% males, mean age 64 years) with at least 60% stenosis in angiography, underwent renal artery stenting. Translesional systolic pressure gradient (TSPG), Pd/Pa ratio (the ratio of mean distal to lesion and mean proximal pressures) and hyperemic rFFR - after intrarenal administration of papaverine - were measured before stent implantation. Ambulatory blood pressure measurements (ABPM) were recorded before the procedure and after 6 months. The ABPM results were presented as blood pressure changes in subgroups of patients with normal (≥ 0.9) vs. abnormal (renal artery stenting. Median changes of 24-h systolic/diastolic blood pressure were comparable in patients with abnormal vs. normal Pd/Pa ratio (-4/-3 vs. 0/2 mm Hg; p = NS) and with abnormal vs. normal rFFR (-2/-1 vs. -2/-0.5 mm Hg, respectively). Physiological assessment of renal artery stenosis using Pd/Pa ratio and papaverine- induced renal fractional fl ow reserve did not predict hypertension response after renal artery stenting.

Effects of preoperative aspirin and clopidogrel therapy on perioperative blood loss and blood transfusion requirements in patients undergoing off-pump coronary artery bypass graft surgery.

Science.gov (United States)

Shim, Jae Kwang; Choi, Yong Seon; Oh, Young Jun; Bang, Sou Ouk; Yoo, Kyung Jong; Kwak, Young Lan

2007-07-01

Preoperative exposure to clopidogrel and aspirin significantly increases postoperative bleeding in patients undergoing on-pump coronary artery bypass graft surgery. Off-pump coronary bypass grafting has been proposed as an alternative technique to attenuate postoperative bleeding associated with clopidogrel. This study aimed to determine the effects of aspirin and clopidogrel therapy on perioperative blood loss and blood transfusion requirements in off-pump coronary artery bypass grafting. One hundred six patients scheduled for off-pump coronary artery bypass grafting were divided into three groups: aspirin and clopidogrel discontinued more than 6 days before surgery (group 1, n = 35), aspirin and clopidogrel continued until 3 to 5 days before surgery (group 2, n = 51), and both medications continued within 2 days of surgery (group 3, n = 20). Thromboelastographic tracings were analyzed before induction of anesthesia. Routine coagulation profiles were measured before and after surgery. A cell salvage device was used during surgery and salvaged blood was reinfused. Chest tube drainage and blood transfusion requirement were recorded postoperatively. Patient characteristics, operative data, and thromboelastographic tracings were similar among the groups. There were significant decreases in hematocrit level and platelet count and prolongation in prothrombin time postoperatively in all groups without any intergroup differences. The amounts of perioperative blood loss and blood transfusion required were all similar among the groups. Preoperative clopidogrel and aspirin exposure even within 2 days of surgery does not increase perioperative blood loss and blood transfusion requirements in patients undergoing elective off-pump coronary artery bypass grafting.

Roles of Arterial Stiffness and Blood Pressure in Hypertension-Associated Cognitive Decline in Healthy Adults.

Science.gov (United States)

Hajjar, Ihab; Goldstein, Felicia C; Martin, Greg S; Quyyumi, Arshed A

2016-01-01

Although there is strong evidence that hypertension leads to cognitive decline, especially in the executive domain, the relationship between blood pressure and cognition has been conflicted. Hypertension is characterized by blood pressure elevation and increased arterial stiffness. We aimed at investigating whether arterial stiffness would be superior to blood pressure in predicting cognitive decline and explaining the hypertension-executive decline association. A randomly selected asymptomatic population (n=591, age=49.2 years, 70% women, 27% black, and education=18 years) underwent annual vascular and cognitive assessments. Cognition was assessed using computerized versions commonly used cognitive tests, and principal component analysis was used for deriving cognitive scores for executive function, memory, and working memory. Arterial stiffness was measured by carotid-femoral pulse wave velocity (PWV). Higher PWV, but not blood pressure, was associated with a steeper decline in executive (P=0.0002), memory (P=0.05), and working memory (P=0.02) scores after adjusting for demographics, education, and baseline cognitive performance. This remained true after adjusting for hypertension. Hypertension was associated with greater decline in executive score (P=0.0029) and those with combined hypertension and elevated PWV (>7 m/s) had the greatest decline in executive score (P value hypertension×PWV=0.02). PWV explained the association between hypertension and executive function (P value for hypertension=0.0029 versus 0.24 when adjusting for PWV). In healthy adults, increased arterial stiffness is superior to blood pressure in predicting cognitive decline in all domains and in explaining the hypertension-executive function association. Arterial stiffness, especially in hypertension, may be a target in the prevention of cognitive decline. © 2015 American Heart Association, Inc.

21 CFR 870.4410 - Cardiopulmonary bypass in-line blood gas sensor.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cardiopulmonary bypass in-line blood gas sensor... Cardiopulmonary bypass in-line blood gas sensor. (a) Identification. A cardiopulmonary bypass in-line blood gas sensor is a transducer that measures the level of gases in the blood. (b) Classification. Class II...

Non-dipping blood pressure patterns and arterial stiffness parameters in patients with Behcet's disease.

Science.gov (United States)

Celik, Gulperi; Yilmaz, Sema; Ergulu Esmen, Serpil

2015-12-01

Behcet's disease is a multisystemic vasculitis involving veins and arteries of various sizes. Non-dipping status, augmentation index and pulse wave velocity are important determinants of cardiovascular mortality and morbidity. We investigated the non-dipping status and arterial stiffness in patients with Behcet's disease. In this cross-sectional study, we examined the vascular parameters of 96 patients with Behcet's disease (53% female) and 60 age- and sex-matched control subjects. The non-dipping status and arterial distensibility were assessed using a Mobil-O-Graph Arteriograph, an automatic oscillometric device. In total, 65.6% of 96 patients were systolic non-dippers, and 34.4% exhibited high augmentation indices. Ten percent of the control subjects were systolic non-dippers, and 11.7% exhibited high augmentation indices. Nocturnal decreases in systolic blood pressure correlated with central systolic blood pressure and diastolic blood pressure, as well as nocturnal decreases in diastolic blood pressure. Furthermore, non-dipper patients with Behcet's disease exhibited higher nocturnal cardiac outputs than did dipper patients with Behcet's disease. Augmentation index correlated negatively with C-reactive protein and correlated positively with both 24 h and nocturnal peripheral resistance, as well as 24 h pulse wave velocity. The patients with high augmentation indices exhibited lower creatinine clearance, as well as lower nocturnal cardiac outputs, higher 24 h peripheral resistance and higher 24 h pulse wave velocities. Non-dipping status and arterial stiffness may exacerbate the harmful cardiovascular effects of the other. In addition to conventional risk factors, non-dipping status and arterial stiffness should be examined during the follow-up evaluations of patients with Behcet's disease.

Relationship between haemodynamic impairment and collateral blood flow in carotid artery disease.

Science.gov (United States)

Hartkamp, Nolan S; Petersen, Esben T; Chappell, Michael A; Okell, Thomas W; Uyttenboogaart, Maarten; Zeebregts, Clark J; Bokkers, Reinoud Ph

2017-01-01

Collateral blood flow plays a pivotal role in steno-occlusive internal carotid artery (ICA) disease to prevent irreversible ischaemic damage. Our aim was to investigate the effect of carotid artery disease upon cerebral perfusion and cerebrovascular reactivity and whether haemodynamic impairment is influenced at brain tissue level by the existence of primary and/or secondary collateral. Eighty-eight patients with steno-occlusive ICA disease and 29 healthy controls underwent MR examination. The presence of collaterals was determined with time-of-flight, two-dimensional phase contrast MRA and territorial arterial spin labeling (ASL) imaging. Cerebral blood flow and cerebrovascular reactivity were assessed with ASL before and after acetazolamide. Cerebral haemodynamics were normal in asymptomatic ICA stenosis patients, as opposed to patients with ICA occlusion, in whom the haemodynamics in both hemispheres were compromised. Haemodynamic impairment in the affected brain region was always present in symptomatic patients. The degree of collateral blood flow was inversely correlated with haemodynamic impairment. Recruitment of secondary collaterals only occurred in symptomatic ICA occlusion patients. In conclusion, both CBF and cerebrovascular reactivity were found to be reduced in symptomatic patients with steno-occlusive ICA disease. The presence of collateral flow is associated with further haemodynamic impairment. Recruitment of secondary collaterals is associated with severe haemodynamic impairment.

Resting quantitative cerebral blood flow in schizophrenia measured by pulsed arterial spin labeling perfusion MRI

OpenAIRE

Pinkham, Amy; Loughead, James; Ruparel, Kosha; Wu, Wen-Chau; Overton, Eve; Gur, Raquel; Gur, Ruben

2011-01-01

Arterial spin labeling imaging (ASL) perfusion MRI is a relatively novel technique that can allow for quantitative measurement of cerebral blood flow (CBF) by using magnetically labeled arterial blood water as an endogenous tracer. Available data on resting CBF in schizophrenia primarily comes from invasive and expensive nuclear medicine techniques that are often limited to small samples and yield mixed results. The noninvasive nature of ASL offers promise for larger-scale studies. The utilit...

Noninvasive arterial blood pressure waveforms in patients with continuous-flow left ventricular assist devices.

Science.gov (United States)

Martina, Jerson R; Westerhof, Berend E; de Jonge, Nicolaas; van Goudoever, Jeroen; Westers, Paul; Chamuleau, Steven; van Dijk, Diederik; Rodermans, Ben F M; de Mol, Bas A J M; Lahpor, Jaap R

2014-01-01

Arterial blood pressure and echocardiography may provide useful physiological information regarding cardiac support in patients with continuous-flow left ventricular assist devices (cf-LVADs). We investigated the accuracy and characteristics of noninvasive blood pressure during cf-LVAD support. Noninvasive arterial pressure waveforms were recorded with Nexfin (BMEYE, Amsterdam, The Netherlands). First, these measurements were validated simultaneously with invasive arterial pressures in 29 intensive care unit patients. Next, the association between blood pressure responses and measures derived by echocardiography, including left ventricular end-diastolic dimensions (LVEDDs), left ventricular end-systolic dimensions (LVESDs), and left ventricular shortening fraction (LVSF) were determined during pump speed change procedures in 30 outpatients. Noninvasive arterial blood pressure waveforms by the Nexfin monitor slightly underestimated invasive measures during cf-LVAD support. Differences between noninvasive and invasive measures (mean ± SD) of systolic, diastolic, mean, and pulse pressures were -7.6 ± 5.8, -7.0 ± 5.2, -6.9 ± 5.1, and -0.6 ± 4.5 mm Hg, respectively (all blood pressure responses did not correlate with LVEDD, LVESD, or LVSF, while LVSF correlated weakly with both pulse pressure (r = 0.24; p = 0.005) and (dP(art)/dt)max (r = 0.25; p = 0.004). The dicrotic notch in the pressure waveform was a better predictor of aortic valve opening (area under the curve [AUC] = 0.87) than pulse pressure (AUC = 0.64) and (dP(art)/dt)max (AUC = 0.61). Patients with partial support rather than full support at 9,000 rpm had a significant change in systolic pressure, pulse pressure, and (dP(art)/dt)max during ramp studies, while echocardiographic measures did not change. Blood pressure measurements by Nexfin were reliable and may thereby act as a compliment to the assessment of the cf-LVAD patient.

Conventional blood conservation techniques in 500 consecutive coronary artery bypass operations.

Science.gov (United States)

Ovrum, E; Holen, E A; Abdelnoor, M; Oystese, R

1991-09-01

With use of a nonpharmacological, simple, and inexpensive program for blood conservation, 500 consecutive patients underwent elective coronary artery bypass grafting without need of homologous red cell transfusions in 493 (98.6%). At least one internal mammary artery was grafted in all but 1 patient, with supplemental saphenous vein grafts. Intraoperatively, autologous heparinized blood was removed before bypass and retransfused at the conclusion of extracorporeal circulation. The volume remaining in the oxygenator and tubing set was returned without cell processing or hemofiltration. Using the hard-shell cardiotomy reservoir from the heart-lung machine, autotransfusion of the shed mediastinal blood was continued hourly up to 18 hours after operation. The mean postoperative mediastinal blood loss was 643 +/- 354 mL, whereas 624 +/- 296 mL was autotransfused. Thirteen patients (2.6%) needed reexploration for bleeding, of whom 7 (7/500, 1.4%) received homologous blood. No other patients required red cell transfusions. In addition, 9 patients were given a mean of 2.6 units of fresh frozen plasma because of suspected coagulopathy. No platelets were transfused, and no cryoprecipitate therapy was undertaken. Thus, in total, 484 patients (96.8%) were not exposed to any homologous blood products during the hospital stay. At discharge, the mean hemoglobin concentration was 121 +/- 14 g/L (12.1 +/- 1.4 g/dL) and the hematocrit, 0.36 +/- 0.04. Postoperative complications were few. There was one in-hospital death (0.2%).

Ultrasonic Doppler measurement of renal artery blood flow

Science.gov (United States)

Freund, W. R.; Meindl, J. D.

1975-01-01

An extensive evaluation of the practical and theoretical limitations encountered in the use of totally implantable CW Doppler flowmeters is provided. Theoretical analyses, computer models, in-vitro and in-vivo calibration studies describe the sources and magnitudes of potential errors in the measurement of blood flow through the renal artery, as well as larger vessels in the circulatory system. The evaluation of new flowmeter/transducer systems and their use in physiological investigations is reported.

The effect of time from last food intake on arterial blood gases: Implication on reference values

Directory of Open Access Journals (Sweden)

Zahedpour Anaraki M

2000-08-01

Full Text Available Arterial blood gas parameters were analyzed in forty-nine healthy persons (31 males, 18 females to detemine reference values fo these parameters and their relation to the time from last food intake to arterial puncture (T. The mean ± standard deviation of arterial oxygen pressure, arterial carbon dioxide pressure and pH at core body temperature were 84.4±7.0 mmHg (Male: 83.0±6.5, Female: 86.7±73, 37.7±2.8 mmHg (Male: 38.5±2.7, Female: 36.2±2.4 respectively 7.41±0.02 (Male: 7.41±0.02 Female: 7.42±0.03. the mean PCO2 was lower in comparison with most of the studies at sea level. The difference between males and females was significant in PCO2 and PH (P=0.004, P=0.02 respectively but in was not significant in PO2 (P=0.07. The PCO2 and pH had no statistically significant relatioship with age (P=0.42, P=0.25 respectively. The relationship between Po2 with age, PCO2 and T was significant (P=0.02, P=0.017, and P=0.019 respectively. The best linear predictive equation was: Po2= 1.28 AO2-29.4 for T10hours Þ AO2 = 0.21(Baro-47 – (1.2PCO2

Plasma volume changes during hypoglycaemia: the effect of arterial blood sampling

DEFF Research Database (Denmark)

Hilsted, J; Bendtsen, F; Christensen, N J

1990-01-01

To investigate whether previously reported changes in venous blood volume and composition induced by acute hypoglycaemia in humans are representative for the entire body we measured erythrocyte 51Cr content, haematocrit, plasma volume, intravascular albumin content and transcapillary escape rate...... hypoglycaemia. The magnitude of the changes in arterial and venous blood were not significantly different. These results indicate that the above changes in blood volume and composition are whole-body phenomena: furthermore, the major part of the changes are likely to occur in tissues other than upper extremity...

The relationship between fasting blood glucose variability and coronary artery collateral formation in type 2 diabetes patients with coronary artery disease.

Science.gov (United States)

Cheng, Gang; Mahmoudi, Hilda; Chokshi, Binna; Fernandez, Marlena; Kazemi, Vahid; Lamaa, Nader

2017-09-01

Coronary collaterals are an alternative source of blood supply to ischemic myocardium. Well-developed coronary collateral arteries in patients with coronary artery disease (CAD) limit the size of acute myocardial infarction and improves survival. The aim of this study was to investigate the relationship between glycemic variability and coronary collateral formation in patients with type 2 diabetes mellitus and CAD. Consecutive patients undergoing percutaneous coronary intervention or coronary artery bypass grafting procedures were studied. Multivariate logistic regression models were used to examine the association between coronary artery collateral formation graded by Rentrope classification and glycemic variability, measured by coefficient variation of fasting blood glucose. In our study, we retrospectively enrolled 300 patients, of whom 239 were diabetic (age: 70.1±11.9, 56% men) and 61 were nondiabetic (age: 71.5±11.5, 72% men). Diabetic patients were further stratified as follows: those with poor coronary collateral artery development (n=171, age: 69.7±12.4, 55% men) and those with good coronary collateral artery development (n=68, age 71.1±10.8, 59% men) according to the Rentrope classification. Our findings did not show association between glycemic variability and coronary collateral vessels development after controlling for potential confounders (odds ratio: 2.51; 95% confidence interval: 0.57-11.03; P=0.22). The culprit lesion (≥75% stenosis) in the left anterior descending artery and the right coronary artery was more frequent in the good collateral group compared with the poor collateral group (66 vs. 50%, P=0.02; 63 vs. 45%, P=0.01 respectively). Glycemic variability is not associated with coronary collateral artery formation in patients with type 2 diabetes mellitus and CAD.

Twenty-four-hour exposure to altered blood flow modifies endothelial Ca2+-activated K+ channels in rat mesenteric arteries

DEFF Research Database (Denmark)

Hilgers, Rob H P; Janssen, Ger M J; Fazzi, Gregorio E

2010-01-01

We tested the hypothesis that changes in arterial blood flow modify the function of endothelial Ca2+-activated K+ channels [calcium-activated K+ channel (K(Ca)), small-conductance calcium-activated K+ channel (SK3), and intermediate calcium-activated K+ channel (IK1)] before arterial structural...... remodeling. In rats, mesenteric arteries were exposed to increased [+90%, high flow (HF)] or reduced blood flow [-90%, low flow (LF)] and analyzed 24 h later. There were no detectable changes in arterial structure or in expression level of endothelial nitric-oxide synthase, SK3, or IK1. Arterial relaxing...... arteries, the balance between the NO/prostanoid versus EDHF response was unaltered. However, the contribution of IK1 to the EDHF response was enhanced, as indicated by a larger effect of TRAM-34 and a larger residual NS309-induced relaxation in the presence of UCL 1684. Reduction of blood flow selectively...

Gas chromatography in blood carbon monoxide monitoring

Energy Technology Data Exchange (ETDEWEB)

Drasche, H.; Funk, L.; Herbolsheimer, R.

1975-05-01

A description of a gas chromatography method for monitoring blood carboxyhaemoglobin (HbCO) levels in a very small quantity (100 mcl) of capillary blood: reagents and apparatus, procedures, calculation of results. To calculate HbCO content, an aliquot portion of water-diluted blood is saturated with CO; this saturation obviates the need to determine the haemoglobin or iron blood levels.

A Pulse Wave Velocity Based Method to Assess the Mean Arterial Blood Pressure Limits of Autoregulation in Peripheral Arteries

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Ananya Tripathi

2017-11-01

Full Text Available Background: Constant blood flow despite changes in blood pressure, a phenomenon called autoregulation, has been demonstrated for various organ systems. We hypothesized that by changing hydrostatic pressures in peripheral arteries, we can establish these limits of autoregulation in peripheral arteries based on local pulse wave velocity (PWV.Methods: Electrocardiogram and plethysmograph waveforms were recorded at the left and right index fingers in 18 healthy volunteers. Each subject changed their left arm position, keeping the right arm stationary. Pulse arrival times (PAT at both fingers were measured and used to calculate PWV. We calculated ΔPAT (ΔPWV, the differences between the left and right PATs (PWVs, and compared them to the respective calculated blood pressure at the left index fingertip to derive the limits of autoregulation.Results: ΔPAT decreased and ΔPWV increased exponentially at low blood pressures in the fingertip up to a blood pressure of 70 mmHg, after which changes in ΔPAT and ΔPWV were minimal. The empirically chosen 20 mmHg window (75–95 mmHg was confirmed to be within the autoregulatory limit (slope = 0.097, p = 0.56. ΔPAT and ΔPWV within a 20 mmHg moving window were not significantly different from the respective data points within the control 75–95 mmHg window when the pressure at the fingertip was between 56 and 110 mmHg for ΔPAT and between 57 and 112 mmHg for ΔPWV.Conclusions: Changes in hydrostatic pressure due to changes in arm position significantly affect peripheral arterial stiffness as assessed by ΔPAT and ΔPWV, allowing us to estimate peripheral autoregulation limits based on PWV.

Noninvasive arterial blood pressure waveforms in patients with continuous-flow left ventricular assist devices

NARCIS (Netherlands)

Martina, Jerson R.; Westerhof, Berend E.; de Jonge, Nicolaas; van Goudoever, Jeroen; Westers, Paul; Chamuleau, Steven; van Dijk, Diederik; Rodermans, Ben F. M.; de Mol, Bas A. J. M.; Lahpor, Jaap R.

2014-01-01

Arterial blood pressure and echocardiography may provide useful physiological information regarding cardiac support in patients with continuous-flow left ventricular assist devices (cf-LVADs). We investigated the accuracy and characteristics of noninvasive blood pressure during cf-LVAD support.

Contribution of the Arterial System and the Heart to Blood Pressure during Normal Aging - A Simulation Study.

Science.gov (United States)

Maksuti, Elira; Westerhof, Nico; Westerhof, Berend E; Broomé, Michael; Stergiopulos, Nikos

2016-01-01

During aging, systolic blood pressure continuously increases over time, whereas diastolic pressure first increases and then slightly decreases after middle age. These pressure changes are usually explained by changes of the arterial system alone (increase in arterial stiffness and vascular resistance). However, we hypothesise that the heart contributes to the age-related blood pressure progression as well. In the present study we quantified the blood pressure changes in normal aging by using a Windkessel model for the arterial system and the time-varying elastance model for the heart, and compared the simulation results with data from the Framingham Heart Study. Parameters representing arterial changes (resistance and stiffness) during aging were based on literature values, whereas parameters representing cardiac changes were computed through physiological rules (compensated hypertrophy and preservation of end-diastolic volume). When taking into account arterial changes only, the systolic and diastolic pressure did not agree well with the population data. Between 20 and 80 years, systolic pressure increased from 100 to 122 mmHg, and diastolic pressure decreased from 76 to 55 mmHg. When taking cardiac adaptations into account as well, systolic and diastolic pressure increased from 100 to 151 mmHg and decreased from 76 to 69 mmHg, respectively. Our results show that not only the arterial system, but also the heart, contributes to the changes in blood pressure during aging. The changes in arterial properties initiate a systolic pressure increase, which in turn initiates a cardiac remodelling process that further augments systolic pressure and mitigates the decrease in diastolic pressure.

Radionuclide scanning in a study of the pulmonary blood flow with the open arterial canal

International Nuclear Information System (INIS)

Rizaev, M.N.; Gulyamov, D.S.; Khodzhibekov, M.Kh.; Anvarov, M.A.

1980-01-01

Characteristic features of the distribution of the arterial pulmonary blood flow have been studied in 32 patients with the open arterial flow by lung scanning with albumin macroaggregate and 131 I. Research was conducted using the gamma-Ochamber ''Fo Gamma LFV'' and the scanner ''Magnaskaner 500I''. Disordered distribution of the pulmonary blood flow expressed in its unilateral decrease was detected in 17 patients (52.9%). A higher frequency of pulmonary hypertension was noted in these patients versus those with a relatively normal distribution of the pulmonary blood flow. A severe course of the disease was observed in high pulmonary hypertension combined with sharp suppression of the blood flow in one of the lungs or with signs of the shift from the right to the left side

Intraoperative changes of transcranial Doppler velocity: relation to arterial oxygen content and whole-blood viscosity

NARCIS (Netherlands)

Schuurman, P. R.; Albrecht, K. W.

1999-01-01

The association of arterial oxygen content (CaO2) and viscosity with transcranial Doppler (TCD) blood flow velocity in the middle cerebral artery was studied in 20 adults without cerebrovascular disease undergoing abdominal surgery associated with significant fluctuations in hematology. TCD

Reducing blood loss during laparoscopic myomectomy by temporary uterine artery clamping using bulldog clamp

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Kai-Jo Chiang

2014-01-01

Full Text Available Uterine myoma is the most common benign gynecologic tumor worldwide. Mini-invasive surgery has become popular for myomectomy, with advantages over laparotomy. However, reducing blood loss during laparoscopic myomectomy is a major concern for the surgeon because of the limitation in making a quick control bleeding during the operation. Several methods have proved to decrease blood flow, but are not always effective or available. We present a case of uterine myoma with the uterine arteries clamped by bulldog clamps during laparoscopic myomectomy. The myoma was removed successfully with minimal blood loss (<50 ml during the operation. This is an effective, safe, and reliable method for reducing bleeding during laparoscopic myomectomy that does not require ligation of the uterine artery.

Heat stress exacerbates the reduction in middle cerebral artery blood velocity during prolonged self-paced exercise.

Science.gov (United States)

Périard, J D; Racinais, S

2015-06-01

This study examined the influence of hyperthermia on middle cerebral artery mean blood velocity (MCA Vmean). Eleven cyclists undertook a 750 kJ self-paced time trial in HOT (35 °C) and COOL (20 °C) conditions. Exercise time was longer in HOT (56 min) compared with COOL (49 min; P blood flow, and heart rate were higher throughout HOT compared with COOL (P blood pressure and oxygen uptake were lower from 50% of work completed onward in HOT compared with COOL (P heat appears to have exacerbated the reduction in MCA Vmean, in part via increases in peripheral blood flow and a decrease in arterial blood pressure. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Regional cerebral blood flow measurements by a noninvasive microsphere method using 123I-IMP. Comparison with the modified fractional uptake method and the continuous arterial blood sampling method

International Nuclear Information System (INIS)

Nakano, Seigo; Matsuda, Hiroshi; Tanizaki, Hiroshi; Ogawa, Masafumi; Miyazaki, Yoshiharu; Yonekura, Yoshiharu

1998-01-01

A noninvasive microsphere method using N-isopropyl-p-( 123 I)iodoamphetamine ( 123 I-IMP), developed by Yonekura et al., was performed in 10 patients with neurological diseases to quantify regional cerebral blood flow (rCBF). Regional CBF values by this method were compared with rCBF values simultaneously estimated from both the modified fractional uptake (FU) method using cardiac output developed by Miyazaki et al. and the conventional method with continuous arterial blood sampling. In comparison, we designated the factor which converted raw SPECT voxel counts to rCBF values as a CBF factor. A highly significant correlation (r=0.962, p<0.001) was obtained in the CBF factors between the present method and the continuous arterial blood sampling method. The CBF factors by the present method were only 2.7% higher on the average than those by the continuous arterial blood sampling method. There were significant correlation (r=0.811 and r=O.798, p<0.001) in the CBF factor between modified FU method (threshold for estimating total brain SPECT counts; 10% and 30% respectively) and the continuous arterial blood sampling method. However, the CBF factors of the modified FU method showed 31.4% and 62.3% higher on the average (threshold; 10% and 30% respectively) than those by the continuous arterial blood sampling method. In conclusion, this newly developed method for rCBF measurements was considered to be useful for routine clinical studies without any blood sampling. (author)

Application of Micropore Filter Technology: Exploring the Blood Flow Path in Arterial-Line Filters and Its Effect on Bubble Trapping Functions.

Science.gov (United States)

Herbst, Daniel P

2017-03-01

Conventional arterial-line filters commonly use a large volume circular shaped housing, a wetted micropore screen, and a purge port to trap, separate, and remove gas bubbles from extracorporeal blood flow. Focusing on the bubble trapping function, this work attempts to explore how the filter housing shape and its resulting blood flow path affect the clinical application of arterial-line filters in terms of gross air handling. A video camera was used in a wet-lab setting to record observations made during gross air-bolus injections in three different radially designed filters using a 30-70% glycerol-saline mixture flowing at 4.5 L/min. Two of the filters both had inlet ports attached near the filter-housing top with bottom oriented outlet ports at the bottom, whereas the third filter had its inlet and outlet ports both located at the bottom of the filter housing. The two filters with top-in bottom-out fluid paths were shown to direct the incoming flow downward as it passed through the filter, placing the forces of buoyancy and viscous drag in opposition to each other. This contrasted with the third filter's bottom-in bottom-out fluid path, which was shown to direct the incoming flow upward so that the forces of buoyancy and viscous drag work together. The direction of the blood flow path through a filter may be important to the application of arterial-line filter technology as it helps determine how the forces of buoyancy and flow are aligned with one another.

Does mean arterial blood pressure scale with body mass in mammals?

DEFF Research Database (Denmark)

Poulsen, C B; Wang, T; Assersen, K

2018-01-01

For at least the last 30 years, it has been discussed whether mean arterial blood pressure (MAP) is independent of body mass or whether it increases in accordance with the vertical height between the heart and the brain. The debate has centred on the most appropriate mathematical models for analy......For at least the last 30 years, it has been discussed whether mean arterial blood pressure (MAP) is independent of body mass or whether it increases in accordance with the vertical height between the heart and the brain. The debate has centred on the most appropriate mathematical models......-Altman analysis showed a bias of 1 mm Hg with 95% confidence interval (from -35 to 36 mm Hg); that is, the limits of agreement between radiotelemetric studies and studies in restrained animals were double the supposed difference in the MAP between the mouse and elephant. In conclusion, the existing literature...

Experimental investigation of the flow of a blood analogue fluid in a replica of a bifurcated small artery.

Science.gov (United States)

Anastasiou, A D; Spyrogianni, A S; Koskinas, K C; Giannoglou, G D; Paras, S V

2012-03-01

The scope of this work is to study the pulsatile flow of a blood mimicking fluid in a micro channel that simulates a bifurcated small artery, in which the Fahraeus-Lindqvist effect is insignificant. An aqueous glycerol solution with small amounts of xanthan gum was used for simulating viscoelastic properties of blood and in vivo flow conditions were reproduced. Local flow velocities were measured using micro Particle Image Velocimetry (μ-PIV). From the measured velocity distributions, the wall shear stress (WSS) and its variation during a pulse were estimated. The Reynolds numbers employed are relatively low, i.e. similar to those prevailing during blood flow in small arteries. Experiments both with a Newtonian and a non-Newtonian fluid (having asymptotic viscosity equal to the viscosity of the Newtonian one) proved that the common assumption that blood behaves as a Newtonian fluid is not valid for blood flow in small arteries. It was also shown that the outer wall of the bifurcation, which is exposed to a lower WSS, is more predisposed to atherosclerotic plaque formation. Moreover, this region in small vessels is shorter than the one in large arteries, as the developed secondary flow decays faster. Finally, the WSS values in small arteries were found to be lower than those in large ones. Copyright © 2011 IPEM. Published by Elsevier Ltd. All rights reserved.

Classification of peripheral occlusive arterial diseases based on symptoms, signs and distal blood pressure measurements

DEFF Research Database (Denmark)

Tønnesen, K H; Noer, Ivan; Paaske, William

1980-01-01

Systolic blood pressures at toe and ankle were measured in 459 consecutive patients with occlusive arterial disease. Fifty-eight per cent had intermittent claudication with arterial disease of all degrees of severity. Seventeen per cent complained of rest pain having toe systolic pressures below 30...

Middle cerebral artery thrombosis: acute blood-brain barrier consequences

Energy Technology Data Exchange (ETDEWEB)

Dietrich, W.D.; Prado, R.; Watson, B.D.; Nakayama, H.

1988-07-01

The effect of middle cerebral artery (MCA) thrombosis on the integrity of the blood-brain barrier (BBB) was studied in rats using horseradish peroxidase (HRP). Endothelial injury with subsequent platelet thrombosis was produced by means of a rose bengal-sensitized photochemical reaction, facilitated by irradiating the right proximal MCA segment with the focused beam of an argon laser. At 15 minutes following thrombosis formation, diffuse leakage of HRP was observed bilaterally within cortical and subcortical brain areas. Peroxidase extravasation was most dense within the territory of the occluded artery including neocortical areas and dorso-lateral striatum. Contralaterally, a similar distribution was observed but with less intense HRP leakage. Ultrastructural studies demonstrated an increase in permeability to HRP within arterioles, venules and capillaries. At these sites, the vascular endothelium contained HRP-filled pinocytotic vesicles and tubular profiles. Although less intense, bilateral HRP leakage was also observed following MCA stenosis or femoral artery occlusion. Endothelial-platelet interactions at the site of vascular injury may be responsible for releasing substances or neurohumoral factors which contribute to the acute opening of the BBB.

A simple method for regional cerebral blood flow measurement by one-point arterial blood sampling and 123I-IMP microsphere model (part 2). A study of time correction of one-point blood sample count

International Nuclear Information System (INIS)

Masuda, Yasuhiko; Makino, Kenichi; Gotoh, Satoshi

1999-01-01

In our previous paper regarding determination of the regional cerebral blood flow (rCBF) using the 123 I-IMP microsphere model, we reported that the accuracy of determination of the integrated value of the input function from one-point arterial blood sampling can be increased by performing correction using the 5 min: 29 min ratio for the whole-brain count. However, failure to carry out the arterial blood collection at exactly 5 minutes after 123 I-IMP injection causes errors with this method, and there is thus a time limitation. We have now revised out method so that the one-point arterial blood sampling can be performed at any time during the interval between 5 minutes and 20 minutes after 123 I-IMP injection, with addition of a correction step for the sampling time. This revised method permits more accurate estimation of the integral of the input functions. This method was then applied to 174 experimental subjects: one-point blood samples collected at random times between 5 and 20 minutes, and the estimated values for the continuous arterial octanol extraction count (COC) were determined. The mean error rate between the COC and the actual measured continuous arterial octanol extraction count (OC) was 3.6%, and the standard deviation was 12.7%. Accordingly, in 70% of the cases, the rCBF was able to be estimated within an error rate of 13%, while estimation was possible in 95% of the cases within an error rate of 25%. This improved method is a simple technique for determination of the rCBF by 123 I-IMP microsphere model and one-point arterial blood sampling which no longer shows a time limitation and does not require any octanol extraction step. (author)

Acrolein inhalation alters arterial blood gases and triggers carotid body-mediated cardiovascular responses in hypertensive rats.

Science.gov (United States)

Perez, Christina M; Hazari, Mehdi S; Ledbetter, Allen D; Haykal-Coates, Najwa; Carll, Alex P; Cascio, Wayne E; Winsett, Darrell W; Costa, Daniel L; Farraj, Aimen K

2015-01-01

Air pollution exposure affects autonomic function, heart rate, blood pressure and left ventricular function. While the mechanism for these effects is uncertain, several studies have reported that air pollution exposure modifies activity of the carotid body, the major organ that senses changes in arterial oxygen and carbon dioxide levels, and elicits downstream changes in autonomic control and cardiac function. We hypothesized that exposure to acrolein, an unsaturated aldehyde and mucosal irritant found in cigarette smoke and diesel exhaust, would activate the carotid body chemoreceptor response and lead to secondary cardiovascular responses in rats. Spontaneously hypertensive (SH) rats were exposed once for 3 h to 3 ppm acrolein gas or filtered air in whole body plethysmograph chambers. To determine if the carotid body mediated acrolein-induced cardiovascular responses, rats were pretreated with an inhibitor of cystathionine γ-lyase (CSE), an enzyme essential for carotid body signal transduction. Acrolein exposure induced several cardiovascular effects. Systolic, diastolic and mean arterial blood pressure increased during exposure, while cardiac contractility decreased 1 day after exposure. The cardiovascular effects were associated with decreases in pO2, breathing frequency and expiratory time, and increases in sympathetic tone during exposure followed by parasympathetic dominance after exposure. The CSE inhibitor prevented the cardiovascular effects of acrolein exposure. Pretreatment with the CSE inhibitor prevented the cardiovascular effects of acrolein, suggesting that the cardiovascular responses with acrolein may be mediated by carotid body-triggered changes in autonomic tone. (This abstract does not reflect EPA policy.).

Use of a blood gas analyzer and a laboratory autoanalyzer in routine practice to measure electrolytes in intensive care unit patients

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Budak Yasemin U

2012-08-01

Full Text Available Abstract Background Electrolyte values are measured in most critically ill intensive care unit (ICU patients using both an arterial blood gas analyzer (ABG and a central laboratory auto-analyzer (AA. The aim of the present study was to investigate whether electrolyte levels assessed using an ABG and an AA were equivalent; data on sodium and potassium ion concentrations were examined. Methods We retrospectively studied patients hospitalized in the ICU between July and August 2011. Of 1,105 test samples, we identified 84 instances of simultaneous sampling of arterial and venous blood, where both Na+ and K+ levels were measured using a pHOx Stat Profile Plus L blood gas analyzer (Nova Biomedical, Waltham MA, USA and a Roche Modular P autoanalyzer (Roche Diagnostics, Mannheim, Germany. Statistical measures employed to compare the data included Spearman's correlation coefficients, paired Student’s t-tests, Deming regression analysis, and Bland-Altman plots. Results The mean sodium concentration was 138.1 mmol/L (SD 10.2 mmol/L using the ABG and 143.0 mmol/L (SD 10.5 using the AA (p + and Na+, with biases of 0.150-0.352 and −0.97-10.05 respectively; the associated correlation coefficients were 0.88 and 0.90. Conclusions We conclude that the ABG and AA do not yield equivalent Na+ and K+ data. Concordance between ABG and AA should be established prior to introduction of new ABG systems.

Induced renal artery stenosis in rabbits: magnetic resonance imaging, angiography, and radionuclide determination of blood volume and blood flow

International Nuclear Information System (INIS)

Mitchell, D.G.; Tobin, M.; LeVeen, R.; Tomaczewski, J.; Alavi, A.; Staum, M.; Kundel, H.

1988-01-01

To investigate the ability of MRI to detect alterations due to renal ischemia, a rabbit renal artery stenosis (RAS) model was developed. Seven rabbits had RAS induced by surgically encircling the artery with a polyethylene band which had a lumen of 1 mm, 1 to 2 weeks prior to imaging. The stenosis was confirmed by angiography, and the rabbits were then imaged in a 1.4 T research MRI unit. T1 was calculated using four inversion recovery sequences with different inversion times. Renal blood flow, using 113 Sn-microspheres, and regional water content by drying were then measured. The average T1 of the inner medulla was shorter for the ischemia (1574 msec) than for the contralateral kidney (1849 msec), while no change ws noted in the cortex. Ischemic kidneys had less distinct outer medullary zones on IR images with TI = 600 msec than did contralateral or control kidneys. Blood flow to both the cortex and medulla were markedly reduced in ischemic kidneys compared with contralateral kidneys (119.5 vs. 391 ml/min/100 gm for cortex and 19.8 vs. 50.8 ml/min/100 gm for medulla). Renal water and blood content were less affected. Our rabbit model of renal artery stenosis with MRI, radionuclide, and angiographic correlation has the potential to increase our understanding of MR imaging of the rabbit kidney

Investigation of blood flow rheology using second-grade viscoelastic model (Phan-Thien-Tanner) within carotid artery.

Science.gov (United States)

Ramiar, Abas; Larimi, Morsal Momenti; Ranjbar, Ali Akbar

2017-01-01

Hemodynamic factors, such as Wall Shear Stress (WSS), play a substantial role in arterial diseases. In the larger arteries, such as the carotid artery, interaction between the vessel wall and blood flow affects the distribution of hemodynamic factors. The fluid is considered to be non-Newtonian, whose flow is governed by the equation of a second-grade viscoelastic fluid and the effects of viscoelastic on blood flow in carotid artery is investigated. Pulsatile flow studies were carried out in a 3D model of carotid artery. The governing equations were solved using finite volume C++ based on open source code, OpenFOAM. To describe blood flow, conservation of mass and momentum, a constitutive relation of simplified Phan-Thien-Tanner (sPTT), and appropriate relations were used to explain shear thinning behavior. The first recirculation was observed at t = 0.2 s, in deceleration phase. In the acceleration phase from t = 0.3 s to t = 0.5 s, vortex and recirculation sizes in bulb regions in both ECA and ICA gradually increased. As is observed in the line graphs based on extracted data from ICA, at t = 0.2 s, τyy is the maximum amount of wall shear stress and τxy the minimum one. The maximum shear stress occurred in the inner side of the main branch (inner side of ICA and ECA) because the velocity of blood flow in the inner side of the bulb region was maximum due to the created recirculation zone in the opposite side in this area. The rheology of blood flow and shear stress in various important parts (the area that are in higher rates of WSS such as bifurcation region and the regions after bulb areas in both branches, Line1-4 in Fig. 7) were also analyzed. The investigation of velocity stream line, velocity profile and shear stress in various sections of carotid artery showed that the maximum shear stress occurred in acceleration phase and in the bifurcation region between ECA and ICA which is due to velocity gradients and changes in thinning behavior of blood and

A case of reocclusion of the renal artery diagnosed by the color Doppler method with evaluation of blood flow direction in the collateral circulation of the kidney in addition to the non-detectable blood signal in the renal artery.

Science.gov (United States)

Hirano, Megumi; Ohta, Tomoyuki; Nakata, Norio; Kawakami, Reina; Takamura, Kimihiro; Matsuda, Tosiharu; Nishioka, Makiko; Sakurai, Tomoo; Matsuo, Kouichi; Miyamoto, Yukio

2014-10-01

A 23-year-old woman was referred to our hospital for an interventional procedure for chronic total occlusion of the right renal artery, probably due to fibromuscular dysplasia (FMD), and for control of renal vascular hypertension. Before percutaneous transluminal renal angioplasty (PTRA), aortography revealed collateral circulation to the right kidney from the lower lumbar artery. After PTRA, however, blood flow in the renal side of the collateral circulation flowed outside from the right renal parenchyma. 4 months later, we could not find a blood flow signal in the right renal artery, and there was a contrary flow signal in the right kidney parenchyma continuously from the extrahilar vessel, possibly a collateral artery. These findings indicated reocclusion of the right artery. We confirmed reocclusion of the renal artery and collateral feeding by contrast dynamic computed tomography (CT), and PTRA was performed again without any complications or reocclusion for 5 months. This is the first case report showing that a back-flowing signal in the right renal parenchyma from the extrahilar artery is useful as an indirect finding suggesting reocclusion.

Effectiveness of the Stewart Method in the Evaluation of Blood Gas Parameters.

Science.gov (United States)

Gezer, Mustafa; Bulucu, Fatih; Ozturk, Kadir; Kilic, Selim; Kaldirim, Umit; Eyi, Yusuf Emrah

2015-03-01

In 1981, Peter A. Stewart published a paper describing his concept for employing Strong Ion Difference. In this study we compared the HCO3 levels and Anion Gap (AG) calculated using the classic method and the Stewart method. Four hundred nine (409) arterial blood gases of 90 patients were collected retrospectively. Some were obtained from the same patients in different times and conditions. All blood samples were evaluated using the same device (ABL 800 Blood Gas Analyzer). HCO3 level and AG were calculated using the Stewart method via the website AcidBase.org. HCO3 levels, AG and strong ion difference (SID) were calculated using the Stewart method, incorporating the parameters of age, serum lactate, glucose, sodium, and pH, etc. According to classic method, the levels of HCO3 and AG were 22.4±7.2 mEq/L and 20.1±4.1 mEq/L respectively. According to Stewart method, the levels of HCO3 and AG were 22.6±7.4 and 19.9±4.5 mEq/L respectively. There was strong correlation between the classic method and the Stewart method for calculating HCO3 and AG. The Stewart method may be more effective in the evaluation of complex metabolic acidosis.

An effective fractal-tree closure model for simulating blood flow in large arterial networks.

Science.gov (United States)

Perdikaris, Paris; Grinberg, Leopold; Karniadakis, George Em

2015-06-01

The aim of the present work is to address the closure problem for hemodynamic simulations by developing a flexible and effective model that accurately distributes flow in the downstream vasculature and can stably provide a physiological pressure outflow boundary condition. To achieve this goal, we model blood flow in the sub-pixel vasculature by using a non-linear 1D model in self-similar networks of compliant arteries that mimic the structure and hierarchy of vessels in the meso-vascular regime (radii [Formula: see text]). We introduce a variable vessel length-to-radius ratio for small arteries and arterioles, while also addressing non-Newtonian blood rheology and arterial wall viscoelasticity effects in small arteries and arterioles. This methodology aims to overcome substantial cut-off radius sensitivities, typically arising in structured tree and linearized impedance models. The proposed model is not sensitive to outflow boundary conditions applied at the end points of the fractal network, and thus does not require calibration of resistance/capacitance parameters typically required for outflow conditions. The proposed model convergences to a periodic state in two cardiac cycles even when started from zero-flow initial conditions. The resulting fractal-trees typically consist of thousands to millions of arteries, posing the need for efficient parallel algorithms. To this end, we have scaled up a Discontinuous Galerkin solver that utilizes the MPI/OpenMP hybrid programming paradigm to thousands of computer cores, and can simulate blood flow in networks of millions of arterial segments at the rate of one cycle per 5 min. The proposed model has been extensively tested on a large and complex cranial network with 50 parent, patient-specific arteries and 21 outlets to which fractal trees where attached, resulting to a network of up to 4,392,484 vessels in total, and a detailed network of the arm with 276 parent arteries and 103 outlets (a total of 702,188 vessels

Continuous monitoring of arterial blood gases and pH during intraoperative rapid blood administration using a Paratrend sensor.

Science.gov (United States)

Vretzakis, G; Papaziogas, B; Matsaridou, E; Vasiliadou, G; Papadopoulos, G; Patsialas, C; Kostopoulou, F

2000-01-01

The aim of this study was to determine the effects of rapid transfusion of packed red cells on the arterial blood gases and acid-base status of the recipient. We studied 16 patients (mean age 66.3+/-9.9 years) who received rapid transfusion of 632.8+/-287.2 g of packed red cells in CPDA-1, stored before use for a period of 15.2+/-4.4 days. During transfusion, monitoring of pH, PCO2 and PO2 was continuous using an intra-arterial multiparameter sensor (Paratrend 7, Biomedical Sensors, UK). The rate of the transfusion was 73.1+/-9.6 g/min and the duration of observation was 35.8+/-12.8 min. Arterial pH decreased from 7.446+/-0.023 to 7.385+/-0.034 (pDelta pH and delta PCO2 showed significant correlation to the weight and the age of the transfused blood (pPO2 were not specific and our clinical impression was that they were related to unmeasured parameters. Our findings suggest that the fall in pH and the elevation in PCO2 which occur during rapid transfusion of packed red cells may go undetected or be misinterpreted if the acid-base status of the recipient is not monitored continuously. These alterations are mainly of metabolic character and depend on the amount and age of the transfused component. Our data suggest that arterial sampling is essential during massive transfusions.

FDM Analysis for Blood Flow through Stenosed Tapered Arteries

Directory of Open Access Journals (Sweden)

Sankar DS

2010-01-01

Full Text Available Abstract A computational model is developed to analyze the unsteady flow of blood through stenosed tapered narrow arteries, treating blood as a two-fluid model with the suspension of all the erythrocytes in the core region as Herschel-Bulkley fluid and the plasma in the peripheral layer as Newtonian fluid. The finite difference method is employed to solve the resulting system of nonlinear partial differential equations. The effects of stenosis height, peripheral layer thickness, yield stress, viscosity ratio, angle of tapering and power law index on the velocity, wall shear stress, flow rate and the longitudinal impedance are analyzed. It is found that the velocity and flow rate increase with the increase of the peripheral layer thickness and decrease with the increase of the angle of tapering and depth of the stenosis. It is observed that the flow rate decreases nonlinearly with the increase of the viscosity ratio and yield stress. The estimates of the increase in the longitudinal impedance to flow are considerably lower for the two-fluid Herschel-Bulkley model compared with those of the single-fluid Herschel-Bulkley model. Hence, it is concluded that the presence of the peripheral layer helps in the functioning of the diseased arterial system.

C1-esterase inhibitor protects against early vein graft remodeling under arterial blood pressure.

Science.gov (United States)

Krijnen, Paul A J; Kupreishvili, Koba; de Vries, Margreet R; Schepers, Abbey; Stooker, Wim; Vonk, Alexander B A; Eijsman, Leon; Van Hinsbergh, Victor W M; Zeerleder, Sacha; Wouters, Diana; van Ham, Marieke; Quax, Paul H A; Niessen, Hans W M

2012-01-01

Arterial pressure induced vein graft injury can result in endothelial loss, accelerated atherosclerosis and vein graft failure. Inflammation, including complement activation, is assumed to play a pivotal role herein. Here, we analyzed the effects of C1-esterase inhibitor (C1inh) on early vein graft remodeling. Human saphenous vein graft segments (n=8) were perfused in vitro with autologous blood either supplemented or not with purified human C1inh at arterial pressure for 6h. The vein segments and perfusion blood were analyzed for cell damage and complement activation. In addition, the effect of purified C1inh on vein graft remodeling was analyzed in vivo in atherosclerotic C57Bl6/ApoE3 Leiden mice, wherein donor caval veins were interpositioned in the common carotid artery. Application of C1inh in the in vitro perfusion model resulted in significantly higher blood levels and significantly more depositions of C1inh in the vein wall. This coincided with a significant reduction in endothelial loss and deposition of C3d and C4d in the vein wall, especially in the circular layer, compared to vein segments perfused without supplemented C1inh. Administration of purified C1inh significantly inhibited vein graft intimal thickening in vivo in atherosclerotic C57Bl6/ApoE3 Leiden mice, wherein donor caval veins were interpositioned in the common carotid artery. C1inh significantly protects against early vein graft remodeling, including loss of endothelium and intimal thickening. These data suggest that it may be worth considering its use in patients undergoing coronary artery bypass grafting. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Arterial blood gases and oxygen content in climbers on Mount Everest

NARCIS (Netherlands)

Grocott, Michael P. W.; Martin, Daniel S.; Levett, Denny Z. H.; McMorrow, Roger; Windsor, Jeremy; Montgomery, Hugh E.; Ahuja, V.; Aref-Adib, G.; Burnham, R.; Chisholm, A.; Clarke, K.; Coates, D.; Coates, M.; Cook, D.; Cox, M.; Dhillon, S.; Dougall, C.; Doyle, P.; Duncan, P.; Edsell, M.; Edwards, L.; Evans, L.; Gardiner, P.; Grocott, M.; Gunning, P.; Hart, N.; Harrington, J.; Harvey, J.; Holloway, C.; Howard, D.; Hurlbut, D.; Imray, C.; Ince, C.; Jonas, M.; van der Kaaij, J.; Khosravi, M.; Kolfschoten, N.; Levett, D.; Luery, H.; Luks, A.; Martin, D.; McMorrow, R.; Meale, P.; Mitchell, K.; Montgomery, H.; Morgan, G.; Morgan, J.; Murray, A.; Mythen, M.; Newman, S.

2009-01-01

BACKGROUND: The level of environmental hypobaric hypoxia that affects climbers at the summit of Mount Everest (8848 m [29,029 ft]) is close to the limit of tolerance by humans. We performed direct field measurements of arterial blood gases in climbers breathing ambient air on Mount Everest. METHODS:

Noninvasive estimation of pulmonary arterial pressure by analysis of pulmonary blood-flow distribution

International Nuclear Information System (INIS)

Konstam, M.A.; Strauss, H.W.; Alpert, N.M.; Miller, S.W.; Murphy, R.X.; Greene, R.E.; McKusick, K.A.

1979-01-01

To determine whether a correlation exists between pulmonary arterial (PA) pressure (P/sub a/) and the distribution of pulmonary blood flow, this distribution was measured in four upright dogs in the control state and during intravenous infusions of epinephrine or prostaglandin F/sub 2α/. During suspension of respiration, 15 mCi of Xe-133 were injected intravenously, and perfusion and equilibration lung images were recorded with a scintillation camera. The procedure was performed several times on each dog, with and without pharmacological elevation of PA pressure by 5 to 50 cm H 2 O. For each scintigram, the relative blood flow per unit ventilated lung volume (F) was plotted against centimeters above the hilum (h). Pulmonary arterial pressure was derived from each curve, assuming the relation F = B(P/sub a/ - hD) 2 , where B = constant and D = specific gravity of blood. Calculated PA pressure correlated strongly (r = 0.83) with measured PA pressure, suggesting a possible means of noninvasive estimation of PA pressure

Acute arterial occlusion - kidney

Science.gov (United States)

... main artery to the kidney is called the renal artery. Reduced blood flow through the renal artery can hurt kidney function. ... need include: Duplex Doppler ultrasound exam of the renal arteries to test blood flow MRI of the kidney arteries, which can show ...

The involvement of splenic artery in the blood supply of hepatomas: its DSA findings and interventional treatment

International Nuclear Information System (INIS)

Duan Xuhua; Liang Huiming; Feng Gansheng; Zheng Chuangsheng; Ren Jianzhuang

2009-01-01

Objective: To investigate the DSA manifestations of the involvement of splenic artery in supplying blood to hepatomas and to assess the therapeutic value of super-selective interventional embolization. Methods: During the period of March 2005-June 2008, 897 patients with hepatoma underwent angiography and the involvement of splenic artery in the blood supply of hepatoma was confirmed in 7 cases. Splenic arteriography was performed by means of super-selective catheterization with 5 F Yashiro catheter together with 3 F SP catheter. The splenic arteries which supplied blood to hepatomas were embolized with hyper-liquid iodized-oil emulsion mixed with chemotherapy drug, which was followed by the injection of sufficient gelatin sponge or ethanol. The clinical results were analyzed. Results: Splenic arteriography revealed that the splenic artery was the main supplying vessel of the hepatoma in two cases, and was not the main supplying vessel of the hepatoma in five cases. The splenic supplying vessels were completely embolized in all 7 cases. After the procedure, AFP level was decreased over 50%, and in two patients it dropped to normal. CT checkup 4-6 weeks after the surgery revealed that the diameter of tumor decreased to 2.5 - 4.6 cm. Conclusion: The involvement of splenic artery in supplying blood to hepatomas is not common. Super-selective catheterization and sufficient embolization of the splenic supplying vessels are very important for improving the interventional effectiveness. (authors)

Two-Fluid Mathematical Models for Blood Flow in Stenosed Arteries: A Comparative Study

Directory of Open Access Journals (Sweden)

Sankar DS

2009-01-01

Full Text Available The pulsatile flow of blood through stenosed arteries is analyzed by assuming the blood as a two-fluid model with the suspension of all the erythrocytes in the core region as a non-Newtonian fluid and the plasma in the peripheral layer as a Newtonian fluid. The non-Newtonian fluid in the core region of the artery is assumed as a (i Herschel-Bulkley fluid and (ii Casson fluid. Perturbation method is used to solve the resulting system of non-linear partial differential equations. Expressions for various flow quantities are obtained for the two-fluid Casson model. Expressions of the flow quantities obtained by Sankar and Lee (2006 for the two-fluid Herschel-Bulkley model are used to get the data for comparison. It is found that the plug flow velocity and velocity distribution of the two-fluid Casson model are considerably higher than those of the two-fluid Herschel-Bulkley model. It is also observed that the pressure drop, plug core radius, wall shear stress and the resistance to flow are significantly very low for the two-fluid Casson model than those of the two-fluid Herschel-Bulkley model. Hence, the two-fluid Casson model would be more useful than the two-fluid Herschel-Bulkley model to analyze the blood flow through stenosed arteries.

Modeling and analysis of biomagnetic blood Carreau fluid flow through a stenosis artery with magnetic heat transfer: A transient study.

Science.gov (United States)

Abdollahzadeh Jamalabadi, Mohammad Yaghoub; Daqiqshirazi, Mohammadreza; Nasiri, Hossein; Safaei, Mohammad Reza; Nguyen, Truong Khang

2018-01-01

We present a numerical investigation of tapered arteries that addresses the transient simulation of non-Newtonian bio-magnetic fluid dynamics (BFD) of blood through a stenosis artery in the presence of a transverse magnetic field. The current model is consistent with ferro-hydrodynamic (FHD) and magneto-hydrodynamic (MHD) principles. In the present work, blood in small arteries is analyzed using the Carreau-Yasuda model. The arterial wall is assumed to be fixed with cosine geometry for the stenosis. A parametric study was conducted to reveal the effects of the stenosis intensity and the Hartman number on a wide range of flow parameters, such as the flow velocity, temperature, and wall shear stress. Current findings are in a good agreement with recent findings in previous research studies. The results show that wall temperature control can keep the blood in its ideal blood temperature range (below 40°C) and that a severe pressure drop occurs for blockages of more than 60 percent. Additionally, with an increase in the Ha number, a velocity drop in the blood vessel is experienced.

Vasoactive enzymes and blood flow responses to passive and active exercise in peripheral arterial disease

DEFF Research Database (Denmark)

Walker, Meegan A.; Høier, Birgitte; Walker, Philip J.

2016-01-01

Background: Peripheral arterial disease (PAD) is characterised by impaired leg blood flow, which contributes to claudication and reduced exercise capacity. This study investigated to what extent vasoactive enzymes might contribute to altered blood flow in PAD (Fontaine stage II). Methods: We...... compared femoral artery blood flow during reactive hyperaemia, leg-extension exercise and passive leg movement, and determined the level of vasoactive enzymes in skeletal muscle samples from the vastus lateralis in PAD (n = 10, 68.5 ± 6.5 years) and healthy controls (CON, n = 9, 62.1 ± 12.3 years). Leg...... than CON (1.04 ± 0.19 vs 0.50 ± 0.06 AU, P = 0.02), with no differences for other enzymes. Leg blood flow during exercise was correlated with prostacyclin synthase (P = 0.001). Conclusion: Elevated NADPH oxidase indicates that oxidative stress may be a primary cause of low nitric oxide availability...

Determining the Arterial Blood Pressure of People Living in Yesilyurt Local Healthcare Office

Directory of Open Access Journals (Sweden)

Feyza Dereli

2009-02-01

Full Text Available AIM: Whereas the prevalance of arterial blood pressure which was a chronical health problem was 20%-25% among 30 year-old people, them showing an increase in aging, the percentage went as high as 50% in 60’s and later ages. What was that worrisome was that despite the high prevalance, only half of these received treathment. This is study was descriptively and cross-sectionally planned to determine whether the people asking their tensions to be measured in and around the Yesilyurt local healthcare office region. METHODS: The environment of the research consisted of 1400 people over 35 age and registered Yesilyurt Local healthcare Office and the whole of the environment were included in this sample. The study was conducted over 340 voluntaries. The data was collected by a questionnaire of 14 questions containing socio-demografic features and by measuring the arterial blood pressure, height and weight of the individuals. In the evaluation of the data, chi-square test was used and the level of significantly was accepted as 0.05. RESULTS: In this study, the rate of high sistolic blood pressure was found to be 21.47% and the rate of high diastolic blood pressure to be 8.23%. It was determined that age and body mass index varrieties were effective on sistolic hipertension. It was also found that in their behaviors of the use of hypertensive medicine, of regular arterial pressure controls and of having the hypertesion diagnosis significant differnces varied statistically on both sistolic and diastolic blood pressure people having. CONCLUSION: In order to improve the health, informative information abouth hypertension was provided for the participants for too days consisting of 4 sessions. [TAF Prev Med Bull 2009; 8(1.000: 53-58

Study Impact of Gas Delivery Systems on Imaging Studies of Human Cerebral Blood Flow

International Nuclear Information System (INIS)

Cain, J.R.; Parkes, L.M.; Jackson, A.; Parkes, L.M.; Eadsforth, P.; Beards, S.C.

2013-01-01

To compare a semiopen breathing circuit with a non-rebreathing (Hudson mask) for MRI experiments involving gas delivery. Methods and Materials. Cerebral blood flow (CBF) was measured by quantitative phase contrast angiography of the internal carotid and basilar arteries in 18 volunteers (20-31 years). In 8 subjects, gases were delivered via a standard non-re breathing (Hudson mask). In 10 subjects, gases were delivered using a modified “Mapleson A” semiopen anesthetic gas circuit and mouthpiece. All subjects were given 100% O 2 , medical air, and carbogen gas (95% O 2 and 5% CO 2 ) delivered at 15 L/min in a random order. Results. The Hudson mask group showed significant increases in CBF in response to increased FiCO 2 compared to air (+9.8%). A small nonsignificant reduction in CBF (-2.4%) was seen in response to increased inspired concentrations of oxygen (FiO 2 ). The Mapleson A group showed significantly larger changes in CBF in response to both increased inspired concentrations of carbon dioxide (FiCO 2 ) (+32.2%, Ρ<0.05) and FiO 2 (-14.6%, Ρ<0.01). Conclusions. The use of an anaesthetic gas delivery circuit avoids entrainment of room air and re breathing effects that may otherwise adversely affect the experimental results.

The effect of sensory stimulation provided by family on arterial blood oxygen saturation in critical care patients.

Science.gov (United States)

Yousefi, Hojatollah; Naderi, Mojgan; Daryabeigi, Reza

2015-01-01

Stressors in the intensive care unit (ICU) impair patients' comfort, excite the stress response, and increase oxygen consumption in their body. Non-medical interventions are recommended by several studies as a treatment to improve comfort in the ICU patients. Sensory stimulation is one of the most important interventions. Since arterial blood oxygen saturation is an important index of patients' clinical and respiratory condition, this study aimed to investigate the effect of sensory stimulation provided by family on arterial blood oxygen saturation in critical care patients. This study is a clinical trial conducted on 64 patients hospitalized in the ICU wards of Al-Zahra and Kashani hospitals in Isfahan, Iran in 2012 and 2013. The patients were selected by simple sampling method and were randomly assigned to two groups (study and control). Patients' arterial blood oxygen saturations were measured 10 min before, immediately after, 10 min and 30 min after sensory stimulation in the study group, and simultaneously in the control group without any intervention. Repeated measures analysis of variance (ANOVA) showed a significant difference in the mean of arterial blood oxygen saturation levels 10 min before, immediately after, 10 min and 30 min after sensory stimulation in the study group (P 0.18). Application of sensory stimulations as a nursing and non-medical intervention by the family members improves comfort and increases the level of blood oxygen saturation in critical care patients.

Quantitative agreement between [(15)O]H2O PET and model free QUASAR MRI-derived cerebral blood flow and arterial blood volume

NARCIS (Netherlands)

Heijtel, D. F. R.; Petersen, E. T.; Mutsaerts, H. J. M. M.; Bakker, E.; Schober, P.; Stevens, M. F.; van Berckel, B. N. M.; Majoie, C. B. L. M.; Booij, J.; van Osch, M. J. P.; van Bavel, E. T.; Boellaard, R.; Lammertsma, A. A.; Nederveen, A. J.

2016-01-01

The purpose of this study was to assess whether there was an agreement between quantitative cerebral blood flow (CBF) and arterial cerebral blood volume (CBVA) measurements by [(15)O]H2O positron emission tomography (PET) and model-free QUASAR MRI. Twelve healthy subjects were scanned within a week

Changes in distribution of hepatic blood flow induced by intra-arterial infusion of angiotensin II in human hepatic cancer

International Nuclear Information System (INIS)

Sasaki, Y.; Imaoka, S.; Hasegawa, Y.

1985-01-01

Changes in the distribution of the hepatic blood flow induced by intra-arterial infusion of angiotensin II (AT-II) were studied in human hepatic cancers using extremely short-lived radioisotope (RI) (krypton 81 m [/sup 81m/Kr]; half-life, 13 seconds). After the start of continuous infusion of AT-II, the radioactivity of the tumor showed about a two-fold increase, whereas that of the nontumor region decreased to about one half as much as the level before the infusion. Consequently, the mean ratio of the arterial blood flow in the tumor region to that in the nontumor region (T/N ratio) increased to 3.30 (P less than 0.001). The T/N ratio showed a peak before the peripheral blood pressure reached the maximum, and thereafter tended to decrease. Intra-arterial infusion of AT-II raised the T/N ratio more obviously than did intravenous infusion of the drug, with less rise in the peripheral blood pressure. It is believed that intra-arterial infusion chemotherapy with local use of AT-II enables better accessibility of chemotherapeutic drugs to tumors

Inert gas transport in blood and tissues.

Science.gov (United States)

Baker, A Barry; Farmery, Andrew D

2011-04-01

This article establishes the basic mathematical models and the principles and assumptions used for inert gas transfer within body tissues-first, for a single compartment model and then for a multicompartment model. From these, and other more complex mathematical models, the transport of inert gases between lungs, blood, and other tissues is derived and compared to known experimental studies in both animals and humans. Some aspects of airway and lung transfer are particularly important to the uptake and elimination of inert gases, and these aspects of gas transport in tissues are briefly described. The most frequently used inert gases are those that are administered in anesthesia, and the specific issues relating to the uptake, transport, and elimination of these gases and vapors are dealt with in some detail showing how their transfer depends on various physical and chemical attributes, particularly their solubilities in blood and different tissues. Absorption characteristics of inert gases from within gas cavities or tissue bubbles are described, and the effects other inhaled gas mixtures have on the composition of these gas cavities are discussed. Very brief consideration is given to the effects of hyper- and hypobaric conditions on inert gas transport. © 2011 American Physiological Society. Compr Physiol 1:569-592, 2011.

Modelling of impaired cerebral blood flow due to gaseous emboli

International Nuclear Information System (INIS)

Hague, J P; Banahan, C; Chung, E M L

2013-01-01

Bubbles introduced to the arterial circulation during invasive medical procedures can have devastating consequences for brain function but their effects are currently difficult to quantify. Here we present a Monte Carlo simulation investigating the impact of gas bubbles on cerebral blood flow. For the first time, this model includes realistic adhesion forces, bubble deformation, fluid dynamical considerations, and bubble dissolution. This allows investigation of the effects of buoyancy, solubility, and blood pressure on embolus clearance. Our results illustrate that blockages depend on several factors, including the number and size distribution of incident emboli, dissolution time and blood pressure. We found it essential to model the deformation of bubbles to avoid overestimation of arterial obstruction. Incorporation of buoyancy effects within our model slightly reduced the overall level of obstruction but did not decrease embolus clearance times. We found that higher blood pressures generate lower levels of obstruction and improve embolus clearance. Finally, we demonstrate the effects of gas solubility and discuss potential clinical applications of the model. (paper)

A pressão arterial está sendo medida? Is the blood pressure being measured?

Directory of Open Access Journals (Sweden)

Débora C. Alavarce

2000-03-01

Full Text Available A medida da pressão arterial faz parte do exame físico e deve ser realizada em toda consulta médica. Para avaliar se a pressão arterial é medida nas consultas médicas, foram consultados 500 prontuários de pacientes de primeira consulta ambulatorial, sendo 335 (67% provenientes de clínicas médicas e cirúrgicas e 165 (33% das clínicas ginecológica e obstétrica. A pressão arterial foi anotada em 39% das consultas realizadas (135±32/85±19 mm Hg, sendo que em 11% destas anotações a pressão diastólica estava acima de 90 mm Hg. Em relação ao diagnóstico prévio de hipertensão arterial verificou-se que: a em 62% dos prontuários não havia esta informação; b 20% referiram ter hipertensão, e em 79% destes a pressão arterial foi anotada; e c 18% referiram não ter hipertensão e 46% destes tiveram registro da pressão arterial. Portanto, a maior parte dos pacientes não teve sua pressão arterial anotada.The blood pressure measure is part of the physical exam and it should be accomplished in every medical consultation. To verify the blood pressure measured in the accomplished medical consultations record of first they were consulted it consults 500 patient's ambulatorial being 335 (67% coming of medical and surgical clinics and 165 (33% of the gynecological and obstetric clinics. The blood pressure was written down in 39% of the accomplished consultations (135+32 mm Hg 85+19 mm Hg, and 11% of this annotations the pressure diastólica was above 90 mm Hg. In relation to the previous diagnosis of hypertension it was verified that: a in 62% of the records there was not this information; b 20% referred to have hypertension, and in 79% of these the arterial pressure was scored; and c 18% referred not to have hypertension and 46% of these had registration of the arterial pressure. Therefore, most of the patients didn't have its logged arterial pressure.

Prehospital point of care testing of blood gases and electrolytes — an evaluation of IRMA

OpenAIRE

Prause, Gerhard; Ratzenhofer-Komenda, Beatrice; Offner, Anton; Lauda, Peter; Voit, Henrika; Pojer, Horst

1997-01-01

Background: This study evaluated the feasibility of blood gas analysis and electrolyte measurements during emergency transport prior to hospital admission. Results: A portable, battery-powered blood analyzer was used on patients in life threatening conditions to determine pH, pCO2, pO2, sodium, potassium and ionized calcium. Arterial blood was used for blood gas analysis and electrolyte measurements. Venous blood was used for electrolyte measurement alone. During the observation period of 4 m...

The genetic basis for altered blood vessel function in disease: large artery stiffening

Directory of Open Access Journals (Sweden)

Alex Agrotis

2005-12-01

Full Text Available Alex AgrotisThe Cell Biology Laboratory, Baker Heart Research Institute, Melbourne, Victoria, AustraliaAbstract: The progressive stiffening of the large arteries in humans that occurs during aging constitutes a potential risk factor for increased cardiovascular morbidity and mortality, and is accompanied by an elevation in systolic blood pressure and pulse pressure. While the underlying basis for these changes remains to be fully elucidated, factors that are able to influence the structure and composition of the extracellular matrix and the way it interacts with arterial smooth muscle cells could profoundly affect the properties of the large arteries. Thus, while age and sex represent important factors contributing to large artery stiffening, the variation in growth-stimulating factors and those that modulate extracellular production and homeostasis are also being increasingly recognized to play a key role in the process. Therefore, elucidating the contribution that genetic variation makes to large artery stiffening could ultimately provide the basis for clinical strategies designed to regulate the process for therapeutic benefit.Keywords: arterial stiffness, genes, polymorphism, extracellular matrix proteins

Changes in cerebral artery blood flow velocity after intermittent cerebrospinal fluid drainage.

OpenAIRE

Kempley, S T; Gamsu, H R

1993-01-01

Doppler ultrasound was used to measure blood flow velocity in the anterior cerebral artery of six premature infants with posthaemorrhagic hydrocephalus, before and after intermittent cerebrospinal fluid (CSF) drainage, on 23 occasions. There was a significant increase in mean blood flow velocity after the drainage procedures (+5.6 cm/s, 95% confidence interval +2.9 to +8.3 cm/s), which was accompanied by a decrease in velocity waveform pulsatility. CSF pressure also fell significantly. In pat...

Measurement of Blood Pressure Using an Arterial Pulsimeter Equipped with a Hall Device

Directory of Open Access Journals (Sweden)

Jong-Gu Choi

2011-01-01

Full Text Available To measure precise blood pressure (BP and pulse rate without using a cuff, we have developed an arterial pulsimeter consisting of a small, portable apparatus incorporating a Hall device. Regression analysis of the pulse wave measured during testing of the arterial pulsimeter was conducted using two equations of the BP algorithm. The estimated values of BP obtained by the cuffless arterial pulsimeter over 5 s were compared with values obtained using electronic or liquid mercury BP meters. The standard deviation between the estimated values and the measured values for systolic and diastolic BP were 8.3 and 4.9, respectively, which are close to the range of values of the BP International Standard. Detailed analysis of the pulse wave measured by the cuffless radial artery pulsimeter by detecting changes in the magnetic field can be used to develop a new diagnostic algorithm for BP, which can be applied to new medical apparatus such as the radial artery pulsimeter.

A prospective study of glomerular filtration rate and arterial blood pressure in insulin-dependent diabetics with diabetic nephropathy

DEFF Research Database (Denmark)

Parving, H H; Smidt, U M; Friisberg, B

1981-01-01

Glomerular filtration rate (GFR, single bolus 51Cr-EDTA technique), serum creatinine, proteinuria and arterial blood pressure have been measured prospectively in 14 young onset insulin-dependent diabetics selected by of persistent proteinuria (greater than 0.5 g/day) secondary to diabetic...... in arterial blood pressure to a hypertensive level is an early feature of diabetic nephropathy in young insulin-dependent diabetics....... and 112/mumol/l (NS), proteinuria increased from 1.8 to 3.3 g/day (p less than 0.001) and arterial blood pressure rose from 132/88 to 153/101 mmHg (p less than 0.001). Glomerular filtration rate decreased linearly with time (slope = -0.75, r = 0.99, p less than 0.001) by a mean of 0.75 ml/min/month (range...

Appropriate xenon-inhalation speed in xenon-enhanced CT using the end-tidal gas-sampling method

International Nuclear Information System (INIS)

Suga, Sadao; Toya, Shigeo; Kawase, Takeshi; Koyama, Hideki; Shiga, Hayao

1986-01-01

This report describes some problems when end-tidal xenon gas is substituted for the arterial xenon concentration in xenon-enhanced CT. The authors used a newly developed xenon inhalator with a xenon-gas-concentration analyzer and performed xenon-enhanced CT by means of the ''arterio-venous shunt'' method and the ''end-tidal gas-sampling'' method simultaneously. By the former method, the arterial build-up rate (K) was obtained directly from the CT slices of a blood circuit passing through the phantom. By the latter method, it was calculated from the xenon concentration of end-tidal gas sampled from the mask. The speed of xenon supply was varied between 0.6 - 1.2 L/min. in 11 patients with or without a cerebral lesion. The results revealed that rapid xenon inhalation caused a discrepancy in the arterial K between the ''shunt'' method and the ''end-tidal'' method. This discrepancy may be responsible for the mixing of inhalated gas and expired gas in respiratory dead space, such as the nasal cavity or the mask. The cerebral blood flow was underestimated because of the higher arterial K in the latter method. Too much slow inhalation, however, was timewasting, and it increased the body motion in the subanesthetic state. Therefore, an inhalation speed of the arterial K of as much as 0.2 was ideal to represent the end-tidal xenon concentration for the arterial K in the ''end-tidal gas-sampling'' method. When attention is given to this point, this method may offer a reliable absolute value in xenon-enhanced CT. (author)

Assessment of resting-state blood flow through anterior cerebral arteries using trans-cranial doppler recordings.

Science.gov (United States)

Huang, Hanrui; Sejdić, Ervin

2013-12-01

Trans-cranial Doppler (TCD) recordings are used to monitor cerebral blood flow in the main cerebral arteries. The resting state is usually characterized by the mean velocity or the maximum Doppler shift frequency (an envelope signal) by insonating the middle cerebral arteries. In this study, we characterized cerebral blood flow in the anterior cerebral arteries. We analyzed both envelope signals and raw signals obtained from bilateral insonation. We recruited 20 healthy patients and conducted the data acquisition for 15 min. Features were extracted from the time domain, the frequency domain and the time-frequency domain. The results indicate that a gender-based statistical difference exists in the frequency and time-frequency domains. However, no handedness effect was found. In the time domain, information-theoretic features indicated that mutual dependence is higher in raw signals than in envelope signals. Finally, we concluded that insonation of the anterior cerebral arteries serves as a complement to middle cerebral artery studies. Additionally, investigation of the raw signals provided us with additional information that is not otherwise available from envelope signals. Use of direct trans-cranial Doppler raw data is therefore validated as a valuable method for characterizing the resting state. Copyright © 2013 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

A retrospective analysis of blood gases with two different insulin ...

African Journals Online (AJOL)

A retrospective analysis of blood gases with two different insulin infusion protocols in patients undergoing cardiovascular surgery. ... In this study, we aimed to look into the effect of glycemic control on arterial blood gas parameters, serum electrolytes, and hemoglobin (Hb). Materials and Methods: We collected data from ...

ANGIOGRAPHIC ANATOMY OF THE MAJOR ABDOMINAL ARTERIAL BLOOD SUPPLY IN THE DOG.

Science.gov (United States)

Culp, William T N; Mayhew, Philipp D; Pascoe, Peter J; Zwingenberger, Allison

2015-01-01

Vascular-based interventional radiology (IR) procedures are being more regularly performed in veterinary patients for both diagnostic and therapeutic purposes. A complete description of the fluoroscopic arterial anatomy of the canine abdominal cavity has not been published. This information is essential for performance of IR procedures to allow for improved preparation before and during a particular procedure. The primary purpose of this study was to provide a fluoroscopic description of the vascular branching from the abdominal aorta in a ventro-dorsal projection with a secondary goal of producing pictorial reference images of the major abdominal arterial blood vessels. Five healthy female hound type dogs were enrolled and underwent fluoroscopic arteriography. During fluoroscopy, both nonselective and selective arteriography were performed. The nonselective arteriograms were obtained in the aorta at four locations: cranial to the celiac artery, cranial to the renal arteries, cranial to the caudal mesenteric artery, and cranial to the branching of the external iliac arteries. Selective arteriography was conducted by performing injections into the following arteries: celiac, splenic, common hepatic, cranial mesenteric, left and right renal, and caudal mesenteric. Fluoroscopic arteriography allowed for excellent characterization of the aortic ostia and the location of the lower order vascular branches. Future evaluation of vascular-based treatment options will likely increase as the understanding of the normal and pathologic anatomy improves. © 2015 American College of Veterinary Radiology.

Contribution of the Arterial System and the Heart to Blood Pressure during Normal Aging - A Simulation Study

NARCIS (Netherlands)

Maksuti, Elira; Westerhof, Nico; Westerhof, Berend E.; Broomé, Michael; Stergiopulos, Nikos

2016-01-01

During aging, systolic blood pressure continuously increases over time, whereas diastolic pressure first increases and then slightly decreases after middle age. These pressure changes are usually explained by changes of the arterial system alone (increase in arterial stiffness and vascular

Pelvic magnetic resonance imaging angioanatomy of the arterial blood supply to the penis in suspected prostate cancer patients

International Nuclear Information System (INIS)

Thai, Cao Tan; Karam, Ibrahim Michel; Nguyen-Thi, Phi Linh; Lefèvre, Frédéric; Hubert, Jacques; Felblinger, Jacques; Eschwège, Pascal

2015-01-01

Highlights: • Three patterns of penile arterial supply (according to the classification of Stéphane Droupy). • Our classification about accessory pudendal artery. • Origin of accessory pudendal artery. - Abstract: Purpose: To describe the internal pudendal artery (IPA) and accessory pudendal artery (APA) detected by magnetic resonance (MR) angiography to help surgeons to find and preserve them during radical prostatectomy (RP). Materials and methods: Constrast-enhanced MR 3.0 T angiography of the pelvis were performed in 111 male patients suspected diagnosis of prostate cancer (PCa), and describe the penile arterial blood supply. Results: There are three patterns of the arterial blood supply to the penis (IPA and/or APA) accounting for 51.4%, 46.8% and 1.8% of cases, respectively. About the accessory pudendal artery (APA): 54/111 (48.6%) patients had APA with five different branching patterns, they were type I (APA bilateral symmetry): 17 (31.5%); type II (APA bilateral asymmetry): 1 (1.9%); type III (APA unilateral lateral): 13 (24%); type IV (APA unilateral apical): 21 (38.9%); type V (APA unilateral mix): 2 (3.7%). APA origin were from inferior epigastric artery (IEA): 7 (9.5%); from inferior vesical artery (IVA): 32 (43.2%); from obturator artery (OA): 35 (47.3%). Conclusion: A precise angioanatomic evalutation of arteries destined to the penis by MR angiography pre-operation for male pelvic organs will help surgeons to preserve them and contributes to reduce the erectile dysfunction after these procedures

Pelvic magnetic resonance imaging angioanatomy of the arterial blood supply to the penis in suspected prostate cancer patients

Energy Technology Data Exchange (ETDEWEB)

Thai, Cao Tan, E-mail: bstanhatinh@gmail.com [Department of Urology, Brabois Hospital, University Hospital of Nancy, Rue du Morvan, 54500 Vandoeuvre Lès Nancy Cedex (France); IADI Laboratory, INSERM-U947, Brabois Hospital, University Hospital of Nancy, Tour Drouet, rue du Morvan, 54511 Vandoeuvre Lès Nancy Cedex (France); Karam, Ibrahim Michel [Clinical Epidemiology and Evaluation Department, University Hospital of Nancy (France); Department of Anatomy, Faculty of Medicine Nancy, 9 Avenue de la Foret de haye BP, 54505 Vandoeuvre Lès Nancy Cedex (France); Nguyen-Thi, Phi Linh [Clinical Epidemiology and Evaluation Department, University Hospital of Nancy (France); INSERM, CIC-EC CIE6, 92 Avenue du Maréchal de Lattre de Tassigny, 54000 Nancy (France); Lefèvre, Frédéric [Department of Radiology, Brabois Hospital, University Hospital of Nancy, Rue du Morvan, 54500 Vandoeuvre Lès Nancy Cedex (France); Hubert, Jacques [Department of Urology, Brabois Hospital, University Hospital of Nancy, Rue du Morvan, 54500 Vandoeuvre Lès Nancy Cedex (France); IADI Laboratory, INSERM-U947, Brabois Hospital, University Hospital of Nancy, Tour Drouet, rue du Morvan, 54511 Vandoeuvre Lès Nancy Cedex (France); Felblinger, Jacques [IADI Laboratory, INSERM-U947, Brabois Hospital, University Hospital of Nancy, Tour Drouet, rue du Morvan, 54511 Vandoeuvre Lès Nancy Cedex (France); Eschwège, Pascal [Department of Urology, Brabois Hospital, University Hospital of Nancy, Rue du Morvan, 54500 Vandoeuvre Lès Nancy Cedex (France)

2015-05-15

Highlights: • Three patterns of penile arterial supply (according to the classification of Stéphane Droupy). • Our classification about accessory pudendal artery. • Origin of accessory pudendal artery. - Abstract: Purpose: To describe the internal pudendal artery (IPA) and accessory pudendal artery (APA) detected by magnetic resonance (MR) angiography to help surgeons to find and preserve them during radical prostatectomy (RP). Materials and methods: Constrast-enhanced MR 3.0 T angiography of the pelvis were performed in 111 male patients suspected diagnosis of prostate cancer (PCa), and describe the penile arterial blood supply. Results: There are three patterns of the arterial blood supply to the penis (IPA and/or APA) accounting for 51.4%, 46.8% and 1.8% of cases, respectively. About the accessory pudendal artery (APA): 54/111 (48.6%) patients had APA with five different branching patterns, they were type I (APA bilateral symmetry): 17 (31.5%); type II (APA bilateral asymmetry): 1 (1.9%); type III (APA unilateral lateral): 13 (24%); type IV (APA unilateral apical): 21 (38.9%); type V (APA unilateral mix): 2 (3.7%). APA origin were from inferior epigastric artery (IEA): 7 (9.5%); from inferior vesical artery (IVA): 32 (43.2%); from obturator artery (OA): 35 (47.3%). Conclusion: A precise angioanatomic evalutation of arteries destined to the penis by MR angiography pre-operation for male pelvic organs will help surgeons to preserve them and contributes to reduce the erectile dysfunction after these procedures.

Arterial blood pressure changes in acute T. brucei infection of dogs ...

African Journals Online (AJOL)

The aim of this study is to find out the usefulness of serial arterial blood pressure measurements in predicting severity and outcome of acute Trypanosoma brucei infection in dogs. Twenty adult dogs of mixed sexes and aged between 2 and 5 years were used for this study. The dogs were of good cardiac health and were ...

Peripheral arterial volume distensibility: significant differences with age and blood pressure measured using an applied external pressure

International Nuclear Information System (INIS)

Zheng, Dingchang; Murray, Alan

2011-01-01

A new arterial distensibility measurement technique was assessed in 100 healthy normotensive subjects. Arterial transmural pressures on the whole right arm were reduced with a 50 cm long cuff inflated to 10, 20, 30 and 40 mmHg. The electrocardiogram, and finger and ear photoplethysmograms were recorded simultaneously. Arm pulse propagation time, pulse wave velocity (PWV) and arterial volume distensibility were determined. With a 40 mmHg reduction in transmural pressure, arm pulse propagation time increased from 61 to 83 ms, PWV decreased from 12 to 8 m s −1 and arterial distensibility increased from 0.102% to 0.232% per mmHg (all P < 0.0001). At all cuff pressures, arterial distensibility was significantly related to resting mean arterial pressure (MAP), diastolic blood pressure (DBP) and age, and for systolic blood pressure at 30 and 40 mmHg (all P < 0.05). At 40 mmHg cuff pressure, arterial distensibility fell by 54% for a MAP increase from 75 to 105 mmHg, 57% for a DBP increase from 60 to 90 mmHg and 47% for an age increase from 20 to 70 years. These changes were more than double than those without cuff pressure. Our technique showed that systemic volume distensibility of the peripheral arm artery reduced with age, with a greater effect at higher external and lower transmural pressures

Determination of natural in vivo noble-gas concentrations in human blood.

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Yama Tomonaga

Full Text Available Although the naturally occurring atmospheric noble gases He, Ne, Ar, Kr, and Xe possess great potential as tracers for studying gas exchange in living beings, no direct analytical technique exists for simultaneously determining the absolute concentrations of these noble gases in body fluids in vivo. In this study, using human blood as an example, the absolute concentrations of all stable atmospheric noble gases were measured simultaneously by combining and adapting two analytical methods recently developed for geochemical research purposes. The partition coefficients determined between blood and air, and between blood plasma and red blood cells, agree with values from the literature. While the noble-gas concentrations in the plasma agree rather well with the expected solubility equilibrium concentrations for air-saturated water, the red blood cells are characterized by a distinct supersaturation pattern, in which the gas excess increases in proportion to the atomic mass of the noble-gas species, indicating adsorption on to the red blood cells. This study shows that the absolute concentrations of noble gases in body fluids can be easily measured using geochemical techniques that rely only on standard materials and equipment, and for which the underlying concepts are already well established in the field of noble-gas geochemistry.

Doppler Flow Wire Evaluation of Renal Blood Flow Reserve in Hypertensive Patients with Normal Renal Arteries

International Nuclear Information System (INIS)

Beregi, Jean-Paul; Mounier-Vehier, Claire; Devos, Patrick; Gautier, Corinne; Libersa, Christian; McFadden, Eugene P.; Carre, Alain

2000-01-01

Purpose: To study the vasomotor responses of the renal microcirculation in patients with essential hypertension.Methods: We studied the reactivity of the renal microcirculation to papaverine, with intraarterial Doppler and quantitative arteriography, in 34 renal arteries of 19 hypertensive patients without significant renal artery stenosis. Isosorbide dinitrate was given to maximally dilate proximal renal arteries. APV (average peak blood flow velocity) was used as an index of renal blood flow.Results: Kidneys could be divided into two distinct subgroups based on their response to papaverine. An increase in APV of up to 55% occurred in 21 kidneys, an increase > 55% in 13 kidneys. Within each group the values were normally distributed. Both baseline APV and the effect of papaverine on mean velocity differed significantly between groups.Conclusion: There seems to be a subgroup of patients with essential hypertension that has an impaired reactivity to papaverine, consistent with a functional impairment of the renal microcirculation. Further studies are required to determine whether this abnormality contributes to or results from elevated blood pressure

The effect of ultrasound on arterial blood flow: 1. Steady fully developed flow

International Nuclear Information System (INIS)

Bestman, A.R.

1990-12-01

The paper models the effects of ultrasound heating of the tissues and the resultant perturbation on blood flow in the arteries and veins. It is assumed that the blood vessel is rigid and the undisturbed flow is fully developed. Acoustical perturbation on this Poiseuille flow, for the general three-dimensional flow with heat transfer in an infinitely long pipe is considered. Closed form analytical solutions are obtained to the problem. It is discovered that the effects of the ultrasound heating are concentrated at the walls of the blood vessels. (author). 4 refs

The measurement of blood speed in the pulmonary artery trunk

Energy Technology Data Exchange (ETDEWEB)

Saro, J P; Bula-Cruz, J [UTAD - 5000 Vila Real (Spain); Rafael, J A [Dep. Electronica e Telecomunicacoes da Univ. de Aveiro - 3800 Aveiro (Spain); Botelho, M F; Lima, J P [IBILI - Faculdade de Medicina da Univ. de Coimbra - 3000 Coimbra (Spain)

1999-12-31

The paper describes a non invasive methodology for the measurement of blood speed in the pulmonary artery trunk. The methodology has been tested with a moving radioactive tracer (nuclear medicine). An image processing technique is proposed, for detection and analysis of a moving object with variable shape and intensity over time (radioactive bolus). Experiments on the application of the technique in nuclear medicine are critically analysed. (authors) 9 refs., 7 figs.

Radioimmunological determination of 5a-pregnane-3,20-dione and progesterone in arterial and venous blood from the umbilical cord

International Nuclear Information System (INIS)

Tannich, E.

1985-01-01

Radioimmunological investigations of arterial and venous blood from the umbilical cord for 5a-DHP and progesterone were carried out in 60 newly delivered infants using 3 H as a tracer substance. The following findings were revealed: 1) The correlation between progesterone and 5a-DHP was better in the venous blood than in the arterial blood from the umbilical cord and the concentrations measured for the two hormones were higher in the vein. 2) Both the umbilical vein and artery showed more elevated hormone levels in male infants as compared to female infants. 3) The duration of gestation, the concentration of hydrogen ions in the fetal plasma and various other maternal and fetal factors have an influence on the height of the 5a-DHP and progesterone levels in the umbilical blood. This was also concluded from the fact that the (arterial and venous) hormone concentrations measured in infants from primiparae were higher than those in infants from multiparae. The metabolisation of 5a-DHP varies between the sexes, which does not hold true for progosterone. (TRV) [de

Balloon test occlusion of the internal carotid artery with stable xenon/CT cerebral blood flow imaging

International Nuclear Information System (INIS)

Erba, S.M.; Horton, J.A.; Latchaw, R.E.; Yonas, H.; Sekhar, L.; Schramm, V.; Pentheny, S.

1988-01-01

We describe a technique to predict preoperatively the safety of permanently occluding an internal carotid artery. The method was performed by imaging stable xenon cerebral blood flow (CBF) with the internal carotid artery both open and temporarily occluded with a nondetachable balloon on a double lumen Swan-Ganz catheter. Patients were those in whom we planned to sacrifice the internal carotid artery (those with giant or inaccessible aneurysms) or those in whom such a sacrifice was at least likely (those with skull base tumors). Patients were divided into three groups on the basis of a comparison of occluded and nonoccluded CBF values. Group-I patients had no significant change in CBF with internal carotid artery occlusion; group-II patients showed a symmetric decrease in CBF; and group-III patients had an asymmetric decrease in CBF, always greater on the occluded side. A fourth group clinically failed to tolerate even brief carotid occlusion. The internal carotid artery in one patients from group III was sacrificed at surgery: the size and shape of his postoperative infarct corresponded almost exactly to the area of asymmetrically decreased CBF on his occluded study. The data suggest that if surgery is likely to result in permanent occlusion of the internal carotid artery, then patients who are at risk for delayed neurologic injury due to a compromised cerebral blood flow should have arterial bypass grafts before such surgery is performed

Measurement of stenotic rate and blood flow of carotid artery of the dogs with digital subtraction angiography

International Nuclear Information System (INIS)

Kobayashi, Keisuke; Kagawa, Masaaki; Asai, Masaaki; Yasue, Hiroshi; Kawabata, Kazuhiro; Yue, Shuzengmr

1987-01-01

Hemodynamic analysis of stenotic rate and local mean blood flow of the common carotid artery of the dogs with electromagnetic flowmeter and DSA was evaluated. Measurement of stenotic rate using local profile curve was very accurate and it was though to be useful in evaluation of local blood flow of the cervical carotid artery in the patients with carotid stenosis pre-and postoperatively. Although the measurement of absolute blood flow in the case of known diameter of the vessel is exactly reliable, the measured flow is not so reliable in the clinical application for the difficulty in the accurate measurement of the diameter. But hemodynamic analysis of the relative blood flow in the clinical ground can be estimated from this study. The theory and practical measurement are discussed. (author)

Influence of acute jugular vein compression on the cerebral blood flow velocity, pial artery pulsation and width of subarachnoid space in humans.

Directory of Open Access Journals (Sweden)

Andrzej F Frydrychowski

Full Text Available PURPOSE: The aim of this study was to assess the effect of acute bilateral jugular vein compression on: (1 pial artery pulsation (cc-TQ; (2 cerebral blood flow velocity (CBFV; (3 peripheral blood pressure; and (4 possible relations between mentioned parameters. METHODS: Experiments were performed on a group of 32 healthy 19-30 years old male subjects. cc-TQ and the subarachnoid width (sas-TQ were measured using near-infrared transillumination/backscattering sounding (NIR-T/BSS, CBFV in the left anterior cerebral artery using transcranial Doppler, blood pressure was measured using Finapres, while end-tidal CO(2 was measured using medical gas analyser. Bilateral jugular vein compression was achieved with the use of a sphygmomanometer held on the neck of the participant and pumped at the pressure of 40 mmHg, and was performed in the bend-over (BOPT and swayed to the back (initial position. RESULTS: In the first group (n = 10 during BOPT, sas-TQ and pulse pressure (PP decreased (-17.6% and -17.9%, respectively and CBFV increased (+35.0%, while cc-TQ did not change (+1.91%. In the second group, in the initial position (n = 22 cc-TQ and CBFV increased (106.6% and 20.1%, respectively, while sas-TQ and PP decreases were not statistically significant (-15.5% and -9.0%, respectively. End-tidal CO(2 remained stable during BOPT and venous compression in both groups. Significant interdependence between changes in cc-TQ and PP after bilateral jugular vein compression in the initial position was found (r = -0.74. CONCLUSIONS: Acute bilateral jugular venous insufficiency leads to hyperkinetic cerebral circulation characterised by augmented pial artery pulsation and CBFV and direct transmission of PP into the brain microcirculation. The Windkessel effect with impaired jugular outflow and more likely increased intracranial pressure is described. This study clarifies the potential mechanism linking jugular outflow insufficiency with arterial small vessel cerebral

Decreased muscle oxygenation and increased arterial blood flow in the non-exercising limb during leg exercise.

Science.gov (United States)

Shiroishi, Kiyoshi; Kime, Ryotaro; Osada, Takuya; Murase, Norio; Shimomura, Kousuke; Katsumura, Toshihito

2010-01-01

We evaluated arterial blood flow, muscle tissue oxygenation and muscle metabolism in the non-exercising limb during leg cycling exercise. Ten healthy male volunteers performed a graded leg cycling exercise at 0, 40, 80, 120 and 160 watts (W) for 5 min each. Tissue oxygenation index (TOI) of the non-exercising left forearm muscle was measured using a near-infrared spatially resolved spectroscopy (NIR(SRS)), and non-exercising forearm blood flow ((NONEX)FBF) in the brachial artery was also evaluated by a Doppler ultrasound system. We also determined O(2) consumption of the non-exercising forearm muscle (NONEXV(O)(2mus)) by the rate of decrease in O(2)Hb during arterial occlusion at each work rate. TOI was significantly decreased at 160 W (p exercising muscle may be reduced, even though (NONEX)FBF increases at high work rates during leg cycling exercise.

Measurement of regional pulmonary blood volume in patients with increased pulmonary blood flow or pulmonary arterial hypertension

International Nuclear Information System (INIS)

Wollmer, P.; Rozcovek, A.; Rhodes, C.G.; Allan, R.M.; Maseri, A.

1984-01-01

The effects of chronic increase in pulmonary blood flow and chronic pulmonary hypertension on regional pulmonary blood volume was measured in two groups of patients. One group of patients had intracardiac, left-to-right shunts without appreciable pulmonary hypertension, and the other consisted of patients with Eisenmenger's syndrome or primary pulmonary hypertension, i.e. patients with normal or reduced blood flow and severe pulmonary hypertension. A technique based on positron tomography was used to measure lung density (by transmission scanning) and regional pulmonary blood volume (after inhalation of /sup 11/CO). The distribution of pulmonary blood volume was more uniform in patients with chronic increase in pulmonary blood flow than in normal subjects. There were also indications of an absolute increase in intrapulmonary blood volume by about 15%. In patients with chronic pulmonary arterial hypertension, the distribution of pulmonary blood volume was also abnormally uniform. There was, however, no indication that overall intrapulmonary blood volume was substantially different from normal subjects. The abnormally uniform distribution of pulmonary blood volume can be explained by recruitment and/or dilatation of vascular beds. Intrapulmonary blood volume appears to be increased in patients with intracardiac, left-to-right shunts. With the development of pulmonary hypertension, intrapulmonary blood volume falls, which may be explained by reactive changes in the vasculature and/or obliteration of capillaries

DOES TRANEXAMIC ACID REDUCE BLOOD LOSS IN OFF-PUMP CORONARY ARTERY BYPASS?

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A. Mehr-Aein

2006-09-01

Full Text Available Tranexamic acid is now used on a routine basis for on-pump coronary artery bypass grafting (CABG. We assessed the hemostatic effects of tranexamic acid to decrease bleeding tendency and transfusion requirements in patients undergoing off-pump coronary artery bypass surgery (OPCAB. A total of 66 patients were enrolled to elective OPCAB in a double-blind, prospective randomized study. Of these, 33 patients received tranexamic acid (15 mg/kg before the infusion of heparin and 15 mg/kg after protamin infusion, and 33 patients received only saline. Preoperative hematologic variables, postoperative bleeding and allogeneic transfusions were considered. D-dimer plasma levels were also evaluated to monitor the activation of fibrinolysis. Postoperative bleeding was significantly lower in the tranexamic acid group compared with the control group (320 ± 38 mL vs. 480 ± 75 mL at 12 hour, P < 0.001. The tranexamic acid group had significantly lesser need for allogeneic blood products (0.46 units/patients vs. 0.94 units/patients, P < 0.001. They had also lower post-operative D-dimer plasma levels. No postoperative thrombotic complications were observed in either group. The defective hemostasis occurs even in the OPCABG. Tranexamic acid effectively reduces postoperative blood loss and the need for allogeneic blood products after OPCAB is decreased.

[Effect of hemodilution with 10% hydroxyethyl starch solution (MW 200,000/9.5) on the flow properties of blood, arterial blood gases and conjunctival oxygen partial pressure in patients with cerebral infarct].

Science.gov (United States)

Staedt, U; Hütt, M; Herrmann, B; Seufzer, U; Leweling, H

1989-06-01

Hemorheological parameters, arterial blood gases and conjunctival oxygen tension were measured in 15 patients with acute ischemic stroke and compared with values obtained in an age matched reference group. Since the conjunctival capillary bed is perfused by the ophthalmic artery, it reflects the oxygen delivery to the areas supplied by the internal carotid artery. Measurements of conjunctival oxygen tension are simple and safe. Patients with acute ischemic stroke showed a lowered conjunctival oxygen tension; this holds true especially to the ipsilateral side, i.e. the side where the attack occurred, and to a lesser extent to the other side. By contrast, the ratio of arterial/conjunctival pO2 was disturbed only on the ipsilateral side. Furthermore, these patients had pathologically elevated values for red cell aggregation, whole blood and plasma viscosity. After infusing 500 ml 10% middle-molecular-weight hydroxyethyl starch (10% HAES-steril) and phlebotomy (250 ml) blood fluidity was normalized, although the hematokrit was only slightly reduced. Arterial pO2 improved slightly while pCO2 remained unchanged. Conjunctival oxygen tension improved by 30% on the ipsilateral and by 10% on the contralateral side, the ipsilateral values always remaining significantly lower. The ratio conjunctival/arterial pO2 raised only on the ipsilateral side where it was below the reference range before hemodilution. In addition to the well known improvement of blood fluidity and augmentation of cerebral blood flow following hemodilution in patients with acute ischemic stroke, there seems to be an increase in oxygen supply in the territories of both internal carotid arteries, especially on the ipsilateral side as indicated by the values of conjunctival oxygen tension and the ratio of conjunctival to arterial pO2.

Considerations for SphygmoCor radial artery pulse wave analysis: side selection and peripheral arterial blood pressure calibration.

Science.gov (United States)

Martin, Jeffrey S; Borges, Alexandra R; Christy, John B; Beck, Darren T

2015-10-01

Methods employed for pulse wave analysis (PWA) and peripheral blood pressure (PBP) calibration vary. The purpose of this study was to evaluate the agreement of SphygmoCor PWA parameters derived from radial artery tonometry when considering (1) timing (before vs. after tonometry) and side selection (ipsilateral vs. contralateral limb) for PBP calibration and (2) side selection for tonometry (left vs. right arm). In 34 subjects (aged 21.9 ± 2.3 years), bilateral radial artery tonometry was performed simultaneously on three instances. PBP assessment via oscillometric sphygmomanometry in the left arm only and both arms simultaneously occurred following the first and second instances of tonometry, respectively. Significant within arm differences in PWA parameters derived before and after PBP measurement were observed in the right arm only (for example, aortic systolic blood pressure, Δ=0.38 ± 0.64 mm Hg). Simultaneously captured bilateral PWA variables demonstrated significant between arm differences in 88% (14/16) and 56% (9/16) of outcome variables when calibrated to within arm and equivalent PBP, respectively. Moreover, the right arm consistently demonstrated lower values for clinical PWA variables (for example, augmentation index, bias=-2.79%). However, 26% (n=9) of participants presented with clinically significant differences (>10 mm Hg) in bilateral PBP and their exclusion from analysis abolished most between arm differences observed. SphygmoCor PWA in the right radial artery results in greater variability independent of the timing of PBP measurement and magnitude of calibration pressures in young subjects. Moreover, bilateral PBP measurement is imperative to identify subjects in whom a significant difference in bilateral PWA outcomes may exist.

Investigating complex patterns of blocked intestinal artery blood pressure signals by empirical mode decomposition and linguistic analysis

International Nuclear Information System (INIS)

Yeh, J-R; Lin, T-Y; Shieh, J-S; Chen, Y; Huang, N E; Wu, Z; Peng, C-K

2008-01-01

In this investigation, surgical operations of blocked intestinal artery have been conducted on pigs to simulate the condition of acute mesenteric arterial occlusion. The empirical mode decomposition method and the algorithm of linguistic analysis were applied to verify the blood pressure signals in simulated situation. We assumed that there was some information hidden in the high-frequency part of the blood pressure signal when an intestinal artery is blocked. The empirical mode decomposition method (EMD) has been applied to decompose the intrinsic mode functions (IMF) from a complex time series. But, the end effects and phenomenon of intermittence damage the consistence of each IMF. Thus, we proposed the complementary ensemble empirical mode decomposition method (CEEMD) to solve the problems of end effects and the phenomenon of intermittence. The main wave of blood pressure signals can be reconstructed by the main components, identified by Monte Carlo verification, and removed from the original signal to derive a riding wave. Furthermore, the concept of linguistic analysis was applied to design the blocking index to verify the pattern of riding wave of blood pressure using the measurements of dissimilarity. Blocking index works well to identify the situation in which the sampled time series of blood pressure signal was recorded. Here, these two totally different algorithms are successfully integrated and the existence of the existence of information hidden in high-frequency part of blood pressure signal has been proven

Relationship between segmental thallium-201 uptake and regional myocardial blood flow in patients with coronary artery disease

International Nuclear Information System (INIS)

Nichols, A.B.; Weiss, M.B.; Sciacca, R.R.; Cannon, P.J.; Blood, D.K.

1983-01-01

The relationship between the spatial distribution of thallium-201 in myocardial perfusion scintigrams and the distribution of left ventricular regional myocardial blood flow was examined in 25 patients undergoing coronary arteriography. Thallium-201 myocardial scintigrams were obtained after symptom-limited exercise and after a 4 hr delay. Regional myocardial blood flow was measured by the xenon-133 clearance method in patients at rest and during rapid atrial pacing to a double product comparable with that achieved during exercise stress testing. Patterns of regional thallium-201 activity and regional myocardial blood flow, recorded in similar left anterior oblique projections, were compared for left ventricular segments supplied by the left anterior descending (LAD) and left circumflex (CIRC) arteries. In 11 patients without significant lesions of the left coronary artery (group 1), thallium-201 was homogeneously distributed in the LAD and CIRC distributions in scintigrams taken during peak exercise; these scintigrams correspond to homogeneous regional myocardial blood flow in the LAD and CIRC regions during pacing-induced stress. In 14 patients with significant lesions of the left coronary artery (group 2), ratios of regional thallium-201 activity in the LAD and CIRC distributions of exercise scintigrams correlated well (r . .84) with ratios of regional myocardial blood flow measured during rapid pacing. Background subtraction altered the relationship between relative thallium-201 uptake and regional myocardial blood flow, causing overestimation of the magnitude of flow reduction on exercise scintigrams

Investigating complex patterns of blocked intestinal artery blood pressure signals by empirical mode decomposition and linguistic analysis

Energy Technology Data Exchange (ETDEWEB)

Yeh, J-R; Lin, T-Y; Shieh, J-S [Department of Mechanical Engineering, Yuan Ze University, 135 Far-East Road, Chung-Li, Taoyuan, Taiwan (China); Chen, Y [Far Eastern Memorial Hospital, Taiwan (China); Huang, N E [Research Center for Adaptive Data Analysis, National Central University, Taiwan (China); Wu, Z [Center for Ocean-Land-Atmosphere Studies (United States); Peng, C-K [Beth Israel Deaconess Medical Center, Harvard Medical School (United States)], E-mail: s939205@ mail.yzu.edu.tw

2008-02-15

In this investigation, surgical operations of blocked intestinal artery have been conducted on pigs to simulate the condition of acute mesenteric arterial occlusion. The empirical mode decomposition method and the algorithm of linguistic analysis were applied to verify the blood pressure signals in simulated situation. We assumed that there was some information hidden in the high-frequency part of the blood pressure signal when an intestinal artery is blocked. The empirical mode decomposition method (EMD) has been applied to decompose the intrinsic mode functions (IMF) from a complex time series. But, the end effects and phenomenon of intermittence damage the consistence of each IMF. Thus, we proposed the complementary ensemble empirical mode decomposition method (CEEMD) to solve the problems of end effects and the phenomenon of intermittence. The main wave of blood pressure signals can be reconstructed by the main components, identified by Monte Carlo verification, and removed from the original signal to derive a riding wave. Furthermore, the concept of linguistic analysis was applied to design the blocking index to verify the pattern of riding wave of blood pressure using the measurements of dissimilarity. Blocking index works well to identify the situation in which the sampled time series of blood pressure signal was recorded. Here, these two totally different algorithms are successfully integrated and the existence of the existence of information hidden in high-frequency part of blood pressure signal has been proven.

The effects of fenoldopam on coronary conduit blood flow after coronary artery bypass graft surgery.

LENUS (Irish Health Repository)

Halpenny, M

2012-02-03

OBJECTIVE: To quantify the effects of fenoldopam, 0.1 microg\\/kg\\/min, on left internal mammary artery (LIMA) and saphenous vein blood flow after coronary anastomosis. DESIGN: Prospective, randomized, double-blind, placebo-controlled trial. SETTING: University teaching hospital, single institution. PARTICIPANTS: Thirty-one American Society of Anesthesiologists III patients undergoing elective coronary revascularization. INTERVENTIONS: A perivascular ultrasonic flow probe (Linton Instrumentation, Norfolk, UK) was placed around the LIMA and saphenous vein graft after coronary anastomosis. MEASUREMENTS AND MAIN RESULTS: Immediately before and at 5-minute intervals for 15 minutes after starting the infusion, blood flow was measured in the LIMA and one saphenous vein graft using a transit time ultrasonic flow probe. Heart rate, blood pressure, and central venous pressure were documented at these time points. Administration of fenoldopam, 0.1 microg\\/kg\\/min, did not alter heart rate or blood pressure. A small, nonsignificant increase in LIMA blood flow occurred during the 15-minute study period (30 +\\/- 12 to 35 +\\/- 10 mL\\/min) in patients who received fenoldopam. No significant changes occurred in the placebo group. CONCLUSIONS: The findings indicate that fenoldopam, 0.1 microg\\/kg\\/min, did not influence coronary conduit blood flow to a clinically significant extent. The small increase in LIMA blood flow may be of greater importance in high-risk patients or in the prevention of coronary arterial spasm.

Arterial Blood Supply to the Spinal Cord in Animal Models of Spinal Cord Injury. A Review.

Science.gov (United States)

Mazensky, David; Flesarova, Slavka; Sulla, Igor

2017-12-01

Animal models are used to examine the results of experimental spinal cord injury. Alterations in spinal cord blood supply caused by complex spinal cord injuries contribute significantly to the diversity and severity of the spinal cord damage, particularly ischemic changes. However, the literature has not completely clarified our knowledge of anatomy of the complex three-dimensional arterial system of the spinal cord in experimental animals, which can impede the translation of experimental results to human clinical applications. As the literary sources dealing with the spinal cord arterial blood supply in experimental animals are limited and scattered, the authors performed a review of the anatomy of the arterial blood supply to the spinal cord in several experimental animals, including pigs, dogs, cats, rabbits, guinea pigs, rats, and mice and created a coherent format discussing the interspecies differences. This provides researchers with a valuable tool for the selection of the most suitable animal model for their experiments in the study of spinal cord ischemia and provides clinicians with a basis for the appropriate translation of research work to their clinical applications. Anat Rec, 300:2091-2106, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Arterial blood supply to midbrain, thalamus and internal capsule on CT, 3

International Nuclear Information System (INIS)

Takeshita, Gen; Ottomo, Michinori; Sasaki, Taisuke; Fukuda, Eiko.

1984-01-01

The selective injection of dye into the anterior choroidal artery (blue), the medial posterior choroidal artery (green), and the lateral posterior choroidal artery (red), using seven post-mortem brains, was performed. After fixation, sections parallel with the orbito-meatal line were obtained. The distribution of the anterior choroidal artery was visualized in the uncal region of the temporal lobe and the cerebral peduncle below the slice of the third ventricle. On the slice of the third ventricle, the lateral part of the geniculate region, the globus pallidus, and the posterior limb of the internal capsule were supplied by the anterior choroidal artery. The blood supply of the posterior limb of the internal capsule was also demonstrated on the slice of the anterior horn and on the body of the lateral ventricle. The distribution of the medial posterior choroidal artery was visualized in the tegmentum of the midbrain below the slice of the third ventricle, and on the slice of the anterior horn, the pineal body and the posterior part of the thalamus were also supplied. The distribution of the lateral posterior choroidal artery was visualized in the lateral part of the midbrain, around the red nucleus, below the slice of the third ventricle, and on the slice of the third ventricle, the upper part of the cerebral peduncle, the posterior part of the hypothalamus, and the medial part of the geniculate region were also supplied. Also, distribution to the medial and posterior parts of the thalamus was noted on the slice of the anterior horn. It was quite useful to identify the distribution of each choroidal artery on CT sections for the CT diagnosis of cerebrovascular disorders. (author)

Evaluation of blood flow in Allograft Renal Arteries anastomosed with two different techniques

International Nuclear Information System (INIS)

Zomorrodi, A.; Bohluli, A.; Tarzamany, M.K.

2008-01-01

Renal artery stenosis in renal transplantation (TRAS) is an avoidable short or long term surgical complication. The etiology is multifactorial, but faulty anastomosis is a major factor. In our transplant center, we evaluated the incidence of TRAS with the use of two different suturing techniques of the anastomosis site between allograft renal and renal and iliac arteries in two groups of renal transplant recipients, group A: 14 patients (6 males and 8 females with age 16 to 59 and mean age of 38 years) in whom allograft arteries were anastomosed with a continuous suture technique and group B: 14 patients (7 males and 7 females with age 32 to 61 and mean age of 46.6 years) in whom the allograft arteries were anastomosed with a combined suture technique (continuous and uninterrupted. Post transplantation, the velocity of blood flow in the renal and iliac arteries at the site of anastomosis was measured by color Doppler ultrasound. The ultrasonographer was blinded to the surgical technique in both study groups. The ratio of the maximum velocity of blood at the site of anastomosis to that in the iliac artery of less than 2.5 was considered as non-significant stenosis, while a ratio of more than 2.5 was considered significant stenosis. In group A there were 9 cases of non-significant stenosis in comparison to 3 cases in group B, while there were no cases of significant stenosis in group A in comparison to 3 cases in group B; the difference was not statistically significant. We conclude that there was no difference in the compared surgical techniques of anastomosis in our study groups. This suggests that other factors such as gentle handling of tissue, enough spatula, margin reversion and comparable diameter of the anastomosed vessels may be more important in the prevention of renal allograft stenosis than the type of suture technique. (author)

Blood Pressure Response to Main Renal Artery and Combined Main Renal Artery Plus Branch Renal Denervation in Patients With Resistant Hypertension.

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Fengler, Karl; Ewen, Sebastian; Höllriegel, Robert; Rommel, Karl-Philipp; Kulenthiran, Saaraaken; Lauder, Lucas; Cremers, Bodo; Schuler, Gerhard; Linke, Axel; Böhm, Michael; Mahfoud, Felix; Lurz, Philipp

2017-08-10

Single-electrode ablation of the main renal artery for renal sympathetic denervation showed mixed blood pressure (BP)-lowering effects. Further improvement of the technique seems crucial to optimize effectiveness of the procedure. Because sympathetic nerve fibers are closer to the lumen in the distal part of the renal artery, treatment of the distal main artery and its branches has been shown to reduce variability in treatment effects in preclinical studies and a recent randomized trial. Whether this optimized technique improves clinical outcomes remains uncertain. We report a 2-center experience of main renal artery and combined main renal artery plus branches renal denervation in patients with resistant hypertension using a multielectrode catheter. Twenty-five patients with therapy-resistant hypertension underwent renal sympathetic denervation with combined main renal artery and renal branch ablation and were compared to matched controls undergoing an ablation of the main renal artery only. BP change was assessed by ambulatory measurement at baseline and after 3 months. At baseline, BP was balanced between the groups. After 3 months, BP changed significantly in the combined ablation group (systolic/diastolic 24-hour mean and daytime mean BP -8.5±9.8/-7.0±10.7 and -9.4±9.8/-7.1±13.5 mm Hg, P renal artery and branches appears to improve BP-lowering efficacy and should be further investigated. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

Comparison of two-dimensional MR angiography and microsphere measurement of renal blood flow for detection of renal artery stenosis

International Nuclear Information System (INIS)

Powers, T.A.; Lorenz, C.H.; Shetty, A.N.; Holburn, G.E.; Price, R.R.

1990-01-01

This paper compares depiction of the renal arteries by MR angiography to renal blood flow as determined with microspheres in a dog model of renal artery stenosis. A left renal artery stenosis was created by placement of a silk ligature. Nb-95-labeled microspheres were injected into the left ventricle and a reference blood sample was drawn. The dog was imaged in the 1.5-T MR imager with two-dimensional MR angiography sequences. The kidneys were excised, weighted, divided into sections, and counted. Two dogs were studied to date. In dog 1, left renal blood flow (RBF) was 42 mL/min/100 g and right RBF was 337 mL/min/100 g. In dog 2 left RBF was 44 mL/min/100 g and right RBF was 608 mL/min/100 g

Healing of ulcers on the feet correlated with distal blood pressure measurements in occlusive arterial disease

DEFF Research Database (Denmark)

Holstein, P; Lassen, N A

1980-01-01

The frequency of healing in subchronic ulcers in 66 feet in 62 patients with arterial occlusive disease was correlated with the systolic digital blood pressure (SDBP) and the systolic ankle blood pressure (SABP), both measured with a strain gauge, and with the skin perfusion pressure on the heel...

A new noninvasive device for continuous arterial blood pressure monitoring in the superficial temporal artery

International Nuclear Information System (INIS)

Chin, K Y; Panerai, R B

2013-01-01

Continuous recording of arterial blood pressure (ABP) has many applications in cardiovascular physiology, but existing alternatives rely on measurements performed in the fingers or radial artery. Peripheral recordings have significant differences from central ABP regarding the pattern of the waveform and corresponding systolic and diastolic values. To address the need for noninvasive measurements closer to the ascending aorta, a new device was constructed to measure ABP in the superficial temporal artery (STA) using photoplethysmography and the arterial volume clamping technique. The optoelectronic circuitry to generate the photoplethysmogram is contained in a specially designed probe placed over the STA and kept in place with a head frame. The prototype (STAbp) also includes original designs for the pneumatic, electronic, signal processing, control and display sub-systems. A self-calibration feature regularly updates the photoplethysmogram operating point to improve accuracy. The performance of the STAbp was compared against the Finapres in 19 healthy subjects. At rest, the bias (SD d ) was −23.1 (15.05), −10.8 (13.83) and −12.4 (12.93) mmHg for systolic, mean and diastolic pressures respectively, without significant differences in drift between the two devices. The 99% bandwidth (SD) for the spectral distribution of ABP waveforms was 5.3 (1.46) Hz for STAbp and 6.8 (0.73) Hz for the Finapres (p < 0.01). Handgrip manoeuvre showed a very similar response to the Finapres, including the rapid return to baseline on release. The new STAbp device has considerable potential as a new tool for clinical and research applications where continuous recording of more central ABP is advantageous compared to peripheral alternatives. (paper)

Resistance training controls arterial blood pressure in rats with L-NAME- induced hypertension.

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Araujo, Ayslan Jorge Santos de; Santos, Anne Carolline Veríssimo dos; Souza, Karine dos Santos; Aires, Marlúcia Bastos; Santana-Filho, Valter Joviniano; Fioretto, Emerson Ticona; Mota, Marcelo Mendonça; Santos, Márcio Roberto Viana

2013-04-01

Arterial hypertension is a multifactorial chronic condition caused by either congenital or acquired factors. To evaluate the effects of Resistance Training (RT) on arterial pressure, and on vascular reactivity and morphology, of L-NAME-treated hypertensive rats. Male Wistar rats (200 - 250 g) were allocated into Sedentary Normotensive (SN), Sedentary Hypertensive (SH) and Trained Hypertensive (TH) groups. Hypertension was induced by adding L-NAME (40 mg/Kg) to the drinking water for four weeks. Arterial pressure was evaluated before and after RT. RT was performed using 50% of 1RM, 3 sets of 10 repetitions, 3 times per week for four weeks. Vascular reactivity was measured in rat mesenteric artery rings by concentration-response curves to sodium nitroprusside (SNP); phenylephrine (PHE) was also used for histological and stereological analysis. Resistance training inhibited the increase in mean and diastolic arterial pressures. Significant reduction was observed in Rmax (maximal response) and pD2 (potency) of PHE between SH and TH groups. Arteries demonstrated normal intima, media and adventitia layers in all groups. Stereological analysis demonstrated no significant difference in luminal, tunica media, and total areas of arteries in the SH and TH groups when compared to the SN group. Wall-to-lumen ratio of SH arteries was significantly different compared to SN arteries (parteries. RT was able to prevent an increase in blood pressure under the conditions in this study. This appears to involve a vasoconstrictor regulation mechanism and maintenance of luminal diameter in L-NAME induced hypertensive rats.

Blood flow quantification from 2D phase contrast MRI in renal arteries using an unsupervised data driven approach

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Zoellner, Frank Gerrit [Computer Assisted Clinical Medicine, Faculty of Medicine Mannheim, Univ. of Heidelberg, Mannheim (Germany); Section for Radiology, Dept. of Surgical Sciences, Univ. of Bergen (Norway); Monssen, Jan Ankar [Dept. of Radiology, Haukeland Univ. Hospital, Bergen (Norway); Roervik, Jarie [Section for Radiology, Dept. of Surgical Sciences, Univ. of Bergen (Norway); Dept. of Radiology, Haukeland Univ. Hospital, Bergen (Norway); Lundervold, Arvid [Dept. of Radiology, Haukeland Univ. Hospital, Bergen (Norway); Dept. of Biomedicine, Univ. of Bergen (Norway); Schad, Lothar R. [Computer Assisted Clinical Medicine, Faculty of Medicine Mannheim, Univ. of Heidelberg, Mannheim (Germany)

2009-07-01

We present a clustering approach to segment the renal artery from 2D PC Cine MR images to measure arterial blood velocity and flow. Such information is important in grading renal artery stenosis and to support the decision on surgical interventions like percutaneous transluminal angioplasty. Results from 20 data sets (volunteers, 7 patients) show that the renal arteries could be extracted automatically and the corresponding velocity profiles were close (r = 0.977) to that obtained by manual delineations of the vessel areas. (orig.)

Blood flow quantification from 2D phase contrast MRI in renal arteries using an unsupervised data driven approach

International Nuclear Information System (INIS)

Zoellner, Frank Gerrit; Monssen, Jan Ankar; Roervik, Jarie; Lundervold, Arvid; Schad, Lothar R.

2009-01-01

We present a clustering approach to segment the renal artery from 2D PC Cine MR images to measure arterial blood velocity and flow. Such information is important in grading renal artery stenosis and to support the decision on surgical interventions like percutaneous transluminal angioplasty. Results from 20 data sets (volunteers, 7 patients) show that the renal arteries could be extracted automatically and the corresponding velocity profiles were close (r = 0.977) to that obtained by manual delineations of the vessel areas. (orig.)

On the mechanisms of blunted nocturnal decline in arterial blood pressure in NIDDM patients with diabetic nephropathy

DEFF Research Database (Denmark)

Nielsen, Flemming Steen; Rossing, P; Bang, L E

1995-01-01

Nondiabetic hypertensive patients lacking the normal nocturnal decline in arterial blood pressure have enhanced cardiovascular complications. Since cardiovascular morbidity and mortality are increased in non-insulin-dependent diabetes mellitus (NIDDM), we performed a prospective cross......-sectional case-controlled study comparing the diurnal variation in arterial blood pressure, prevalence of dippers, cardiac autonomic nervous function (beat-to-beat variation during deep breathing), and extracellular fluid volume (51Cr-labeled EDTA) in 55 NIDDM patients with diabetic nephropathy (group 1), 55...... NIDDM patients with normoalbuminuria (group 2), and 22 nondiabetic control subjects (group 3). All antihypertensive treatments were withdrawn at least 2 weeks before the study. The nocturnal blood pressure reduction (daytime-to-nighttime)/daytime (mean +/- SE) was impaired in group 1 (6.6 +/- 1...

Arterial Transit Time-corrected Renal Blood Flow Measurement with Pulsed Continuous Arterial Spin Labeling MR Imaging.

Science.gov (United States)

Shimizu, Kazuhiro; Kosaka, Nobuyuki; Fujiwara, Yasuhiro; Matsuda, Tsuyoshi; Yamamoto, Tatsuya; Tsuchida, Tatsuro; Tsuchiyama, Katsuki; Oyama, Nobuyuki; Kimura, Hirohiko

2017-01-10

The importance of arterial transit time (ATT) correction for arterial spin labeling MRI has been well debated in neuroimaging, but it has not been well evaluated in renal imaging. The purpose of this study was to evaluate the feasibility of pulsed continuous arterial spin labeling (pcASL) MRI with multiple post-labeling delay (PLD) acquisition for measuring ATT-corrected renal blood flow (ATC-RBF). A total of 14 volunteers were categorized into younger (n = 8; mean age, 27.0 years) and older groups (n = 6; 64.8 years). Images of pcASL were obtained at three different PLDs (0.5, 1.0, and 1.5 s), and ATC-RBF and ATT were calculated using a single-compartment model. To validate ATC-RBF, a comparative study of effective renal plasma flow (ERPF) measured by 99m Tc-MAG3 scintigraphy was performed. ATC-RBF was corrected by kidney volume (ATC-cRBF) for comparison with ERPF. The younger group showed significantly higher ATC-RBF (157.68 ± 38.37 mL/min/100 g) and shorter ATT (961.33 ± 260.87 ms) than the older group (117.42 ± 24.03 mL/min/100 g and 1227.94 ± 226.51 ms, respectively; P renal ASL-MRI as debated in brain imaging.

Comparison of pulseoximetry oxygen saturation and arterial oxygen saturation in open heart intensive care unit

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Alireza Mahoori

2013-08-01

Full Text Available Background: Pulseoximetry is widely used in the critical care setting, currently used to guide therapeutic interventions. Few studies have evaluated the accuracy of SPO2 (puls-eoximetry oxygen saturation in intensive care unit after cardiac surgery. Our objective was to compare pulseoximetry with arterial oxygen saturation (SaO2 during clinical routine in such patients, and to examine the effect of mild acidosis on this relationship.Methods: In an observational prospective study 80 patients were evaluated in intensive care unit after cardiac surgery. SPO2 was recorded and compared with SaO2 obtained by blood gas analysis. One or serial arterial blood gas analyses (ABGs were performed via a radial artery line while a reliable pulseoximeter signal was present. One hundred thirty seven samples were collected and for each blood gas analyses, SaO2 and SPO2 we recorded.Results: O2 saturation as a marker of peripheral perfusion was measured by Pulseoxim-etry (SPO2. The mean difference between arterial oxygen saturation and pulseoximetry oxygen saturation was 0.12%±1.6%. A total of 137 paired readings demonstrated good correlation (r=0.754; P<0.0001 between changes in SPO2 and those in SaO2 in samples with normal hemoglobin. Also in forty seven samples with mild acidosis, paired readings demonstrated good correlation (r=0.799; P<0.0001 and the mean difference between SaO2 and SPO2 was 0.05%±1.5%.Conclusion: Data showed that in patients with stable hemodynamic and good signal quality, changes in pulseoximetry oxygen saturation reliably predict equivalent changes in arterial oxygen saturation. Mild acidosis doesn’t alter the relation between SPO2 and SaO2 to any clinically important extent. In conclusion, the pulse oximeter is useful to monitor oxygen saturation in patients with stable hemodynamic.

Heat stress redistributes blood flow in arteries of the brain during dynamic exercise.

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Sato, Kohei; Oue, Anna; Yoneya, Marina; Sadamoto, Tomoko; Ogoh, Shigehiko

2016-04-01

We hypothesized that heat stress would decrease anterior and posterior cerebral blood flow (CBF) during exercise, and the reduction in anterior CBF would be partly associated with large increase in extracranial blood flow (BF). Nine subjects performed 40 min of semirecumbent cycling at 60% of the peak oxygen uptake in hot (35°C; Heat) and thermoneutral environments (25°C; Control). We evaluated BF and conductance (COND) in the external carotid artery (ECA), internal carotid artery (ICA), and vertebral artery (VA) using ultrasonography. During the Heat condition, ICA and VA BF were significantly increased 10 min after the start of exercise (P Heat. Compared with the Control, either BF or COND of ICA and VA at the end of Heat tended to be lower, but not significantly. In contrast, ECA BF and COND at the end of Heat were both higher than levels in the Control condition (P Heat, a reduction in ICA BF appears to be associated with a decline in end-tidal CO2 tension (r = 0.84), whereas VA BF appears to be affected by a change in cardiac output (r = 0.87). In addition, a change in ECA BF during Heat was negatively correlated with a change in ICA BF (r = -0.75). Heat stress resulted in modification of the vascular response of head and brain arteries to exercise, which resulted in an alteration in the distribution of cardiac output. Moreover, a hyperthermia-induced increase in extracranial BF might compromise anterior CBF during exercise with heat stress. Copyright © 2016 the American Physiological Society.

Impact on early and late mortality after blood transfusion in coronary artery bypass graft surgery.

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Santos, Antonio Alceu dos; Sousa, Alexandre Gonçalves; Thomé, Hugo Oliveira de Souza; Machado, Roberta Longo; Piotto, Raquel Ferrari

2013-03-01

To assess the 30-day and 1-year mortality associated to the red blood cell transfusion after coronary artery bypass grafting surgery. This procedure has been questioned by the international medical community, but it is still widely used in cardiac surgery. Therefore, it is needed more evidence of this medical practice in our country. We retrospectively analyzed 3,004 patients who underwent coronary artery bypass grafting surgery between June 2009 and July 2010. Patients were divided into two groups: non-transfused and transfused. The transfused group totaled 1,888 (63%) and non-transfused 1,116 (37%). There were 129 deaths in 30 days, with 108 (84%) in the transfused group and 21 (16%) in the non-transfused (Pconservation strategies should be encouraged to reduce blood products transfusions.

[Digital necrosis in a patient with anorexia nervosa. Association of vasculopathy and radial artery injury].

Science.gov (United States)

Launay, D; Queyrel, V; Hatron, P Y; Michon-Pasturel, U; Hachulla, E; Devulder, B

2000-11-13

Patients with anorexia nervosa can develop distal vasculopathy sometimes leading to severe Raynaud's phenomenon or acrocyanosis. We report a cas of anorexia nervosa-related vasculopathy associated with iatrogenic injury to the radial artery that led to digital necrosis. An 18-year-old woman, with a history of severe anorexia nervosa of 5 years duration and who acknowledged regular use of tobacco and cannabis, was hospitalized for necrosis of the left index and thumb that had occurred shortly after left radial artery puncture for blood gas analysis. Acrocyanosis of the 4 limbs had been present since the onset of anorexia nervosa. Arteriography of the upper limbs showed major spasm of the left radial and cubital arteries and thromboses in the left interdigital arteries of the left index and thumb. The distal portions of the arteries were then on the left and on the right. The nectrotic lesions healed after intravenous administration of ilomedine and interruption of tobacco and cannabis. Acrocyanosis of the four limbs persisted. We report a case of digital necrosis occurring after arterial puncture for blood gas analysis in a patient with a vascular bed weakened by tobacco and cannabis intoxication but also by anorexia nervosa-related vasculopathy. This observation underlines the potentially dangerous nature of invasive intravascular procedures in this context. Indications for vessel puncture must be assessed with prudence.

Long-term monitoring of arterial pO2 in burned patients.

Science.gov (United States)

Nilsson, E; Arnander, C

1984-02-01

Five patients, who were treated in a special ward for burns were followed by continuous intra-arterial pO2 monitoring for a total of 1612 h (range 13-604 h). The pao2 catheter electrodes used were surface-heparinized, and inserted either in the radial or the femoral artery. Some electrodes were accidentally withdrawn. Recalibration was performed for two of the 10 electrodes used. These electrodes presented a changed sensitivity after heavy stretching of the sensor during the nursing. The sensitivity of one of these electrodes was altered downwards and the other one upwards. After recalibration the pao2 electrodes presented accurate values for the rest of the monitoring period. Without compensation for drift, the pao2 electrode readout was compared to the results of traditional blood-gas analysis, which served as a reference. The regression function found was y = -0.62 + 1.04 chi (r = 0.93, SD = 1.40, n = 60). The blood flow velocity around some of the pao2 electrodes was studied by the pulsed Doppler technique. There was no influence of the surface-heparinized pao2 electrode on the femoral artery blood flow velocity as compared to the contralateral, non-catheterized femoral artery. The blood flow velocity proximal to a traditional radial artery catheter was compared to the flow velocity in the contralateral radial artery containing a surface-heparinized pao2 electrode. The surface-heparinized electrode did not decrease the mean flow velocity in contrast with the traditional radial artery catheter, which had to be withdrawn after 8 days because of clotting. The surface-heparinized catheter electrode was still monitoring pao2 accurately after 25 days in the artery, which was the longest period studied for a particular sensor.

Pulsatile spiral blood flow through arterial stenosis.

Science.gov (United States)

Linge, Fabian; Hye, Md Abdul; Paul, Manosh C

2014-11-01

Pulsatile spiral blood flow in a modelled three-dimensional arterial stenosis, with a 75% cross-sectional area reduction, is investigated by using numerical fluid dynamics. Two-equation k-ω model is used for the simulation of the transitional flow with Reynolds numbers 500 and 1000. It is found that the spiral component increases the static pressure in the vessel during the deceleration phase of the flow pulse. In addition, the spiral component reduces the turbulence intensity and wall shear stress found in the post-stenosis region of the vessel in the early stages of the flow pulse. Hence, the findings agree with the results of Stonebridge et al. (2004). In addition, the results of the effects of a spiral component on time-varying flow are presented and discussed along with the relevant pathological issues.

Patient Specific Multiscale Simulations of Blood Flow in Coronary Artery Bypass Surgery

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Bangalore Ramachandra, Abhay; Sankaran, Sethuraman; Kahn, Andrew M.; Marsden, Alison L.

2013-11-01

Coronary artery bypass surgery is performed to revascularize blocked coronary arteries in roughly 400,000 patients per year in the US.While arterial grafts offer superior patency, vein grafts are used in more than 70% of procedures, as most patients require multiple grafts. Vein graft failure (approx. 50% within 10 years) remains a major clinical issue. Mounting evidence suggests that hemodynamics plays a key role as a mechano-biological stimulus contributing to graft failure. However, quantifying relevant hemodynamic quantities (e.g. wall shear stress) invivo is not possible directly using clinical imaging techniques. We numerically compute graft hemodynamics in a cohort of 3-D patient specific models using a stabilized finite element method. The 3D flow domain is coupled to a 0D lumped parameter circulatory model. Boundary conditions are tuned to match patient specific blood pressures, stroke volumes & heart rates. Results reproduce clinically observed coronary flow waveforms. We quantify differences in multiple hemodynamic quantities between arterial & venous grafts & discuss possible correlations between graft hemodynamics & clinically observed graft failure.Such correlations will provide further insight into mechanisms of graft failure and may lead to improved clinical outcomes.

Fourier Analysis of Peripheral Blood Pressure and Flow in Intraoperative Assessment of Infrainguinal Arterial Reconstructions

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Cheshmedzhiev Mihail V.

2014-08-01

Full Text Available AIM: To assess infrainguinal arterial reconstructions by intraoperative flowmetry under the distal anastomosis using a fast Fourier transformation; calculate and compare the amplitude ratios of peripheral arterial blood pressure and volume flow before and after drug-induced vasodilation of occluded bypass grafts and bypass grafts that have been patent at least for 1 year. To find what magnitude of the change of these ratios indicate a long-term patency of the bypass grafting. PATIENTS AND METHODS: We compared the results of the intraoperative flowmetry tests of 97 patients with infrainguinal arterial reconstructions. The patients were divided into two groups based on the graft status: the grafts in 49 patients were patent for at least a year, and 48 patients had failed bypass. We used a fast Fourier transform (FFT of the pressure and blood flow waves and compared the ratios of their amplitudes before and after administration of a vasodilator drug into the graft. Comparing the ratios obtained before and those after administration of the drug we quantified their change in each group and analysed them. RESULTS: After a drug-induced vasodilation, the blood pressure and flow amplitude ratios for the group with compromised reconstructions were less than 1.9 times smaller than those before drug infusion, while for the group with bypass grafts that had been functional for at least 12 months the ratios declined by more than 1.9≈2 times. CONCLUSION: The magnitude of the change of amplitude ratios of the peripheral pressure and volume flow after drug-induced vasodilation can be used to make an assessment of the bypass graft and the distal arterial segment.

Dependence of renal blood flow on renal artery stenosis measured using CT angiography

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Luedemann, Lutz [Charite - Universitaetsmedizin Berlin (Germany). Dept. of Radiotherapy; Nafz, B.; Persson, P. [Charite - Universitaetsmedizin Berlin (Germany). Inst. for Vegetative Physiology; Elsner, F. [Krankenhaus am Urban, Berlin (Germany). Dept. of Anesthesiology; Grosse-Siestrup, C.; Meissler, M. [Charite - Universitaetsmedizin Berlin (Germany). Experimental Animal Unit; Gutberlet, M. [Charite - Universitaetsmedizin Berlin (Germany). Dept. of Diagnostic and Interventional Radiology; Univ. Leipzig/ Leipzig Heart Center (Germany). Dept. of Diagnostic and Interventional Radiology; Lengsfeld, P.; Voth, M. [Bayer-Schering Pharma AG, Berlin (Germany). Global Medical Affairs Diagnostic Imaging

2011-03-15

The present study investigates the suitability of computed tomography angiography (CTA) depicting the degree of renal artery stenosis for estimating renal blood flow (RBF) in a kidney. Materials and Methods: We investigated renal artery stenosis assessment by CTA in eight adult female hybrid pigs with an ultrasound probe implanted at the renal vein for RBF measurement. An inflatable metal-free cuff was placed around the renal artery to control the RBF. The RBF was then reduced in four steps. For each reduced RBF value and baseline RBF, CTA with a reconstructed slice thickness of 0.625 mm was performed in the arterial phase following injection of 80 ml of nonionic intravenous contrast medium. The radius of the stenotic and non-stenotic renal artery segment was measured in the reconstructed images. Results: A significant linear correlation (p < 0.0001) was found between the relative apparent stenosis (calculated as the ratio of the radii of the actual stenotic segment and a non-stenotic renal artery segment) and RBF. The linear regression yielded a slope of 0.57 and a y-axis of 24.1 %. A significant linear correlation (p < 0.0001) was also found between the relative true stenosis (the ratio of the radii of the actual stenotic segment and a non-stenotic renal artery segment at baseline) and the RBF. The linear regression yielded a slope of 0.67 and a y-axis of 13.8 %. Conclusion: The results show that the relative stenosis apparent on CTA differs from the true degree of renal artery stenosis. Nevertheless, the degree of renal artery stenosis determined by CTA provides a reliable estimate of the resulting RBF reduction. (orig.)

Dependence of renal blood flow on renal artery stenosis measured using CT angiography

International Nuclear Information System (INIS)

Luedemann, Lutz; Nafz, B.; Persson, P.; Elsner, F.; Grosse-Siestrup, C.; Meissler, M.; Gutberlet, M.; Univ. Leipzig/ Leipzig Heart Center; Lengsfeld, P.; Voth, M.

2011-01-01

The present study investigates the suitability of computed tomography angiography (CTA) depicting the degree of renal artery stenosis for estimating renal blood flow (RBF) in a kidney. Materials and Methods: We investigated renal artery stenosis assessment by CTA in eight adult female hybrid pigs with an ultrasound probe implanted at the renal vein for RBF measurement. An inflatable metal-free cuff was placed around the renal artery to control the RBF. The RBF was then reduced in four steps. For each reduced RBF value and baseline RBF, CTA with a reconstructed slice thickness of 0.625 mm was performed in the arterial phase following injection of 80 ml of nonionic intravenous contrast medium. The radius of the stenotic and non-stenotic renal artery segment was measured in the reconstructed images. Results: A significant linear correlation (p < 0.0001) was found between the relative apparent stenosis (calculated as the ratio of the radii of the actual stenotic segment and a non-stenotic renal artery segment) and RBF. The linear regression yielded a slope of 0.57 and a y-axis of 24.1 %. A significant linear correlation (p < 0.0001) was also found between the relative true stenosis (the ratio of the radii of the actual stenotic segment and a non-stenotic renal artery segment at baseline) and the RBF. The linear regression yielded a slope of 0.67 and a y-axis of 13.8 %. Conclusion: The results show that the relative stenosis apparent on CTA differs from the true degree of renal artery stenosis. Nevertheless, the degree of renal artery stenosis determined by CTA provides a reliable estimate of the resulting RBF reduction. (orig.)

A favorable outcome despite a 39-hour treatment delay for arterial gas embolism: case report.

Science.gov (United States)

Covington, Derek; Bielawski, Anthony; Sadler, Charlotte; Latham, Emi

2016-01-01

Cerebral arterial gas embolism (CAGE) occurs when gas enters the cerebral arterial vasculature. CAGE can occur during sitting craniotomies, cranial trauma or secondary to gas embolism from the heart. A far less common cause of CAGE is vascular entrainment of gas during endoscopic procedures. We present the case of a 49-year-old male who developed a CAGE following an esophagoduodenoscopy (EGD) biopsy. Due to a delay in diagnosis, the patient was not treated with hyperbaric oxygen (HBO₂) therapy until 39 hours after the inciting event. Despite presenting to our institution non-responsive and with decorticate posturing, the patient was eventually discharged to a rehabilitation facility, with only mild left upper extremity weakness. This delay in HBO₂ treatment represents the longest delay in treatment to our knowledge for a patient suffering from CAGE secondary to EGD. In addition to the clinical case report, we discuss the etiology of CAGE and the evidence supporting early HBO₂ treatment, as well as the data demonstrating efficacy even after considerable treatment delay. Copyright© Undersea and Hyperbaric Medical Society.

Demonstration of blood flow by color doppler in the femoral artery distal to arterial cannula during peripheral venoarterial-extracorporeal membrane oxygenation

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K G Suresh Rao

2017-01-01

Full Text Available In spite of distal perfusion of the limb using a cannula, the limb can have ischemic events if there is an undetected kink or clot anywhere in the line or thrombus in the artery. There are several ways to monitor and assess the limb ischemia. Monitoring for clinical signs of limb ischemia like temperature change and pallor is reliable and mandatory. We report a method where we used color Doppler to document the blood flow. Curvilinear vascular probe of an echo machine is used to identify the flow in the distal femoral artery of the lower limb. . As we have demonstrated in the video attached, once flow to the distal limb perfusion system is shut off by closing the three way stop cock, we can appreciate the immediate cessation of flow in the artery by Doppler.

Agreement of high definition oscillometry with direct arterial blood pressure measurement at different blood pressure ranges in horses under general anaesthesia.

Science.gov (United States)

Tünsmeyer, Julia; Hopster, Klaus; Feige, Karsten; Kästner, Sabine Br

2015-05-01

To determine the agreement of high definition oscillometry (HDO) with direct arterial blood pressure measurements in normotensive, hypotensive and hypertensive horses during general anaesthesia. Experimental study. Seven healthy warmblood horses, aged 3-11 years, weighing 470-565 kg. Measurements from a HDO device with the cuff placed around the base of the tail were compared with pressures measured invasively from the facial artery. High blood pressures were induced by intravenous (IV) administration of dobutamine (5 μg kg(-1) minute(-1)) over ten minutes followed by norepinephrine (0.1 mg kg(-1) IV) and low pressures by increasing the inspired fraction of isoflurane and administration of nitroglycerine (0.05 mg kg(-1) IV). For analysis three pressure levels were determined: high (MAP>110 mmHg), normal (60 mmHgstandard deviation for SAP, MAP and DAP were 0.1 ± 19.4 mmHg, 0.5 ± 14.0, 4.7 ± 15.6, respectively. At high pressure levels bias and SD were 26.1 ± 37.3 (SAP), 4.2 ± 19.4 (MAP), 1.5 ± 16.8 (DAP) and at low pressures -20.0 ± 20.9 (SAP), -11.4 ± 19.6 (MAP), -4.7 ± 20.1 (DAP), with HDO measurements at a MAP <50 mmHg often failing. Good agreement with invasive arterial blood pressures was obtained with HDO at normotensive levels in horses. At high and low pressure ranges HDO was unreliable. Therefore, if haemodynamic instability is expected, invasive measurement remains preferable. © 2014 Association of Veterinary Anaesthetists and the American College of Veterinary Anesthesia and Analgesia.

Spiral blood flows in an idealized 180-degree curved artery model

Science.gov (United States)

Bulusu, Kartik V.; Kulkarni, Varun; Plesniak, Michael W.

2017-11-01

Understanding of cardiovascular flows has been greatly advanced by the Magnetic Resonance Velocimetry (MRV) technique and its potential for three-dimensional velocity encoding in regions of anatomic interest. The MRV experiments were performed on a 180-degree curved artery model using a Newtonian blood analog fluid at the Richard M. Lucas Center at Stanford University employing a 3 Tesla General Electric (Discovery 750 MRI system) whole body scanner with an eight-channel cardiac coil. Analysis in two regions of the model-artery was performed for flow with Womersley number=4.2. In the entrance region (or straight-inlet pipe) the unsteady pressure drop per unit length, in-plane vorticity and wall shear stress for the pulsatile, carotid artery-based flow rate waveform were calculated. Along the 180-degree curved pipe (curvature ratio =1/7) the near-wall vorticity and the stretching of the particle paths in the vorticity field are visualized. The resultant flow behavior in the idealized curved artery model is associated with parameters such as Dean number and Womersley number. Additionally, using length scales corresponding to the axial and secondary flow we attempt to understand the mechanisms leading to the formation of various structures observed during the pulsatile flow cycle. Supported by GW Center for Biomimetics and Bioinspired Engineering (COBRE), MRV measurements in collaboration with Prof. John K. Eaton and, Dr. Chris Elkins at Stanford University.

Po2 temperature blood factor for blood gas apparatus.

Science.gov (United States)

Teisseire, B P; Hérigault, R A; Teisseire, L J; Laurent, D N

1984-01-01

PO2 temperature formulae supplied by manufacturers on automatic blood gas apparatus, PO2 corr. = PO2 37 degrees C X 10F X delta T were studied and compared to the experimental determination of the delta log PO2/delta T ratio (Hérigault et al. [10]). Acid-base status at 37 degrees C appeared to have a measurable influence on the PO2 temperature factor; alkalosis increased the delta log PO2/delta T ratio, and the contrary was found for acidosis in comparison with normal acid-base status at 37 degrees C. For the same PO2, measured at 37 degrees C, all the proposed formulae of commercial blood gas automatic apparatus did not give the same temperature corrected PO2. The observed difference between the corrected PO2 may be important and greater than the precision of the initial measurement. To correct the measured PO2 for temperature, a relationship between delta log PO2/delta T and PO2 is proposed, between PO2 zero and PO2 180 mmHg, which takes into account measured pH and PO2 values at 37 degrees C:delta log PO2/delta T = [(-0.35 pH + 0.658) X 10(-4) X PO2] + 0.035.

Constriction of collateral arteries induced by "head-up tilt" in patients with occlusive arterial disease of the legs

DEFF Research Database (Denmark)

Agerskov, K; Henriksen, O; Tønnesen, K H

1981-01-01

The effect of head-up tilt on leg blood flow and segmental arterial blood pressures was studied in 21 patients with occlusion or severe stenosis of the common or superficial femoral artery. Arterial pressure was measured directly in the brachial artery, common femoral artery and popliteal artery....... Relative change in blood flow in the leg during tilt was estimated by changes in arterio-venous oxygen differences and by the indicator dilution technique in nine patients. Head-up tilt caused a decrease in leg blood flow of 36% corresponding to an increase in total vascular resistance of 57%. Tilt did...... not change the pressure gradient from femoral to popliteal artery in the patients with occlusion of the superficial femoral artery, indicating that the flow resistance offered by the collateral arteries had increased. In a bilateral sympathectomised patient the increase in collateral resistance was almost...

Insulin resistance is associated with lower arterial blood flow and reduced cortical perfusion in cognitively asymptomatic middle-aged adults

Science.gov (United States)

Hoscheidt, Siobhan M; Kellawan, J Mikhail; Berman, Sara E; Rivera-Rivera, Leonardo A; Krause, Rachel A; Oh, Jennifer M; Beeri, Michal S; Rowley, Howard A; Wieben, Oliver; Carlsson, Cynthia M; Asthana, Sanjay; Johnson, Sterling C; Schrage, William G

2016-01-01

Insulin resistance (IR) is associated with poor cerebrovascular health and increased risk for dementia. Little is known about the unique effect of IR on both micro- and macrovascular flow particularly in midlife when interventions against dementia may be most effective. We examined the effect of IR as indexed by the Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) on cerebral blood flow in macro- and microvessels utilizing magnetic resonance imaging (MRI) among cognitively asymptomatic middle-aged individuals. We hypothesized that higher HOMA-IR would be associated with reduced flow in macrovessels and lower cortical perfusion. One hundred and twenty cognitively asymptomatic middle-aged adults (57 ± 5 yrs) underwent fasting blood draw, phase contrast-vastly undersampled isotropic projection reconstruction (PC VIPR) MRI, and arterial spin labeling (ASL) perfusion. Higher HOMA-IR was associated with lower arterial blood flow, particularly within the internal carotid arteries (ICAs), and lower cerebral perfusion in several brain regions including frontal and temporal lobe regions. Higher blood flow in bilateral ICAs predicted greater cortical perfusion in individuals with lower HOMA-IR, a relationship not observed among those with higher HOMA-IR. Findings provide novel evidence for an uncoupling of macrovascular blood flow and microvascular perfusion among individuals with higher IR in midlife. PMID:27488909

Secondhand tobacco smoke, arterial stiffness, and altered circadian blood pressure patterns are associated with lung inflammation and oxidative stress in rats.

Science.gov (United States)

Gentner, Nicole J; Weber, Lynn P

2012-02-01

Chronic smoking and secondhand tobacco smoke exposure are major risk factors for cardiovascular disease that are known to adversely alter the structural and mechanical properties of arteries. The objective of this study was to determine the effects of subchronic secondhand tobacco smoke exposure on circadian blood pressure patterns, arterial stiffness, and possible sources of oxidative stress in conscious, unsedated radiotelemetry-implanted rats. Pulse wave change in pressure over time (dP/dt) was used an indicator of arterial stiffness and was compared with both structural (wall thickness) and functional (nitric oxide production and bioactivity and endothelin-1 levels) features of the arterial wall. In addition, histology of lung, heart, and liver was examined as well as pulmonary and hepatic detoxifying enzyme activity (cytochrome P450, specifically CYP1A1). Subchronic secondhand tobacco smoke exposure altered the circadian pattern of heart rate and blood pressure, with a loss in the normal dipping pattern of blood pressure during sleep. Secondhand tobacco smoke exposure also increased pulse wave dP/dt in the absence of any structural modifications in the arterial wall. Furthermore, although nitric oxide production and endothelin-1 levels were not altered by secondhand tobacco smoke, there was increased inactivation of nitric oxide as indicated by peroxynitrite production. Increased lung neutrophils or pulmonary CYP1A1 may be responsible for the increase in oxidative stress in rats exposed to secondhand tobacco smoke. In turn, this may be related to the observed failure of blood pressure to dip during periods of sleep and a possible increase in arterial stiffness.

Blood Transfusion and 30-Day Mortality in Patients With Coronary Artery Disease and Anemia Following Noncardiac Surgery.

Science.gov (United States)

Hollis, Robert H; Singletary, Brandon A; McMurtrie, James T; Graham, Laura A; Richman, Joshua S; Holcomb, Carla N; Itani, Kamal M; Maddox, Thomas M; Hawn, Mary T

2016-02-01

Although liberal blood transfusion thresholds have not been beneficial following noncardiac surgery, it is unclear whether higher thresholds are appropriate for patients who develop postoperative myocardial infarction (MI). To evaluate the association between postoperative blood transfusion and mortality in patients with coronary artery disease and postoperative MI following noncardiac surgery. Retrospective cohort study involving Veterans Affairs facilities from January 1, 2000, to December 31, 2012. A total of 7361 patients with coronary artery disease who underwent inpatient noncardiac surgery and had a nadir postoperative hematocrit between 20% and 30%. Patients with significant bleeding, including any preoperative blood transfusion or transfusion of greater than 4 units during the intraoperative or postoperative setting, were excluded. Mortality rates were compared using both logistic regression and propensity score matching. Patients were stratified by postoperative nadir hematocrit and the presence of postoperative MI. Initial postoperative blood transfusion. The 30-day postoperative mortality rate. Of the 7361 patients, 2027 patients (27.5%) received at least 1 postoperative blood transfusion. Postoperative mortality occurred in 267 (3.6%), and MI occurred in 271 (3.7%). Among the 5334 patients without postoperative blood transfusion, lower nadir hematocrit was associated with an increased risk for mortality (hematocrit of 20% to blood transfusion was associated with lower mortality, for those with hematocrit of 20% to 24% (odds ratio, 0.28; 95% CI, 0.13-0.64). In patients without postoperative MI, transfusion was associated with significantly higher mortality for those with hematocrit of 27% to 30% (odds ratio, 3.21; 95% CI, 1.85-5.60). These findings support a restrictive postoperative transfusion strategy in patients with stable coronary artery disease following noncardiac surgery. However, interventional studies are needed to evaluate the use of a more

Oscillometric blood pressure measurement: a simple method in screening for peripheral arterial disease

DEFF Research Database (Denmark)

Mehlsen, Jesper; Wiinberg, Niels; Bruce, Christopher

2008-01-01

Blood pressure at the ankle level is a reliable indicator of peripheral arterial disease (PAD) and the ankle brachial index (ABI) is a useful non-invasive screening tool for the early detection of atherosclerosis. In the first part of the study, systolic blood pressures obtained by oscillometry...... of PAD was sufficiently high in subjects over the age of 60 years to warrant screening. The ankle brachial index based on measurements with an oscillometric device was shown reliable in the exclusion of PAD, thereby fulfilling an important criterion for the use in screening....

No benefit of intraoperative whole blood sequestration and autotransfusion during coronary artery bypass grafting : results of a randomized clinical trial

NARCIS (Netherlands)

Ramnath, A N; Naber, H R; de Boer, A; Leusink, J A

OBJECTIVES: In a randomized clinical trial of patients undergoing elective coronary artery bypass grafting, we evaluated the effect of intraoperative whole blood sequestration and autotransfusion on postoperative blood loss and the use of allogeneic blood products. METHODS: Male patients were

COMPARISON OF HIGH-DEFINITION OSCILLOMETRIC AND DIRECT ARTERIAL BLOOD PRESSURE MEASUREMENT IN ANESTHETIZED CHEETAHS (ACINONYX JUBATUS).

Science.gov (United States)

Sant Cassia, Emma V; Boswood, Adrian; Tordiffe, Adrian S W

2015-09-01

Blood pressure measurement reveals important insights into the health of conscious and anesthetized individuals. This is of particular interest in cheetahs (Acinonyx jubatus), which in captivity are known to suffer from chronic diseases that may be associated with hypertension and which often require immobilization for transport or veterinary treatment. Invasive testing methods are considered the gold standard but are not practical in many settings. Consequently, it is important to evaluate the use of noninvasive methods in this species. Measurements for systolic, diastolic, and mean arterial pressure obtained using high-definition oscillometry (HDO) at the coccygeal artery were compared to simultaneous direct measurements obtained via catheterization of the femoral or dorsal pedal artery in eight anesthetized captive cheetahs during nine anesthetic events. Overall, HDO and direct measurements agreed most closely for mean arterial pressure, and the poorest agreement was observed for systolic pressure. There was a tendency for low diastolic pressures to be underestimated and for high diastolic pressures to be overestimated. Across all three parameters, HDO measurements from the tail overestimated directly measured pressures in the femoral artery and underestimated those in the dorsal pedal artery. HDO agreed most closely with directly measured dorsal pedal pressures. Mean arterial pressure showed the greatest precision (standard deviation of 10.2 mm Hg) and lowest bias (-1.2 mm Hg), with 75.9% of readings within 10 mm Hg of the direct dorsal pedal pressure. Agreement with systolic pressure was hindered by a high bias (-10.4 mm Hg), but if a correction factor of +10 mm Hg was applied to all systolic measurements, agreement was improved and 65.7% of readings were within 10 mm Hg of the direct pressure. When compared to criteria defined by the American College of Veterinary Internal Medicine for validation of blood pressure devices, results were favorable, but a

Automated artery-venous classification of retinal blood vessels based on structural mapping method

Science.gov (United States)

Joshi, Vinayak S.; Garvin, Mona K.; Reinhardt, Joseph M.; Abramoff, Michael D.

2012-03-01

Retinal blood vessels show morphologic modifications in response to various retinopathies. However, the specific responses exhibited by arteries and veins may provide a precise diagnostic information, i.e., a diabetic retinopathy may be detected more accurately with the venous dilatation instead of average vessel dilatation. In order to analyze the vessel type specific morphologic modifications, the classification of a vessel network into arteries and veins is required. We previously described a method for identification and separation of retinal vessel trees; i.e. structural mapping. Therefore, we propose the artery-venous classification based on structural mapping and identification of color properties prominent to the vessel types. The mean and standard deviation of each of green channel intensity and hue channel intensity are analyzed in a region of interest around each centerline pixel of a vessel. Using the vector of color properties extracted from each centerline pixel, it is classified into one of the two clusters (artery and vein), obtained by the fuzzy-C-means clustering. According to the proportion of clustered centerline pixels in a particular vessel, and utilizing the artery-venous crossing property of retinal vessels, each vessel is assigned a label of an artery or a vein. The classification results are compared with the manually annotated ground truth (gold standard). We applied the proposed method to a dataset of 15 retinal color fundus images resulting in an accuracy of 88.28% correctly classified vessel pixels. The automated classification results match well with the gold standard suggesting its potential in artery-venous classification and the respective morphology analysis.

Middle cerebral artery blood velocity and cerebral blood flow and O2 uptake during dynamic exercise

DEFF Research Database (Denmark)

Madsen, P L; Sperling, B K; Warming, T

1993-01-01

Results obtained by the 133Xe clearance method with external detectors and by transcranial Doppler sonography (TCD) suggest that dynamic exercise causes an increase of global average cerebral blood flow (CBF). These data are contradicted by earlier data obtained during less-well-defined conditions....... To investigate this controversy, we applied the Kety-Schmidt technique to measure the global average levels of CBF and cerebral metabolic rate of oxygen (CMRO2) during rest and dynamic exercise. Simultaneously with the determination of CBF and CMRO2, we used TCD to determine mean maximal flow velocity...... in the middle cerebral artery (MCA Vmean). For values of CBF and MCA Vmean a correction for an observed small drop in arterial PCO2 was carried out. Baseline values for global CBF and CMRO2 were 50.7 and 3.63 ml.100 g-1.min-1, respectively. The same values were found during dynamic exercise, whereas a 22% (P

The relationship between exercise-induced muscle fatigue, arterial blood flow and muscle perfusion after 56 days local muscle unloading.

Science.gov (United States)

Weber, Tobias; Ducos, Michel; Mulder, Edwin; Beijer, Åsa; Herrera, Frankyn; Zange, Jochen; Degens, Hans; Bloch, Wilhelm; Rittweger, Jörn

2014-05-01

In the light of the dynamic nature of habitual plantar flexor activity, we utilized an incremental isokinetic exercise test (IIET) to assess the work-related power deficit (WoRPD) as a measure for exercise-induced muscle fatigue before and after prolonged calf muscle unloading and in relation to arterial blood flow and muscle perfusion. Eleven male subjects (31 ± 6 years) wore the HEPHAISTOS unloading orthosis unilaterally for 56 days. It allows habitual ambulation while greatly reducing plantar flexor activity and torque production. Endpoint measurements encompassed arterial blood flow, measured in the femoral artery using Doppler ultrasound, oxygenation of the soleus muscle assessed by near-infrared spectroscopy, lactate concentrations determined in capillary blood and muscle activity using soleus muscle surface electromyography. Furthermore, soleus muscle biopsies were taken to investigate morphological muscle changes. After the intervention, maximal isokinetic torque was reduced by 23·4 ± 8·2% (Pflow, tissue oxygenation, lactate concentrations and EMG median frequency kinematics during the exercise test were comparable before and after the intervention, whereas the increase of RMS in response to IIET was less following the intervention (P = 0·03). In conclusion, following submaximal isokinetic muscle work exercise-induced muscle fatigue is unaffected after prolonged local muscle unloading. The observation that arterial blood flow was maintained may underlie the unchanged fatigability. © 2013 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

Inhibition of breathing after surfactant depletion is achieved at a higher arterial PCO2 during ventilation with liquid than with gas

Directory of Open Access Journals (Sweden)

Sindelar Richard

2005-03-01

Full Text Available Abstract Background Inhibition of phrenic nerve activity (PNA can be achieved when alveolar ventilation is adequate and when stretching of lung tissue stimulates mechanoreceptors to inhibit inspiratory activity. During mechanical ventilation under different lung conditions, inhibition of PNA can provide a physiological setting at which ventilatory parameters can be compared and related to arterial blood gases and pH. Objective To study lung mechanics and gas exchange at inhibition of PNA during controlled gas ventilation (GV and during partial liquid ventilation (PLV before and after lung lavage. Methods Nine anaesthetised, mechanically ventilated young cats (age 3.8 ± 0.5 months, weight 2.3 ± 0.1 kg (mean ± SD were studied with stepwise increases in peak inspiratory pressure (PIP until total inhibition of PNA was attained before lavage (with GV and after lavage (GV and PLV. Tidal volume (Vt, PIP, oesophageal pressure and arterial blood gases were measured at inhibition of PNA. One way repeated measures analysis of variance and Student Newman Keuls-tests were used for statistical analysis. Results During GV, inhibition of PNA occurred at lower PIP, transpulmonary pressure (Ptp and Vt before than after lung lavage. After lavage, inhibition of inspiratory activity was achieved at the same PIP, Ptp and Vt during GV and PLV, but occurred at a higher PaCO2 during PLV. After lavage compliance at inhibition was almost the same during GV and PLV and resistance was lower during GV than during PLV. Conclusion Inhibition of inspiratory activity occurs at a higher PaCO2 during PLV than during GV in cats with surfactant-depleted lungs. This could indicate that PLV induces better recruitment of mechanoreceptors than GV.

Regional quality control survey of blood-gas analysis.

Science.gov (United States)

Minty, B D; Nunn, J F

1977-09-01

We undertook an external quality control survey of blood-gas analysis in 16 laboratories at 13 hospitals. All samples were prepared in the laboratories under investigation by equilibration of blood or serum with gas mixtures of known composition. pH of serum was measured with no significant bias but with an SD of random error 0.026 pH units, which was almost twice the SD of the reference range (0.015). An acceptable random error (half SD of reference range) was not obtained in a longitudinal internal quality control suvey although there were acceptable results for buffer pH in both field and internal surveys. Blood PO2 was measured with no significant bias but with SD of random error 1.38 kPa which reduced to 0.72 kPa by excluding one egregious result. The latter value was just over half of the SD of the reference range (1.2 kPa). PCO2 of blood was also measured without significant bias but with a much smaller SD of random error of 0.28 kPa (by excluding one egregious result), which was again just over half the SD of the reference range (0.51 kPa). Measurements of blood PO2 and PCO2 seem generally acceptable in relation to their respective reference ranges but measurements of pH were unsatisfactory in both internal and external trials.

Reference Values for Umbilical Cord Blood Gases of Newborns Delivered by Elective Cesarean Section.

Science.gov (United States)

Manomayangkul, Kattiya; Siriussawakul, Arunotai; Nimmannit, Akarin; Yuyen, Thassayu; Ngerncham, Sopapan; Reesukumal, Kanit

2016-05-01

Umbilical cord blood gas values are better indicators of perinatal asphyxia than Apgar scores. Many studies have reported normal ranges of umbilical cord blood gases, which vary greatly due to many factors. This study aimed to establish the reference values of umbilical cord blood gases of normal cesarean newborns in a university hospital setting. Blood samples from the umbilical artery and vein were collected from 160 newborns delivered by elective cesarean section. The indications for caesarean section were not due to fetal distress, intrauterine growth retardation, or non-reassuring fetal heart rate. The blood samples were collected immediately after birth in the operating room and then sent for blood-gas analysis. The blood-gas values were statistically analyzed and reported. The cord blood collected from 160 newborns was analyzed in this study. Seventy-eight percent (115) of the parturients were hypotensive before delivery. All Apgar scores at one and five minutes after delivery were at least 7. The calculated reference range of the umbilical arterial pH was 7.18-7.42, of pO₂was 6.43-29.43 mmHg, of pCO₂was 33.44-66.56 mmHg, and of HCO₃was 15.60-30.70 mEq/L. The reference range obtained for the umbilical venous pH was 7.28-7.44,for pO₂was 13.97-37.13 mmHg, for pCO₂was 30.70-57.0 mmHg, and for HCO₃was 18.50-29.90 mEq/L. The study determined normal reference values as a result of umbilical cord blood gas analyses.

Influence of different storage times and temperatures on blood gas ...

African Journals Online (AJOL)

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 ...

Arterial stick

Science.gov (United States)

... be some throbbing. Why the Test Is Performed Blood transports oxygen, nutrients, waste products, and other materials within ... venous blood) mainly in its content of dissolved gases . Testing arterial blood shows the makeup of the blood before any ...

Blood flow of the right and left submandibular gland during unilateral carotid artery occlusion in rat: role of nitric oxide.

Science.gov (United States)

Vág, J; Hably, C; Fazekas, A; Bartha, J

1999-01-01

The aim of the present study was to investigate the effect of unilateral carotid artery occlusion on the blood flow of submandibular gland in anesthetized rats and identify the role of nitric oxide (NO) in blood flow changes after the artery occlusion. L-NAME (N omega-nitro-L-arginine-methyl-ester; 10 mg/kg/day, per os) dissolved in tap water was used to block nitric oxide synthase. Glandular blood flow was measured using Sapirstein's indicator (86Rb) distribution technique. In the control animals the blood flow of left (ligated side) submandibular gland was lower than in the right (unligated side) one (right: 76.4+/-15.4 ml/min/100 g, 64.1+/-13.4 ml/min/100 g, ptinder this condition.

En bloc resection of skull base tumor including internal carotid artery. Preoperative evaluation of cerebral blood flow

International Nuclear Information System (INIS)

Okamoto, Yoshitaka; Matsuzaki, Zensei; Kamijo, Atsushi; Ogino, Jun; Nagaseki, Yoshishige; Nukui, Hideaki; Yokomizo, Michinori; Togawa, Kiyoshi

1998-01-01

Carotid artery resection yields a possibility of cure in patients with advanced head and neck carcinoma involving the carotid artery. However, the criteria for the identification of those who are vulnerable to neurologic injury after resection have not been established. Interposition graft covered with a well-vascularized flap could minimize the rate of perioperative morbidity. Particularly, when an extensive resection of the skull base including carotid artery and sigmoid vein, is planned, extracranial-intracranial bypass should be considered to minimize the risks of neurologic morbidity, even if preresection positron emission tomography during balloon test occlusion of internal carotid artery suggested the adequacy of hemispheric collateral blood flow. In these cases, the temporary occlusion of the carotid artery is not an accurate prediction of the morbidity after permanent occlusion. (author)

Ultrasonic character istics and clinical significance of umbilical cord blood flow in acute fetal distress

Directory of Open Access Journals (Sweden)

Wei Dai, Yin Xu

2016-11-01

Full Text Available Objective: To study ultrasonic characteristics of umbilical cord blood flow in acute fetal distress and its correlation with umbilical artery blood gas parameters, oxidative stress parameters, neonatal brain injury and myocardial injury. Methods: The pregnant women delivered in Department of Obstetrics of our hospital were chosen during the period from May 2012 to August 2015. The pregnant women with acute fetal distress were included in the distress group, and the healthy pregnant women with no acute fetal distress were included in the control group. The resistance index (RI, pulsatility index (PI and systolic/diastolic (S/D ratio of umbilical artery were measured at 24–30 weeks, 31–36 weeks and 37–41 weeks of pregnancy. After delivery, umbilical artery blood was taken for analysis of blood gas and determination of oxidative stress parameters. The venous blood of newborns was taken to measure the myocardial injury and brain injury parameters. Results: At 24–30 weeks, 31–36 weeks and 37–41 weeks of pregnancy, RI, S/D and PI in pregnant women of distress group were significantly higher than those in control group. The pH, contents of arterial partial pressure of oxygen, vitamin C, vitamin E, superoxide dismutase and glutathione peroxidase in umbilical artery blood in pregnant women of distress group was significantly lower than those in control group and negatively correlated with the umbilical artery RI, PI and S/D. The contents of partial pressure of carbon dioxide in artery, lactic acid and malondialdehyde in pregnant women of distress group were significantly higher than those in control group and positively correlated with the umbilical artery RI, PI and S/D. The contents of lactate dehydrogenase, hydroxybutyrate dehydrogenase, creatine kinase, creatine kinase-MB, S100B, neuron-specific enolase, creatine kinase-BB and Tau in newborns' venous blood in distress group were significantly higher than those in control group and

Impact of airway gas exchange on the multiple inert gas elimination technique: theory.

Science.gov (United States)

Anderson, Joseph C; Hlastala, Michael P

2010-03-01

The multiple inert gas elimination technique (MIGET) provides a method for estimating alveolar gas exchange efficiency. Six soluble inert gases are infused into a peripheral vein. Measurements of these gases in breath, arterial blood, and venous blood are interpreted using a mathematical model of alveolar gas exchange (MIGET model) that neglects airway gas exchange. A mathematical model describing airway and alveolar gas exchange predicts that two of these gases, ether and acetone, exchange primarily within the airways. To determine the effect of airway gas exchange on the MIGET, we selected two additional gases, toluene and m-dichlorobenzene, that have the same blood solubility as ether and acetone and minimize airway gas exchange via their low water solubility. The airway-alveolar gas exchange model simulated the exchange of toluene, m-dichlorobenzene, and the six MIGET gases under multiple conditions of alveolar ventilation-to-perfusion, VA/Q, heterogeneity. We increased the importance of airway gas exchange by changing bronchial blood flow, Qbr. From these simulations, we calculated the excretion and retention of the eight inert gases and divided the results into two groups: (1) the standard MIGET gases which included acetone and ether and (2) the modified MIGET gases which included toluene and m-dichlorobenzene. The MIGET mathematical model predicted distributions of ventilation and perfusion for each grouping of gases and multiple perturbations of VA/Q and Qbr. Using the modified MIGET gases, MIGET predicted a smaller dead space fraction, greater mean VA, greater log(SDVA), and more closely matched the imposed VA distribution than that using the standard MIGET gases. Perfusion distributions were relatively unaffected.

Relations between a novel, reliable, and rapid index of arterial compliance (PP-HDI) and well-established inidices of arterial blood pressure (ABP) in a sample of hypertensive elderly subjects.

Science.gov (United States)

Bergamini, L; Finelli, M E; Bendini, C; Ferrari, E; Veschi, M; Neviani, F; Manni, B; Pelosi, A; Rioli, G; Neri, M

2009-01-01

Hypertension is a risk factor for a long-lasting arterial wall-remodelling leading to stiffness. The rapid method measuring the pulse pressure (PP) by means of the tool of Hypertension Diagnostic Instruments (HDI) called PP-HDI, overcomes some of the problems arising with more-time consuming methods, like ambulatory blood pressure monitoring (ABPM), and give information about the elasticity of the arterial walls. We studied the relationship between the PP-HDI, the large artery compliance (LA-C) and small artery compliance (SA-C) and few well-established indices of arterial blood pressure (ABP) in a sample of 75 hypertensive subjects, aged 65 years and over. Significant correlations between LA-C and heart rate (HR), PP-ABPM and PP-HDI were found. SA-C relates with HR and systolic blood pressure (SBP) measured in lying and standing positions. Applying a stepwise regression analysis, we found that LA-C variance stems from PP-HDI and HR, while SA-C variance stems from SBP in lying position. Receiver operator characteristic (ROC) curves for thresholds of PP showed that PP-HDI reached levels of sensitivity/specificity similar to PP-ABPM. In conclusion, surveillance of ABP through hemo-dynamic indices, in particular of SBP, is essential, nevertheless the advantage of this control is not known in an elderly population where the organ damage is already evident. PP needs necessarily an instrumental measurement. The PP-HDI result is similar in reliability with respect to PPABPM, but is more rapid and well applicable in an elderly population.

Estimation of arterial arrival time and cerebral blood flow from QUASAR arterial spin labeling using stable spline.

Science.gov (United States)

Castellaro, Marco; Peruzzo, Denis; Mehndiratta, Amit; Pillonetto, Gianluigi; Petersen, Esben Thade; Golay, Xavier; Chappell, Michael A; Bertoldo, Alessandra

2015-12-01

QUASAR arterial spin labeling (ASL) permits the application of deconvolution approaches for the absolute quantification of cerebral perfusion. Currently, oscillation index regularized singular value decomposition (oSVD) combined with edge-detection (ED) is the most commonly used method. Its major drawbacks are nonphysiological oscillations in the impulse response function and underestimation of perfusion. The aim of this work is to introduce a novel method to overcome these limitations. A system identification method, stable spline (SS), was extended to address ASL peculiarities such as the delay in arrival of the arterial blood in the tissue. The proposed framework was compared with oSVD + ED in both simulated and real data. SS was used to investigate the validity of using a voxel-wise tissue T1 value instead of using a single global value (of blood T1 ). SS outperformed oSVD + ED in 79.9% of simulations. When applied to real data, SS exhibited a physiologically realistic range for perfusion and a higher mean value with respect to oSVD + ED (55.5 ± 9.5 SS, 34.9 ± 5.2 oSVD + ED mL/100 g/min). SS can represent an alternative to oSVD + ED for the quantification of QUASAR ASL data. Analysis of the retrieved impulse response function revealed that using a voxel wise tissue T1 might be suboptimal. © 2014 Wiley Periodicals, Inc.

Passive heat therapy improves endothelial function, arterial stiffness and blood pressure in sedentary humans.

Science.gov (United States)

Brunt, Vienna E; Howard, Matthew J; Francisco, Michael A; Ely, Brett R; Minson, Christopher T

2016-09-15

A recent 30 year prospective study showed that lifelong sauna use reduces cardiovascular-related and all-cause mortality; however, the specific cardiovascular adaptations that cause this chronic protection are currently unknown. We investigated the effects of 8 weeks of repeated hot water immersion ('heat therapy') on various biomarkers of cardiovascular health in young, sedentary humans. We showed that, relative to a sham group which participated in thermoneutral water immersion, heat therapy increased flow-mediated dilatation, reduced arterial stiffness, reduced mean arterial and diastolic blood pressure, and reduced carotid intima media thickness, with changes all on par or greater than what is typically observed in sedentary subjects with exercise training. Our results show for the first time that heat therapy has widespread and robust effects on vascular function, and as such, could be a viable treatment option for improving cardiovascular health in a variety of patient populations, particularly those with limited exercise tolerance and/or capabilities. The majority of cardiovascular diseases are characterized by disorders of the arteries, predominantly caused by endothelial dysfunction and arterial stiffening. Intermittent hot water immersion ('heat therapy') results in elevations in core temperature and changes in cardiovascular haemodynamics, such as cardiac output and vascular shear stress, that are similar to exercise, and thus may provide an alternative means of improving health which could be utilized by patients with low exercise tolerance and/or capabilities. We sought to comprehensively assess the effects of 8 weeks of heat therapy on biomarkers of vascular function in young, sedentary subjects. Twenty young, sedentary subjects were assigned to participate in 8 weeks (4-5 times per week) of heat therapy (n = 10; immersion in a 40.5°C bath sufficient to maintain rectal temperature ≥ 38.5°C for 60 min per session) or thermoneutral water

Evaluation of hematologic, blood gas, and select biochemical variables in ovine whole blood stored in CPDA-1 bags.

Science.gov (United States)

Sousa, Rejane S; Barrêto, Raimundo A; Sousa, Isadora K F; Chaves, Dowglish F; Soares, Herbert S; Barros, Isabella O; Minervino, Antonio H H; Ortolani, Enrico L

2013-03-01

The economic consequences from mortality of sheep after blood loss can be considerable. To date there are no reports addressing hematologic, blood gas, and biochemical changes in ovine blood stored in CPDA-1 bags. The aim of this study was to investigate hematologic, blood gas, and biochemical alterations resulting from storage of ovine blood in CPDA-1 bags to establish transfusion protocols in sheep. From each of 7 healthy 8-month-old sheep 450 mL of blood were collected into CPDA-1 bags and stored for 35 days in at 3-6°C. Samples were taken from the bags at days 0, 7, 14, 21, and 35. Whole blood was used to assess PCV, MCV, RBC count, pH, pO2 , pCO2 , and concentrations of bicarbonate, sodium, and lactate. Plasma was used to measure potassium, hemoglobin, and glucose concentrations. The PCV remained stable throughout the storage period, while plasma hemoglobin and MCV began to increase on days 7 and 21, respectively. The RBC count began to decrease on day 21. Blood pH decreased and pCO2 increased steadily throughout the storage period. Potassium concentration increased from 3.8 to 18.3 mmol/L on day 7 and remained high thereafter. In contrast, sodium concentration began to decrease on day 7. The results show that ovine blood undergoes hematologic, blood gas, and biochemical changes during storage. Further studies are required to establish RBC viability in CPDA-1 bags after a storage period of 35 days. © 2012 American Society for Veterinary Clinical Pathology.

Decompression sickness in breath-hold diving, and its probable connection to the growth and dissolution of small arterial gas emboli.

Science.gov (United States)

Goldman, Saul; Solano-Altamirano, J M

2015-04-01

We solved the Laplace equation for the radius of an arterial gas embolism (AGE), during and after breath-hold diving. We used a simple three-region diffusion model for the AGE, and applied our results to two types of breath-hold dives: single, very deep competitive-level dives and repetitive shallower breath-hold dives similar to those carried out by indigenous commercial pearl divers in the South Pacific. Because of the effect of surface tension, AGEs tend to dissolve in arterial blood when arteries remote from supersaturated tissue. However if, before fully dissolving, they reach the capillary beds that perfuse the brain and the inner ear, they may become inflated with inert gas that is transferred into them from these contiguous temporarily supersaturated tissues. By using simple kinetic models of cerebral and inner ear tissue, the nitrogen tissue partial pressures during and after the dive(s) were determined. These were used to theoretically calculate AGE growth and dissolution curves for AGEs lodged in capillaries of the brain and inner ear. From these curves it was found that both cerebral and inner ear decompression sickness are expected to occur occasionally in single competitive-level dives. It was also determined from these curves that for the commercial repetitive dives considered, the duration of the surface interval (the time interval separating individual repetitive dives from one another) was a key determinant, as to whether inner ear and/or cerebral decompression sickness arose. Our predictions both for single competitive-level and repetitive commercial breath-hold diving were consistent with what is known about the incidence of cerebral and inner ear decompression sickness in these forms of diving. Copyright © 2015 Elsevier Inc. All rights reserved.

An efficient parallel simulation of unsteady blood flows in patient-specific pulmonary artery.

Science.gov (United States)

Kong, Fande; Kheyfets, Vitaly; Finol, Ender; Cai, Xiao-Chuan

2018-04-01

Simulation of blood flows in the pulmonary artery provides some insight into certain diseases by examining the relationship between some continuum metrics, eg, the wall shear stress acting on the vascular endothelium, which responds to flow-induced mechanical forces by releasing vasodilators/constrictors. V. Kheyfets, in his previous work, studies numerically a patient-specific pulmonary circulation to show that decreasing wall shear stress is correlated with increasing pulmonary vascular impedance. In this paper, we develop a scalable parallel algorithm based on domain decomposition methods to investigate an unsteady model with patient-specific pulsatile waveforms as the inlet boundary condition. The unsteady model offers tremendously more information about the dynamic behavior of the flow field, but computationally speaking, the simulation is a lot more expensive since a problem which is similar to the steady-state problem has to be solved many times, and therefore, the traditional sequential approach is not suitable anymore. We show computationally that simulations using the proposed parallel approach with up to 10 000 processor cores can be obtained with much reduced compute time. This makes the technology potentially usable for the routine study of the dynamic behavior of blood flows in the pulmonary artery, in particular, the changes of the blood flows and the wall shear stress in the spatial and temporal dimensions. Copyright © 2017 John Wiley & Sons, Ltd.

Combined exercise reduces arterial stiffness, blood pressure, and blood markers for cardiovascular risk in postmenopausal women with hypertension.

Science.gov (United States)

Son, Won-Mok; Sung, Ki-Dong; Cho, Jae-Min; Park, Song-Young

2017-03-01

Postmenopausal women exhibit elevated brachial-ankle pulse wave velocity (baPWV), an indicator of arterial stiffness, which is associated with an increased risk of cardiovascular events and mortality. The purpose of this study is to examine the impact of combined resistance and aerobic exercise training on baPWV, blood pressure (BP), and cardiovascular fitness in postmenopausal women with stage 1 hypertension. Twenty postmenopausal women (age, 75 ± 2 y; systolic BP, 152 ± 2 mm Hg, diastolic BP, 95 ± 3 mm Hg) were randomly assigned to a "no-exercise" (CON, n = 10) or combined exercise (EX, n = 10) group. The EX group performed resistance and aerobic exercise for 12 weeks, 3 times per week. Exercise intensity was increased gradually, from 40% to 70% of heart rate reserve, every 4 weeks. BaPWV, BP, blood nitrite/nitrate, endothelin-1 (ET-1), cardiovascular fitness, and body composition were measured before and after the 12-week intervention. BP, baPWV (-1.2 ± 0.4 m/s), ET-1 (-2.7 ± 0.3 μmol/mL), nitrite/nitrate (+4.5 ± 0.5 μM), functional capacity, and body composition were significantly improved (P exercise training improves arterial stiffness, BP, ET-1, blood nitrite/nitrate, functional capacity, and body composition in postmenopausal women with stage 1 hypertension. Thus, this study provides evidence that combined exercise training is a useful therapeutic method to improve cardiovascular health which can reduce cardiovascular disease risk in postmenopausal women with hypertension.

Mean blood velocities and flow impedance in the fetal descending thoracic aortic and common carotid artery in normal pregnancy.

Science.gov (United States)

Bilardo, C M; Campbell, S; Nicolaides, K H

1988-12-01

A linear array pulsed Doppler duplex scanner was used to establish reference ranges for mean blood velocities and flow impedance (Pulsatility Index = PI) in the descending thoracic aorta and in the common carotid artery from 70 fetuses in normal pregnancies at 17-42 weeks' gestation. The aortic velocity increased with gestation up to 32 weeks, then remained constant until term, when it decreased. In contrast, the velocity in the common carotid artery increased throughout pregnancy. The PI in the aorta remained constant throughout pregnancy, while in the common carotid artery it fell steeply after 32 weeks. These results suggest that with advancing gestation there is a redistribution of the fetal circulation with decreased impedance to flow to the fetal brain, presumably to compensate for the progressive decrease in fetal blood PO2.

Basilar artery angulation and vertigo due to the hemodynamic effect of dominant vertebral artery.

Science.gov (United States)

Cosar, Murat; Yaman, Mehmet; Eser, Olcay; Songur, Ahmet; Ozen, Oguz A

2008-01-01

Vertebral arteries form the basilar artery at the pontobulbar junction. The vertebral artery may have dominancy in one of them. The branches of basilar arteries supply blood for the vestibular nuclei and its connections. Vertigo is seen generally in the upper middle aged patients. Vertigo can be observed in dolichoectasia of basilar artery such as angulation and elongation, because of the diminished blood supply and changed hemodynamic factors of vestibular nuclei and its connections. We hypothesized that angulation or elongation of basilar artery can be estimated according to the unilateral vertebral artery dominant hypertensive patients. The basilar artery can angulate from the dominant side of vertebral artery to the recessive side. These angulation and elongation can effect the hemodynamic factors in absence of growing collateral arteries. So, the vertigo attacks may occur in these patients.

Relationship between haemodynamic impairment and collateral blood flow in carotid artery disease

DEFF Research Database (Denmark)

Hartkamp, Nolan S; Petersen, Esben T; Chappell, Michael A

2018-01-01

Collateral blood flow plays a pivotal role in steno-occlusive internal carotid artery (ICA) disease to prevent irreversible ischaemic damage. Our aim was to investigate the effect of carotid artery disease upon cerebral perfusion and cerebrovascular reactivity and whether haemodynamic impairment...... is influenced at brain tissue level by the existence of primary and/or secondary collateral. Eighty-eight patients with steno-occlusive ICA disease and 29 healthy controls underwent MR examination. The presence of collaterals was determined with time-of-flight, two-dimensional phase contrast MRA and territorial....... In conclusion, both CBF and cerebrovascular reactivity were found to be reduced in symptomatic patients with steno-occlusive ICA disease. The presence of collateral flow is associated with further haemodynamic impairment. Recruitment of secondary collaterals is associated with severe haemodynamic impairment....

Intermittent pneumatic leg compressions enhance muscle performance and blood flow in a model of peripheral arterial insufficiency.

Science.gov (United States)

Roseguini, Bruno T; Arce-Esquivel, Arturo A; Newcomer, Sean C; Yang, Hsiao T; Terjung, Ronald; Laughlin, M H

2012-05-01

Despite the escalating prevalence in the aging population, few therapeutic options exist to treat patients with peripheral arterial disease. Application of intermittent pneumatic leg compressions (IPC) is regarded as a promising noninvasive approach to treat this condition, but the clinical efficacy, as well the mechanistic basis of action of this therapy, remain poorly defined. We tested the hypothesis that 2 wk of daily application of IPC enhances exercise tolerance by improving blood flow and promoting angiogenesis in skeletal muscle in a model of peripheral arterial insufficiency. Male Sprague-Dawley rats were subjected to bilateral ligation of the femoral artery and randomly allocated to treatment or sham groups. Animals were anesthetized daily and exposed to 1-h sessions of bilateral IPC or sham treatment for 14-16 consecutive days. A third group of nonligated rats was also studied. Marked increases in treadmill exercise tolerance (∼33%, P < 0.05) and improved muscle performance in situ (∼10%, P < 0.05) were observed in IPC-treated animals. Compared with sham-treated controls, blood flow measured with isotope-labeled microspheres during in situ contractions tended to be higher in IPC-treated animals in muscles composed of predominantly fast-twitch white fibers, such as the plantaris (∼93%, P = 0.02). Capillary contacts per fiber and citrate synthase activity were not significantly altered by IPC treatment. Collectively, these data indicate that IPC improves exercise tolerance in a model of peripheral arterial insufficiency in part by enhancing blood flow to collateral-dependent tissues.

Effect of pregnancy on regional cerebral blood flow

International Nuclear Information System (INIS)

Nagamachi, Shigeki; Hoshi, Hiroaki; Jinnouchi, Seishi; Ohnishi, Takashi; Futami, Shigemi; Watanabe, Katsushi; Ikeda, Tomoaki; Mori, Norimasa

1993-01-01

Regional cerebral blood flow (r-CBF) of 10 pregnant women were quantified by 133 Xe SPECT study with inhalation method before and after artificial abortion. During pregnancy, value of r-CBF in each region except occipital lobe was significantly higher than that of the post abortion. Arterial blood gas was analyzed after SPECT procedure. P co2 concentration increased significantly after artificial abortion. Although its mechanism is unknown, our preliminary work demonstrates that r-CBF increased by pregnancy. (author)

Renal artery blood flow assessed by video dilution technique before and after percutaneous transluminal angioplasty

International Nuclear Information System (INIS)

Lantz, B.M.T.; Link, D.P.; Lewis, E.L.; Foerster, J.M.; Lee, G.

1981-01-01

Successful percutaneous transluminal angioplasty was performed in 3 cases of renal artery stenosis where the effect upon renal blood flow was quantified by video dilution technique. This technique adds important information to pressure gradients and renin assays obtained during the dilatation procedure. (Auth.)

Validation of myocardial blood flow estimation with nitrogen-13 ammonia PET by the argon inert gas technique in humans

International Nuclear Information System (INIS)

Kotzerke, J.; Glatting, G.; Neumaier, B.; Reske, S.N.; Hoff, J. van den; Hoeher, M.; Woehrle, J. n

2001-01-01

We simultaneously determined global myocardial blood flow (MBF) by the argon inert gas technique and by nitrogen-13 ammonia positron emission tomography (PET) to validate PET-derived MBF values in humans. A total of 19 patients were investigated at rest (n=19) and during adenosine-induced hyperaemia (n=16). Regional coronary artery stenoses were ruled out by angiography. The argon inert gas method uses the difference of arterial and coronary sinus argon concentrations during inhalation of a mixture of 75% argon and 25% oxygen to estimate global MBF. It can be considered as valid as the microspheres technique, which, however, cannot be applied in humans. Dynamic PET was performed after injection of 0.8±0.2 GBq 13 N-ammonia and MBF was calculated applying a two-tissue compartment model. MBF values derived from the argon method at rest and during the hyperaemic state were 1.03±0.24 ml min -1 g -1 and 2.64±1.02 ml min -1 g -1 , respectively. MBF values derived from ammonia PET at rest and during hyperaemia were 0.95±0.23 ml min -1 g -1 and 2.44±0.81 ml min -1 g -1 , respectively. The correlation between the two methods was close (y=0.92x+0.14, r=0.96; P 13 N-ammonia PET. (orig.)

Pressão arterial entre trabalhadores de curtume Blood pressure among tannery workers

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Ricardo Cordeiro

1998-10-01

Full Text Available INTRODUÇÃO: O grupo das doenças cardiovasculares tem sido apontado como a principal causa de óbito no Brasil desde os anos 70, sendo a hipertensão arterial sistêmica (HAS o fator de risco mais importante para esse grupo. Entre os trabalhadores observa-se correlação negativa entre o status ocupacional e a pressão arterial. Tais fatos ressaltam a importância do conhecimento da distribuição da pressão arterial sistêmica entre os distintos grupos profissionais. Assim, foi realizado estudo para descrever o status pressórico de uma população homogênea e estável de trabalhadores do setor secundário da economia, pouco especializados e que ganham baixos salários, estabelecendo a prevalência da HAS nesse grupo específico, relacionando-a com algumas covariáveis biológicas e socioeconômicas, e comparando-a com a prevalência de HAS em outros grupos profissionais no Brasil. MÉTODO: Foram estudados 73 trabalhadores regularmente empregados em julho de 1993 em um curtume situado no Município de Botucatu, cidade de médio porte da região Centro-Oeste do Estado de São Paulo, os quais foram submetidos a exame antropométrico, aferição de pressão arterial, anamnese e exame clínico. Os resultados foram comparados com os obtidos em estudos semelhantes, controlando-se o confundimento da idade por intermédio de diferentes técnicas. RESULTADOS: A prevalência bruta da HAS encontrada foi de 56,1%, sendo 15,8% a prevalência de hipertensão sistólica isolada. Ambas se associaram ao etilismo e ao tabagismo na população estudada. DISCUSSÃO: A prevalência da hipertensão foi consideravelmente alta e significativamente maior do que a encontrada em outros grupos de trabalhadores estudados no Brasil. Tal achado ressalta a necessidade da continuidade da investigação, objetivando o isolamento dos fatores implicados na elevação pressórica do grupo estudado.INTRODUCTION: Cardiovascular diseases have been shown to be the leading cause of

Unsteady Blood Flow with Nanoparticles Through Stenosed Arteries in the Presence of Periodic Body Acceleration

Science.gov (United States)

Fatin Jamil, Dzuliana; Roslan, Rozaini; Abdulhameed, Mohammed; Che-Him, Norziha; Sufahani, Suliadi; Mohamad, Mahathir; Ghazali Kamardan, Muhamad

2018-04-01

The effects of nanoparticles such as Fe 3O4,TiO2, and Cu on blood flow inside a stenosed artery are studied. In this study, blood was modelled as non-Newtonian Bingham plastic fluid subjected to periodic body acceleration and slip velocity. The flow governing equations were solved analytically by using the perturbation method. By using the numerical approaches, the physiological parameters were analyzed, and the blood flow velocity distributions were generated graphically and discussed. From the flow results, the flow speed increases as slip velocity increases and decreases as the values of yield stress increases.

The effect of blood inflow and B(1)-field inhomogeneity on measurement of the arterial input function in axial 3D spoiled gradient echo dynamic contrast-enhanced MRI.

Science.gov (United States)

Roberts, Caleb; Little, Ross; Watson, Yvonne; Zhao, Sha; Buckley, David L; Parker, Geoff J M

2011-01-01

A major potential confound in axial 3D dynamic contrast-enhanced magnetic resonance imaging studies is the blood inflow effect; therefore, the choice of slice location for arterial input function measurement within the imaging volume must be considered carefully. The objective of this study was to use computer simulations, flow phantom, and in vivo studies to describe and understand the effect of blood inflow on the measurement of the arterial input function. All experiments were done at 1.5 T using a typical 3D dynamic contrast-enhanced magnetic resonance imaging sequence, and arterial input functions were extracted for each slice in the imaging volume. We simulated a set of arterial input functions based on the same imaging parameters and accounted for blood inflow and radiofrequency field inhomogeneities. Measured arterial input functions along the vessel length from both in vivo and the flow phantom agreed with simulated arterial input functions and show large overestimations in the arterial input function in the first 30 mm of the vessel, whereas arterial input functions measured more centrally achieve accurate contrast agent concentrations. Use of inflow-affected arterial input functions in tracer kinetic modeling shows potential errors of up to 80% in tissue microvascular parameters. These errors emphasize the importance of careful placement of the arterial input function definition location to avoid the effects of blood inflow. © 2010 Wiley-Liss, Inc.

Hsa-circRNA11783-2 in peripheral blood is correlated with coronary artery disease and type 2 diabetes mellitus.

Science.gov (United States)

Li, Xuejie; Zhao, Zhenzhou; Jian, Dongdong; Li, Wentao; Tang, Haiyu; Li, Muwei

2017-11-01

The purpose of this study was to identify the expression characteristics of circular RNAs in the peripheral blood of coronary artery disease patients and type 2 diabetes mellitus patients. Circular RNA in the peripheral blood from 6 control individuals, 6 coronary artery disease patients, 6 type 2 diabetes mellitus patients and 6 coronary artery disease combined with type 2 diabetes mellitus patients was collected for microarray analysis, and a further independent cohort consisting of 20 normal individuals, 20 type 2 diabetes mellitus subjects and 20 coronary artery disease subjects was used to verify the expression of five circular RNAs chosen for further analysis. The findings were then tested in a third cohort using quantitative real-time polymerase chain reaction. In total, 40 circular RNAs differentially expressed between the three experimental groups and the control group were identified by microarray analysis: 13 were upregulated in the experimental groups, while 27 were downregulated. Of the five circular RNAs chosen for further analysis, three were significantly downregulated in the experimental groups. The crude odds ratios and adjusted odds ratios of hsa-circRNA11783-2 showed significant differences in both the coronary artery disease group and type 2 diabetes mellitus group. We then verified hsa-circRNA11783-2 in the third cohort, and it remained closely related to both coronary artery disease and type 2 diabetes mellitus. Hsa-circRNA11783-2 is closely related to both coronary artery disease and type 2 diabetes mellitus.

Effects of a nitrate-rich meal on arterial stiffness and blood pressure in healthy volunteers.

Science.gov (United States)

Liu, Alex H; Bondonno, Catherine P; Croft, Kevin D; Puddey, Ian B; Woodman, Richard J; Rich, Lisa; Ward, Natalie C; Vita, Joseph A; Hodgson, Jonathan M

2013-11-30

An increase in nitrate intake can augment circulating nitrite and nitric oxide. This may lead to lower blood pressure and improved vascular function. Green leafy vegetables, such as spinach, are rich sources of nitrate. We aimed to assess the acute effects of a nitrate-rich meal containing spinach on arterial stiffness and blood pressure in healthy men and women. Twenty-six participants aged 38-69years were recruited to a randomized controlled cross-over trial. The acute effects of two energy-matched (2000kJ) meals, administered in random order, were compared. The meals were either high nitrate (220mg of nitrate derived from spinach [spinach]) or low nitrate [control]. Outcome measurements were performed pre-meal and at specific time points up to 210min post meal. Spinach resulted in an eightfold increase in salivary nitrite and a sevenfold increase in salivary nitrate concentrations from pre-meal (Pnitrate-rich meal can lower systolic blood pressure and pulse pressure and increase large artery compliance acutely in healthy men and women. If sustained, these effects could contribute to better cardiovascular health. Copyright © 2013 Elsevier Inc. All rights reserved.

Evaluation of MR angiography and blood flow measurement in abdominal and peripheral arterial occlusive disease

Energy Technology Data Exchange (ETDEWEB)

Tabuchi, Kenji [Dokkyo Univ. School of Medicine, Mibu, Tochigi (Japan)

2000-03-01

To assess the characteristics of blood flow measurement with MR Angiography (MRA) to evaluate the status of vascular stenoses, two or three dimensional time-of-flight MRA and velocity-encoded cine MR were performed in the 230 segments of 35 patients, with abdominal and peripheral arterial occlusive diseases. In 11 of these 35 patients digital subtraction angiography was additionally underwent, and the stenotic findings was compared with MRA. There were 17 segments in which the velocity could not be measured, because the blood flow exceeded the upper limit of peak-encoded velocity (VENC) which was set at 120 cm/sec. Therefore, it is necessary to set the upper limit of VENC at higher than 120 cm/sec. There were 11 stenotic findings in DSA and 20 stenotic findings in MRA. Pulsatility Index (PI=(max velocity-min. velocity)/average velocity) were used for evaluating the blood flow waveform, and there were significant difference between the 11 stenotic findings of DSA and the others'. In summery, MRA was considered as useful examination to assess the degree of the vascular stenoses in abdominal and peripheral arterial occlusive disease. (author)

Comparison of arterial and venous blood biomarker levels in chronic obstructive pulmonary disease [v1; ref status: indexed, http://f1000r.es/9x

Directory of Open Access Journals (Sweden)

Emer Kelly

2013-04-01

Full Text Available Purpose: The development of novel biomarkers is an unmet need in chronic obstructive pulmonary disease (COPD. Arterial blood comes directly from the lung and venous blood drains capillary beds of the organ or tissue supplied. We hypothesized that there would be a difference in levels of the biomarkers metalloproteinase 9 (MMP-9, vascular endothelial growth factor A (VEGF-A and interleukin 6 (IL-6 in arterial compared with venous blood.  Methods: Radial artery and brachial vein blood samples were taken simultaneously in each of 12 patients with COPD and seven controls with normal lung function. Circulating immunoreactive MMP-9, VEGF-A and IL-6 levels in serum were measured using quantitative enzyme-linked immunosorbent assays. Results were compared using a Student’s paired t test. The study was powered to determine whether significant differences in cytokine levels were present between paired arterial and venous blood samples.   Results: In the 12 patients with COPD, four were female, and age ranged 53-85 years, mean age 69 years. Three patients in the control group were female, with age range 46-84 years, mean age 64.7 years. In the COPD group, three patients had mild, five moderate and four severe COPD. No significant difference was found between arterial and venous levels of MMP-9, VEGF-A or IL-6.  Conclusions: In this pilot study, levels of the measured biomarkers in arterial compared with venous blood in both COPD patients and healthy controls did not differ. This suggests that as we continue to chase the elusive biomarker in COPD as a potential tool to measure disease activity, we should focus on venous blood for this purpose.

Studies on blood supply of liver metastasis with DSA, CT and portal vein perfusion CT during superior mesenteric arterial portography

International Nuclear Information System (INIS)

Li Zhigang; Shi Gaofeng; Huang Jingxiang; Li Shunzong; Liang Guoqing; Wang Hongguang; Han Pengyin; Wang Qi; Gu Tieshu

2008-01-01

Objective: To probe the blood supply of liver metastasis by celiac artery, proper hepatic artery DSA, portal vein perfusion CT during superior mesenteric arterial portography (PCTAP). Methods: One hundred patients with liver metastases were examined prospectively by plain CT scan, multiphase enhanced CT scan, celiac arteriography and proper hepatic arteriography. Of them, 56 patients were examined by PCTAP. All primary lesions were confirmed by operation and (or) pathology examination. In order to investigate the blood supply of metastasis lesions, the software of Photoshop was used to obtain the time-attenuation curves (TDC) of tumor center, tumor edge, portal vein and normal liver parenchyma adjacent to the tumor to calculate liver perfusion for DSA image analysis, while a deconvolution model from CT perfusion software was designed for the dual blood supply. Results: DSA findings: TDC of proper hepatic arteriography showed: the mean peak concentration (K value) in tumor centers was (67 ± 12)%, and it was (76 ± 15)% for peritumor tissue, (51 ± 10)% in normal liver parenchyma. TDC of celiac arteriogaphy showed that the contrast concentration of tumor centers and tumor edge increased fast in early stage, then maintained a slight upward plateau, in the meanwhile, the contrast concentration of normal liver parenchyma kept increasing slowly. PCTAP findings: tumors exhibited no enhancement during 30 s continued scans. Conclusion: The blood supply of liver metastasis mainly comes from hepatic artery, but barely from portal vein. (authors)

Evaluation of the carotid artery stenosis based on minimization of mechanical energy loss of the blood flow.

Science.gov (United States)

Sia, Sheau Fung; Zhao, Xihai; Li, Rui; Zhang, Yu; Chong, Winston; He, Le; Chen, Yu

2016-11-01

Internal carotid artery stenosis requires an accurate risk assessment for the prevention of stroke. Although the internal carotid artery area stenosis ratio at the common carotid artery bifurcation can be used as one of the diagnostic methods of internal carotid artery stenosis, the accuracy of results would still depend on the measurement techniques. The purpose of this study is to propose a novel method to estimate the effect of internal carotid artery stenosis on the blood flow based on the concept of minimization of energy loss. Eight internal carotid arteries from different medical centers were diagnosed as stenosed internal carotid arteries, as plaques were found at different locations on the vessel. A computational fluid dynamics solver was developed based on an open-source code (OpenFOAM) to test the flow ratio and energy loss of those stenosed internal carotid arteries. For comparison, a healthy internal carotid artery and an idealized internal carotid artery model have also been tested and compared with stenosed internal carotid artery in terms of flow ratio and energy loss. We found that at a given common carotid artery bifurcation, there must be a certain flow distribution in the internal carotid artery and external carotid artery, for which the total energy loss at the bifurcation is at a minimum; for a given common carotid artery flow rate, an irregular shaped plaque at the bifurcation constantly resulted in a large value of minimization of energy loss. Thus, minimization of energy loss can be used as an indicator for the estimation of internal carotid artery stenosis.

Effects of two newly synthesized analogues of lidocaine on rat arterial blood pressure and heart rate.

Science.gov (United States)

Al Rasheed, N M; Al Sayed, M I; Al Zuhair, H H; Al Obaid, A R; Fatani, A J

2001-04-01

Two new analogues of lidocaine were synthesized at the College of Pharmacy, King Saud University: compound I (Methyl-2-[2-(N,N-diethylamino) acetamido]-3-cyano-4,5-dimethylbenzoate) and compound II (Methyl-2-[2-(piperidino) acetamido]-3-cyano-4,5-dimethylbenzoate). Their influence on the arterial blood pressure and the heart rate of urethane-anaesthetized rats was studied and compared with the actions of lidocaine. Compounds I, II and lidocaine induced significant dose-dependent decreases in the arterial blood pressure and heart rate, which usually returned to basal values within 3-5 min. There were significant differences in the potency of the three compounds in producing their effects on blood pressure and heart rate (Plidocaine and compound I, respectively. The results of this study also indicated the ineffectiveness of antagonists of autonomic, histaminergic and 5-HT receptor, and various vasodilators in blocking the actions of the three compounds on blood pressure and heart rate. Pretreatment with CaCl(2)significantly reduced the hypotension and bradycardia induced by the three compounds, suggesting the involvement of calcium channels, probably of the L type. Several possible mechanisms are postulated. In conclusion, the results direct attention to the capability of the two new compounds to decrease blood pressure and heart rate; affects that may have clinical potential. Copyright 2001 Academic Press.

Reduction of Blood Pressure Following After Renal Artery Adventitia Stripping During Total Nephroureterectomy: Potential Effect of Renal Sympathetic Denervation.

Science.gov (United States)

Okamura, Keisuke; Satou, Shunsuke; Setojima, Keita; Shono, Shinjiro; Miyajima, Shigero; Ishii, Tatsu; Shirai, Kazuyuki; Urata, Hidenori

2018-05-16

BACKGROUND Catheter-based renal sympathetic denervation has been reported to be effective for treatment resistance hypertension in Australia and Europe. However, in the blinded SYMPLICITY HTN-3 trial, renal denervation did not achieve a significant decrease in blood pressure (BP) in comparison to sham controls. There have been various discussions on the factors that influenced this result. CASE REPORT Two men on antihypertensive therapy underwent unilateral radical nephroureterectomy for cancer of the renal pelvis. When the renal artery adventitia was stripped and cauterized just before renal artery ligation, the measured BP of the 2 men increased after stripping adventitia and decreased gradually after cauterization of the renal artery. This was presumably due to removal of renal artery sympathetic nerves, similar to the mechanism of catheter-based renal sympathetic denervation, although anesthesia, fluid infusion, and/or mesenteric traction may have had an influence. CONCLUSIONS A similar strategy involving thoracolumbar sympathectomy was reported about 50 years ago. The clinically significant blood pressure reduction in these patients suggests renal denervation is effective.

Menopausia, hipertensión arterial y terapia de reemplazo hormonal Menopause, blood hypertension and hormone replacement therapy

Directory of Open Access Journals (Sweden)

Daysi Navarro Despaigne

2003-04-01

Full Text Available Para evaluar la influencia de la terapia de reemplazo hormonal (THR sobre el síndrome climatérico (SC y los niveles de tensión arterial en mujeres posmenopáusicas con hipertensión arterial (HTA, se realizó un ensayo terapéutico abierto, el cual incluyó 45 mujeres no obesas con HTA ligera/moderada. En cada mujer se evaluó la evolución de los síntomas climatéricos y de los niveles de tensión arterial, así como los efectos indeseables a la THR. Como medicamento las pacientes recibieron Estradiol 2mg + Levonorgestrel 1 mg por día durante 12 meses. Durante la THR disminuyeron los síntomas climatéricos, en particular los vasomotores (de 86,6 a 10 % y los genitourinarios (de 56,7 a 15 %. En la totalidad de las mujeres existió estabilidad en los niveles de tensión arterial. En 5 mujeres hubo necesidad de incrementar la dosis de medicamentos antihipertensivos. En el resto esta se mantuvo o disminuyó. Como efectos indeseables se reportó sangramiento vaginal, mastodinia, cefalea, vasculitis e isquemia del quinto dedo del pie. Las dos últimas pacientes debieron suspender el tratamiento y se presentaron al sexto mes de haber iniciado la THR. En conclusión, en mujeres de edad mediana con hipertensión arterial la THR mejora el síndrome climatérico sin empeorar los niveles de tensión arterial.To evaluate the influence of hormone replacement therapy on the climateric syndrome (CS and the blood pressure values in postmenopausal women with hypertension, an open therapeutic assay was carried out, which included 45 non-obese women with slight/moderate hypertension. The course of the climateric symptoms and the blood pressure levels as well as the adverse effects of HRT were evaluated in every woman. The patients took Estradiol 2mg plus Levonorgestrel 1 mg per day for 12 months as drug therapy. During the application of the HRT, the climateric symptoms, particularly vasomotor (from 86,6 to 10% and genitourinary (from 56,7 to 15% decreased

Influence of hemodialysis on the mean blood flow velocity in the middle cerebral artery.

Science.gov (United States)

Stefanidis, I; Bach, R; Mertens, P R; Liakopoulos, V; Liapi, G; Mann, H; Heintz, B

2005-08-01

Several effects of hemodialysis, including hemoconcentration, alterations of hemostasis or hemorheology and endothelial activation, could potentially interfere with cerebral blood flow (CBF) regulation. These treatment-specific changes may also be crucial for the enhanced incidence of stroke in uremic patients. Nevertheless, the influence of hemodialysis on CBF has not been yet adequately studied. We registered mean blood flow velocity (MFV) in the middle cerebral artery (MCA) during hemodialysis treatment in order to evaluate its contribution on CBF changes. Transcranial Doppler ultrasonography (TCD) of the MCA was performed continuously during hemodialysis treatment in 18 stable patients (10 males and 8 females, mean age 62 +/- 11 years) with end-stage renal disease of various origin. Blood pressure (mmHg), heart rate (/min), ultrafiltration volume (ml), BV changes (deltaBV by hemoglobinometry, %), arterial blood gases (pO2, blood oxygen content, pCO2), hemostasis activation (thrombin-antithrombin III complex, ELISA) and fibrinogen (Clauss) were measured simultaneously at the beginning of treatment and every hour thereafter. Before the hemodialysis session the MFV in the MCA was within normal range (57.5 +/- 13.0 cm/s, ref. 60 +/- 12) and was mainly dependent on the patients' age (r = -0.697, p delta%MFV) were interrelated to the ultrafiltration volume (r = -0.486, p delta%acO2, r = -0.420, p delta%fibrinogen, r = 0.244, p < 0.05). A significant continuous decrease of the MFV in the MCA was observed during hemodialysis treatment, which inversely correlated both with ultrafiltration volume, BV changes and changes of plasma fibrinogen. The ultrafiltration-induced hemoconcentration with concomitant rise of hematocrit and oxygen transport capacity, may partly explain the alterations in the cerebral MFV observed during hemodialysis.

Intraspecific scaling of arterial blood pressure in the Burmese python.

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Enok, Sanne; Slay, Christopher; Abe, Augusto S; Hicks, James W; Wang, Tobias

2014-07-01

Interspecific allometric analyses indicate that mean arterial blood pressure (MAP) increases with body mass of snakes and mammals. In snakes, MAP increases in proportion to the increased distance between the heart and the head, when the heart-head vertical distance is expressed as ρgh (where ρ is the density of blood, G: is acceleration due to gravity and h is the vertical distance above the heart), and the rise in MAP is associated with a larger heart to normalize wall stress in the ventricular wall. Based on measurements of MAP in Burmese pythons ranging from 0.9 to 3.7 m in length (0.20-27 kg), we demonstrate that although MAP increases with body mass, the rise in MAP is merely half of that predicted by heart-head distance. Scaling relationships within individual species, therefore, may not be accurately predicted by existing interspecific analyses. © 2014. Published by The Company of Biologists Ltd.

Intra-arterial thrombolysis of digital artery occlusions in a patient with polycythemia vera.

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Jud, Philipp; Hafner, Franz; Gary, Thomas; Ghanim, Leyla; Lipp, Rainer; Brodmann, Marianne

2017-01-01

There are limited therapeutic options for the resolution of digital artery occlusions. Intra-arterial thrombolysis with anticoagulative and thrombolytic drugs successfully restored the blood flow in the affected digital arteries.

The artery blood supply variant of the upper limb

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MASLARSKI, IVAN

2015-01-01

Variations of arterial patterns in the upper limb have represented the most common subject of vascular anatomy. Different types of artery branching pattern of the upper limb are very important for orthopedists in angiographic and microvascular surgical practice. The brachial artery (BA) is the most important vessel in the normal vascular anatomy of the upper limb. The classical pattern of the palmar hand region distribution shows the superficial palmar arch. Normally this arch is formed by the superficial branch of the ulnar artery and completed on the lateral side by one of these arteries: the superficial palmar branch of the radial artery, the princeps pollicis artery, the superficial palmar branch of the radial artery or the median artery. After the routine dissection of the right upper limb of an adult male cadaver, we found a very rare variant of the superficial arch artery – a division in a higher level brachial artery. We found this division at 10.4 cm from the beginning of the brachial artery. This superficial brachial artery became a radial artery and was not involved in the formation of the palm arch. In the forearm region, the artery variant was present with the median artery and the ulnar artery, which form the superficial palm arch. PMID:26733754

Elevated arterial blood pressure after superior cavo-pulmonary anastomosis is associated with elevated pulmonary artery pressure and cerebrovascular dysautoregulation.

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Cabrera, Antonio G; Kibler, Kathleen K; Blaine Easley, R; Goldsworthy, Michelle; Shekerdemian, Lara S; Andropoulos, Dean B; Heinle, Jeffrey; Gottlieb, Erin A; Vu, Eric; Brady, Ken M

2018-04-18

BackgroundElevated arterial blood pressure (ABP) is common after superior bidirectional cavopulmonary anastomosis (BCPA). The effects of elevated ABP after BCPA on cerebrovascular hemodynamics are unknown. We sought to determine the relationship between elevated ABP and cerebrovascular autoregulation after BCPA.MethodsProspective, observational study on infants with single-ventricle physiology after BCPA surgery. Continuous recordings of mean ABP, mean cavopulmonary artery pressure (PAP), near-infrared spectroscopy measures of cerebral oximetry (regional cerebral oxygen saturation (rSO 2 )), and relative cerebral blood volume index were obtained from admission to extubation. Autoregulation was measured as hemoglobin volume index (HVx). Physiologic variables, including the HVx, were tested for variance across ABP.ResultsSixteen subjects were included in the study. Elevated ABP post-BCPA was associated with both, elevated PAP (PABP and alterations in rSO 2 . Using piecewise regression, the relationship of PAP to ABP demonstrated a breakpoint at 68 mm Hg (interquartile range (IQR) 62-70 mm Hg). Curve fit of HVx as a function of ABP identified optimal ABP supporting robust autoregulation at a median ABP of 55 mm Hg (IQR 51-64 mm Hg).ConclusionsElevated ABP post-BCPA is associated with cerebrovascular dysautoregulation, and elevated PAP. The effects, of prolonged dysautoregulation within this population, require further study.Pediatric Research advance online publication, 18 April 2018; doi:10.1038/pr.2018.31.

Agreement between arterial partial pressure of carbon dioxide and saturation of hemoglobin with oxygen values obtained by direct arterial blood measurements versus noninvasive methods in conscious healthy and ill foals.

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Wong, David M; Alcott, Cody J; Wang, Chong; Bornkamp, Jennifer L; Young, Jessica L; Sponseller, Brett A

2011-11-15

To determine agreement between indirect measurements of end-tidal partial pressure of carbon dioxide (PetCO(2)) and saturation of hemoglobin with oxygen as measured by pulse oximetry (SpO(2)) with direct measurements of PaCO(2) and calculated saturation of hemoglobin with oxygen in arterial blood (SaO(2)) in conscious healthy and ill foals. Validation study. 10 healthy and 21 ill neonatal foals. Arterial blood gas analysis was performed on healthy and ill foals examined at a veterinary teaching hospital to determine direct measurements of PaCO(2) and PaO(2) along with SaO(2). Concurrently, PetCO(2) was measured with a capnograph inserted into a naris, and SpO(2) was measured with a reflectance probe placed at the base of the tail. Paired values were compared by use of Pearson correlation coefficients, and level of agreement was assessed with the Bland-Altman method. Mean ± SD difference between PaCO(2) and PetCO(2) was 0.1 ± 5.0 mm Hg. There was significant strong correlation (r = 0.779) and good agreement between PaCO(2) and PetCO(2). Mean ± SD difference between SaO(2) and SpO(2) was 2.5 ± 3.5%. There was significant moderate correlation (r = 0.499) and acceptable agreement between SaO(2) and SpO(2). Both PetCO(2) obtained by use of nasal capnography and SpO(2) obtained with a reflectance probe are clinically applicable and accurate indirect methods of estimating and monitoring PaCO(2) and SaO(2) in neonatal foals. Indirect methods should not replace periodic direct measurement of corresponding parameters.

Does dairy food intake predict arterial stiffness and blood pressure in men?: Evidence from the Caerphilly Prospective Study.

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Livingstone, Katherine M; Lovegrove, Julie A; Cockcroft, John R; Elwood, Peter C; Pickering, Janet E; Givens, D Ian

2013-01-01

Arterial stiffness is an independent predictor of cardiovascular disease events and mortality, and like blood pressure, may be influenced by dairy food intake. Few studies have investigated the effects of consumption of these foods on prospective measures of arterial stiffness. The present analysis aimed to investigate the prospective relationship between milk, cheese, cream, and butter consumption and aortic pulse wave velocity, augmentation index, systolic and diastolic blood pressure, as well as cross-sectional relationships between these foods and systolic and diastolic blood pressure and metabolic markers using data from the Caerphilly Prospective Study. Included in this cohort were 2512 men, aged 45 to 59 years, who were followed up at 5-year intervals for a mean of 22.8 years (number follow-up 787). Augmentation index was 1.8% lower in subjects in the highest quartiles of dairy product intake compared with the lowest (P trend=0.021), whereas in the highest group of milk consumption systolic blood pressure was 10.4 mm Hg lower (P trend=0.033) than in nonmilk consumers after a 22.8-year follow-up. Cross-sectional analyses indicated that across increasing quartiles of butter intake, insulin (P trend=0.011), triacylglycerol (P trend=0.023), total cholesterol (P trend=0.002), and diastolic blood pressure (P trend=0.027) were higher. Across increasing groups of milk intake and quartiles of dairy product intake, glucose (P trend=0.032) and triglyceride concentrations (P trend=0.031) were lower, respectively. The present results confirm that consumption of milk predicts prospective blood pressure, whereas dairy product consumption, excluding butter, is not detrimental to arterial stiffness and metabolic markers. Further research is needed to better understand the mechanisms that underpin these relationships.

Systemic arterial hypertension, blood pressure levels and associated factors in schoolchildren

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Priscila Heleno

Full Text Available Summary Introduction: Hypertension is a major public health problem in contemporary times and it has high prevalence throughout the world. Objective: To investigate the situation of Systemic Arterial Hypertension in schoolchildren aged 6 to 10 years in Divinópolis/MG-Brazil and associated factors. Method: This is a cross-sectional, epidemiological, descriptive and analytical study, whose population was children aged 6 to 10 years enrolled in public schools in Divinópolis-MG-Brazil. Data collection was conducted from October 2014 to May 2015. Multivariate linear regressions were used to test associations between blood pressure, socioeconomic, anthropometric, dietary and physical activity. Results: The prevalence of hypertension was 15.2% in a sample of 284 children and mean values of systolic blood pressure of 101.7 (±13.2 mmHg and diastolic blood pressure of 66.0 (±11.2 mmHg. The body fat percentage showed significant differences between the genders, with 24.2 and 26.2%, respectively for boys and girls. Significant associations were made between blood pressure levels, body weight, body mass index, waist circumference, body fat percentage, consumption of yogurt, beef /chicken, beans, pizza, sandwich and some behaviors variables. Conclusion: The presented data show important aspects of school profile in the age range 6-10 years, especially related to the behavior of blood pressure.

Results of ambulatory arterial blood pressure monitoring in children with obesity

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Faruk Öktem

2010-12-01

Full Text Available Objectives: The relationship between obesity and essential hypertension is well known. In this study, we aimed to evaluate ambulatory arterial blood pressure monitoring of obese and non-obese children who had similar demographic characteristics.Materials and methods: Seventy one children and adolescents (n=39 obesity, n=32 controls were studied. Blood pressure of the children were measured by 24 hour ambulatory blood pressure monitoring device.Results: Obese children had significantly higher mean blood pressure values (systolic 121.9±11.7 mmHg, diastolic 70.2±5.3 mmHg than control subjects (systolic 109.3±6.7 mmHg, diastolic 65.1±4.6 mmHg, p0.05. Blood pressure load was found to be increased in obese children compared to the controls (%13.6±12.9 and %2.6±3.4, respectively; p<0.05. Serum total cholesterol and LDL-cholesterol levels of obese children (181.1±33.4 and 131.1±23.1mg/dl were significantly higher than those of the controls (134.3±11.1 and 103.3±14.2 mg/dl, p<0.05.Conclusions: Obesity in children and adolescents should not be regarded as variations of normality, but as abnormality with an extremely high risk for the development of hypertension and hyperlipidemia in adulthood.

Arterial spin labeling in patients with chic cerebral artery steno-occlusive disease - Correlation with 15O-PET

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Kamano, Hironori; Yoshiura, Takashi; Hiwatashi, Akio; Abe, Koichiro; Yamashita, Koji; Honda, Hiroshi; Togao, Osamu

2013-01-01

Background: Heterogeneity of arterial transit time due to cerebral artery steno-occlusive lesions hampers accurate regional cerebral blood flow measurement by arterial spin labeling (ASL). Purpose: To assess the feasibility of regional cerebral blood flow measurement by ASL with multiple-delay time sampling in patients with steno-occlusive diseases by comparing with positron emission tomography (PET), and to determine whether regional arterial transit time measured by this ASL technique is correlated with regional mean transit time, a PET index of perfusion pressure. Material and Methods: Sixteen patients with steno-occlusive diseases received both ASL and 15 O-PET. The mean regional cerebral blood flow measured by ASL and PET, regional arterial transit time by ASL, and regional mean transit time by PET were obtained by a region-of-interest analysis. Correlation between regional cerebral blood flow by ASL and that by PET, and correlation between regional arterial transit time by ASL and regional mean transit time by PET were tested using Pearson's correlation coefficient for both absolute and relative values. A multivariate regression analysis was performed to test whether regional arterial transit time by ASL was a significant contributor in modeling regional mean transit time by PET after controlling the effect of regional cerebral blood flow by ASL. Results: A significant positive correlation was found between regional cerebral blood flow by ASL and that by PET for both absolute (r = 0.520, P < 0.0001) and relative (r = 0.691, P < 0.0001) values. A significant positive correlation was found between regional arterial transit time by ASL and regional mean transit time by PET both for absolute (r = 0.369, P = 0.0002) and relative (r = 0.443, P < 0.0001) values. The regression analysis revealed that regional arterial transit time by ASL was a significant contributor in modeling regional mean transit time by PET after controlling regional cerebral blood flow by ASL