WorldWideScience

Sample records for volume minute ventilation

  1. Heliox allows for lower minute volume ventilation in an animal model of ventilator-induced lung injury.

    Directory of Open Access Journals (Sweden)

    Charlotte J Beurskens

    Full Text Available BACKGROUND: Helium is a noble gas with a low density, allowing for lower driving pressures and increased carbon dioxide (CO2 diffusion. Since application of protective ventilation can be limited by the development of hypoxemia or acidosis, we hypothesized that therefore heliox facilitates ventilation in an animal model of ventilator-induced lung injury. METHODS: Sprague-Dawley rats (N=8 per group were mechanically ventilated with heliox (50% oxygen; 50% helium. Controls received a standard gas mixture (50% oxygen; 50% air. VILI was induced by application of tidal volumes of 15 mL kg(-1; lung protective ventilated animals were ventilated with 6 mL kg(-1. Respiratory parameters were monitored with a pneumotach system. Respiratory rate was adjusted to maintain arterial pCO2 within 4.5-5.5 kPa, according to hourly drawn arterial blood gases. After 4 hours, bronchoalveolar lavage fluid (BALF was obtained. Data are mean (SD. RESULTS: VILI resulted in an increase in BALF protein compared to low tidal ventilation (629 (324 vs. 290 (181 μg mL(-1; p<0.05 and IL-6 levels (640 (8.7 vs. 206 (8.7 pg mL(-1; p<0.05, whereas cell counts did not differ between groups after this short course of mechanical ventilation. Ventilation with heliox resulted in a decrease in mean respiratory minute volume ventilation compared to control (123 ± 0.6 vs. 146 ± 8.9 mL min(-1, P<0.001, due to a decrease in respiratory rate (22 (0.4 vs. 25 (2.1 breaths per minute; p<0.05, while pCO2 levels and tidal volumes remained unchanged, according to protocol. There was no effect of heliox on inspiratory pressure, while compliance was reduced. In this mild lung injury model, heliox did not exert anti-inflammatory effects. CONCLUSIONS: Heliox allowed for a reduction in respiratory rate and respiratory minute volume during VILI, while maintaining normal acid-base balance. Use of heliox may be a useful approach when protective tidal volume ventilation is limited by the development of

  2. Low minute ventilation episodes during anesthesia recovery following intraperitoneal surgery as detected by a non-invasive respiratory volume monitor.

    Science.gov (United States)

    Cavalcante, Alexandre N; Martin, Yvette N; Sprung, Juraj; Imsirovic, Jasmin; Weingarten, Toby N

    2017-12-20

    An electrical impedance-based noninvasive respiratory volume monitor (RVM) accurately reports minute volume, tidal volume and respiratory rate. Here we used the RVM to quantify the occurrence of and evaluate the ability of clinical factors to predict respiratory depression in the post-anesthesia care unit (PACU). RVM generated respiratory data were collected from spontaneously breathing patients following intraperitoneal surgeries under general anesthesia admitted to the PACU. Respiratory depression was defined as low minute ventilation episode (LMVe, respiratory rate (respiratory rate was a poor predictor of LMVe (sensitivity = 11.8%). Other clinical variables (e.g., obstructive sleep apnea) were not found to be predictors of LMVe. Using RVM we identified that mild, clinically nondetectable, respiratory depression prior to opioid administration in the PACU was associated with the development of substantial subsequent respiratory depression during the PACU stay.

  3. Heliox allows for lower minute volume ventilation in an animal model of ventilator-induced lung injury

    NARCIS (Netherlands)

    Beurskens, Charlotte J.; Aslami, Hamid; de Beer, Friso M.; Vroom, Margreeth B.; Preckel, Benedikt; Horn, Janneke; Juffermans, Nicole P.

    2013-01-01

    Helium is a noble gas with a low density, allowing for lower driving pressures and increased carbon dioxide (CO2) diffusion. Since application of protective ventilation can be limited by the development of hypoxemia or acidosis, we hypothesized that therefore heliox facilitates ventilation in an

  4. Minute Ventilation Limitations of Two Field Transport Ventilators.

    Science.gov (United States)

    Szpisjak, Dale F; Horn, Gregory; Shalov, Samuel; Abes, Alvin Angelo; Van Decar, Lauren

    2017-01-01

    Knowledge of transport ventilator performance impacts patient safety. This study compared minute ventilation (V E ) of the MOVES and Uni-Vent 731 when ventilating the VentAid Training Test Lung with compliance (C) ranging from 0.02 to 0.10 L/cm H 2 O and three different airway resistances (R) (none, Rp5, or Rp20). Tidal volume (V T ) was 800 ± 25 mL. Respiratory rate was increased to ventilator's maximum or until auto-PEEP > 5 cm H 2 O. Respiratory parameters were recorded with the RSS 100HR Research Pneumotach. Data were reported as median (interquartile range). Peak inspiratory pressure (PIP) of the Uni-Vent and MOVES ranged from 22.3 (22.2-22.5) to 82.6 (82.2-83.2) and 20.8 (20.6-20.9) to 50.6 (50.2-50.9) cm H 2 O, respectively. V E of the Uni-Vent and MOVES ranged from 17.7 (17.7-17.7) to 31.5 (31.5-31.5) and 11.3 (10.5-11.3) to 20.2 (19.7-20.5) L/min, respectively. Linear regression demonstrated strong, negative correlation of V E with PIP for the MOVES (V E [L/min] = 26 - 0.31 × PIP [cm H 2 O], r = -0.97) but weak, positive correlation for the Uni-Vent (r = 0.05). Uni-Vent V E exceeded MOVES V E under each test condition (p = 0.0002). If patient V E requirements exceed those predicted by the MOVES regression equation, then using the Uni-Vent should be considered. Reprint & Copyright © 2017 Association of Military Surgeons of the U.S.

  5. Intrinsic positive end-expiratory pressure during one-lung ventilation of patients with pulmonary hyperinflation. Influence of low respiratory rate with unchanged minute volume.

    Science.gov (United States)

    Szegedi, L L; Barvais, L; Sokolow, Y; Yernault, J C; d'Hollander, A A

    2002-01-01

    We measured lung mechanics and gas exchange during one-lung ventilation (OLV) of patients with chronic obstructive pulmonary disease, using three respiratory rates (RR) and unchanged minute volume. We studied 15 patients about to undergo lung surgery, during anaesthesia, and placed in the lateral position. Ventilation was with constant minute volume, inspiratory flow and FIO2. For periods of 15 min, RR of 5, 10, and 15 bpm were applied in a random sequence and recordings were made of lung mechanics and an arterial blood gas sample was taken. Data were analysed with the repeated measures ANOVA and paired t-test with Bonferroni correction. PaO2 changes were not significant. At the lowest RR, PaCO2 decreased (from 42 (SD 4) mm Hg at RR 15-41 (4) mm Hg at RR 10 and 39 (4) mm Hg at RR 5, P<0.01), and end-tidal carbon dioxide increased (from 33 (5) mm Hg at RR 15 to 35 (5) mm Hg at RR 10 and 36 (6) mm Hg at RR 5, P<0.01). Intrinsic positive end-expiratory pressure (PEEPi) was reduced even with larger tidal volumes (from 6 (4) cm H2O at RR 15-5 (4) cm H2O at RR 10, and 3 (3) cm H2O at RR 5, P<0.01), most probably caused by increased expiratory time at the lowest RR. A reduction in RR reduces PEEPi and hypercapnia during OLV in anaesthetized patients with chronic obstructive lung disease.

  6. Limiting volume with modern ventilators.

    Science.gov (United States)

    Wing, Thomas J; Haan, Lutana; Ashworth, Lonny J; Anderson, Jeff

    2015-06-01

    The acute respiratory distress syndrome (ARDS) network low tidal-volume study comparing tidal volumes of 12 ml/kg versus 6 ml/kg was published in 2000. The study was stopped early as data revealed a 22% relative reduction in mortality rate when using 6 ml/kg tidal volume. The current generation of critical care ventilators allows the tidal volume to be set during volume-targeted, assist/control (volume A/C); however, some ventilators include options that may prevent the tidal volume from being controlled. The purpose of this bench study was to evaluate the delivered tidal volume, when these options are active, in a spontaneously breathing lung model using an electronic breathing simulator. Four ventilators were evaluated: CareFusion AVEA (AVEA), Dräger Evita® XL (Evita XL), Covidien Puritan Bennett® 840(TM) (PB 840), and Maquet SERVO-i (SERVO-i). Each ventilator was connected to the Hans Rudolph Electronic Breathing Simulator at an amplitude of 0 cm H2O and then 10 cm H2O. All four ventilators were set to deliver volume A/C, tidal volume 400 ml, respiratory rate 20 bpm, positive end-expiratory pressure 5 cm H2O, peak flowrate 60 L/min. The displayed tidal volume was recorded for each ventilator at the above settings with additional options OFF and then ON. The AVEA has two options in volume A/C: demand breaths and V-sync. When activated, these options allow the patient to exceed the set tidal volume. When using the Evita XL, the option AutoFlow can be turned ON or OFF, and when this option is ON, the tidal volume may vary. The PB 840 does not have any additional options that affect volume delivery, and it maintains the set tidal volume regardless of patient effort. The SERVO-i's demand valve allows additional flow if the patient's inspiratory flowrate exceeds the set flowrate, increasing the delivered tidal volume; this option can be turned OFF with the latest software upgrade. Modern ventilators have an increasing number of optional settings. These settings may

  7. Standardization of pulmonary ventilation technique using volume-controlled ventilators in rats with congenital diaphragmatic hernia

    Directory of Open Access Journals (Sweden)

    Rodrigo Melo Gallindo

    Full Text Available OBJECTIVE: To standardize a technique for ventilating rat fetuses with Congenital Diaphragmatic Hernia (CDH using a volume-controlled ventilator. METHODS: Pregnant rats were divided into the following groups: a control (C; b exposed to nitrofen with CDH (CDH; and c exposed to nitrofen without CDH (N-. Fetuses of the three groups were randomly divided into the subgroups ventilated (V and non-ventilated (N-V. Fetuses were collected on day 21.5 of gestation, weighed and ventilated for 30 minutes using a volume-controlled ventilator. Then the lungs were collected for histological study. We evaluated: body weight (BW, total lung weight (TLW, left lung weight (LLW, ratios TLW / BW and LLW / BW, morphological histology of the airways and causes of failures of ventilation. RESULTS: BW, TLW, LLW, TLW / BW and LLW / BW were higher in C compared with N- (p 0.05. The morphology of the pulmonary airways showed hypoplasia in groups N- and CDH, with no difference between V and N-V (p <0.05. The C and N- groups could be successfully ventilated using a tidal volume of 75 ìl, but the failure of ventilation in the CDH group decreased only when ventilated with 50 ìl. CONCLUSION: Volume ventilation is possible in rats with CDH for a short period and does not alter fetal or lung morphology.

  8. Minute ventilation of cyclists, car and bus passengers: an experimental study

    Directory of Open Access Journals (Sweden)

    Hazel Peter

    2009-10-01

    Full Text Available Abstract Background Differences in minute ventilation between cyclists, pedestrians and other commuters influence inhaled doses of air pollution. This study estimates minute ventilation of cyclists, car and bus passengers, as part of a study on health effects of commuters' exposure to air pollutants. Methods Thirty-four participants performed a submaximal test on a bicycle ergometer, during which heart rate and minute ventilation were measured simultaneously at increasing cycling intensity. Individual regression equations were calculated between heart rate and the natural log of minute ventilation. Heart rates were recorded during 280 two hour trips by bicycle, bus and car and were calculated into minute ventilation levels using the individual regression coefficients. Results Minute ventilation during bicycle rides were on average 2.1 times higher than in the car (individual range from 1.3 to 5.3 and 2.0 times higher than in the bus (individual range from 1.3 to 5.1. The ratio of minute ventilation of cycling compared to travelling by bus or car was higher in women than in men. Substantial differences in regression equations were found between individuals. The use of individual regression equations instead of average regression equations resulted in substantially better predictions of individual minute ventilations. Conclusion The comparability of the gender-specific overall regression equations linking heart rate and minute ventilation with one previous American study, supports that for studies on the group level overall equations can be used. For estimating individual doses, the use of individual regression coefficients provides more precise data. Minute ventilation levels of cyclists are on average two times higher than of bus and car passengers, consistent with the ratio found in one small previous study of young adults. The study illustrates the importance of inclusion of minute ventilation data in comparing air pollution doses between

  9. Minute ventilation of cyclists, car and bus passengers: an experimental study.

    Science.gov (United States)

    Zuurbier, Moniek; Hoek, Gerard; van den Hazel, Peter; Brunekreef, Bert

    2009-10-27

    Differences in minute ventilation between cyclists, pedestrians and other commuters influence inhaled doses of air pollution. This study estimates minute ventilation of cyclists, car and bus passengers, as part of a study on health effects of commuters' exposure to air pollutants. Thirty-four participants performed a submaximal test on a bicycle ergometer, during which heart rate and minute ventilation were measured simultaneously at increasing cycling intensity. Individual regression equations were calculated between heart rate and the natural log of minute ventilation. Heart rates were recorded during 280 two hour trips by bicycle, bus and car and were calculated into minute ventilation levels using the individual regression coefficients. Minute ventilation during bicycle rides were on average 2.1 times higher than in the car (individual range from 1.3 to 5.3) and 2.0 times higher than in the bus (individual range from 1.3 to 5.1). The ratio of minute ventilation of cycling compared to travelling by bus or car was higher in women than in men. Substantial differences in regression equations were found between individuals. The use of individual regression equations instead of average regression equations resulted in substantially better predictions of individual minute ventilations. The comparability of the gender-specific overall regression equations linking heart rate and minute ventilation with one previous American study, supports that for studies on the group level overall equations can be used. For estimating individual doses, the use of individual regression coefficients provides more precise data. Minute ventilation levels of cyclists are on average two times higher than of bus and car passengers, consistent with the ratio found in one small previous study of young adults. The study illustrates the importance of inclusion of minute ventilation data in comparing air pollution doses between different modes of transport.

  10. Minute ventilation of cyclists, car and bus passengers: an experimental study.

    NARCIS (Netherlands)

    Zuurbier, M.; Hoek, G.; van den Hazel, P.J.; Brunekreef, B.

    2009-01-01

    ABSTRACT: BACKGROUND: Differences in minute ventilation between cyclists, pedestrians and other commuters influence inhaled doses of air pollution. This study estimates minute ventilation of cyclists, car and bus passengers, as part of a study on health effects of commuters' exposure to air

  11. Evaluation of the minute ventilation recovery time as a predictor of weaning in mechanically ventilated COPD patients in respiratory failure

    Directory of Open Access Journals (Sweden)

    Alaa Eldin Elgazzar

    2013-04-01

    Conclusion: The minute ventilation recovery time is a good, reliable predictor of weaning success and it is the most independent parameter among other weaning predictors that can predict a successful spontaneous breathing trial (SBT.

  12. Assessment of minute volume of lung in NPP workers for Korean reference man

    International Nuclear Information System (INIS)

    Lee, Y. J.; Song, S. H.; Lee, J.; Jin, Y. W.; Yim, Y. K.; Kim, J. S.

    2001-01-01

    To formulation of the reference Korean for radiation protection purpose, we measured the forced vital capacity(FVC), forced expiratory volume in second(FEVI), minute ventilation(MV) of Nuclear Power Plant workers using SP-1 Spirometry Unit(Schiller AG. 1998) and eatimated the liters of breathed for working and resting, also compared these data with ICRP 23

  13. Assessment of minute volume of lung in NPP workers for Korean reference man

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Y. J.; Song, S. H.; Lee, J.; Jin, Y. W.; Yim, Y. K.; Kim, J. S. [KNETEC, Seoul (Korea, Republic of)

    2001-05-01

    To formulation of the reference Korean for radiation protection purpose, we measured the forced vital capacity(FVC), forced expiratory volume in second(FEVI), minute ventilation(MV) of Nuclear Power Plant workers using SP-1 Spirometry Unit(Schiller AG. 1998) and eatimated the liters of breathed for working and resting, also compared these data with ICRP 23.

  14. Do new anesthesia ventilators deliver small tidal volumes accurately during volume-controlled ventilation?

    Science.gov (United States)

    Bachiller, Patricia R; McDonough, Joseph M; Feldman, Jeffrey M

    2008-05-01

    During mechanical ventilation of infants and neonates, small changes in tidal volume may lead to hypo- or hyperventilation, barotrauma, or volutrauma. Partly because breathing circuit compliance and fresh gas flow affect tidal volume delivery by traditional anesthesia ventilators in volume-controlled ventilation (VCV) mode, pressure-controlled ventilation (PCV) using a circle breathing system has become a common approach to minimizing the risk of mechanical ventilation for small patients, although delivered tidal volume is not assured during PCV. A new generation of anesthesia machine ventilators addresses the problems of VCV by adjusting for fresh gas flow and for the compliance of the breathing circuit. In this study, we evaluated the accuracy of new anesthesia ventilators to deliver small tidal volumes. Four anesthesia ventilator systems were evaluated to determine the accuracy of volume delivery to the airway during VCV at tidal volume settings of 100, 200, and 500 mL under different conditions of breathing circuit compliance (fully extended and fully contracted circuits) and lung compliance. A mechanical test lung (adult and infant) was used to simulate lung compliances ranging from 0.0025 to 0.03 L/cm H(2)O. Volumes and pressures were measured using a calibrated screen pneumotachograph and custom software. We tested the Smartvent 7900, Avance, and Aisys anesthesia ventilator systems (GE Healthcare, Madison, WI) and the Apollo anesthesia ventilator (Draeger Medical, Telford, PA). The Smartvent 7900 and Avance ventilators use inspiratory flow sensors to control the volume delivered, whereas the Aisys and Apollo ventilators compensate for the compliance of the circuit. We found that the anesthesia ventilators that use compliance compensation (Aisys and Apollo) accurately delivered both large and small tidal volumes to the airway of the test lung under conditions of normal and low lung compliance during VCV (ranging from 95.5% to 106.2% of the set tidal volume

  15. Mask leak increases and minute ventilation decreases when chest compressions are added to bag ventilation in a neonatal manikin model.

    Science.gov (United States)

    Tracy, Mark B; Shah, Dharmesh; Hinder, Murray; Klimek, Jan; Marceau, James; Wright, Audrey

    2014-05-01

    To determine changes in respiratory mechanics when chest compressions are added to mask ventilation, as recommended by the International Liaison Committee on Resuscitation (ILCOR) guidelines for newborn infants. Using a Laerdal Advanced Life Support leak-free baby manikin and a 240-mL self-inflating bag, 58 neonatal staff members were randomly paired to provide mask ventilation, followed by mask ventilation with chest compressions with a 1:3 ratio, for two minutes each. A Florian respiratory function monitor was used to measure respiratory mechanics, including mask leak. The addition of chest compressions to mask ventilation led to a significant reduction in inflation rate, from 63.9 to 32.9 breaths per minute (p mask leak of 6.8% (p mask ventilation, in accordance with the ILCOR guidelines, in a manikin model is associated with a significant reduction in delivered ventilation and increase in mask leak. If similar findings occur in human infants needing an escalation in resuscitation, there is a potential risk of either delay in recovery or inadequate response to resuscitation. ©2014 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

  16. [Evaluation of tidal volume delivered by ventilators during volume-controlled ventilation].

    Science.gov (United States)

    Zhou, Juan; Yan, Yong; Cao, Desen

    2014-12-01

    To study the ways which ensure the delivery of enough tidal volume to patients under various conditions close to the demand of the physician. The volume control ventilation model was chosen, and the simulation lung type was active servo lung ASL 5000 or Michigan lung 1601. The air resistance, air compliance and lung type in simulation lungs were set. The tidal volume was obtained from flow analyzer PF 300. At the same tidal volume, the displaying values of tidal volume of E5, Servo i, Evital 4, and Evital XL ventilators with different lung types of patient, compliance of gas piping, leakage, gas types, etc. were evaluated. With the same setting tidal volume of a same ventilator, the tidal volume delivered to patients was different with different lung types of patient, compliance of gas piping, leakage, gas types, etc. Reducing compliance and increasing resistance of the patient lungs caused high peak airway pressure, the tidal volume was lost in gas piping, and the tidal volume be delivered to the patient lungs was decreased. If the ventilator did not compensate to leakage, the tidal volume delivered to the patient lungs was decreased. When the setting gas type of ventilator did not coincide with that applying to the patient, the tidal volume be delivered to the patient lungs might be different with the setting tidal volume of ventilator. To ensure the delivery of enough tidal volume to patients close to the demand of the physician, containable factors such as the compliance of gas piping, leakage, and gas types should be controlled.

  17. Minutes

    International Nuclear Information System (INIS)

    1998-01-01

    In the minutes of II Uruguayan Geological Congress have been included the following topics: structural geology, tectonic, sedimentology, stratigraphy, mineralogy, petrology, geochemistry, paleontology, mineral prospecting, economic, regional and applied geology. (author)

  18. Volume-Targeted Ventilation in the Neonate: Benchmarking Ventilators on an Active Lung Model.

    Science.gov (United States)

    Krieger, Tobias J; Wald, Martin

    2017-03-01

    Mechanically ventilated neonates have been observed to receive substantially different ventilation after switching ventilator models, despite identical ventilator settings. This study aims at establishing the range of output variability among 10 neonatal ventilators under various breathing conditions. Relative benchmarking test of 10 neonatal ventilators on an active neonatal lung model. Neonatal ICU. Ten current neonatal ventilators. Ventilators were set identically to flow-triggered, synchronized, volume-targeted, pressure-controlled, continuous mandatory ventilation and connected to a neonatal lung model. The latter was configured to simulate three patients (500, 1,500, and 3,500 g) in three breathing modes each (passive breathing, constant active breathing, and variable active breathing). Averaged across all weight conditions, the included ventilators delivered between 86% and 110% of the target tidal volume in the passive mode, between 88% and 126% during constant active breathing, and between 86% and 120% under variable active breathing. The largest relative deviation occurred during the 500 g constant active condition, where the highest output machine produced 147% of the tidal volume of the lowest output machine. All machines deviate significantly in volume output and ventilation regulation. These differences depend on ventilation type, respiratory force, and patient behavior, preventing the creation of a simple conversion table between ventilator models. Universal neonatal tidal volume targets for mechanical ventilation cannot be transferred from one ventilator to another without considering necessary adjustments.

  19. Modelling and Simulation of Volume Controlled Mechanical Ventilation System

    Directory of Open Access Journals (Sweden)

    Yan Shi

    2014-01-01

    Full Text Available Volume controlled mechanical ventilation system is a typical time-delay system, which is applied to ventilate patients who cannot breathe adequately on their own. To illustrate the influences of key parameters of the ventilator on the dynamics of the ventilated respiratory system, this paper firstly derived a new mathematical model of the ventilation system; secondly, simulation and experimental results are compared to verify the mathematical model; lastly, the influences of key parameters of ventilator on the dynamics of the ventilated respiratory system are carried out. This study can be helpful in the VCV ventilation treatment and respiratory diagnostics.

  20. Bench test evaluation of volume delivered by modern ICU ventilators during volume-controlled ventilation.

    Science.gov (United States)

    Lyazidi, Aissam; Thille, Arnaud W; Carteaux, Guillaume; Galia, Fabrice; Brochard, Laurent; Richard, Jean-Christophe M

    2010-12-01

    During volume-controlled ventilation, part of the volume delivered is compressed into the circuit. To correct for this phenomenon, modern ventilators use compensation algorithms. Humidity and temperature also influence the delivered volume. In a bench study at a research laboratory in a university hospital, we compared nine ICU ventilators equipped with compensation algorithms, one with a proximal pneumotachograph and one without compensation. Each ventilator was evaluated under normal, obstructive, and restrictive conditions of respiratory mechanics. For each condition, three tidal volumes (V (T)) were set (300, 500, and 800 ml), with and without an inspiratory pause. The insufflated volume and the volume delivered at the Y-piece were measured independently, without a humidification device, under ambient temperature and pressure and dry gas conditions. We computed the actually delivered V (T) to the lung under body temperature and pressure and saturated water vapour conditions (BTPS). For target V (T) values of 300, 500, and 800 ml, actually delivered V (T) under BTPS conditions ranged from 261 to 396 ml (-13 to +32%), from 437 to 622 ml (-13 to +24%), and from 681 to 953 ml (-15 to +19%), respectively (p ventilators.

  1. Comparison of actual tidal volume in neonatal lung model volume control ventilation using three ventilators.

    Science.gov (United States)

    Toyama, H; Endo, Y; Ejima, Y; Matsubara, M; Kurosawa, S

    2011-07-01

    In neonates, small changes in tidal volumes (V(T)) may lead to complications. Previous studies have shown a significant difference between ventilator-measured tidal volume and tidal volume delivered (actual V(T)). We evaluated the accuracy of three different ventilators to deliver small V(T) during volume-controlled ventilation. We tested Servo 300, 840 ventilator and Evita 4 Neoflow ventilators with lung models simulating normal and injured neonatal lung compliance models. Gas volume delivered from the ventilator into the test circuit (V(TV)) and actual V(T) to the test lung were measured using Ventrak respiration monitors at set V(T) (30 ml). The gas volume increase of the breathing circuit was then calculated. Tidal volumes of the SV300 and PB840 in both lung models were similar to the set V(T) and the actual tidal volumes in the injured model (20.7 ml and 19.8 ml, respectively) were significantly less than that in the normal model (27.4 ml and 23.4 ml). PB840 with circuit compliance compensation could not improve the actual V(T). V(TV) of the EV4N in the normal and the injured models (37.8 ml and 46.6 ml) were markedly increased compared with set V(T), and actual V(T) were similar to set V(T) in the normal and injured model (30.2 ml and 31.9 ml, respectively). EV4N measuring V(T) close to the lung could match actual V(T) to almost the same value as the set V(T) however the gas volume of the breathing circuit was increased. If an accurate value for the patient's actual V(T) is needed, this V(T) must be measured by a sensor located between the Y-piece and the tracheal tube.

  2. High tidal volume ventilation in infant mice.

    Science.gov (United States)

    Cannizzaro, Vincenzo; Zosky, Graeme R; Hantos, Zoltán; Turner, Debra J; Sly, Peter D

    2008-06-30

    Infant mice were ventilated with either high tidal volume (V(T)) with zero end-expiratory pressure (HVZ), high V(T) with positive end-expiratory pressure (PEEP) (HVP), or low V(T) with PEEP. Thoracic gas volume (TGV) was determined plethysmographically and low-frequency forced oscillations were used to measure the input impedance of the respiratory system. Inflammatory cells, total protein, and cytokines in bronchoalveolar lavage fluid (BALF) and interleukin-6 (IL-6) in serum were measured as markers of pulmonary and systemic inflammatory response, respectively. Coefficients of tissue damping and tissue elastance increased in all ventilated mice, with the largest rise seen in the HVZ group where TGV rapidly decreased. BALF protein levels increased in the HVP group, whereas serum IL-6 rose in the HVZ group. PEEP keeps the lungs open, but provides high volumes to the entire lungs and induces lung injury. Compared to studies in adult and non-neonatal rodents, infant mice demonstrate a different response to similar ventilation strategies underscoring the need for age-specific animal models.

  3. Delivery of tidal volume from four anaesthesia ventilators during volume-controlled ventilation: a bench study.

    Science.gov (United States)

    Wallon, G; Bonnet, A; Guérin, C

    2013-06-01

    Tidal volume (V(T)) must be accurately delivered by anaesthesia ventilators in the volume-controlled ventilation mode in order for lung protective ventilation to be effective. However, the impact of fresh gas flow (FGF) and lung mechanics on delivery of V(T) by the newest anaesthesia ventilators has not been reported. We measured delivered V(T) (V(TI)) from four anaesthesia ventilators (Aisys™, Flow-i™, Primus™, and Zeus™) on a pneumatic test lung set with three combinations of lung compliance (C, ml cm H2O(-1)) and resistance (R, cm H2O litre(-1) s(-2)): C60R5, C30R5, C60R20. For each CR, three FGF rates (0.5, 3, 10 litre min(-1)) were investigated at three set V(T)s (300, 500, 800 ml) and two values of PEEP (0 and 10 cm H2O). The volume error = [(V(TI) - V(Tset))/V(Tset)] ×100 was computed in body temperature and pressure-saturated conditions and compared using analysis of variance. For each CR and each set V(T), the absolute value of the volume error significantly declined from Aisys™ to Flow-i™, Zeus™, and Primus™. For C60R5, these values were 12.5% for Aisys™, 5% for Flow-i™ and Zeus™, and 0% for Primus™. With an increase in FGF, absolute values of the volume error increased only for Aisys™ and Zeus™. However, in C30R5, the volume error was minimal at mid-FGF for Aisys™. The results were similar at PEEP 10 cm H2O. Under experimental conditions, the volume error differed significantly between the four new anaesthesia ventilators tested and was influenced by FGF, although this effect may not be clinically relevant.

  4. Influence of gestational age on dead space and alveolar ventilation in preterm infants ventilated with volume guarantee.

    Science.gov (United States)

    Neumann, Roland P; Pillow, Jane J; Thamrin, Cindy; Larcombe, Alexander N; Hall, Graham L; Schulzke, Sven M

    2015-01-01

    Ventilated preterm infant lungs are vulnerable to overdistension and underinflation. The optimal ventilator-delivered tidal volume (VT) in these infants is unknown and may depend on the extent of alveolarisation at birth. We aimed to calculate respiratory dead space (VD) from the molar mass (MM) signal of an ultrasonic flowmeter (VD,MM) in very preterm infants on volume-targeted ventilation (VT target, 4-5 ml/kg) and to study the association between gestational age (GA) and VD,MM-to-VT ratio (VD,MM/VT), alveolar tidal volume (VA) and alveolar minute volume (AMV). This was a single-centre, prospective, observational, cohort study in a neonatal intensive care unit. Tidal breathing analysis was performed in ventilated very preterm infants (GA range 23-32 weeks) on day 1 of life. Valid measurements were obtained in 43/51 (87%) infants. Tidal breathing variables were analysed using multivariable linear regression. VD,MM/VT was negatively associated with GA after adjusting for birth weight Z score (p volume guarantee setting of 4-5 ml/kg in the Dräger Babylog® 8000 plus ventilator may be inappropriate as a universal target across the GA range of 23-32 weeks. Differences between measured and set VT and the dependence of this difference on GA require further investigation. © 2014 S. Karger AG, Basel.

  5. Radiocardiographic determination of the stroke volume and of the heart minute volume in athletes

    Energy Technology Data Exchange (ETDEWEB)

    Sattler, R; Stoll, W [Friedrich-Schiller-Universitaet, Jena (German Democratic Republic). Radiologische Klinik

    1981-11-01

    Radiocardiography, a novel radioisotope method for the problemless determination of many cardiodynamic parameters which can be applied also at given physical exercise is presented. On the basis of stroke volume and heart minute volume values from 35 athletes practising different sports and of a comparison with normal values reported in the literature, differences in the cardiac adaptation and the function of athletic hearts and so-called normal hearts are pointed out. The stroke volume of endurance-trained athletes exceeds that of untrained individuals by 30-40 ml. Under exercise the increase of the stroke volume is considerably greater in endurance athletes than in individuals practising other sports or in untrained subjects. At rest the values of the heart minute volume are almost the same in athletes and untrained individuals. Under exercise the heart minute volume of endurance athletes (40 l/min) is nearly twice that of untrained individuals (volume reserve of the athlete).

  6. Radiocardiographic determination of the stroke volume and of the heart minute volume in athletes

    International Nuclear Information System (INIS)

    Sattler, R.; Stoll, W.

    1981-01-01

    Radiocardiography, a novel radioisotope method for the problemless determination of many cardiodynamic parameters which can be applied also at given physical exercise is presented. On the basis of stroke volume and heart minute volume values from 35 athletes practising different sports and of a comparison with normal values reported in the literature, differences in the cardiac adaptation and the function of athletic hearts and so-called normal hearts are pointed out. The stroke volume of endurance-trained athetes exceed that of untrained individuals by 30-40 ml. Under exercise the increase of the stroke volume is considerably greater in endurance athletes than in individuals practising other sports or in untrained subjects. At rest the values of the heart minute volume are almost the same in athletes and untrained individuals. Under exercise the heart minute volume of endurance athletes (40 l/min) is nearly twice that of untrained individuals (volume reserve of the athlete). (author)

  7. Maintenance of Minute Circulation Volume during Orthotopic Liver Transplantation

    Directory of Open Access Journals (Sweden)

    D. A. Levit

    2011-01-01

    Full Text Available Objective: to optimize procedures to maintain minute circulation volume at different stages of orthotopic liver transplantation. Subjects and methods. In the period 2005—2010, Sverdlovsk Regional Clinical Hospital One performed 32 orthotopic liver transplantations, including one retransplantation. The patients’ ASA class was (4—5. The operations were carried out under general anesthesia. The mean duration of surgery was 8.1 (range 5.8—10.5 hours. The investigators applied anesthesia based on iso-fluorane 0.6—0.9 MAC (by monitoring the anesthesia depth index with cerebral state index (CSI-40-60, as well as extended central hemodynamic monitoring (prepulmonary hemodilution. All the operations were made via portofemoroaxillary bypass, by using a centrifugal Biopump. Eight surgical stages were identified: 1 run-in (after tracheal intubation; 2 liver mobilization; 3 partial bypass; 4 complete bypass (hepatectomy, a liver-free period; 5 reperfusion; 6 a postreperfusion period (bypass end; 7 biliary repair; 8 the end of an operation. The concentrations of blood parameters, electrolytes, acid-base balance, and the levels of lactate and glucose were examined. The data were processed statistically. Central hemodynamics was monitored by prepulmonary thermodilution, by calculating cardiac index (CI, stroke index, and total peripheral vascular resistance index (TPVRI at the stages: liver mobilization, postreperfusion period (bypass end, and the end of surgery. Results. Even during partial bypass, there was a significant drop in mean blood pressure (MBP as compared to the baseline levels (p<0.05. Reperfusion was also accompanied by a significant decrease in MBP and an increase in heart rate. At the end of reperfusion and in the postreperfusion period, TPVRI was halved (689.2±68.0 as compared to the baseline levels. In the postreperfusion period, central venous and pulmonary artery pressures were significantly increased by 32 and 21%, respectively

  8. Performance of Leak Compensation in All-Age ICU Ventilators During Volume-Targeted Neonatal Ventilation: A Lung Model Study.

    Science.gov (United States)

    Itagaki, Taiga; Bennett, Desmond J; Chenelle, Christopher T; Fisher, Daniel F; Kacmarek, Robert M

    2017-01-01

    Volume-targeted ventilation is increasingly used in low birthweight infants because of the potential for reducing volutrauma and avoiding hypocapnea. However, it is not known what level of air leak is acceptable during neonatal volume-targeted ventilation when leak compensation is activated concurrently. Four ICU ventilators (Servo-i, PB980, V500, and Avea) were compared in available invasive volume-targeted ventilation modes (pressure control continuous spontaneous ventilation [PC-CSV] and pressure control continuous mandatory ventilation [PC-CMV]). The Servo-i and PB980 were tested with (+) and without (-) their proximal flow sensor. The V500 and Avea were tested with their proximal flow sensor as indicated by their manufacturers. An ASL 5000 lung model was used to simulate 4 neonatal scenarios (body weight 0.5, 1, 2, and 4 kg). The ASL 5000 was ventilated via an endotracheal tube with 3 different leaks. Two minutes of data were collected after each change in leak level, and the asynchrony index was calculated. Tidal volume (V T ) before and after the change in leak was assessed. The differences in delivered V T between before and after the change in leak were within ±5% in all scenarios with the PB980 (-/+) and V500. With the Servo-i (-/+), baseline V T was ≥10% greater than set V T during PC-CSV, and delivered V T markedly changed with leak. The Avea demonstrated persistent high V T in all leak scenarios. Across all ventilators, the median asynchrony index was 1% (interquartile range 0-27%) in PC-CSV and 1.8% (0-45%) in PC-CMV. The median asynchrony index was significantly higher in the Servo-i (-/+) than in the PB980 (-/+) and V500 in 1 and 2 kg scenarios during PC-CSV and PC-CMV. The PB980 and V500 were the only ventilators to acclimate to all leak scenarios and achieve targeted V T . Further clinical investigation is needed to validate the use of leak compensation during neonatal volume-targeted ventilation. Copyright © 2017 by Daedalus Enterprises.

  9. Adaptive support ventilation may deliver unwanted respiratory rate-tidal volume combinations in patients with acute lung injury ventilated according to an open lung concept.

    Science.gov (United States)

    Dongelmans, Dave A; Paulus, Frederique; Veelo, Denise P; Binnekade, Jan M; Vroom, Margreeth B; Schultz, Marcus J

    2011-05-01

    With adaptive support ventilation, respiratory rate and tidal volume (V(T)) are a function of the Otis least work of breathing formula. We hypothesized that adaptive support ventilation in an open lung ventilator strategy would deliver higher V(T)s to patients with acute lung injury. Patients with acute lung injury were ventilated according to a local guideline advising the use of lower V(T) (6-8 ml/kg predicted body weight), high concentrations of positive end-expiratory pressure, and recruitment maneuvers. Ventilation parameters were recorded when the ventilator was switched to adaptive support ventilation, and after recruitment maneuvers. If V(T) increased more than 8 ml/kg predicted body weight, airway pressure was limited to correct for the rise of V(T). Ten patients with a mean (±SD) Pao(2)/Fio(2) of 171 ± 86 mmHg were included. After a switch from pressure-controlled ventilation to adaptive support ventilation, respiratory rate declined (from 31 ± 5 to 21 ± 6 breaths/min; difference = 10 breaths/min, 95% CI 3-17 breaths/min, P = 0.008) and V(T) increased (from 6.5 ± 0.8 to 9.0 ± 1.6 ml/kg predicted body weight; difference = 2.5 ml, 95% CI 0.4-4.6 ml/kg predicted body weight, P = 0.02). Pressure limitation corrected for the rise of V(T), but minute ventilation declined, forcing the user to switch back to pressure-controlled ventilation. Adaptive support ventilation, compared with pressure-controlled ventilation in an open lung strategy setting, delivers a lower respiratory rate-higher V(T) combination. Pressure limitation does correct for the rise of V(T), but leads to a decline in minute ventilation.

  10. Changes in lung volume and ventilation during surfactant treatment in ventilated preterm infants

    NARCIS (Netherlands)

    Miedema, Martijn; de Jongh, Frans H.; Frerichs, Inez; van Veenendaal, Mariëtte B.; van Kaam, Anton H.

    2011-01-01

    The immediate and regional effects of exogenous surfactant in open lung high-frequency oscillatory ventilated (HFOV) preterm infants are unknown. To assess regional changes in lung volume, mechanics, and ventilation during and after surfactant administration in HFOV preterm infants with respiratory

  11. Accuracy of tidal volume delivered by home mechanical ventilation during mouthpiece ventilation

    Science.gov (United States)

    Prigent, Helene; Falaize, Line; Leroux, Karl; Santos, Dante; Vaugier, Isabelle; Orlikowski, David; Lofaso, Frederic

    2016-01-01

    The aim of our study was to evaluate efficacy and reliability of currently available ventilators for mouthpiece ventilation (MPV). Five life-support home ventilators were assessed in a bench test using different settings simulating the specificities of MPV, such as intermittent circuit disconnection and presence of continuous leaks. The intermittent disconnection of the circuit caused relevant swings in the delivered tidal volume (VT), showing a VT overshoot during the disconnection periods and a VT decrease when the interface was reconnected to the test lung. The five ventilators showed substantial differences in the number of respiratory cycles necessary to reach a stable VT in the volume-controlled setting, ranging from 1.3 ± 0.6 to 7.3 ± 1.2 cycles. These differences were less accentuated in the volume-assisted setting (MPV-dedicated mode, when available). Our data show large differences in the capacity of the different ventilators to deal with the rapidly changing respiratory load features that characterize MPV, which can be further accentuated according to the used ventilator setting. The dedicated MPV modes allow improvement in the performance of ventilators only in some defined situations. This has practical consequences for the choice of the ventilator to be used for MPV in a specific patient. PMID:27146811

  12. Inspiratory time and tidal volume during intermittent positive pressure ventilation.

    OpenAIRE

    Field, D; Milner, A D; Hopkin, I E

    1985-01-01

    We measured the tidal volume achieved during intermittent positive pressure ventilation using various inspiratory times with a minimum of 0.2 seconds. Results indicate that tidal volume shows no reduction with inspiratory times down to 0.4 seconds. An inspiratory time of 0.3 seconds, however, is likely to reduce tidal volume by 8%, and at 0.2 seconds a 22% fall may be anticipated.

  13. Measurement of tidal volume using respiratory ultrasonic plethysmography in anaesthetized, mechanically ventilated horses.

    Science.gov (United States)

    Russold, Elena; Ambrisko, Tamas D; Schramel, Johannes P; Auer, Ulrike; Van Den Hoven, Rene; Moens, Yves P

    2013-01-01

    To compare tidal volume estimations obtained from Respiratory Ultrasonic Plethysmography (RUP) with simultaneous spirometric measurements in anaesthetized, mechanically ventilated horses. Prospective randomized experimental study. Five experimental horses. Five horses were anaesthetized twice (1 week apart) in random order in lateral and in dorsal recumbency. Nine ventilation modes (treatments) were scheduled in random order (each lasting 4 minutes) applying combinations of different tidal volumes (8, 10, 12 mL kg(-1)) and positive end-expiratory pressures (PEEP) (0, 10, 20 cm H(2)O). Baseline ventilation mode (tidal volume=15 mL kg(-1), PEEP=0 cm H(2)O) was applied for 4 minutes between all treatments. Spirometry and RUP data were downloaded to personal computers. Linear regression analyses (RUP versus spirometric tidal volume) were performed using different subsets of data. Additonally RUP was calibrated against spirometry using a regression equation for all RUP signal values (thoracic, abdominal and combined) with all data collectively and also by an individually determined best regression equation (highest R(2)) for each experiment (horse versus recumbency) separately. Agreement between methods was assessed with Bland-Altman analyses. The highest correlation of RUP and spirometric tidal volume (R(2)=0.81) was found with the combined RUP signal in horses in lateral recumbency and ventilated without PEEP. The bias ±2 SD was 0±2.66 L when RUP was calibrated for collective data, but decreased to 0±0.87 L when RUP was calibrated with individual data. A possible use of RUP for tidal volume measurement during IPPV needs individual calibration to obtain limits of agreement within ±20%. © 2012 The Authors. Veterinary Anaesthesia and Analgesia. © 2012 Association of Veterinary Anaesthetists and the American College of Veterinary Anesthesiologists.

  14. Humidification and secretion volume in mechanically ventilated patients.

    Science.gov (United States)

    Solomita, Mario; Palmer, Lucy B; Daroowalla, Feroza; Liu, Jeffrey; Miller, Dori; LeBlanc, Deniese S; Smaldone, Gerald C

    2009-10-01

    To determine potential effects of humidification on the volume of airway secretions in mechanically ventilated patients. Water vapor delivery from devices providing non-heated-wire humidification, heated-wire humidification, and heat and moisture exchanger (HME) were quantified on the bench. Then, patients requiring 24-hour mechanical ventilation were exposed sequentially to each of these humidification devices, and secretions were removed and measured by suctioning every hour during the last 4 hours of the 24-hour study period. In vitro water vapor delivery was greater using non-heated-wire humidification, compared to heated-wire humidification and HME. In vivo, a total of 9 patients were studied. Secretion volume following humidification by non-heated-wire humidification was significantly greater than for heated-wire humidification and HME (P=.004). The volume of secretions appeared to be linked to humidification, as greater water vapor delivery measured in vitro was associated with greater secretion volume in vivo.

  15. Low tidal volume ventilation ameliorates left ventricular dysfunction in mechanically ventilated rats following LPS-induced lung injury.

    Science.gov (United States)

    Cherpanath, Thomas G V; Smeding, Lonneke; Hirsch, Alexander; Lagrand, Wim K; Schultz, Marcus J; Groeneveld, A B Johan

    2015-10-07

    High tidal volume ventilation has shown to cause ventilator-induced lung injury (VILI), possibly contributing to concomitant extrapulmonary organ dysfunction. The present study examined whether left ventricular (LV) function is dependent on tidal volume size and whether this effect is augmented during lipopolysaccharide(LPS)-induced lung injury. Twenty male Wistar rats were sedated, paralyzed and then randomized in four groups receiving mechanical ventilation with tidal volumes of 6 ml/kg or 19 ml/kg with or without intrapulmonary administration of LPS. A conductance catheter was placed in the left ventricle to generate pressure-volume loops, which were also obtained within a few seconds of vena cava occlusion to obtain relatively load-independent LV systolic and diastolic function parameters. The end-systolic elastance / effective arterial elastance (Ees/Ea) ratio was used as the primary parameter of LV systolic function with the end-diastolic elastance (Eed) as primary LV diastolic function. Ees/Ea decreased over time in rats receiving LPS (p = 0.045) and high tidal volume ventilation (p = 0.007), with a lower Ees/Ea in the rats with high tidal volume ventilation plus LPS compared to the other groups (p tidal volume ventilation without LPS (p = 0.223). A significant interaction (p tidal ventilation and LPS for Ees/Ea and Eed, and all rats receiving high tidal volume ventilation plus LPS died before the end of the experiment. Low tidal volume ventilation ameliorated LV systolic and diastolic dysfunction while preventing death following LPS-induced lung injury in mechanically ventilated rats. Our data advocates the use of low tidal volumes, not only to avoid VILI, but to avert ventilator-induced myocardial dysfunction as well.

  16. Low Tidal Volume Ventilation in Patients without Acute Respiratory Distress Syndrome: A Paradigm Shift in Mechanical Ventilation

    OpenAIRE

    Lipes, Jed; Bojmehrani, Azadeh; Lellouche, Francois

    2012-01-01

    Protective ventilation with low tidal volume has been shown to reduce morbidity and mortality in patients suffering from acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). Low tidal volume ventilation is associated with particular clinical challenges and is therefore often underutilized as a therapeutic option in clinical practice. Despite some potential difficulties, data have been published examining the application of protective ventilation in patients without lung inj...

  17. A comparison of volume control and pressure-regulated volume control ventilation in acute respiratory failure

    OpenAIRE

    Guldager, Henrik; Nielsen, Soeren L; Carl, Peder; Soerensen, Mogens B

    1997-01-01

    Background: The aim of this study was to test the hypothesis that a new mode of ventilation (pressure-regulated volume control; PRVC) is associated with improvements in respiratory mechanics and outcome when compared with conventional volume control (VC) ventilation in patients with acute respiratory failure. We conducted a randomised, prospective, open, cross over trial on 44 patients with acute respiratory failure in the general intensive care unit of a university hospital. After a stabiliz...

  18. Performance of current intensive care unit ventilators during pressure and volume ventilation.

    Science.gov (United States)

    Marchese, Andrew D; Sulemanji, Demet; Chipman, Daniel; Villar, Jesús; Kacmarek, Robert M

    2011-07-01

    Intensive-care mechanical ventilators regularly enter the market, but the gas-delivery capabilities of many have never been assessed. We evaluated 6 intensive-care ventilators in the pressure support (PS), pressure assist/control (PA/C), and volume assist/control (VA/C) modes, with lung-model mechanics combinations of compliance and resistance of 60 mL/cm H(2)O and 10 cm H(2)O/L/s, 60 mL/cm H(2)O and 5 cm H(2)O/L/s, and 30 mL/cm H(2)O and 10 cm H(2)O/L/s, and inspiratory muscle effort of 5 and 10 cm H(2)O. PS and PA/C were set to 15 cm H(2)O, and PEEP to 5 and 15 cm H(2)O in all modes. During VA/C, tidal volume was set at 500 mL and inspiratory time was set at 0.8 second. Rise time and termination criteria were set at the manufacturers' defaults, and to an optimal level during PS and PA/C. There were marked differences in ventilator performance in all 3 modes. VA/C had the greatest difficulty meeting lung model demand and the greatest variability across all tested scenarios and ventilators. From high to low inspiratory muscle effort, pressure-to-trigger, time for pressure to return to baseline, and triggering pressure-time product decreased in all modes. With increasing resistance and decreasing compliance, tidal volume, pressure-to-trigger, time-to-trigger, time for pressure to return to baseline, time to 90% of peak pressure, and pressure-time product decreased. There were large differences between the default and optimal settings for all the variables in PS and PA/C. Performance was not affected by PEEP. Most of the tested ventilators performed at an acceptable level during the majority of evaluations, but some ventilators performed inadequately during specific settings. Bedside clinical evaluation is needed.

  19. Increased requirement for minute ventilation and negative arterial to end-tidal carbon dioxide gradient may indicate malignant hyperthermia

    Directory of Open Access Journals (Sweden)

    Ho-Tien Lin

    2014-04-01

    Full Text Available Characteristic signs of malignant hyperthermia (MH include unexplained tachycardia, increased end-tidal carbon dioxide (Etco2 concentration, metabolic and respiratory acidosis, and an increase in body temperature above 38.8°C. We present the case of a patient with highly probable MH. In addition to sinus tachycardia and metabolic and respiratory acidosis, this patient also had a negative arterial to Etco2 gradient and an increased requirement for minute ventilation to maintain a normal Etco2 concentration, with signs of increased CO2 production. Despite these signs of MH, the patient's rectal temperature monitoring equipment did not show an increase in temperature, although the temperature measured in the mouth was increased. This case illustrates the unreliability of measuring rectal temperature as a means of reflecting body temperature during MH and the usefulness of increased CO2 production signs in helping to diagnose MH.

  20. Ventilation

    DEFF Research Database (Denmark)

    Nielsen, Toke Rammer; Svendsen, Sv Aa Højgaard

    1999-01-01

    The note concerns ventilation in residential buildings. Describes components in ventilation systems, electric energy consumption and different ventilation systems with heat exchanger.......The note concerns ventilation in residential buildings. Describes components in ventilation systems, electric energy consumption and different ventilation systems with heat exchanger....

  1. A comparison of volume control and pressure-regulated volume control ventilation in acute respiratory failure

    Science.gov (United States)

    Guldager, Henrik; Nielsen, Soeren L; Carl, Peder; Soerensen, Mogens B

    1997-01-01

    Background: The aim of this study was to test the hypothesis that a new mode of ventilation (pressure-regulated volume control; PRVC) is associated with improvements in respiratory mechanics and outcome when compared with conventional volume control (VC) ventilation in patients with acute respiratory failure. We conducted a randomised, prospective, open, cross over trial on 44 patients with acute respiratory failure in the general intensive care unit of a university hospital. After a stabilization period of 8 h, a cross over trial of 2 × 2 h was conducted. Apart from the PRVC/VC mode, ventilator settings were comparable. The following parameters were recorded for each patient: days on ventilator, failure in the assigned mode of ventilation (peak inspiratory pressure > 50 cmH2O) and survival. Results: In the crossover trial, peak inspiratory pressure was significantly lower using PRVC than with VC (20 cmH2O vs 24 cmH2O, P < 0.0001). No other statistically significant differences were found. Conclusions: Peak inspiratory pressure was significantly lower during PRVC ventilation than during VC ventilation, and thus PRVC may be superior to VC in certain patients. However, in this small group of patients, we could not demonstrate that PRVC improved outcome. PMID:11056699

  2. Low Tidal Volume Ventilation in Patients without Acute Respiratory Distress Syndrome: A Paradigm Shift in Mechanical Ventilation

    Directory of Open Access Journals (Sweden)

    Jed Lipes

    2012-01-01

    Full Text Available Protective ventilation with low tidal volume has been shown to reduce morbidity and mortality in patients suffering from acute lung injury (ALI and acute respiratory distress syndrome (ARDS. Low tidal volume ventilation is associated with particular clinical challenges and is therefore often underutilized as a therapeutic option in clinical practice. Despite some potential difficulties, data have been published examining the application of protective ventilation in patients without lung injury. We will briefly review the physiologic rationale for low tidal volume ventilation and explore the current evidence for protective ventilation in patients without lung injury. In addition, we will explore some of the potential reasons for its underuse and provide strategies to overcome some of the associated clinical challenges.

  3. Low Tidal Volume Ventilation in Patients without Acute Respiratory Distress Syndrome: A Paradigm Shift in Mechanical Ventilation

    Science.gov (United States)

    Lipes, Jed; Bojmehrani, Azadeh; Lellouche, Francois

    2012-01-01

    Protective ventilation with low tidal volume has been shown to reduce morbidity and mortality in patients suffering from acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). Low tidal volume ventilation is associated with particular clinical challenges and is therefore often underutilized as a therapeutic option in clinical practice. Despite some potential difficulties, data have been published examining the application of protective ventilation in patients without lung injury. We will briefly review the physiologic rationale for low tidal volume ventilation and explore the current evidence for protective ventilation in patients without lung injury. In addition, we will explore some of the potential reasons for its underuse and provide strategies to overcome some of the associated clinical challenges. PMID:22536499

  4. Low tidal volume mechanical ventilation against no ventilation during cardiopulmonary bypass heart surgery (MECANO): study protocol for a randomized controlled trial.

    Science.gov (United States)

    Nguyen, Lee S; Merzoug, Messaouda; Estagnasie, Philippe; Brusset, Alain; Law Koune, Jean-Dominique; Aubert, Stephane; Waldmann, Thierry; Grinda, Jean-Michel; Gibert, Hadrien; Squara, Pierre

    2017-12-02

    Postoperative pulmonary complications are a leading cause of morbidity and mortality after cardiac surgery. There are no recommendations on mechanical ventilation associated with cardiopulmonary bypass (CPB) during surgery and anesthesiologists perform either no ventilation (noV) at all during CPB or maintain low tidal volume (LTV) ventilation. Indirect evidence points towards better pulmonary outcomes when LTV is performed but no large-scale prospective trial has yet been published in cardiac surgery. The MECANO trial is a single-center, double-blind, randomized, controlled trial comparing two mechanical ventilation strategies, noV and LTV, during cardiac surgery with CPB. In total, 1500 patients are expected to be included, without any restrictions. They will be randomized between noV and LTV on a 1:1 ratio. The noV group will receive no ventilation during CPB. The LTV group will receive 5 breaths/minute with a tidal volume of 3 mL/kg and positive end-expiratory pressure of 5 cmH2O. The primary endpoint will be a composite of all-cause mortality, early respiratory failure defined as a ratio of partial pressure of oxygen/fraction of inspired oxygen ventilation, mechanical ventilation or high-flow oxygen) at 2 days after arrival in the ICU or ventilator-acquired pneumonia defined by the Center of Disease Control. Lung recruitment maneuvers will be performed in the noV and LTV groups at the end of surgery and at arrival in ICU with an insufflation at +30 cmH20 for 5 seconds. Secondary endpoints are those composing the primary endpoint with the addition of pneumothorax, CPB duration, quantity of postoperative bleeding, red blood cell transfusions, revision surgery requirements, length of stay in the ICU and in the hospital and total hospitalization costs. Patients will be followed until hospital discharge. The MECANO trial is the first of its kind to compare in a double-blind design, a no-ventilation to a low-tidal volume strategy for mechanical ventilation during

  5. Effects of tidal volume on work of breathing during lung-protective ventilation in patients with acute lung injury and acute respiratory distress syndrome.

    Science.gov (United States)

    Kallet, Richard H; Campbell, Andre R; Dicker, Rochelle A; Katz, Jeffrey A; Mackersie, Robert C

    2006-01-01

    To assess the effects of step-changes in tidal volume on work of breathing during lung-protective ventilation in patients with acute lung injury (ALI) or the acute respiratory distress syndrome (ARDS). Prospective, nonconsecutive patients with ALI/ARDS. Adult surgical, trauma, and medical intensive care units at a major inner-city, university-affiliated hospital. Ten patients with ALI/ARDS managed clinically with lung-protective ventilation. Five patients were ventilated at a progressively smaller tidal volume in 1 mL/kg steps between 8 and 5 mL/kg; five other patients were ventilated at a progressively larger tidal volume from 5 to 8 mL/kg. The volume mode was used with a flow rate of 75 L/min. Minute ventilation was maintained constant at each tidal volume setting. Afterward, patients were placed on continuous positive airway pressure for 1-2 mins to measure their spontaneous tidal volume. Work of breathing and other variables were measured with a pulmonary mechanics monitor (Bicore CP-100). Work of breathing progressively increased (0.86 +/- 0.32, 1.05 +/- 0.40, 1.22 +/- 0.36, and 1.57 +/- 0.43 J/L) at a tidal volume of 8, 7, 6, and 5 mL/kg, respectively. In nine of ten patients there was a strong negative correlation between work of breathing and the ventilator-to-patient tidal volume difference (R = -.75 to -.998). : The ventilator-delivered tidal volume exerts an independent influence on work of breathing during lung-protective ventilation in patients with ALI/ARDS. Patient work of breathing is inversely related to the difference between the ventilator-delivered tidal volume and patient-generated tidal volume during a brief trial of unassisted breathing.

  6. Reductions in dead space ventilation with nasal high flow depend on physiological dead space volume: metabolic hood measurements during sleep in patients with COPD and controls.

    Science.gov (United States)

    Biselli, Paolo; Fricke, Kathrin; Grote, Ludger; Braun, Andrew T; Kirkness, Jason; Smith, Philip; Schwartz, Alan; Schneider, Hartmut

    2018-05-01

    Nasal high flow (NHF) reduces minute ventilation and ventilatory loads during sleep but the mechanisms are not clear. We hypothesised NHF reduces ventilation in proportion to physiological but not anatomical dead space.11 subjects (five controls and six chronic obstructive pulmonary disease (COPD) patients) underwent polysomnography with transcutaneous carbon dioxide (CO 2 ) monitoring under a metabolic hood. During stable non-rapid eye movement stage 2 sleep, subjects received NHF (20 L·min -1 ) intermittently for periods of 5-10 min. We measured CO 2 production and calculated dead space ventilation.Controls and COPD patients responded similarly to NHF. NHF reduced minute ventilation (from 5.6±0.4 to 4.8±0.4 L·min -1 ; pspace ventilation (from 2.5±0.4 to 1.6±0.4 L·min -1 ; pspace ventilation correlated with baseline physiological dead space fraction (r 2 =0.36; pspace volume.During sleep, NHF decreases minute ventilation due to an overall reduction in dead space ventilation in proportion to the extent of baseline physiological dead space fraction. Copyright ©ERS 2018.

  7. The impact of large tidal volume ventilation on the absorption of inhaled insulin in rabbits

    DEFF Research Database (Denmark)

    Petersen, Astrid Heide; Laursen, Torben; Ahrén, Bo

    2007-01-01

    Previous studies have shown that ventilation patterns affect absorption of inhaled compounds. Thus, the aim of this study was to investigate the effect of large tidal volume ventilation (LTVV) on the absorption of inhaled insulin in rabbits. Mechanically ventilated rabbits were given human insulin...

  8. Low Tidal Volume Reduces Lung Inflammation Induced by Liquid Ventilation in Piglets With Severe Lung Injury.

    Science.gov (United States)

    Jiang, Lijun; Feng, Huizhen; Chen, Xiaofan; Liang, Kaifeng; Ni, Chengyao

    2017-05-01

    Total liquid ventilation (TLV) is an alternative treatment for severe lung injury. High tidal volume is usually required for TLV to maintain adequate CO 2 clearance. However, high tidal volume may cause alveolar barotrauma. We aim to investigate the effect of low tidal volume on pulmonary inflammation in piglets with lung injury and under TLV. After the establishment of acute lung injury model by infusing lipopolysaccharide, 12 piglets were randomly divided into two groups, TLV with high tidal volume (25 mL/kg) or with low tidal volume (6 mL/kg) for 240 min, respectively. Extracorporeal CO 2 removal was applied in low tidal volume group to improve CO 2 clearance and in high tidal volume group as sham control. Gas exchange and hemodynamic status were monitored every 30 min during TLV. At the end of the study, pulmonary mRNA expression and plasmatic concentration of interleukin-6 (IL-6) and interleukin-8 (IL-8) were measured by collecting lung tissue and blood samples from piglets. Arterial blood pressure, PaO 2 , and PaCO 2 showed no remarkable difference between groups during the observation period. Compared with high tidal volume strategy, low tidal volume resulted in 76% reduction of minute volume and over 80% reduction in peak inspiratory pressure during TLV. In addition, low tidal volume significantly diminished pulmonary mRNA expression and plasmatic level of IL-6 and IL-8. We conclude that during TLV, low tidal volume reduces lung inflammation in piglets with acute lung injury without compromising gas exchange. © 2016 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  9. The deflation limb of the pressure-volume relationship in infants during high-frequency ventilation.

    Science.gov (United States)

    Tingay, David G; Mills, John F; Morley, Colin J; Pellicano, Anastasia; Dargaville, Peter A

    2006-02-15

    The importance of applying high-frequency oscillatory ventilation with a high lung volume strategy in infants is well established. Currently, a lack of reliable methods for assessing lung volume limits clinicians' ability to achieve the optimum volume range. To map the pressure-volume relationship of the lung during high-frequency oscillatory ventilation in infants, to determine at what point ventilation is being applied clinically, and to describe the relationship between airway pressure, lung volume, and oxygenation. In 12 infants, a partial inflation limb and the deflation limb of the pressure-volume relationship were mapped using a quasi-static lung volume optimization maneuver. This involved stepwise airway pressure increments to total lung capacity, followed by decrements until the closing pressure of the lung was identified. Lung volume and oxygen saturation were recorded at each airway pressure. Lung volume was measured using respiratory inductive plethysmography. A distinct deflation limb could be mapped in each infant. Overall, oxygenation and lung volume were improved by applying ventilation on the deflation limb. Maximal lung volume and oxygenation occurred on the deflation limb at a mean airway pressure of 3 and 5 cm H(2)O below the airway pressure approximating total lung capacity, respectively. Using current ventilation strategies, all infants were being ventilated near the inflation limb. It is possible to delineate the deflation limb in infants receiving high-frequency oscillatory ventilation; in doing so, greater lung volume and oxygenation can be achieved, often at lower airway pressures.

  10. Influence of tidal volume on ventilation inhomogeneity assessed by electrical impedance tomography during controlled mechanical ventilation

    International Nuclear Information System (INIS)

    Becher, T; Kott, M; Schädler, D; Vogt, B; Meinel, T; Weiler, N; Frerichs, I

    2015-01-01

    The global inhomogeneity (GI) index is a parameter of ventilation inhomogeneity that can be calculated from images of tidal ventilation distribution obtained by electrical impedance tomography (EIT). It has been suggested that the GI index may be useful for individual adjustment of positive end-expiratory pressure (PEEP) and for guidance of ventilator therapy. The aim of the present work was to assess the influence of tidal volume (V_T) on the GI index values. EIT data from 9 patients with acute respiratory distress syndrome ventilated with a low and a high V_T of 5   ±   1 (mean  ±  SD) and 9   ±   1 ml kg"−"1 predicted body weight at a high and a low level of PEEP (PEEP_h_i_g_h, PEEP_l_o_w) were analyzed. PEEP_h_i_g_h and PEEP_l_o_w were set 2 cmH_2O above and 5 cmH_2O below the lower inflection point of a quasi-static pressure volume loop, respectively. The lower inflection point was identified at 8.1   ±   1.4 (mean  ±  SD) cmH_2O, resulting in a PEEP_h_i_g_h of 10.1   ±   1.4 and a PEEP_l_o_w of 3.1   ±   1.4 cmH_2O. At PEEP_h_i_g_h, we found no significant trend in GI index with low V_T when compared to high V_T (0.49   ±   0.15 versus 0.44   ±   0.09, p = 0.13). At PEEP_l_o_w, we found a significantly higher GI index with low V_T compared to high V_T (0.66   ±   0.19 versus 0.59   ±   0.17, p = 0.01). When comparing the PEEP levels, we found a significantly lower GI index at PEEP_h_i_g_h both for high and low V_T. We conclude that high V_T may lead to a lower GI index, especially at low PEEP settings. This should be taken into account when using the GI index for individual adjustment of ventilator settings. (paper)

  11. Uranium mine ventilation

    International Nuclear Information System (INIS)

    Katam, K.; Sudarsono

    1982-01-01

    Uranium mine ventilation system aimed basically to control and decreasing the air radioactivity in mine caused by the radon emanating from uranium ore. The control and decreasing the air ''age'' in mine, with adding the air consumption volume, increasing the air rate consumption, closing the mine-out area; using closed drainage system. Air consumption should be 60m 3 /minute for each 9m 2 uranium ore surfaces with ventilation rate of 15m/minute. (author)

  12. Comparison of Tidal Volumes at the Endotracheal Tube and at the Ventilator.

    Science.gov (United States)

    Kim, Paul; Salazar, Adler; Ross, Patrick A; Newth, Christopher J L; Khemani, Robinder G

    2015-11-01

    Lung protective ventilation for children with acute respiratory distress syndrome requires accurate assessment of tidal volume. Although modern ventilators compensate for ventilator tubing compliance, tidal volume measured at the ventilator may not be accurate, particularly in small children. Although ventilator-specific proximal flow sensors that measure tidal volume at the endotracheal tube have been developed, there is little information regarding their accuracy. We sought to test the accuracy of ventilator measured tidal volume with and without proximal flow sensors against a calibrated pneumotachometer in children. Prospective, observational. Tertiary care PICU. Fifty-one endotracheally intubated and mechanically ventilated children younger than 18 years. Tidal volumes were measured at the ventilator, using a ventilator-specific flow sensor, and a calibrated pneumotachometer connected to the SensorMedics 2600A Pediatric Pulmonary Function Cart. In a pressure control mode of ventilation: median tidal volume measured with the pneumotachometer (9.5 mL/kg [interquartile range, 8.2-11.7 mL/kg]) was significantly higher than tidal volume measured either at the ventilator (8.2 mL/kg [7.1-9.6 mL/kg]) or at the proximal flow sensor (8.1 mL/kg [7.2-10.0 mL/kg]) (p tidal volume measured with the pneumotachometer (10.2 mL/kg [8.8-12.4 mL/kg]) was significantly higher than tidal volume measured either at the ventilator (8.0 mL/kg [7.1-9.7 mL/kg]) or at the proximal flow sensor (8.5 mL/kg [7.3-10.4 mL/kg]) (p Tidal volume measured either at the endotracheal tube with a proximal flow sensor or at the ventilator with compensation for tubing compliance are both significantly lower than tidal volume measured with a calibrated pneumotachometer. This underestimation of delivered tidal volume may be particularly important when managing children with acute respiratory distress syndrome.

  13. Failure of Noninvasive Ventilation for De Novo Acute Hypoxemic Respiratory Failure: Role of Tidal Volume.

    Science.gov (United States)

    Carteaux, Guillaume; Millán-Guilarte, Teresa; De Prost, Nicolas; Razazi, Keyvan; Abid, Shariq; Thille, Arnaud W; Schortgen, Frédérique; Brochard, Laurent; Brun-Buisson, Christian; Mekontso Dessap, Armand

    2016-02-01

    A low or moderate expired tidal volume can be difficult to achieve during noninvasive ventilation for de novo acute hypoxemic respiratory failure (i.e., not due to exacerbation of chronic lung disease or cardiac failure). We assessed expired tidal volume and its association with noninvasive ventilation outcome. Prospective observational study. Twenty-four bed university medical ICU. Consecutive patients receiving noninvasive ventilation for acute hypoxemic respiratory failure between August 2010 and February 2013. Noninvasive ventilation was uniformly delivered using a simple algorithm targeting the expired tidal volume between 6 and 8 mL/kg of predicted body weight. Expired tidal volume was averaged and respiratory and hemodynamic variables were systematically recorded at each noninvasive ventilation session. Sixty-two patients were enrolled, including 47 meeting criteria for acute respiratory distress syndrome, and 32 failed noninvasive ventilation (51%). Pneumonia (n = 51, 82%) was the main etiology of acute hypoxemic respiratory failure. The median (interquartile range) expired tidal volume averaged over all noninvasive ventilation sessions (mean expired tidal volume) was 9.8 mL/kg predicted body weight (8.1-11.1 mL/kg predicted body weight). The mean expired tidal volume was significantly higher in patients who failed noninvasive ventilation as compared with those who succeeded (10.6 mL/kg predicted body weight [9.6-12.0] vs 8.5 mL/kg predicted body weight [7.6-10.2]; p = 0.001), and expired tidal volume was independently associated with noninvasive ventilation failure in multivariate analysis. This effect was mainly driven by patients with PaO2/FIO2 up to 200 mm Hg. In these patients, the expired tidal volume above 9.5 mL/kg predicted body weight predicted noninvasive ventilation failure with a sensitivity of 82% and a specificity of 87%. A low expired tidal volume is almost impossible to achieve in the majority of patients receiving noninvasive ventilation

  14. Numerical simulation of volume-controlled mechanical ventilated respiratory system with 2 different lungs.

    Science.gov (United States)

    Shi, Yan; Zhang, Bolun; Cai, Maolin; Zhang, Xiaohua Douglas

    2017-09-01

    Mechanical ventilation is a key therapy for patients who cannot breathe adequately by themselves, and dynamics of mechanical ventilation system is of great significance for life support of patients. Recently, models of mechanical ventilated respiratory system with 1 lung are used to simulate the respiratory system of patients. However, humans have 2 lungs. When the respiratory characteristics of 2 lungs are different, a single-lung model cannot reflect real respiratory system. In this paper, to illustrate dynamic characteristics of mechanical ventilated respiratory system with 2 different lungs, we propose a mathematical model of mechanical ventilated respiratory system with 2 different lungs and conduct experiments to verify the model. Furthermore, we study the dynamics of mechanical ventilated respiratory system with 2 different lungs. This research study can be used for improving the efficiency and safety of volume-controlled mechanical ventilation system. Copyright © 2016 John Wiley & Sons, Ltd.

  15. Adaptive Support Ventilation May Deliver Unwanted Respiratory Rate-Tidal Volume Combinations in Patients with Acute Lung Injury Ventilated According to an Open Lung Concept

    NARCIS (Netherlands)

    Dongelmans, Dave A.; Paulus, Frederique; Veelo, Denise P.; Binnekade, Jan M.; Vroom, Margreeth B.; Schultz, Marcus J.

    2011-01-01

    Background: With adaptive support ventilation, respiratory rate and tidal volume (V(T)) are a function of the Otis least work of breathing formula. We hypothesized that adaptive support ventilation in an open lung ventilator strategy would deliver higher V(T)s to patients with acute lung injury.

  16. Adaptive support ventilation: A translational study evaluating the size of delivered tidal volumes

    NARCIS (Netherlands)

    Veelo, Denise P.; Dongelmans, Dave A.; Binnekade, Jan M.; Paulus, Frederique; Schultz, Marcus J.

    2010-01-01

    Purpose: Adaptive support ventilation (ASV) is a microprocessor-controlled, closed-loop mode of mechanical ventilation that adapts respiratory rates and tidal volumes (V(T)s) based on the Otis least work of breathing formula. We studied calculated V(T)s in a computer simulation model, and V(T)s

  17. Variable tidal volumes improve lung protective ventilation strategies in experimental lung injury.

    Science.gov (United States)

    Spieth, Peter M; Carvalho, Alysson R; Pelosi, Paolo; Hoehn, Catharina; Meissner, Christoph; Kasper, Michael; Hübler, Matthias; von Neindorff, Matthias; Dassow, Constanze; Barrenschee, Martina; Uhlig, Stefan; Koch, Thea; de Abreu, Marcelo Gama

    2009-04-15

    Noisy ventilation with variable Vt may improve respiratory function in acute lung injury. To determine the impact of noisy ventilation on respiratory function and its biological effects on lung parenchyma compared with conventional protective mechanical ventilation strategies. In a porcine surfactant depletion model of lung injury, we randomly combined noisy ventilation with the ARDS Network protocol or the open lung approach (n = 9 per group). Respiratory mechanics, gas exchange, and distribution of pulmonary blood flow were measured at intervals over a 6-hour period. Postmortem, lung tissue was analyzed to determine histological damage, mechanical stress, and inflammation. We found that, at comparable minute ventilation, noisy ventilation (1) improved arterial oxygenation and reduced mean inspiratory peak airway pressure and elastance of the respiratory system compared with the ARDS Network protocol and the open lung approach, (2) redistributed pulmonary blood flow to caudal zones compared with the ARDS Network protocol and to peripheral ones compared with the open lung approach, (3) reduced histological damage in comparison to both protective ventilation strategies, and (4) did not increase lung inflammation or mechanical stress. Noisy ventilation with variable Vt and fixed respiratory frequency improves respiratory function and reduces histological damage compared with standard protective ventilation strategies.

  18. Monitoring tidal volumes in preterm infants at birth: mask versus endotracheal ventilation.

    Science.gov (United States)

    van Vonderen, Jeroen J; Hooper, Stuart B; Krabbe, Vera B; Siew, Melissa L; Te Pas, Arjan B

    2015-01-01

    Upper airway distention during mask ventilation could reduce gas volumes entering the lung compared with ventilation via an endotracheal tube. Therefore, respiratory tract volumes were measured in lambs and tidal volumes were compared in preterm infants before and after intubation. In seven preterm lambs, volumes of the airways (oropharynx, trachea, lungs) were assessed. In 10 preterm infants, delta pressures, tidal volumes and leak were measured during ventilation 2 min before (mask ventilation) and 2 min after intubation (endotracheal ventilation). Inflations coinciding with breaths were excluded. Amount of upper airway distention in lambs and differences in inspiratory and expiratory tidal volume before and after intubation. In lambs, the combined trachea and oropharynx contributed to 14 (12-21) % (median (IQR), whereas the oropharynx contributed to 9 (7-10) % of the total tidal volume measured at the mouth. In preterm infants, inspiratory (11.1 (7.9-22.6) mL/kg vs 5.8 (3.9-9.6) mL/kg (p=0.01)) and expiratory (8.3 (6.8-15.4) mL/kg vs 4.9 (3.9-9.6) mL/kg (p=0.02)) tidal volumes were significantly larger during mask ventilation compared with endotracheal ventilation. Leak was 18.7 (3.3-28.7) % before versus 0 (0-2.3) % after intubation (p0.05). During mask ventilation, expiratory tidal volume increased from 10.0 (5.4-15.6) mL/kg to 11.3 (7.6-17.0) mL/kg (p=0.01), but remained unchanged during endotracheal ventilation. During neonatal mask ventilation, distention of the upper respiratory tract contributes to the tidal volumes measured and should be taken into account when targeting tidal volumes during mask ventilation. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  19. Right ventricular function during one-lung ventilation: effects of pressure-controlled and volume-controlled ventilation.

    Science.gov (United States)

    Al Shehri, Abdullah M; El-Tahan, Mohamed R; Al Metwally, Roshdi; Qutub, Hatem; El Ghoneimy, Yasser F; Regal, Mohamed A; Zien, Haytham

    2014-08-01

    To test the effects of pressure-controlled (PCV) and volume-controlled (VCV) ventilation during one-lung ventilation (OLV) for thoracic surgery on right ventricular (RV) function. A prospective, randomized, double-blind, controlled, crossover study. A single university hospital. Fourteen pairs of consecutive patients scheduled for elective thoracotomy. Patients were assigned randomly to ventilate the dependent lung with PCV or VCV mode, each in a randomized crossover order using tidal volume of 6 mL/kg, I: E ratio 1: 2.5, positive end-expiratory pressure (PEEP) of 5 cm H2O and respiratory rate adjusted to maintain normocapnia. Intraoperative changes in RV function (systolic and early diastolic tricuspid annular velocity (TAV), end-systolic volume (ESV), end-diastolic volume (EDV) and fractional area changes (FAC)), airway pressures, compliance and oxygenation index were recorded. The use of PCV during OLV resulted in faster systolic (10.1±2.39 vs. 5.8±1.67 cm/s, respectively), diastolic TAV (9.2±1.99 vs. 4.6±1.42 cm/s, respectively) (prights reserved.

  20. A prototype of volume-controlled tidal liquid ventilator using independent piston pumps.

    Science.gov (United States)

    Robert, Raymond; Micheau, Philippe; Cyr, Stéphane; Lesur, Olivier; Praud, Jean-Paul; Walti, Hervé

    2006-01-01

    Liquid ventilation using perfluorochemicals (PFC) offers clear theoretical advantages over gas ventilation, such as decreased lung damage, recruitment of collapsed lung regions, and lavage of inflammatory debris. We present a total liquid ventilator designed to ventilate patients with completely filled lungs with a tidal volume of PFC liquid. The two independent piston pumps are volume controlled and pressure limited. Measurable pumping errors are corrected by a programmed supervisor module, which modifies the inserted or withdrawn volume. Pump independence also allows easy functional residual capacity modifications during ventilation. The bubble gas exchanger is divided into two sections such that the PFC exiting the lungs is not in contact with the PFC entering the lungs. The heating system is incorporated into the metallic base of the gas exchanger, and a heat-sink-type condenser is placed on top of the exchanger to retrieve PFC vapors. The prototype was tested on 5 healthy term newborn lambs (<5 days old). The results demonstrate the efficiency and safety of the prototype in maintaining adequate gas exchange, normal acido-basis equilibrium, and cardiovascular stability during a short, 2-hour total liquid ventilator. Airway pressure, lung volume, and ventilation scheme were maintained in the targeted range.

  1. Newer nonconventional modes of mechanical ventilation

    Directory of Open Access Journals (Sweden)

    Preet Mohinder Singh

    2014-01-01

    Full Text Available The conventional modes of ventilation suffer many limitations. Although they are popularly used and are well-understood, often they fail to match the patient-based requirements. Over the years, many small modifications in ventilators have been incorporated to improve patient outcome. The ventilators of newer generation respond to patient′s demands by additional feedback systems. In this review, we discuss the popular newer modes of ventilation that have been accepted in to clinical practice. Various intensive care units over the world have found these modes to improve patient ventilator synchrony, decrease ventilator days and improve patient safety. The various modes discusses in this review are: Dual control modes (volume assured pressure support, volume support, Adaptive support ventilation, proportional assist ventilation, mandatory minute ventilation, Bi-level airway pressure release ventilation, (BiPAP, neurally adjusted ventilatory assist and NeoGanesh. Their working principles with their advantages and clinical limitations are discussed in brief.

  2. Human versus Computer Controlled Selection of Ventilator Settings: An Evaluation of Adaptive Support Ventilation and Mid-Frequency Ventilation

    Directory of Open Access Journals (Sweden)

    Eduardo Mireles-Cabodevila

    2012-01-01

    Full Text Available Background. There are modes of mechanical ventilation that can select ventilator settings with computer controlled algorithms (targeting schemes. Two examples are adaptive support ventilation (ASV and mid-frequency ventilation (MFV. We studied how different clinician-chosen ventilator settings are from these computer algorithms under different scenarios. Methods. A survey of critical care clinicians provided reference ventilator settings for a 70 kg paralyzed patient in five clinical/physiological scenarios. The survey-derived values for minute ventilation and minute alveolar ventilation were used as goals for ASV and MFV, respectively. A lung simulator programmed with each scenario’s respiratory system characteristics was ventilated using the clinician, ASV, and MFV settings. Results. Tidal volumes ranged from 6.1 to 8.3 mL/kg for the clinician, 6.7 to 11.9 mL/kg for ASV, and 3.5 to 9.9 mL/kg for MFV. Inspiratory pressures were lower for ASV and MFV. Clinician-selected tidal volumes were similar to the ASV settings for all scenarios except for asthma, in which the tidal volumes were larger for ASV and MFV. MFV delivered the same alveolar minute ventilation with higher end expiratory and lower end inspiratory volumes. Conclusions. There are differences and similarities among initial ventilator settings selected by humans and computers for various clinical scenarios. The ventilation outcomes are the result of the lung physiological characteristics and their interaction with the targeting scheme.

  3. Moderately high frequency ventilation with a conventional ventilator allows reduction of tidal volume without increasing mean airway pressure.

    Science.gov (United States)

    Cordioli, Ricardo Luiz; Park, Marcelo; Costa, Eduardo Leite Vieira; Gomes, Susimeire; Brochard, Laurent; Amato, Marcelo Britto Passos; Azevedo, Luciano Cesar Pontes

    2014-12-01

    The aim of this study was to explore if positive-pressure ventilation delivered by a conventional ICU ventilator at a moderately high frequency (HFPPV) allows a safe reduction of tidal volume (V T) below 6 mL/kg in a porcine model of severe acute respiratory distress syndrome (ARDS) and at a lower mean airway pressure than high-frequency oscillatory ventilation (HFOV). This is a prospective study. In eight pigs (median weight 34 [29,36] kg), ARDS was induced by pulmonary lavage and injurious ventilation. The animals were ventilated with a randomized sequence of respiratory rates: 30, 60, 90, 120, 150, followed by HFOV at 5 Hz. At each step, V T was adjusted to allow partial pressure of arterial carbon dioxide (PaCO2) to stabilize between 57 and 63 mmHg. Data are shown as median [P25th,P75th]. After lung injury, the PaO2/FiO2 (P/F) ratio was 92 [63,118] mmHg, pulmonary shunt 26 [17,31]%, and static compliance 11 [8,14] mL/cmH2O. Positive end-expiratory pressure (PEEP) was 14 [10,17] cmH2O. At 30 breaths/min, V T was higher than 6 (7.5 [6.8,10.2]) mL/kg, but at all higher frequencies, V T could be reduced and PaCO2 maintained, leading to reductions in plateau pressures and driving pressures. For frequencies of 60 to 150/min, V T progressively fell from 5.2 [5.1,5.9] to 3.8 [3.7,4.2] mL/kg (p mechanics, auto-PEEP generation, hemodynamics, or gas exchange. Mean airway pressure was maintained constant and was increased only during HFOV. During protective mechanical ventilation, HFPPV delivered by a conventional ventilator in a severe ARDS swine model safely allows further tidal volume reductions. This strategy also allowed decreasing airway pressures while maintaining stable PaCO2 levels.

  4. Parameters affecting the tidal volume during expiratory abdominal compression in patients with prolonged tracheostomy mechanical ventilation.

    Science.gov (United States)

    Morino, Akira; Shida, Masahiro; Tanaka, Masashi; Sato, Kimihiro; Seko, Toshiaki; Ito, Shunsuke; Ogawa, Shunichi; Takahashi, Naoaki

    2015-07-01

    [Purpose] The aim of this study was to clarify physical parameters affecting the tidal volume during expiratory abdominal compression in patients with prolonged tracheostomy mechanical ventilation. [Methods] Eighteen patients with prolonged mechanical ventilation were included in this study. Expiratory abdominal compression was performed on patients lying in a supine position. The abdomen above the navel was vertically compressed in synchronization with expiration and released with inspiration. We measured the tidal volume during expiratory abdominal compression. [Results] The mean tidal volume during expiratory abdominal compression was higher than that at rest (430.6 ± 127.1 mL vs. 344.0 ± 94.3 mL). The tidal volume during expiratory abdominal compression was correlated with weight, days of ventilator support, dynamic compliance and abdominal expansion. Stepwise multiple regression analysis revealed that weight (β = 0.499), dynamic compliance (β = 0.387), and abdominal expansion (β = 0.365) were factors contributing to the tidal volume during expiratory abdominal compression. [Conclusion] Expiratory abdominal compression increased the tidal volume in patients with prolonged tracheostomy mechanical ventilation. The tidal volume during expiratory abdominal compression was influenced by each of the pulmonary conditions and the physical characteristics.

  5. Are tidal volume measurements in neonatal pressure-controlled ventilation accurate?

    Science.gov (United States)

    Chow, Lily C; Vanderhal, Andre; Raber, Jorge; Sola, Augusto

    2002-09-01

    Bedside pulmonary mechanics monitors (PMM) have become useful in ventilatory management in neonates. These monitors are used more frequently due to recent improvements in data-processing capabilities. PMM devices are often part of the ventilator or are separate units. The accuracy and reliability of these systems have not been carefully evaluated. We compared a single ventilatory parameter, tidal volume (V(t)), as measured by several systems. We looked at two freestanding PMMs: the Ventrak Respiratory Monitoring System (Novametrix, Wallingford, CT) and the Bicore CP-100 Neonatal Pulmonary Monitor (Allied Health Care Products, Riverside, CA), and three ventilators with built-in PMM: the VIP Bird Ventilator (Bird Products Corp., Palm Springs, CA), Siemens Servo 300A (Siemens-Elema AB, Solna, Sweden), and Drager Babylog 8000 (Drager, Inc., Chantilly, VA). A calibrated syringe (Hans Rudolph, Inc., Kansas City, MO) was used to deliver tidal volumes of 4, 10, and 20 mL to each ventilator system coupled with a freestanding PMM. After achieving steady state, six consecutive V(t) readings were taken simultaneously from the freestanding PMM and each ventilator. In a second portion of the bench study, we used pressure-control ventilation and measured exhaled tidal volume (V(te)) while ventilating a Bear Test Lung with the same three ventilators. We adjusted peak inspiratory pressure (PIP) under controlled conditions to achieve the three different targeted tidal volumes on the paired freestanding PMM. Again, six V(te) measurements were recorded for each tidal volume. Means and standard deviations were calculated.The percentage difference in measurement of V(t) delivered by calibrated syringe varied greatly, with the greatest discrepancy seen in the smallest tidal volumes, by up to 28%. In pressure control mode, V(te) as measured by the Siemens was significantly overestimated by 20-95%, with the biggest discrepancy at the smallest V(te), particularly when paired with the Bicore

  6. : ventilators for noninvasive ventilation

    OpenAIRE

    Fauroux , Brigitte; Leroux , Karl; Desmarais , Gilbert; Isabey , Daniel; Clément , Annick; Lofaso , Frédéric; Louis , Bruno

    2008-01-01

    International audience; The aim of the present study was to evaluate the performance characteristics of all the ventilators proposed for home noninvasive positive-pressure ventilation in children in France. The ventilators (one volume-targeted, 12 pressure-targeted and four dual) were evaluated on a bench which simulated six different paediatric ventilatory patterns. For each ventilator, the quality of the inspiratory and expiratory trigger and the ability to reach and maintain the preset pre...

  7. High-Frequency Percussive Ventilation and Low Tidal Volume Ventilation in Burns: A Randomized Controlled Trial

    Science.gov (United States)

    2010-01-01

    incidence of ventilator-associated pneumonia ( VAP ) in patients with inha- lation injury when supported with HFPV compared with conventional modes of...mean ratio of PaO2 to FIO2 was 58 6 with a mean positive end- expiratory pressure of 22 2 cm H2O before rescue. Two of these patients were...a sample size of 110 patients in each arm would have been required to detect a difference in VAP with 80% power. A multicentered study would be

  8. Effects of respiratory rate and tidal volume on gas exchange in total liquid ventilation.

    Science.gov (United States)

    Bull, Joseph L; Tredici, Stefano; Fujioka, Hideki; Komori, Eisaku; Grotberg, James B; Hirschl, Ronald B

    2009-01-01

    Using a rabbit model of total liquid ventilation (TLV), and in a corresponding theoretical model, we compared nine tidal volume-respiratory rate combinations to identify a ventilator strategy to maximize gas exchange, while avoiding choked flow, during TLV. Nine different ventilation strategies were tested in each animal (n = 12): low [LR = 2.5 breath/min (bpm)], medium (MR = 5 bpm), or high (HR = 7.5 bpm) respiratory rates were combined with a low (LV = 10 ml/kg), medium (MV = 15 ml/kg), or high (HV = 20 ml/kg) tidal volumes. Blood gases and partial pressures, perfluorocarbon gas content, and airway pressures were measured for each combination. Choked flow occurred in all high respiratory rate-high volume animals, 71% of high respiratory rate-medium volume (HRMV) animals, and 50% of medium respiratory rate-high volume (MRHV) animals but in no other combinations. Medium respiratory rate-medium volume (MRMV) resulted in the highest gas exchange of the combinations that did not induce choke. The HRMV and MRHV animals that did not choke had similar or higher gas exchange than MRMV. The theory predicted this behavior, along with spatial and temporal variations in alveolar gas partial pressures. Of the combinations that did not induce choked flow, MRMV provided the highest gas exchange. Alveolar gas transport is diffusion dominated and rapid during gas ventilation but is convection dominated and slow during TLV. Consequently, the usual alveolar gas equation is not applicable for TLV.

  9. [Treatment of acute respiratory distress syndrome using pressure and volume controlled ventilation with lung protective strategy].

    Science.gov (United States)

    Ge, Ying; Wan, Yong; Wang, Da-qing; Su, Xiao-lin; Li, Jun-ying; Chen, Jing

    2004-07-01

    To investigate the significance and effect of pressure controlled ventilation (PCV) as well as volume controlled ventilation (VCV) by lung protective strategy on respiratory mechanics, blood gas analysis and hemodynamics in patients with acute respiratory distress syndrome (ARDS). Fifty patients with ARDS were randomly divided into PCV and VCV groups with permissive hypercapnia and open lung strategy. Changes in respiratory mechanics, blood gas analysis and hemodynamics were compared between two groups. Peak inspiration pressure (PIP) in PCV group was significantly lower than that in VCV group, while mean pressure of airway (MPaw) was significantly higher than that in VCV after 24 hours mechanical ventilation. After 24 hours mechanical ventilation, there were higher central venous pressure (CVP) and slower heart rate (HR) in two groups, CVP was significantly higher in VCV compared with PCV, and PCV group had slower HR than VCV group, the two groups had no differences in mean blood pressure (MBP) at various intervals. All patients showed no ventilator-induced lung injury. Arterial blood oxygenations were obviously improved in two groups after 24 hours mechanical ventilation, PCV group had better partial pressure of oxygen in artery (PaO2) than VCV group. Both PCV and VCV can improve arterial blood oxygenations, prevent ventilator-induced lung injury, and have less disturbance in hemodynamic parameters. PCV with lung protective ventilatory strategy should be early use for patients with ARDS.

  10. Anaesthesia ventilators

    Directory of Open Access Journals (Sweden)

    Rajnish K Jain

    2013-01-01

    Full Text Available Anaesthesia ventilators are an integral part of all modern anaesthesia workstations. Automatic ventilators in the operating rooms, which were very simple with few modes of ventilation when introduced, have become very sophisticated with many advanced ventilation modes. Several systems of classification of anaesthesia ventilators exist based upon various parameters. Modern anaesthesia ventilators have either a double circuit, bellow design or a single circuit piston configuration. In the bellows ventilators, ascending bellows design is safer than descending bellows. Piston ventilators have the advantage of delivering accurate tidal volume. They work with electricity as their driving force and do not require a driving gas. To enable improved patient safety, several modifications were done in circle system with the different types of anaesthesia ventilators. Fresh gas decoupling is a modification done in piston ventilators and in descending bellows ventilator to reduce th incidence of ventilator induced volutrauma. In addition to the conventional volume control mode, modern anaesthesia ventilators also provide newer modes of ventilation such as synchronised intermittent mandatory ventilation, pressure-control ventilation and pressure-support ventilation (PSV. PSV mode is particularly useful for patients maintained on spontaneous respiration with laryngeal mask airway. Along with the innumerable benefits provided by these machines, there are various inherent hazards associated with the use of the ventilators in the operating room. To use these workstations safely, it is important for every Anaesthesiologist to have a basic understanding of the mechanics of these ventilators and breathing circuits.

  11. Anaesthesia ventilators.

    Science.gov (United States)

    Jain, Rajnish K; Swaminathan, Srinivasan

    2013-09-01

    Anaesthesia ventilators are an integral part of all modern anaesthesia workstations. Automatic ventilators in the operating rooms, which were very simple with few modes of ventilation when introduced, have become very sophisticated with many advanced ventilation modes. Several systems of classification of anaesthesia ventilators exist based upon various parameters. Modern anaesthesia ventilators have either a double circuit, bellow design or a single circuit piston configuration. In the bellows ventilators, ascending bellows design is safer than descending bellows. Piston ventilators have the advantage of delivering accurate tidal volume. They work with electricity as their driving force and do not require a driving gas. To enable improved patient safety, several modifications were done in circle system with the different types of anaesthesia ventilators. Fresh gas decoupling is a modification done in piston ventilators and in descending bellows ventilator to reduce th incidence of ventilator induced volutrauma. In addition to the conventional volume control mode, modern anaesthesia ventilators also provide newer modes of ventilation such as synchronised intermittent mandatory ventilation, pressure-control ventilation and pressure-support ventilation (PSV). PSV mode is particularly useful for patients maintained on spontaneous respiration with laryngeal mask airway. Along with the innumerable benefits provided by these machines, there are various inherent hazards associated with the use of the ventilators in the operating room. To use these workstations safely, it is important for every Anaesthesiologist to have a basic understanding of the mechanics of these ventilators and breathing circuits.

  12. Anaesthesia ventilators

    Science.gov (United States)

    Jain, Rajnish K; Swaminathan, Srinivasan

    2013-01-01

    Anaesthesia ventilators are an integral part of all modern anaesthesia workstations. Automatic ventilators in the operating rooms, which were very simple with few modes of ventilation when introduced, have become very sophisticated with many advanced ventilation modes. Several systems of classification of anaesthesia ventilators exist based upon various parameters. Modern anaesthesia ventilators have either a double circuit, bellow design or a single circuit piston configuration. In the bellows ventilators, ascending bellows design is safer than descending bellows. Piston ventilators have the advantage of delivering accurate tidal volume. They work with electricity as their driving force and do not require a driving gas. To enable improved patient safety, several modifications were done in circle system with the different types of anaesthesia ventilators. Fresh gas decoupling is a modification done in piston ventilators and in descending bellows ventilator to reduce th incidence of ventilator induced volutrauma. In addition to the conventional volume control mode, modern anaesthesia ventilators also provide newer modes of ventilation such as synchronised intermittent mandatory ventilation, pressure-control ventilation and pressure-support ventilation (PSV). PSV mode is particularly useful for patients maintained on spontaneous respiration with laryngeal mask airway. Along with the innumerable benefits provided by these machines, there are various inherent hazards associated with the use of the ventilators in the operating room. To use these workstations safely, it is important for every Anaesthesiologist to have a basic understanding of the mechanics of these ventilators and breathing circuits. PMID:24249886

  13. Transfer factor, lung volumes, resistance and ventilation distribution in healthy adults.

    Science.gov (United States)

    Verbanck, Sylvia; Van Muylem, Alain; Schuermans, Daniel; Bautmans, Ivan; Thompson, Bruce; Vincken, Walter

    2016-01-01

    Monitoring of chronic lung disease requires reference values of lung function indices, including putative markers of small airway function, spanning a wide age range.We measured spirometry, transfer factor of the lung for carbon monoxide (TLCO), static lung volume, resistance and ventilation distribution in a healthy population, studying at least 20 subjects per sex and per decade between the ages of 20 and 80 years.With respect to the Global Lung Function Initiative reference data, our subjects had average z-scores for forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and FEV1/FVC of -0.12, 0.04 and -0.32, respectively. Reference equations were obtained which could account for a potential dependence of index variability on age and height. This was done for (but not limited to) indices that are pertinent to asthma and chronic obstructive pulmonary disease studies: forced expired volume in 6 s, forced expiratory flow, TLCO, specific airway conductance, residual volume (RV)/total lung capacity (TLC), and ventilation heterogeneity in acinar and conductive lung zones.Deterioration in acinar ventilation heterogeneity and lung clearance index with age were more marked beyond 60 years, and conductive ventilation heterogeneity showed the greatest increase in variability with age. The most clinically relevant deviation from published reference values concerned RV/TLC values, which were considerably smaller than American Thoracic Society/European Respiratory Society-endorsed reference values. Copyright ©ERS 2016.

  14. Positive pressure ventilation and cranial volume in newborn infants.

    OpenAIRE

    Milligan, D W

    1981-01-01

    The relationship between changes in airways pressure, pleural pressure, and cranial volume was studied in a group of sick newborn infants requiring ventilatory assistance. Cranial volume increased appreciably only when lung compliance was such that more than 20% of the applied airways pressure was transmitted to the pleural space, or if the absolute pleural pressure was greater than 4 cmH2O above atmospheric pressure. The findings stress the need for more-critical monitoring during periods of...

  15. Automatic delineation of functional lung volumes with 68Ga-ventilation/perfusion PET/CT.

    Science.gov (United States)

    Le Roux, Pierre-Yves; Siva, Shankar; Callahan, Jason; Claudic, Yannis; Bourhis, David; Steinfort, Daniel P; Hicks, Rodney J; Hofman, Michael S

    2017-10-10

    Functional volumes computed from 68 Ga-ventilation/perfusion (V/Q) PET/CT, which we have shown to correlate with pulmonary function test parameters (PFTs), have potential diagnostic utility in a variety of clinical applications, including radiotherapy planning. An automatic segmentation method would facilitate delineation of such volumes. The aim of this study was to develop an automated threshold-based approach to delineate functional volumes that best correlates with manual delineation. Thirty lung cancer patients undergoing both V/Q PET/CT and PFTs were analyzed. Images were acquired following inhalation of Galligas and, subsequently, intravenous administration of 68 Ga-macroaggreted-albumin (MAA). Using visually defined manual contours as the reference standard, various cutoff values, expressed as a percentage of the maximal pixel value, were applied. The average volume difference and Dice similarity coefficient (DSC) were calculated, measuring the similarity of the automatic segmentation and the reference standard. Pearson's correlation was also calculated to compare automated volumes with manual volumes, and automated volumes optimized to PFT indices. For ventilation volumes, mean volume difference was lowest (- 0.4%) using a 15%max threshold with Pearson's coefficient of 0.71. Applying this cutoff, median DSC was 0.93 (0.87-0.95). Nevertheless, limits of agreement in volume differences were large (- 31.0 and 30.2%) with differences ranging from - 40.4 to + 33.0%. For perfusion volumes, mean volume difference was lowest and Pearson's coefficient was highest using a 15%max threshold (3.3% and 0.81, respectively). Applying this cutoff, median DSC was 0.93 (0.88-0.93). Nevertheless, limits of agreement were again large (- 21.1 and 27.8%) with volume differences ranging from - 18.6 to + 35.5%. Using the 15%max threshold, moderate correlation was demonstrated with FEV1/FVC (r = 0.48 and r = 0.46 for ventilation and perfusion images, respectively

  16. A comparison of synchronized intermittent mandatory ventilation and pressure-regulated volume control ventilation in elderly patients with acute exacerbations of COPD and respiratory failure.

    Science.gov (United States)

    Chang, Suchi; Shi, Jindong; Fu, Cuiping; Wu, Xu; Li, Shanqun

    2016-01-01

    COPD is the third leading cause of death worldwide. Acute exacerbations of COPD may cause respiratory failure, requiring intensive care unit admission and mechanical ventilation. Intensive care unit patients with acute exacerbations of COPD requiring mechanical ventilation have higher mortality rates than other hospitalized patients. Although mechanical ventilation is the most effective intervention for these conditions, invasive ventilation techniques have yielded variable effects. We evaluated pressure-regulated volume control (PRVC) ventilation treatment efficacy and preventive effects on pulmonary barotrauma in elderly COPD patients with respiratory failure. Thirty-nine intubated patients were divided into experimental and control groups and treated with the PRVC and synchronized intermittent mandatory ventilation - volume control methods, respectively. Vital signs, respiratory mechanics, and arterial blood gas analyses were monitored for 2-4 hours and 48 hours. Both groups showed rapidly improved pH, partial pressure of oxygen (PaO2), and PaO2 per fraction of inspired O2 levels and lower partial pressure of carbon dioxide (PaCO2) levels. The pH and PaCO2 levels at 2-4 hours were lower and higher, respectively, in the test group than those in the control group (P0.05). Vital signs during 2-4 hours and 48 hours of treatment showed no statistical difference in either group (P>0.05). The level of peak inspiratory pressure in the experimental group after mechanical ventilation for 2-4 hours and 48 hours was significantly lower than that in the control group (P0.05). Among elderly COPD patients with respiratory failure, application of PRVC resulted in rapid improvement in arterial blood gas analyses while maintaining a low peak inspiratory pressure. PRVC can reduce pulmonary barotrauma risk, making it a safer protective ventilation mode than synchronized intermittent mandatory ventilation - volume control.

  17. SU-E-J-249: Correlation of Mean Lung Ventilation Value with Ratio of Total Lung Volumes

    International Nuclear Information System (INIS)

    Yu, N; Qu, H; Xia, P

    2014-01-01

    Purpose: Lung ventilation function measured from 4D-CT and from breathing correlated CT images is a novel concept to incorporate the lung physiologic function into treatment planning of radiotherapy. The calculated ventilation functions may vary from different breathing patterns, affecting evaluation of the treatment plans. The purpose of this study is to correlate the mean lung ventilation value with the ratio of the total lung volumes obtained from the relevant CTs. Methods: A ventilation map was calculated from the variations of voxel-to-voxel CT densities from two breathing phases from either 4D-CT or breathing correlated CTs. An open source image registration tool of Plastimatch was used to deform the inhale phase images to the exhale phase images. To calculate the ventilation map inside lung, the whole lung was delineated and the tissue outside the lung was masked out. With a software tool developed in house, the 3D ventilation map was then converted in the DICOM format associated with the planning CT images. The ventilation map was analyzed on a clinical workstation. To correlate ventilation map thus calculated with lung volume change, the total lung volume change was compared the mean ventilation from our method. Results: Twenty two patients who underwent stereotactic body irradiation for lung cancer was selected for this retrospective study. For this group of patients, the ratio of lung volumes for the inhale (Vin ) and exhale phase (Vex ) was shown to be linearly related to the mean of the local ventilation (Vent), Vin/Vex=1.+0.49*Vent (R2=0.93, p<0.01). Conclusion: The total lung volume change is highly correlated with the mean of local ventilation. The mean of local ventilation may be useful to assess the patient's lung capacity

  18. Automated pulmonary lobar ventilation measurements using volume-matched thoracic CT and MRI

    Science.gov (United States)

    Guo, F.; Svenningsen, S.; Bluemke, E.; Rajchl, M.; Yuan, J.; Fenster, A.; Parraga, G.

    2015-03-01

    Objectives: To develop and evaluate an automated registration and segmentation pipeline for regional lobar pulmonary structure-function measurements, using volume-matched thoracic CT and MRI in order to guide therapy. Methods: Ten subjects underwent pulmonary function tests and volume-matched 1H and 3He MRI and thoracic CT during a single 2-hr visit. CT was registered to 1H MRI using an affine method that incorporated block-matching and this was followed by a deformable step using free-form deformation. The resultant deformation field was used to deform the associated CT lobe mask that was generated using commercial software. 3He-1H image registration used the same two-step registration method and 3He ventilation was segmented using hierarchical k-means clustering. Whole lung and lobar 3He ventilation and ventilation defect percent (VDP) were generated by mapping ventilation defects to CT-defined whole lung and lobe volumes. Target CT-3He registration accuracy was evaluated using region- , surface distance- and volume-based metrics. Automated whole lung and lobar VDP was compared with semi-automated and manual results using paired t-tests. Results: The proposed pipeline yielded regional spatial agreement of 88.0+/-0.9% and surface distance error of 3.9+/-0.5 mm. Automated and manual whole lung and lobar ventilation and VDP were not significantly different and they were significantly correlated (r = 0.77, p pulmonary structural-functional maps with high accuracy and robustness, providing an important tool for image-guided pulmonary interventions.

  19. Tracheal tube airleak in clinical practice and impact on tidal volume measurement in ventilated neonates.

    Science.gov (United States)

    Mahmoud, Ramadan A; Proquitté, Hans; Fawzy, Naglaa; Bührer, Christoph; Schmalisch, Gerd

    2011-03-01

    To determine the prevalence, size, and factors affecting tracheal tube (TT) leak in clinical practice and their influence on the displayed tidal volume (Vt) in ventilated newborn infants using uncuffed TTs. Monitoring of Vt is important for implementation of lung-protective ventilation strategies but becomes meaningless in the presence of large TT airleaks. Retrospective clinical study. Neonatal intensive care unit. Patient records of 163 neonates ventilated with Babylog 8000 for ≥ 5 hrs with a median (range) gestation age of 31.1 wks (23.3-41.9 wks) and a median birth weight of 1470 g (410-4475 g) were evaluated. : Ventilatory settings, TT leak, and Vt were recorded every 3 hrs. The lowest, median, and highest TT leaks were noted on the day the first TT leak (>5%) occurred, the day on which TT leak peaked, and the day of extubation. A TT leak of >5% was seen in 122 (75%) infants. Neonates with TT leak, compared with those without TT leak, had a longer duration of mechanical ventilation (p 40% commonly seen on the third day of mechanical ventilation. Regression analysis showed that a TT leak of 40% indicated that the displayed Vt was underestimated by 1.2 mL/kg (about 24% of target Vt). TT leak is highly variable, and TT leak of >40% with clinically relevant Vt errors occurred in nearly half of all ventilated neonates. Preterm infants of low birth weight and with small-diameter TTs ventilated for a long period were at greater risk of TT leak.

  20. Displacement ventilation

    DEFF Research Database (Denmark)

    Kosonen, Risto; Melikov, Arsen Krikor; Mundt, Elisabeth

    The aim of this Guidebook is to give the state-of-the art knowledge of the displacement ventilation technology, and to simplify and improve the practical design procedure. The Guidebook discusses methods of total volume ventilation by mixing ventilation and displacement ventilation and it gives...... insights of the performance of the displacement ventilation. It also shows practical case studies in some typical applications and the latest research findings to create good local micro-climatic conditions....

  1. Lung volumes, pulmonary ventilation, and hypoxia following rapid decompression to 60,000 ft (18,288 m).

    Science.gov (United States)

    Connolly, Desmond M; D'Oyly, Timothy J; McGown, Amanda S; Lee, Vivienne M

    2013-06-01

    Rapid decompressions (RD) to 60,000 ft (18,288 m) were undertaken by six subjects to provide evidence of satisfactory performance of a contemporary, partial pressure assembly life support system for the purposes of flight clearance. A total of 12 3-s RDs were conducted with subjects breathing 56% oxygen (balance nitrogen) at the base (simulated cabin) altitude of 22,500 ft (6858 m), switching to 100% oxygen under 72 mmHg (9.6 kPa) of positive pressure at the final (simulated aircraft) altitude. Respiratory pressures, flows, and gas compositions were monitored continuously throughout. All RDs were completed safely, but one subject experienced significant hypoxia during the minute at final altitude, associated with severe hemoglobin desaturation to a low of 53%. Accurate data on subjects' lung volumes were obtained and individual responses post-RD were reviewed in relation to patterns of pulmonary ventilation. The occurrence of severe hypoxia is explained by hypoventilation in conjunction with unusually large lung volumes (total lung capacity 10.18 L). Subjects' lung volumes and patterns of pulmonary ventilation are critical, but idiosyncratic, determinants of alveolar oxygenation and severity of hypoxia following RD to 60,000 ft (18,288 m). At such extreme altitudes even vaporization of water condensate in the oxygen mask may compromise oxygen delivery. An altitude ceiling of 60,000 ft (18,288 m) is the likely threshold for reliable protection using partial pressure assemblies and aircrew should be instructed to take two deep 'clearing' breaths immediately following RD at such extreme pressure breathing altitudes.

  2. A comparison of synchronized intermittent mandatory ventilation and pressure-regulated volume control ventilation in elderly patients with acute exacerbations of COPD and respiratory failure

    Directory of Open Access Journals (Sweden)

    Chang SC

    2016-05-01

    Full Text Available Suchi Chang,1 Jindong Shi,2 Cuiping Fu,1 Xu Wu,1 Shanqun Li1 1Department of Respiratory Medicine, Zhongshan Hospital, Fudan University, Shanghai, 2Department of Respiratory Medicine, The Fifth People’s Hospital of Shanghai, Fudan University, Shanghai, People’s Republic of China Background: COPD is the third leading cause of death worldwide. Acute exacerbations of COPD may cause respiratory failure, requiring intensive care unit admission and mechanical ventilation. Intensive care unit patients with acute exacerbations of COPD requiring mechanical ventilation have higher mortality rates than other hospitalized patients. Although mechanical ventilation is the most effective intervention for these conditions, invasive ventilation techniques have yielded variable effects. Objective: We evaluated pressure-regulated volume control (PRVC ventilation treatment efficacy and preventive effects on pulmonary barotrauma in elderly COPD patients with respiratory failure. Patients and methods: Thirty-nine intubated patients were divided into experimental and control groups and treated with the PRVC and synchronized intermittent mandatory ventilationvolume control methods, respectively. Vital signs, respiratory mechanics, and arterial blood gas analyses were monitored for 2–4 hours and 48 hours. Results: Both groups showed rapidly improved pH, partial pressure of oxygen (PaO2, and PaO2 per fraction of inspired O2 levels and lower partial pressure of carbon dioxide (PaCO2 levels. The pH and PaCO2 levels at 2–4 hours were lower and higher, respectively, in the test group than those in the control group (P<0.05 for both; after 48 hours, blood gas analyses showed no statistical difference in any marker (P>0.05. Vital signs during 2–4 hours and 48 hours of treatment showed no statistical difference in either group (P>0.05. The level of peak inspiratory pressure in the experimental group after mechanical ventilation for 2–4 hours and 48

  3. Intraoperative ventilation: incidence and risk factors for receiving large tidal volumes during general anesthesia

    Directory of Open Access Journals (Sweden)

    Fernandez-Bustamante Ana

    2011-11-01

    Full Text Available Abstract Background There is a growing concern of the potential injurious role of ventilatory over-distention in patients without lung injury. No formal guidelines exist for intraoperative ventilation settings, but the use of tidal volumes (VT under 10 mL/kg predicted body weight (PBW has been recommended in healthy patients. We explored the incidence and risk factors for receiving large tidal volumes (VT > 10 mL/kg PBW. Methods We performed a cross-sectional analysis of our prospectively collected perioperative electronic database for current intraoperative ventilation practices and risk factors for receiving large tidal volumes (VT > 10 mL/kg PBW. We included all adults undergoing prolonged (≥ 4 h elective abdominal surgery and collected demographic, preoperative (comorbidities, intraoperative (i.e. ventilatory settings, fluid administration and postoperative (outcomes information. We compared patients receiving exhaled tidal volumes > 10 mL/kg PBW with those that received 8-10 or Results Ventilatory settings were non-uniform in the 429 adults included in the analysis. 17.5% of all patients received VT > 10 mL/kg PBW. 34.0% of all obese patients (body mass index, BMI, ≥ 30, 51% of all patients with a height T > 10 mL/kg PBW. Conclusions Ventilation with VT > 10 mL/kg PBW is still common, although poor correlation with PBW suggests it may be unintentional. BMI ≥ 30, female gender and height

  4. A comparison of conventional surfactant treatment and partial liquid ventilation on the lung volume of injured ventilated small lungs

    International Nuclear Information System (INIS)

    Proquitté, Hans; Hartenstein, Sebastian; Wauer, Roland R; Schmalisch, Gerd; Koelsch, Uwe; Rüdiger, Mario

    2013-01-01

    As an alternative to surfactant therapy (ST), partial liquid ventilation (PLV) with perfluorocarbons (PFC) has been considered as a treatment for acute lung injury (ALI) in newborns. The instilled PFC is much heavier than the instilled surfactant and the aim of this study was to investigate whether PLV, compared to ST, increases the end-expiratory volume of the lung (V L ). Fifteen newborn piglets (age <12 h, mean weight 678 g) underwent saline lung lavage to achieve a surfactant depletion. Thereafter animals were randomized to PLV (n = 8), receiving PFC PF5080 (3M, Germany) at 30 mL kg −1 , and ST (n = 7) receiving 120 mg Curosurf®. Blood gases, hemodynamics and static compliance were measured initially (baseline), immediately after ALI, and after 240 min mechanical ventilation with either technique. Subsequently all piglets were killed; the lungs were removed in toto and frozen in liquid N 2 . After freeze-drying the lungs were cut into lung cubes (LCs) with edge lengths of 0.7 cm, to calculate V L . All LCs were weighed and the density of the dried lung tissue was calculated. No statistically significant differences between treatment groups PLV and ST (means ± SD) were noted in body weight (676 ± 16 g versus 679 ± 17 g; P = 0.974) or lung dry weight (1.64 ± 0.29 g versus 1.79 ± 0.48 g; P = 0.48). Oxygenation index and ventilatory efficacy index did not differ significantly between both groups at any time. V L (34.28 ± 6.13 mL versus 26.22 ± 8.1 mL; P < 0.05) and the density of the dried lung tissue (48.07 ± 5.02 mg mL −1 versus 69.07 ± 5.30 mg mL −1 ; P < 0.001), however, differed significantly between the PLV and ST groups. A 4 h PLV treatment of injured ventilated small lungs increased V L by 30% and decreased lung density by 31% compared to ST treatment, indicating greater lung distension after PLV compared to ST. (paper)

  5. Smaller self-inflating bags produce greater guideline consistent ventilation in simulated cardiopulmonary resuscitation.

    Science.gov (United States)

    Nehme, Ziad; Boyle, Malcolm J

    2009-02-20

    Suboptimal bag ventilation in cardiopulmonary resuscitation (CPR) has demonstrated detrimental physiological outcomes for cardiac arrest patients. In light of recent guideline changes for resuscitation, there is a need to identify the efficacy of bag ventilation by prehospital care providers. The objective of this study was to evaluate bag ventilation in relation to operator ability to achieve guideline consistent ventilation rate, tidal volume and minute volume when using two different capacity self-inflating bags in an undergraduate paramedic cohort. An experimental study using a mechanical lung model and a simulated adult cardiac arrest to assess the ventilation ability of third year Monash University undergraduate paramedic students. Participants were instructed to ventilate using 1600 ml and 1000 ml bags for a length of two minutes at the correct rate and tidal volume for a patient undergoing CPR with an advanced airway. Ventilation rate and tidal volume were recorded using an analogue scale with mean values calculated. Ethics approval was granted. Suboptimal ventilation with the use of conventional 1600 ml bag was common, with 77% and 97% of participants unable to achieve guideline consistent ventilation rates and tidal volumes respectively. Reduced levels of suboptimal ventilation arouse from the use of the smaller bag with a 27% reduction in suboptimal tidal volumes (p = 0.015) and 23% reduction in suboptimal minute volumes (p = 0.045). Smaller self-inflating bags reduce the incidence of suboptimal tidal volumes and minute volumes and produce greater guideline consistent results for cardiac arrest patients.

  6. [Study of setting of ventilator volume tidal and airway pressure alarm threshold with continuous extra-sternum heart compression in cardiopulmonary resuscitation].

    Science.gov (United States)

    Luo, Jian-yu; Wang, Xiao-yuan; Cai, Tian-bin; Jiang, Wen-fang

    2013-02-01

    To investigate the setting of ventilator volume tidal (VT) and airway pressure alarm threshold during cardiopulmonary resuscitation (CPR) by continuous extra-sternum heart compression. Forty cases with respiration and cardiac arrest in the department of critical care medicine were randomly divided into low VT ventilation group and conventional VT group. Both groups were given the volume control mode. In the low VT ventilation group, VT was set on 6 - 7 ml/kg, and high pressure alarm threshold was adjusted to 60 cm H2O by the conventional 40 cm H2O during CPR. In the conventional VT group, VT and high pressure alarm threshold were set at 8 - 12 ml/kg and 40 cm H2O, respectively. Real-time actual VT, peak inspiratory pressure (PIP), and arterial blood gas test, blood lactic acid at 10 minutes and 30 minutes after CPR were observed. At 10 minutes after CPR, in the low VT ventilation group, arterial blood pH, arterial partial pressure of oxygen (PaO2), arterial partial pressure of carbon dioxide (PaCO2), HCO3(-), arterial oxygen saturation (SaO2) and blood lactic acid were better as compared with those in the conventional VT ventilation group (pH: 7.21±0.09 vs. 7.13±0.07, PaO2: 45.35±5.92 mm Hg vs. 40.70±4.70 mm Hg, PaCO2: 57.10±7.59 mm Hg vs. 61.60±5.47 mm Hg, HCO3(-): 18.50±3.50 mmol/L vs. 14.75±2.65 mmol/L, SaO2: 0.796±0.069 vs. 0.699±0.066, blood lactic acid: 7.07±1.60 mmol/L vs. 8.13±1.56 mmol/L, all P<0.05). The success rate of resuscitation in the low VT ventilation group was higher than that of the conventional VT ventilation group (45% vs. 15%, P<0.05), and PIP (cm H2O) of low VT ventilation group was lower than that of the conventional VT group (37.25±7.99 cm H2O vs. 42.70±7.40 cm H2O, P<0.05). In all the patients in both groups barotrauma did not occur. The strategy of low ventilator VT (6 - 7 ml/kg) with appropriate elevation of airway pressure alarm threshold was better than that of conventional ventilation setting, with no increase in

  7. Tidal volume delivery from ICU ventilators at BTPS conditions: a bench study.

    Science.gov (United States)

    Duchateau, Paul; Guérin, Claude

    2013-04-01

    Even though it is not a common practice, an external filter to the expiratory limb of the breathing circuit may protect the expiratory valve from water saturation in case of nebulization, or from the environment in case of lung infection with multi-drug-resistant micro-organisms or H1N1 influenza. We added an external filter to the expiratory limb and measured tidal volume (VT) from 6 ICU ventilators: 2 with built-in expiratory filter (Avea, Puritan Bennett 840), and 4 without (Engström Carestation, Evita XL, Evita V500, and Servo-i), set in volume controlled mode, at BTPS (body temperature and pressure saturated) condition, with a heated humidifier and a lung model (compliance 16 mL/cm H2O, resistance 20 cm H2O/L/s) placed inside a neonatal incubator. The temperature was targeted at 37°C for both the heated humidifier and the incubator. The setup was run continuously for 24 hours. In the latter 4 ICU ventilators, a Hygrobac or Sterivent S external filter was placed upstream from the expiratory valve for an additional 24-hour period for each. At the end of this period, VT was measured at 4 nominal VT values (300, 400, 500, and 800 mL) with a pneumotachograph. The volume error computed from the ratio of set to measured VT (% set VT) was the primary end point. In these warm and wet conditions, volume error averaged 96 ± 3% for Avea, 100 ± 7% for Puritan Bennett 840, 90 ± 2% for Evita XL, 100 ± 7% for Evita V500, 105 ± 2% for Servo-i, and 108 ± 4% for Engström Carestation (P ventilators for VT delivery, with further significant changes occurring after addition of a filter at the distal expiratory limb.

  8. Modulating ventilation - low cost VAV for office buildings. [Variable Air Volume]; Modulerende ventilation - low cost VAV til kontor-bygninger. Slutrapport

    Energy Technology Data Exchange (ETDEWEB)

    Hoej Christensen, A.; Olsen, Hans; Drivsholm, C.

    2012-02-15

    The report describes a concept for renovating older existing Constant Air Volume (CAV) ventilation systems to modulating low-cost Variable Air Volume (VAV) systems. The concept is based on the total ventilated area being divided into appropriate indoor climate zones, which can cover from one to several offices with similar climate needs. For this initial climate assessment two relatively ''simple'' tools were developed that can estimate the temperature level in one room from the ventilation airflow, heat loads, etc.: - BSimFast (24-hour mean temperature calculation according to SBI-196, 2000); - BSimLight (Temperature simulation based on Danvak Textbook of Heat and Climate Technology). The concept of 'one room' can also be extended to 'one zone' with appropriate assumptions. However, only one mean room temperature is calculated. The different climate zones were equipped with Halton HFB control unit at the air supply and exhaust side. The project the following feedback options were used: - HFB unit's damper opening degree (0 to 90 degrees); - HFB unit's current flow; - HFB unit's exhaust temperature; and feedback from: - Frequency transformer (fan speed); - The central static duct pressure at the ventilation unit. In the project a control algorithm is developed that ensures a robust control of the entire ventilation system without adverse cyclic variations, based among other things on the exhaust temperature for each climate zone, and with the requirement that at least one throttle valve is always at least 80% open. It turned out that information on the current partial air volumes was necessary in addition to the individual throttle settings. Otherwise, a cyclic variations could not be controlled..Thus, it was the exhaust temperature from individual climate zones that defined the respective volumes of air. The concept was implemented on a complete CAV system and on part of a large CAV system, respectively. (LN)

  9. High tidal volume decreases adult respiratory distress syndrome, atelectasis, and ventilator days compared with low tidal volume in pediatric burned patients with inhalation injury.

    Science.gov (United States)

    Sousse, Linda E; Herndon, David N; Andersen, Clark R; Ali, Arham; Benjamin, Nicole C; Granchi, Thomas; Suman, Oscar E; Mlcak, Ronald P

    2015-04-01

    Inhalation injury, which is among the causes of acute lung injury and acute respiratory distress syndrome (ARDS), continues to represent a significant source of mortality in burned patients. Inhalation injury often requires mechanical ventilation, but the ideal tidal volume strategy is not clearly defined in burned pediatric patients. The aim of this study was to determine the effects of low and high tidal volume on the number of ventilator days, ventilation pressures, and incidence of atelectasis, pneumonia, and ARDS in pediatric burned patients with inhalation injury within 1 year post burn injury. From 1986 to 2014, inhalation injury was diagnosed by bronchoscopy in pediatric burned patients (n = 932). Patients were divided into 3 groups: unventilated (n = 241), high tidal volume (HTV, 15 ± 3 mL/kg, n = 190), and low tidal volume (LTV, 9 ± 3 mL/kg, n = 501). High tidal volume was associated with significantly decreased ventilator days (p tidal volume significantly decreases ventilator days and the incidence of both atelectasis and ARDS compared with low tidal volume in pediatric burned patients with inhalation injury. Therefore, the use of HTV may interrupt sequences leading to lung injury in our patient population. Copyright © 2015 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

  10. [The assessment of ultrasonic measurement of superior vena cava blood flow for the volume responsiveness of patients with mechanical ventilation].

    Science.gov (United States)

    Guo, Zhe; He, Wei; Hou, Jing; Li, Tong; Zhou, Hua; Xu, Yuan; Xi, Xiuming

    2014-09-01

    To approach the evaluative effect of respiratory variation of superior vena cava peak flow velocity measured using transthoracic echocardiography (TTE) on fluid responsiveness in patients with mechanical ventilation. A prospective cohort study was conducted. All mechanical ventilated critically ill patients whose fluid therapy was planned due to hypovolemia in Department of Critical Care Medicine of Beijing Tongren Hospital of Capital Medical University from April 2011 to April 2013 were enrolled. Volume expansion was performed with 500 mL Linger solution within 30 minutes. Patients were classified as responders if pulse pressure variation (PPV) increased ≥ 13% before volume expansion. The respiratory variation in superior vena cava peak velocity was calculated as the difference between maximum and minimum values of velocity in peak A, peak S and peak D over a single respiratory circle, and their variations (ΔA, ΔS, ΔD) were also calculated. The receiver operating characteristic curve (ROC curve) was plotted to assess the evaluative effect of respiratory variation of superior vena cava peak velocity on fluid responsiveness. Twenty-seven patients were enrolled in this study. Volume expansion increased PPV ≥ 13% happened in 14 patients (responders). The velocity of superior vena cava in peak A, peak S, peak D was significantly increased after volume expansion compared with that before volume expansion in responders [peak A (cm/s): 34.6 ± 2.2 vs. 31.3 ± 2.1, t=-2.493, P=0.027; peak S (cm/s): 39.1 ± 1.3 vs. 35.3 ± 2.1, t=-2.564, P=0.024; peak D (cm/s): 28.1 ± 1.2 vs. 23.3 ± 1.4, t=-4.995, P=0.000], but there was no significant difference in ΔA, ΔS and ΔD between before and after volume expansion. The ΔA, ΔS and ΔD were positively correlated with PPV (r=0.040, P=0.854; r=0.350, P=0.074; r=0.749, P=0.000). The area under ROC curve (AUC) of peak S was 0.36 [95% confidence interval (95%CI): 0.11-0.52], but the AUC of ΔS was 0.68 (95%CI 0.47-0.89), the

  11. Initial mechanical ventilator settings and lung protective ventilation in the ED.

    Science.gov (United States)

    Wilcox, Susan R; Richards, Jeremy B; Fisher, Daniel F; Sankoff, Jeffrey; Seigel, Todd A

    2016-08-01

    Mechanical ventilation with low tidal volumes has been shown to improve outcomes for patients both with and without acute respiratory distress syndrome. This study aims to characterize mechanically ventilated patients in the emergency department (ED), describe the initial ED ventilator settings, and assess for associations between lung protective ventilation strategies in the ED and outcomes. This was a multicenter, prospective, observational study of mechanical ventilation at 3 academic EDs. We defined lung protective ventilation as a tidal volume of less than or equal to 8 mL/kg of predicted body weight and compared outcomes for patients ventilated with lung protective vs non-lung protective ventilation, including inhospital mortality, ventilator days, intensive care unit length of stay, and hospital length of stay. Data from 433 patients were analyzed. Altered mental status without respiratory pathology was the most common reason for intubation, followed by trauma and respiratory failure. Two hundred sixty-one patients (60.3%) received lung protective ventilation, but most patients were ventilated with a low positive end-expiratory pressure, high fraction of inspired oxygen strategy. Patients were ventilated in the ED for a mean of 5 hours and 7 minutes but had few ventilator adjustments. Outcomes were not significantly different between patients receiving lung protective vs non-lung protective ventilation. Nearly 40% of ED patients were ventilated with non-lung protective ventilation as well as with low positive end-expiratory pressure and high fraction of inspired oxygen. Despite a mean ED ventilation time of more than 5 hours, few patients had adjustments made to their ventilators. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Effect of leak and breathing pattern on the accuracy of tidal volume estimation by commercial home ventilators: a bench study.

    Science.gov (United States)

    Luján, Manel; Sogo, Ana; Pomares, Xavier; Monsó, Eduard; Sales, Bernat; Blanch, Lluís

    2013-05-01

    New home ventilators are able to provide clinicians data of interest through built-in software. Monitoring of tidal volume (VT) is a key point in the assessment of the efficacy of home mechanical ventilation. To assess the reliability of the VT provided by 5 ventilators in a bench test. Five commercial ventilators from 4 different manufacturers were tested in pressure support mode with the help of a breathing simulator under different conditions of mechanical respiratory pattern, inflation pressure, and intentional leakage. Values provided by the built-in software of each ventilator were compared breath to breath with the VT monitored through an external pneumotachograph. Ten breaths for each condition were compared for every tested situation. All tested ventilators underestimated VT (ranges of -21.7 mL to -83.5 mL, which corresponded to -3.6% to -14.7% of the externally measured VT). A direct relationship between leak and underestimation was found in 4 ventilators, with higher underestimations of the VT when the leakage increased, ranging between -2.27% and -5.42% for each 10 L/min increase in the leakage. A ventilator that included an algorithm that computes the pressure loss through the tube as a function of the flow exiting the ventilator had the minimal effect of leaks on the estimation of VT (0.3%). In 3 ventilators the underestimation was also influenced by mechanical pattern (lower underestimation with restrictive, and higher with obstructive). The inclusion of algorithms that calculate the pressure loss as a function of the flow exiting the ventilator in commercial models may increase the reliability of VT estimation.

  13. Is pulmonary resistance constant, within the range of tidal volume ventilation, in patients with ARDS?

    Science.gov (United States)

    Mols, G; Kessler, V; Benzing, A; Lichtwarck-Aschoff, M; Geiger, K; Guttmann, J

    2001-02-01

    When managing patients with acute respiratory distress syndrome (ARDS), respiratory system compliance is usually considered first and changes in resistance, although recognized, are neglected. Resistance can change considerably between minimum and maximum lung volume, but is generally assumed to be constant in the tidal volume range (V(T)). We measured resistance during tidal ventilation in 16 patients with ARDS or acute lung injury by the slice method and multiple linear regression analysis. Resistance was constant within V(T) in only six of 16 patients. In the remaining patients, resistance decreased, increased or showed complex changes. We conclude that resistance within V(T) varies considerably from patient to patient and that constant resistance within V(T) is not always likely.

  14. Experimental analysis of fuzzy controlled energy efficient demand controlled ventilation economizer cycle variable air volume air conditioning system

    Directory of Open Access Journals (Sweden)

    Rajagopalan Parameshwaran

    2008-01-01

    Full Text Available In the quest for energy conservative building design, there is now a great opportunity for a flexible and sophisticated air conditioning system capable of addressing better thermal comfort, indoor air quality, and energy efficiency, that are strongly desired. The variable refrigerant volume air conditioning system provides considerable energy savings, cost effectiveness and reduced space requirements. Applications of intelligent control like fuzzy logic controller, especially adapted to variable air volume air conditioning systems, have drawn more interest in recent years than classical control systems. An experimental analysis was performed to investigate the inherent operational characteristics of the combined variable refrigerant volume and variable air volume air conditioning systems under fixed ventilation, demand controlled ventilation, and combined demand controlled ventilation and economizer cycle techniques for two seasonal conditions. The test results of the variable refrigerant volume and variable air volume air conditioning system for each techniques are presented. The test results infer that the system controlled by fuzzy logic methodology and operated under the CO2 based mechanical ventilation scheme, effectively yields 37% and 56% per day of average energy-saving in summer and winter conditions, respectively. Based on the experimental results, the fuzzy based combined system can be considered to be an alternative energy efficient air conditioning scheme, having significant energy-saving potential compared to the conventional constant air volume air conditioning system.

  15. FCT (functional computed tomography) evaluation of the lung volumes at different PEEP (positive-end expiratory pressure) ventilation pattern, in mechanical ventilated patients

    International Nuclear Information System (INIS)

    Papi, M.G.; Di Segni, R.; Mazzetti, G.; Staffa, F.; Conforto, F.; Calimici, R.; Salvi, A.; Matteucci, G.

    2007-01-01

    Purpose To evaluate with FCT (functional computed tomography) total lung volume and fractional lung volumes at different PEEP (positive end expiratory pressure) values in acute mechanically ventilated patients. Methods Nine ICU (intensive care unity) patients (1 lung pneumonia, 2 polytrauma, 2 sepsis, 3 brain surgery, 1 pulmonary embolism); mean age 48 ± 15 years, 6 male, 3 female; GE 16 MDCT scan was performed with acquisition from apex to diaphragma in seven seca at different PEEP values. Raw CT data were analysed by an advantage workstation to obtain volume density masks and histograms of both lungs and each lung and these density ranges were applied: - 1000 - 950 hyper-ventilated lung, -900 - 650 well aerated lung, -950 - 500 all aerated lung, -500 + 200 lung tissue. Total and fractional lung volumes, Hounsfield unit (HU) were calculated and compared at different PEEP values (0, 5, 10, 15 cm H 2 O). In four patients lung volumes were compared between the more and the less involved lung at increased PEEP. Statistic analysis: comparison means-medians tests. Results Data calculated at five PEEP showed unexpected decrease of total lung volume and increase of lung density (HU); proportionally no significant improvement of oxigenation. (orig.)

  16. FCT (functional computed tomography) evaluation of the lung volumes at different PEEP (positive-end expiratory pressure) ventilation pattern, in mechanical ventilated patients

    Energy Technology Data Exchange (ETDEWEB)

    Papi, M.G.; Di Segni, R.; Mazzetti, G.; Staffa, F. [Dept. of Radiology, S. Giovanni HS, Rome (Italy); Conforto, F.; Calimici, R.; Salvi, A. [Dept. of Anesthesiology, S. Giovanni HS, Rome (Italy); Matteucci, G. [Dept. of Pneumology, S. Giovanni HS, Rome (Italy)

    2007-06-15

    Purpose To evaluate with FCT (functional computed tomography) total lung volume and fractional lung volumes at different PEEP (positive end expiratory pressure) values in acute mechanically ventilated patients. Methods Nine ICU (intensive care unity) patients (1 lung pneumonia, 2 polytrauma, 2 sepsis, 3 brain surgery, 1 pulmonary embolism); mean age 48 {+-} 15 years, 6 male, 3 female; GE 16 MDCT scan was performed with acquisition from apex to diaphragma in seven seca at different PEEP values. Raw CT data were analysed by an advantage workstation to obtain volume density masks and histograms of both lungs and each lung and these density ranges were applied: - 1000 - 950 = hyper-ventilated lung, -900 - 650 well aerated lung, -950 - 500 all aerated lung, -500 + 200 lung tissue. Total and fractional lung volumes, Hounsfield unit (HU) were calculated and compared at different PEEP values (0, 5, 10, 15 cm H{sub 2}O). In four patients lung volumes were compared between the more and the less involved lung at increased PEEP. Statistic analysis: comparison means-medians tests. Results Data calculated at five PEEP showed unexpected decrease of total lung volume and increase of lung density (HU); proportionally no significant improvement of oxigenation. (orig.)

  17. [Anesthesia ventilators].

    Science.gov (United States)

    Otteni, J C; Beydon, L; Cazalaà, J B; Feiss, P; Nivoche, Y

    1997-01-01

    To review anaesthesia ventilators in current use in France by categories of ventilators. References were obtained from computerized bibliographic search. (Medline), recent review articles, the library of the service and personal files. Anaesthesia ventilators can be allocated into three groups, depending on whether they readminister expired gases or not or allow both modalities. Contemporary ventilators provide either constant volume ventilation, or constant pressure ventilation, with or without a pressure plateau. Ventilators readministering expired gases after CO2 absorption, or closed circuit ventilators, are either of a double- or a single-circuit design. Double-circuit ventilators, or pneumatical bag or bellows squeezers, or bag-in-bottle or bellows-in-bottle (or box) ventilators, consist of a primary, or driving circuit (bottle or box) and a secondary or patient circuit (including a bag or a bellows or membrane chambers). Bellows-in-bottle ventilators have either standing bellows ascending at expiration, or hanging bellows, descending at expiration. Ascending bellows require a positive pressure of about 2 cmH2O throughout exhalation to allow the bellows to refill. The expired gas volume is a valuable indicator for leak and disconnection. Descending bellows generate a slight negative pressure during exhalation. In case of leak or disconnection they aspirate ambient air and cannot act therefore as an indicator for integrity of the circuit and the patient connection. Closed circuit ventilators with a single-circuit (patient circuit) include a insufflating device consisting either in a bellows or a cylinder with a piston, operated by a electric or pneumatic motor. As the hanging bellows of the double circuit ventilators, they generate a slight negative pressure during exhalation and aspirate ambient air in case of leak or disconnection. Ventilators not designed for the readministration of expired gases, or open circuit ventilators, are generally stand

  18. Low tidal volume and high positive end-expiratory pressure mechanical ventilation results in increased inflammation and ventilator-associated lung injury in normal lungs.

    Science.gov (United States)

    Hong, Caron M; Xu, Da-Zhong; Lu, Qi; Cheng, Yunhui; Pisarenko, Vadim; Doucet, Danielle; Brown, Margaret; Aisner, Seena; Zhang, Chunxiang; Deitch, Edwin A; Delphin, Ellise

    2010-06-01

    Protective mechanical ventilation with low tidal volume (Vt) and low plateau pressure reduces mortality and decreases the length of mechanical ventilation in patients with acute respiratory distress syndrome. Mechanical ventilation that will protect normal lungs during major surgical procedures of long duration may improve postoperative outcomes. We performed an animal study comparing 3 ventilation strategies used in the operating room in normal lungs. We compared the effects on pulmonary mechanics, inflammatory mediators, and lung tissue injury. Female pigs were randomized into 3 groups. Group H-Vt/3 (n = 6) was ventilated with a Vt of 15 mL/kg predicted body weight (PBW)/positive end-expiratory pressure (PEEP) of 3 cm H(2)O, group L-Vt/3 (n = 6) with a Vt of 6 mL/kg PBW/PEEP of 3 cm H(2)O, and group L-Vt/10 (n = 6) with a Vt of 6 mL/kg PBW/PEEP of 10 cm H(2)O, for 8 hours. Hemodynamics, airway mechanics, arterial blood gases, and inflammatory markers were monitored. Bronchoalveolar lavage (BAL) was analyzed for inflammatory markers and protein concentration. The right lower lobe was assayed for mRNA of specific cytokines. The right lower lobe and right upper lobe were evaluated histologically. In contrast to groups H-Vt/3 and L-Vt/3, group L-Vt/10 exhibited a 6-fold increase in inflammatory mediators in BAL (P ventilation with high PEEP resulted in increased production of inflammatory markers. Low PEEP resulted in lower levels of inflammatory markers. High Vt/low PEEP resulted in less histologic lung injury.

  19. Tolerance of Volume Control Noninvasive Ventilation in Subjects With Amyotrophic Lateral Sclerosis.

    Science.gov (United States)

    Martínez, Daniel; Sancho, Jesús; Servera, Emilio; Marín, Julio

    2015-12-01

    Noninvasive ventilation (NIV) tolerance has been identified as an independent predictor of survival in amyotrophic lateral sclerosis (ALS). Volume control continuous mandatory ventilation (VC-CMV) NIV has been associated with poor tolerance. The aim of this study was to determine the tolerance of subjects with ALS to VC-CMV NIV. This was a prospective study involving subjects with ALS who were treated with VC-CMV NIV. Respiratory and functional parameters were recorded when the subjects began ventilatory support. NIV tolerance was evaluated after 3 months. Eighty-seven subjects with ALS were included. After 3 months, 80 subjects (92%) remained tolerant of NIV. Tolerant subjects presented greater survival (median 22.0 months, 95% CI 14.78-29.21) than intolerant subjects (median 6.0 months, 95% CI 0.86-11.13) (P = .03). The variables that best predicted NIV tolerance were mechanically assisted cough peak flow (P = .01) and percentage of time spent with SpO2 NIV (P = .03) CONCLUSIONS: VC-CMV NIV provides high rates of NIV tolerance in subjects with ALS. Mechanically assisted cough peak flow and percentage of time spent with SpO2 NIV are the 2 factors associated with tolerance of VC-CMV NIV in subjects with ALS. Copyright © 2015 by Daedalus Enterprises.

  20. Effects of inhalational anaesthesia with low tidal volume ventilation on end-tidal sevoflurane and carbon dioxide concentrations: prospective randomized study.

    Science.gov (United States)

    de la Matta-Martín, M; López-Herrera, D; Luis-Navarro, J C; López-Romero, J L

    2014-02-01

    We investigated how ventilation with low tidal volumes affects the pharmacokinetics of sevoflurane uptake during the first minutes of inhaled anaesthesia. Forty-eight patients scheduled for lung resection were randomly assigned to three groups. Patients in group 1, 2 and 3 received 3% sevoflurane for 3 min via face mask and controlled ventilation with a tidal volume of 2.2, 8 and 12 ml kg(-1), respectively (Phase 1). After tracheal intubation (Phase 2), 3% sevoflurane was supplied for 2 min using a tidal volume of 8 ml kg(-1) (Phase 3). End-tidal sevoflurane concentrations were significantly higher in group 1 at the end of phase 1 and lower at the end of phase 2 than in the other groups as follows: median of 2.5%, 2.2% and 2.3% in phase 1 for groups 1, 2 and 3, respectively (Ptidal carbon dioxide values in group 1 were significantly lower at the end of phase 1 and higher at the end of phase 2 than in the other groups as follows: median of 16.5, 31 and 29.5 mm Hg in phase 1 for groups 1, 2 and 3, respectively (Ptidal volume approximating the airway dead space volume, end-tidal sevoflurane and end-tidal carbon dioxide may not correctly reflect the concentration of these gases in the alveoli, leading to misinterpretation of expired gas data. Copyright © 2013 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Published by Elsevier España. All rights reserved.

  1. Predicting adult pulmonary ventilation volume and wearing complianceby on-board accelerometry during personal level exposure assessments

    Science.gov (United States)

    Rodes, C. E.; Chillrud, S. N.; Haskell, W. L.; Intille, S. S.; Albinali, F.; Rosenberger, M. E.

    2012-09-01

    BackgroundMetabolic functions typically increase with human activity, but optimal methods to characterize activity levels for real-time predictions of ventilation volume (l min-1) during exposure assessments have not been available. Could tiny, triaxial accelerometers be incorporated into personal level monitors to define periods of acceptable wearing compliance, and allow the exposures (μg m-3) to be extended to potential doses in μg min-1 kg-1 of body weight? ObjectivesIn a pilot effort, we tested: 1) whether appropriately-processed accelerometer data could be utilized to predict compliance and in linear regressions to predict ventilation volumes in real-time as an on-board component of personal level exposure sensor systems, and 2) whether locating the exposure monitors on the chest in the breathing zone, provided comparable accelerometric data to other locations more typically utilized (waist, thigh, wrist, etc.). MethodsPrototype exposure monitors from RTI International and Columbia University were worn on the chest by a pilot cohort of adults while conducting an array of scripted activities (all volumes in-situ. For the subset of participants with complete data (n = 22), linear regressions were constructed (processed accelerometric variable versus ventilation rate) for each participant and exposure monitor type, and Pearson correlations computed to compare across scenarios. ResultsTriaxial accelerometer data were demonstrated to be adequately sensitive indicators for predicting exposure monitor wearing compliance. Strong linear correlations (R values from 0.77 to 0.99) were observed for all participants for both exposure sensor accelerometer variables against ventilation volume for recumbent, sedentary, and ambulatory activities with MET values ˜volume data. Computing accelerometric standard deviations allowed good sensitivity for compliance assessments even for sedentary activities. These pilot findings supported the hypothesis that a common linear

  2. Mechanical ventilation with lower tidal volumes and positive end-expiratory pressure prevents alveolar coagulation in patients without lung injury

    NARCIS (Netherlands)

    Choi, Goda; Wolthuis, Esther K.; Bresser, Paul; Levi, Marcel; van der Poll, Tom; Dzoljic, Misa; Vroom, Margreeth B.; Schultz, Marcus J.

    2006-01-01

    BACKGROUND: Alveolar fibrin deposition is a hallmark of acute lung injury, resulting from activation of coagulation and inhibition of fibrinolysis. Previous studies have shown that mechanical ventilation with high tidal volumes may aggravate lung injury in patients with sepsis and acute lung injury.

  3. Tidal volume and mortality in mechanically ventilated children: a systematic review and meta-analysis of observational studies*.

    Science.gov (United States)

    de Jager, Pauline; Burgerhof, Johannes G M; van Heerde, Marc; Albers, Marcel J I J; Markhorst, Dick G; Kneyber, Martin C J

    2014-12-01

    To determine whether tidal volume is associated with mortality in critically ill, mechanically ventilated children. MEDLINE, EMBASE, and CINAHL databases from inception until July 2013 and bibliographies of included studies without language restrictions. Randomized clinical trials and observational studies reporting mortality in mechanically ventilated PICU patients. Two authors independently selected studies and extracted data on study methodology, quality, and patient outcomes. Meta-analyses were performed using the Mantel-Haenszel random-effects model. Heterogeneity was quantified using I. Study quality was assessed using the Newcastle-Ottawa Score for cohort studies. Out of 142 citations, seven studies met the inclusion criteria, and additional two articles were identified from references of the found articles. One was excluded. These eight studies included 1,756 patients. Mortality rates ranged from 13% to 42%. There was no association between tidal volume and mortality when tidal volume was dichotomized at 7, 8, 10, or 12 mL/kg. Comparing patients ventilated with tidal volume less than 7 mL/kg and greater than 10 mL/kg or greater than 12 mL/kg and tidal volume less than 8 mL/kg and greater than 10 mL/kg or greater than 12 mL/kg also showed no association between tidal volume and mortality. Limiting the analysis to patients with acute lung injury/acute respiratory distress syndrome did not change these results. Heterogeneity was observed in all pooled analyses. A relationship between tidal volume and mortality in mechanically ventilated children could not be identified, irrespective of the severity of disease. The significant heterogeneity observed in the pooled analyses necessitates future studies in well-defined patient populations to understand the effects of tidal volume on patient outcome.

  4. A sigmoidal fit for pressure-volume curves of idiopathic pulmonary fibrosis patients on mechanical ventilation: clinical implications

    Directory of Open Access Journals (Sweden)

    Juliana C. Ferreira

    2011-01-01

    Full Text Available OBJECTIVE: Respiratory pressure-volume curves fitted to exponential equations have been used to assess disease severity and prognosis in spontaneously breathing patients with idiopathic pulmonary fibrosis. Sigmoidal equations have been used to fit pressure-volume curves for mechanically ventilated patients but not for idiopathic pulmonary fibrosis patients. We compared a sigmoidal model and an exponential model to fit pressure-volume curves from mechanically ventilated patients with idiopathic pulmonary fibrosis. METHODS: Six idiopathic pulmonary fibrosis patients and five controls underwent inflation pressure-volume curves using the constant-flow technique during general anesthesia prior to open lung biopsy or thymectomy. We identified the lower and upper inflection points and fit the curves with an exponential equation, V = A-B.e-k.P, and a sigmoid equation, V = a+b/(1+e-(P-c/d. RESULTS: The mean lower inflection point for idiopathic pulmonary fibrosis patients was significantly higher (10.5 ± 5.7 cm H2O than that of controls (3.6 ± 2.4 cm H2O. The sigmoidal equation fit the pressure-volume curves of the fibrotic and control patients well, but the exponential equation fit the data well only when points below 50% of the inspiratory capacity were excluded. CONCLUSION: The elevated lower inflection point and the sigmoidal shape of the pressure-volume curves suggest that respiratory system compliance is decreased close to end-expiratory lung volume in idiopathic pulmonary fibrosis patients under general anesthesia and mechanical ventilation. The sigmoidal fit was superior to the exponential fit for inflation pressure-volume curves of anesthetized patients with idiopathic pulmonary fibrosis and could be useful for guiding mechanical ventilation during general anesthesia in this condition.

  5. High frequency oscillatory ventilation with lung volume optimization in very low birth weight newborns – a nine-year experience

    Directory of Open Access Journals (Sweden)

    José Nona

    2009-09-01

    Full Text Available Objective: To evaluate the clinical outcome of very low birth weight newborns, submitted to high frequency oscillatory ventilation with a strategy of early lung volume optimization. Methods: Descriptive prospective study in a nine-year period, between 1999 January 1st to 2008 January 1st. All the very low birth weight newborns were born in Dr. Alfredo da Costa Maternity, Lisbon, Portugal, were admitted to the Neonatal Intensive Care Unit and submitted to high frequency oscillatory ventilation with early lung volume optimization; these newborns were followed-up since birth and their charts were analyzed periodically until hospital discharge. Rresults: From a total population of 730 very low birth weight inborns, 117 babies died (16% and 613 survived (84%. The median of birth weight was 975 g and the gestational age median was 28 weeks. For the survivors, the median ventilation and oxygenation times were 3 and 18 days, respectively. The incidence of chronic lung disease was 9.5%, with nine newborns discharged on oxygen therapy. The incidence of intraventricular hemorrhage III – IV (total population group was 11.5% and the incidence of retinopathy of prematurity grade 3 or higher was 8.0%. Cconclusions: High frequency oscillatory ventilation with early lung volume optimization strategy reduced the need of respiratory support, and improved pulmonary and global outcomes in very low birth weight infants with respiratory distress syndrome.

  6. Mild hypothermia attenuates changes in respiratory system mechanics and modifies cytokine concentration in bronchoalveolar lavage fluid during low lung volume ventilation.

    Science.gov (United States)

    Dostál, P; Senkeřík, M; Pařízková, R; Bareš, D; Zivný, P; Zivná, H; Cerný, V

    2010-01-01

    Hypothermia was shown to attenuate ventilator-induced lung injury due to large tidal volumes. It is unclear if the protective effect of hypothermia is maintained under less injurious mechanical ventilation in animals without previous lung injury. Tracheostomized rats were randomly allocated to non-ventilated group (group C) or ventilated groups of normothermia (group N) and mild hypothermia (group H). After two hours of mechanical ventilation with inspiratory fraction of oxygen 1.0, respiratory rate 60 min(-1), tidal volume 10 ml x kg(-1), positive end-expiratory pressure (PEEP) 2 cm H2O or immediately after tracheostomy in non-ventilated animals inspiratory pressures were recorded, rats were sacrificed, pressure-volume (PV) curve of respiratory system constructed, bronchoalveolar lavage (BAL) fluid and aortic blood samples obtained. Group N animals exhibited a higher rise in peak inspiratory pressures in comparison to group H animals. Shift of the PV curve to right, higher total protein and interleukin-6 levels in BAL fluid were observed in normothermia animals in comparison with hypothermia animals and non-ventilated controls. Tumor necrosis factor-alpha was lower in the hypothermia group in comparison with normothermia and non-ventilated groups. Mild hypothermia attenuated changes in respiratory system mechanics and modified cytokine concentration in bronchoalveolar lavage fluid during low lung volume ventilation in animals without previous lung injury.

  7. Timing of low tidal volume ventilation and intensive care unit mortality in acute respiratory distress syndrome. A prospective cohort study.

    Science.gov (United States)

    Needham, Dale M; Yang, Ting; Dinglas, Victor D; Mendez-Tellez, Pedro A; Shanholtz, Carl; Sevransky, Jonathan E; Brower, Roy G; Pronovost, Peter J; Colantuoni, Elizabeth

    2015-01-15

    Reducing tidal volume decreases mortality in acute respiratory distress syndrome (ARDS). However, the effect of the timing of low tidal volume ventilation is not well understood. To evaluate the association of intensive care unit (ICU) mortality with initial tidal volume and with tidal volume change over time. Multivariable, time-varying Cox regression analysis of a multisite, prospective study of 482 patients with ARDS with 11,558 twice-daily tidal volume assessments (evaluated in milliliter per kilogram of predicted body weight [PBW]) and daily assessment of other mortality predictors. An increase of 1 ml/kg PBW in initial tidal volume was associated with a 23% increase in ICU mortality risk (adjusted hazard ratio, 1.23; 95% confidence interval [CI], 1.06-1.44; P = 0.008). Moreover, a 1 ml/kg PBW increase in subsequent tidal volumes compared with the initial tidal volume was associated with a 15% increase in mortality risk (adjusted hazard ratio, 1.15; 95% CI, 1.02-1.29; P = 0.019). Compared with a prototypical patient receiving 8 days with a tidal volume of 6 ml/kg PBW, the absolute increase in ICU mortality (95% CI) of receiving 10 and 8 ml/kg PBW, respectively, across all 8 days was 7.2% (3.0-13.0%) and 2.7% (1.2-4.6%). In scenarios with variation in tidal volume over the 8-day period, mortality was higher when a larger volume was used earlier. Higher tidal volumes shortly after ARDS onset were associated with a greater risk of ICU mortality compared with subsequent tidal volumes. Timely recognition of ARDS and adherence to low tidal volume ventilation is important for reducing mortality. Clinical trial registered with www.clinicaltrials.gov (NCT 00300248).

  8. Noninvasive ventilation.

    Science.gov (United States)

    Rabatin, J T; Gay, P C

    1999-08-01

    Noninvasive ventilation refers to the delivery of assisted ventilatory support without the use of an endotracheal tube. Noninvasive positive pressure ventilation (NPPV) can be delivered by using a volume-controlled ventilator, a pressure-controlled ventilator, a bilevel positive airway pressure ventilator, or a continuous positive airway pressure device. During the past decade, there has been a resurgence in the use of noninvasive ventilation, fueled by advances in technology and clinical trials evaluating its use. Several manufacturers produce portable devices that are simple to operate. This review describes the equipment, techniques, and complications associated with NPPV and also the indications for both short-term and long-term applications. NPPV clearly represents an important addition to the techniques available to manage patients with respiratory failure. Future clinical trials evaluating its many clinical applications will help to define populations of patients most apt to benefit from this type of treatment.

  9. Mechanical ventilation with lower tidal volumes and positive end-expiratory pressure prevents pulmonary inflammation in patients without preexisting lung injury.

    Science.gov (United States)

    Wolthuis, Esther K; Choi, Goda; Dessing, Mark C; Bresser, Paul; Lutter, Rene; Dzoljic, Misa; van der Poll, Tom; Vroom, Margreeth B; Hollmann, Markus; Schultz, Marcus J

    2008-01-01

    Mechanical ventilation with high tidal volumes aggravates lung injury in patients with acute lung injury or acute respiratory distress syndrome. The authors sought to determine the effects of short-term mechanical ventilation on local inflammatory responses in patients without preexisting lung injury. Patients scheduled to undergo an elective surgical procedure (lasting > or = 5 h) were randomly assigned to mechanical ventilation with either higher tidal volumes of 12 ml/kg ideal body weight and no positive end-expiratory pressure (PEEP) or lower tidal volumes of 6 ml/kg and 10 cm H2O PEEP. After induction of anesthesia and 5 h thereafter, bronchoalveolar lavage fluid and/or blood was investigated for polymorphonuclear cell influx, changes in levels of inflammatory markers, and nucleosomes. Mechanical ventilation with lower tidal volumes and PEEP (n = 21) attenuated the increase of pulmonary levels of interleukin (IL)-8, myeloperoxidase, and elastase as seen with higher tidal volumes and no PEEP (n = 19). Only for myeloperoxidase, a difference was found between the two ventilation strategies after 5 h of mechanical ventilation (P volumes and PEEP may limit pulmonary inflammation in mechanically ventilated patients without preexisting lung injury. The specific contribution of both lower tidal volumes and PEEP on the protective effects of the lung should be further investigated.

  10. 4-D segmentation and normalization of 3He MR images for intrasubject assessment of ventilated lung volumes

    Science.gov (United States)

    Contrella, Benjamin; Tustison, Nicholas J.; Altes, Talissa A.; Avants, Brian B.; Mugler, John P., III; de Lange, Eduard E.

    2012-03-01

    Although 3He MRI permits compelling visualization of the pulmonary air spaces, quantitation of absolute ventilation is difficult due to confounds such as field inhomogeneity and relative intensity differences between image acquisition; the latter complicating longitudinal investigations of ventilation variation with respiratory alterations. To address these potential difficulties, we present a 4-D segmentation and normalization approach for intra-subject quantitative analysis of lung hyperpolarized 3He MRI. After normalization, which combines bias correction and relative intensity scaling between longitudinal data, partitioning of the lung volume time series is performed by iterating between modeling of the combined intensity histogram as a Gaussian mixture model and modulating the spatial heterogeneity tissue class assignments through Markov random field modeling. Evaluation of the algorithm was retrospectively applied to a cohort of 10 asthmatics between 19-25 years old in which spirometry and 3He MR ventilation images were acquired both before and after respiratory exacerbation by a bronchoconstricting agent (methacholine). Acquisition was repeated under the same conditions from 7 to 467 days (mean +/- standard deviation: 185 +/- 37.2) later. Several techniques were evaluated for matching intensities between the pre and post-methacholine images with the 95th percentile value histogram matching demonstrating superior correlations with spirometry measures. Subsequent analysis evaluated segmentation parameters for assessing ventilation change in this cohort. Current findings also support previous research that areas of poor ventilation in response to bronchoconstriction are relatively consistent over time.

  11. Heliox Improves Carbon Dioxide Removal during Lung Protective Mechanical Ventilation.

    Science.gov (United States)

    Beurskens, Charlotte J; Brevoord, Daniel; Lagrand, Wim K; van den Bergh, Walter M; Vroom, Margreeth B; Preckel, Benedikt; Horn, Janneke; Juffermans, Nicole P

    2014-01-01

    Introduction. Helium is a noble gas with low density and increased carbon dioxide (CO2) diffusion capacity. This allows lower driving pressures in mechanical ventilation and increased CO2 diffusion. We hypothesized that heliox facilitates ventilation in patients during lung-protective mechanical ventilation using low tidal volumes. Methods. This is an observational cohort substudy of a single arm intervention study. Twenty-four ICU patients were included, who were admitted after a cardiac arrest and mechanically ventilated for 3 hours with heliox (50% helium; 50% oxygen). A fixed protective ventilation protocol (6 mL/kg) was used, with prospective observation for changes in lung mechanics and gas exchange. Statistics was by Bonferroni post-hoc correction with statistical significance set at P ventilation, respiratory rate decreased (25 ± 4 versus 23 ± 5 breaths min(-1), P = 0.010). Minute volume ventilation showed a trend to decrease compared to baseline (11.1 ± 1.9 versus 9.9 ± 2.1 L min(-1), P = 0.026), while reducing PaCO2 levels (5.0 ± 0.6 versus 4.5 ± 0.6 kPa, P = 0.011) and peak pressures (21.1 ± 3.3 versus 19.8 ± 3.2 cm H2O, P = 0.024). Conclusions. Heliox improved CO2 elimination while allowing reduced minute volume ventilation in adult patients during protective mechanical ventilation.

  12. Mechanical ventilation with lower tidal volumes and positive end-expiratory pressure prevents pulmonary inflammation in patients without preexisting lung injury

    NARCIS (Netherlands)

    Wolthuis, Esther K.; Choi, Goda; Dessing, Mark C.; Bresser, Paul; Lutter, Rene; Dzoljic, Misa; van der Poll, Tom; Vroom, Margreeth B.; Hollmann, Markus; Schultz, Marcus J.

    2008-01-01

    Background: Mechanical ventilation with high tidal volumes aggravates lung injury in patients with acute lung injury or acute respiratory distress syndrome. The authors sought to determine the effects of short-term mechanical ventilation on local inflammatory responses in patients without

  13. Smaller self-inflating bags produce greater guideline consistent ventilation in simulated cardiopulmonary resuscitation

    Directory of Open Access Journals (Sweden)

    Boyle Malcolm J

    2009-02-01

    Full Text Available Abstract Background Suboptimal bag ventilation in cardiopulmonary resuscitation (CPR has demonstrated detrimental physiological outcomes for cardiac arrest patients. In light of recent guideline changes for resuscitation, there is a need to identify the efficacy of bag ventilation by prehospital care providers. The objective of this study was to evaluate bag ventilation in relation to operator ability to achieve guideline consistent ventilation rate, tidal volume and minute volume when using two different capacity self-inflating bags in an undergraduate paramedic cohort. Methods An experimental study using a mechanical lung model and a simulated adult cardiac arrest to assess the ventilation ability of third year Monash University undergraduate paramedic students. Participants were instructed to ventilate using 1600 ml and 1000 ml bags for a length of two minutes at the correct rate and tidal volume for a patient undergoing CPR with an advanced airway. Ventilation rate and tidal volume were recorded using an analogue scale with mean values calculated. Ethics approval was granted. Results Suboptimal ventilation with the use of conventional 1600 ml bag was common, with 77% and 97% of participants unable to achieve guideline consistent ventilation rates and tidal volumes respectively. Reduced levels of suboptimal ventilation arouse from the use of the smaller bag with a 27% reduction in suboptimal tidal volumes (p = 0.015 and 23% reduction in suboptimal minute volumes (p = 0.045. Conclusion Smaller self-inflating bags reduce the incidence of suboptimal tidal volumes and minute volumes and produce greater guideline consistent results for cardiac arrest patients.

  14. Intravenous superoxide dismutase as a protective agent to prevent impairment of lung function induced by high tidal volume ventilation.

    Science.gov (United States)

    Wu, Nan-Chun; Liao, Fan-Ting; Cheng, Hao-Min; Sung, Shih-Hsien; Yang, Yu-Chun; Wang, Jiun-Jr

    2017-07-26

    Positive-pressure mechanical ventilation is essential in assisting patients with respiratory failure in the intensive care unit and facilitating oxygenation in the operating room. However, it was also recognized as a primary factor leading to hospital-acquired pulmonary dysfunction, in which pulmonary oxidative stress and lung inflammation had been known to play important roles. Cu/Zn superoxide dismutase (SOD) is an important antioxidant, and possesses anti-inflammatory capacity. In this study, we aimed to study the efficacy of Cu/Zn SOD, administered intravenously during high tidal volume (HTV) ventilation, to prevent impairment of lung function. Thirty-eight male Sprague-Dawley rats were divided into 3 groups: 5 h ventilation with (A) low tidal volume (LTV; 8 mL/kg; n = 10), (B) high tidal volume (HTV; 18 mL/kg; n = 14), or (C) HTV and intravenous treatment of Cu/Zn SOD at a dose of 1000 U/kg/h (HTV + SOD; n = 14). Lung function was evaluated both at baseline and after 5-h ventilation. Lung injury was assessed by histological examination, lung water and protein contents in the bronchoalveolar lavage fluid (BALF). Pulmonary oxidative stress was examined by concentrations of methylguanidine (MG) and malondialdehyde (MDA) in BALF, and antioxidative activity by protein expression of glutathione peroxidase-1 (GPx-1) in the lung. Severity of lung inflammation was evaluated by white blood cell and differential count in BALF, and protein expression of inducible nitric oxide synthase (iNOS), intercellular adhesion molecule-1 (ICAM-1), tumor necrosis factor-α (TNF-α), matrix metalloproteinase-9 (MMP-9), and mRNA expression of nuclear factor-κB (NF-κB) in the lung. We also examined protein expression of surfactant protein (SP)-A and D and we measured hourly changes in serum nitric oxide (NO) level. Five hours of LTV ventilation did not induce a major change in lung function, whereas 5 h of HTV ventilation induced apparent combined restrictive and

  15. Evaluation of Low versus High Volume per Minute Displacement CO2 Methods of Euthanasia in the Induction and Duration of Panic-Associated Behavior and Physiology

    Directory of Open Access Journals (Sweden)

    Debra L. Hickman

    2016-08-01

    Full Text Available Current recommendations for the use of CO 2 as a euthanasia agent for rats require the use of gradual fill protocols (such as 10% to 30% volume displacement per minute in order to render the animal insensible prior to exposure to levels of CO 2 that are associated with pain. However, exposing rats to CO 2 , concentrations as low as 7% CO 2 are reported to cause distress and 10%–20% CO 2 induces panic-associated behavior and physiology, but loss of consciousness does not occur until CO 2 concentrations are at least 40%. This suggests that the use of the currently recommended low flow volume per minute displacement rates create a situation where rats are exposed to concentrations of CO 2 that induce anxiety, panic, and distress for prolonged periods of time. This study first characterized the response of male rats exposed to normoxic 20% CO 2 for a prolonged period of time as compared to room air controls. It demonstrated that rats exposed to this experimental condition displayed clinical signs consistent with significantly increased panic-associated behavior and physiology during CO 2 exposure. When atmospheric air was then again delivered, there was a robust increase in respiration rate that coincided with rats moving to the air intake. The rats exposed to CO 2 also displayed behaviors consistent with increased anxiety in the behavioral testing that followed the exposure. Next, this study assessed the behavioral and physiologic responses of rats that were euthanized with 100% CO 2 infused at 10%, 30%, or 100% volume per minute displacement rates. Analysis of the concentrations of CO 2 and oxygen in the euthanasia chamber and the behavioral responses of the rats suggest that the use of the very low flow volume per minute displacement rate (10% may prolong the duration of panicogenic ranges of ambient CO 2 , while the use of the higher flow volume per minute displacement rate (100% increases agitation. Therefore, of the volume displacement per

  16. Evaluation of Low versus High Volume per Minute Displacement CO₂ Methods of Euthanasia in the Induction and Duration of Panic-Associated Behavior and Physiology.

    Science.gov (United States)

    Hickman, Debra L; Fitz, Stephanie D; Bernabe, Cristian S; Caliman, Izabela F; Haulcomb, Melissa M; Federici, Lauren M; Shekhar, Anantha; Johnson, Philip L

    2016-08-02

    Current recommendations for the use of CO ₂ as a euthanasia agent for rats require the use of gradual fill protocols (such as 10% to 30% volume displacement per minute) in order to render the animal insensible prior to exposure to levels of CO ₂ that are associated with pain. However, exposing rats to CO ₂ , concentrations as low as 7% CO ₂ are reported to cause distress and 10%-20% CO ₂ induces panic-associated behavior and physiology, but loss of consciousness does not occur until CO ₂ concentrations are at least 40%. This suggests that the use of the currently recommended low flow volume per minute displacement rates create a situation where rats are exposed to concentrations of CO ₂ that induce anxiety, panic, and distress for prolonged periods of time. This study first characterized the response of male rats exposed to normoxic 20% CO ₂ for a prolonged period of time as compared to room air controls. It demonstrated that rats exposed to this experimental condition displayed clinical signs consistent with significantly increased panic-associated behavior and physiology during CO ₂ exposure. When atmospheric air was then again delivered, there was a robust increase in respiration rate that coincided with rats moving to the air intake. The rats exposed to CO ₂ also displayed behaviors consistent with increased anxiety in the behavioral testing that followed the exposure. Next, this study assessed the behavioral and physiologic responses of rats that were euthanized with 100% CO ₂ infused at 10%, 30%, or 100% volume per minute displacement rates. Analysis of the concentrations of CO ₂ and oxygen in the euthanasia chamber and the behavioral responses of the rats suggest that the use of the very low flow volume per minute displacement rate (10%) may prolong the duration of panicogenic ranges of ambient CO ₂ , while the use of the higher flow volume per minute displacement rate (100%) increases agitation. Therefore, of the volume

  17. Intraoperative protective mechanical ventilation for prevention of postoperative pulmonary complications: a comprehensive review of the role of tidal volume, positive end-expiratory pressure, and lung recruitment maneuvers.

    Science.gov (United States)

    Güldner, Andreas; Kiss, Thomas; Serpa Neto, Ary; Hemmes, Sabrine N T; Canet, Jaume; Spieth, Peter M; Rocco, Patricia R M; Schultz, Marcus J; Pelosi, Paolo; Gama de Abreu, Marcelo

    2015-09-01

    Postoperative pulmonary complications are associated with increased morbidity, length of hospital stay, and mortality after major surgery. Intraoperative lung-protective mechanical ventilation has the potential to reduce the incidence of postoperative pulmonary complications. This review discusses the relevant literature on definition and methods to predict the occurrence of postoperative pulmonary complication, the pathophysiology of ventilator-induced lung injury with emphasis on the noninjured lung, and protective ventilation strategies, including the respective roles of tidal volumes, positive end-expiratory pressure, and recruitment maneuvers. The authors propose an algorithm for protective intraoperative mechanical ventilation based on evidence from recent randomized controlled trials.

  18. Performance of mechanical ventilators at the patient's home: a multicentre quality control study.

    Science.gov (United States)

    Farré, R; Navajas, D; Prats, E; Marti, S; Guell, R; Montserrat, J M; Tebe, C; Escarrabill, J

    2006-05-01

    Quality control procedures vary considerably among the providers of equipment for home mechanical ventilation (HMV). A multicentre quality control survey of HMV was performed at the home of 300 patients included in the HMV programmes of four hospitals in Barcelona. It consisted of three steps: (1) the prescribed ventilation settings, the actual settings in the ventilator control panel, and the actual performance of the ventilator measured at home were compared; (2) the different ventilator alarms were tested; and (3) the effect of differences between the prescribed settings and the actual performance of the ventilator on non-programmed readmissions of the patient was determined. Considerable differences were found between actual, set, and prescribed values of ventilator variables; these differences were similar in volume and pressure preset ventilators. The percentage of patients with a discrepancy between the prescribed and actual measured main ventilator variable (minute ventilation or inspiratory pressure) of more than 20% and 30% was 13% and 4%, respectively. The number of ventilators with built in alarms for power off, disconnection, or obstruction was 225, 280 and 157, respectively. These alarms did not work in two (0.9%), 52 (18.6%) and eight (5.1%) ventilators, respectively. The number of non-programmed hospital readmissions in the year before the study did not correlate with the index of ventilator error. This study illustrates the current limitations of the quality control of HMV and suggests that improvements should be made to ensure adequate ventilator settings and correct ventilator performance and ventilator alarm operation.

  19. Stroke volume variation compared with pulse pressure variation and cardiac index changes for prediction of fluid responsiveness in mechanically ventilated patients

    Directory of Open Access Journals (Sweden)

    Randa Aly Soliman

    2015-04-01

    Conclusions: Baseline stroke volume variation ⩾8.15% predicted fluid responsiveness in mechanically ventilated patients with acute circulatory failure. The study also confirmed the ability of pulse pressure variation to predict fluid responsiveness.

  20. Positive outcome of average volume-assured pressure support mode of a Respironics V60 Ventilator in acute exacerbation of chronic obstructive pulmonary disease: a case report

    Directory of Open Access Journals (Sweden)

    Okuda Miyuki

    2012-09-01

    Full Text Available Abstract Introduction We were able to treat a patient with acute exacerbation of chronic obstructive pulmonary disease who also suffered from sleep-disordered breathing by using the average volume-assured pressure support mode of a Respironics V60 Ventilator (Philips Respironics: United States. This allows a target tidal volume to be set based on automatic changes in inspiratory positive airway pressure. This removed the need to change the noninvasive positive pressure ventilation settings during the day and during sleep. The Respironics V60 Ventilator, in the average volume-assured pressure support mode, was attached to our patient and improved and stabilized his sleep-related hypoventilation by automatically adjusting force to within an acceptable range. Case presentation Our patient was a 74-year-old Japanese man who was hospitalized for treatment due to worsening of dyspnea and hypoxemia. He was diagnosed with acute exacerbation of chronic obstructive pulmonary disease and full-time biphasic positive airway pressure support ventilation was initiated. Our patient was temporarily provided with portable noninvasive positive pressure ventilation at night-time following an improvement in his condition, but his chronic obstructive pulmonary disease again worsened due to the recurrence of a respiratory infection. During the initial exacerbation, his tidal volume was significantly lower during sleep (378.9 ± 72.9mL than while awake (446.5 ± 63.3mL. A ventilator that allows ventilation to be maintained by automatically adjusting the inspiratory force to within an acceptable range was attached in average volume-assured pressure support mode, improving his sleep-related hypoventilation, which is often associated with the use of the Respironics V60 Ventilator. Polysomnography performed while our patient was on noninvasive positive pressure ventilation revealed obstructive sleep apnea syndrome (apnea-hypopnea index = 14, suggesting that his chronic

  1. Spontaneous breathing during lung-protective ventilation in an experimental acute lung injury model: high transpulmonary pressure associated with strong spontaneous breathing effort may worsen lung injury.

    Science.gov (United States)

    Yoshida, Takeshi; Uchiyama, Akinori; Matsuura, Nariaki; Mashimo, Takashi; Fujino, Yuji

    2012-05-01

    We investigated whether potentially injurious transpulmonary pressure could be generated by strong spontaneous breathing and exacerbate lung injury even when plateau pressure is limited to ventilation, each combined with weak or strong spontaneous breathing effort. Inspiratory pressure for low tidal volume ventilation was set at 10 cm H2O and tidal volume at 6 mL/kg. For moderate tidal volume ventilation, the values were 20 cm H2O and 7-9 mL/kg. The groups were: low tidal volume ventilation+spontaneous breathingweak, low tidal volume ventilation+spontaneous breathingstrong, moderate tidal volume ventilation+spontaneous breathingweak, and moderate tidal volume ventilation+spontaneous breathingstrong. Each group had the same settings for positive end-expiratory pressure of 8 cm H2O. Respiratory variables were measured every 60 mins. Distribution of lung aeration and alveolar collapse were histologically evaluated. Low tidal volume ventilation+spontaneous breathingstrong showed the most favorable oxygenation and compliance of respiratory system, and the best lung aeration. By contrast, in moderate tidal volume ventilation+spontaneous breathingstrong, the greatest atelectasis with numerous neutrophils was observed. While we applied settings to maintain plateau pressure at ventilation+spontaneous breathingstrong, transpulmonary pressure rose >33 cm H2O. Both minute ventilation and respiratory rate were higher in the strong spontaneous breathing groups. Even when plateau pressure is limited to mechanical ventilation, transpulmonary pressure and tidal volume should be strictly controlled to prevent further lung injury.

  2. Temperature of gas delivered from ventilators.

    Science.gov (United States)

    Chikata, Yusuke; Onodera, Mutsuo; Imanaka, Hideaki; Nishimura, Masaji

    2013-01-01

    Although heated humidifiers (HHs) are the most efficient humidifying device for mechanical ventilation, some HHs do not provide sufficient humidification when the inlet temperature to the water chamber is high. Because portable and home-care ventilators use turbines, blowers, pistons, or compressors to inhale in ambient air, they may have higher gas temperature than ventilators with piping systems. We carried out a bench study to investigate the temperature of gas delivered from portable and home-care ventilators, including the effects of distance from ventilator outlet, fraction of inspiratory oxygen (FIO2), and minute volume (MV). We evaluated five ventilators equipped with turbine, blower, piston, or compressor system. Ambient air temperature was adjusted to 24°C ± 0.5°C, and ventilation was set at FIO2 0.21, 0.6, and 1.0, at MV 5 and 10 L/min. We analyzed gas temperature at 0, 40, 80, and 120 cm from ventilator outlet and altered ventilator settings. While temperature varied according to ventilators, the outlet gas temperature of ventilators became stable after, at the most, 5 h. Gas temperature was 34.3°C ± 3.9°C at the ventilator outlet, 29.5°C ± 2.2°C after 40 cm, 25.4°C ± 1.2°C after 80 cm and 25.1°C ± 1.2°C after 120 cm (P < 0.01). FIO2 and MV did not affect gas temperature. Gas delivered from portable and home-care ventilator was not too hot to induce heated humidifier malfunctioning. Gas soon declined when passing through the limb.

  3. Utilization of the lower inflection point of the pressure-volume curve results in protective conventional ventilation comparable to high frequency oscillatory ventilation in an animal model of acute respiratory distress syndrome

    Directory of Open Access Journals (Sweden)

    Felipe S. Rossi

    2008-01-01

    Full Text Available INTRODUCTION: Studies comparing high frequency oscillatory and conventional ventilation in acute respiratory distress syndrome have used low values of positive end-expiratory pressure and identified a need for better recruitment and pulmonary stability with high frequency. OBJECTIVE: To compare conventional and high frequency ventilation using the lower inflection point of the pressure-volume curve as the determinant of positive end-expiratory pressure to obtain similar levels of recruitment and alveolar stability. METHODS: After lung lavage of adult rabbits and lower inflection point determination, two groups were randomized: conventional (positive end-expiratory pressure = lower inflection point; tidal volume=6 ml/kg and high frequency ventilation (mean airway pressures= lower inflection point +4 cmH2O. Blood gas and hemodynamic data were recorded over 4 h. After sacrifice, protein analysis from lung lavage and histologic evaluation were performed. RESULTS: The oxygenation parameters, protein and histological data were similar, except for the fact that significantly more normal alveoli were observed upon protective ventilation. High frequency ventilation led to lower PaCO2 levels. DISCUSSION: Determination of the lower inflection point of the pressure-volume curve is important for setting the minimum end expiratory pressure needed to keep the airways opened. This is useful when comparing different strategies to treat severe respiratory insufficiency, optimizing conventional ventilation, improving oxygenation and reducing lung injury. CONCLUSIONS: Utilization of the lower inflection point of the pressure-volume curve in the ventilation strategies considered in this study resulted in comparable efficacy with regards to oxygenation and hemodynamics, a high PaCO2 level and a lower pH. In addition, a greater number of normal alveoli were found after protective conventional ventilation in an animal model of acute respiratory distress syndrome.

  4. Relation of exercise capacity with lung volumes before and after 6-minute walk test in subjects with COPD.

    Science.gov (United States)

    Wibmer, Thomas; Rüdiger, Stefan; Kropf-Sanchen, Cornelia; Stoiber, Kathrin M; Rottbauer, Wolfgang; Schumann, Christian

    2014-11-01

    There is growing evidence that exercise-induced variation in lung volumes is an important source of ventilatory limitation and is linked to exercise intolerance in COPD. The aim of this study was to compare the correlations of walk distance and lung volumes measured before and after a 6-min walk test (6MWT) in subjects with COPD. Forty-five subjects with stable COPD (mean pre-bronchodilator FEV1: 47 ± 18% predicted) underwent a 6MWT. Body plethysmography was performed immediately pre- and post-6MWT. Correlations were generally stronger between 6-min walk distance and post-6MWT lung volumes than between 6-min walk distance and pre-6MWT lung volumes, except for FEV1. These differences in Pearson correlation coefficients were significant for residual volume expressed as percent of total lung capacity (-0.67 vs -0.58, P = .043), percent of predicted residual volume expressed as percent of total lung capacity (-0.68 vs -0.59, P = .026), inspiratory vital capacity (0.65 vs 0.54, P = .019), percent of predicted inspiratory vital capacity (0.49 vs 0.38, P = .037), and percent of predicted functional residual capacity (-0.62 vs -0.47, P = .023). In subjects with stable COPD, lung volumes measured immediately after 6MWT are more closely related to exercise limitation than baseline lung volumes measured before 6MWT, except for FEV1. Therefore, pulmonary function testing immediately after exercise should be included in future studies on COPD for the assessment of exercise-induced ventilatory constraints to physical performance that cannot be adequately assessed from baseline pulmonary function testing at rest. Copyright © 2014 by Daedalus Enterprises.

  5. Ventilator-driven xenon ventilation studies

    International Nuclear Information System (INIS)

    Chilcoat, R.T.; Thomas, F.D.; Gerson, J.I.

    1984-01-01

    A modification of a common commercial Xe-133 ventilation device is described for mechanically assisted ventilation imaging. The patient's standard ventilator serves as the power source controlling the ventilatory rate and volume during the xenon study, but the gases in the two systems are not intermixed. This avoids contamination of the ventilator with radioactive xenon. Supplemental oxygen and positive end-expiratory pressure (PEEP) are provided if needed. The system can be converted quickly for conventional studies with spontaneous respiration

  6. Effect of lung-protective ventilation with lower tidal volumes on clinical outcomes among patients undergoing surgery: a meta-analysis of randomized controlled trials.

    Science.gov (United States)

    Gu, Wan-Jie; Wang, Fei; Liu, Jing-Chen

    2015-02-17

    In anesthetized patients undergoing surgery, the role of lung-protective ventilation with lower tidal volumes is unclear. We performed a meta-analysis of randomized controlled trials (RCTs) to evaluate the effect of this ventilation strategy on postoperative outcomes. We searched electronic databases from inception through September 2014. We included RCTs that compared protective ventilation with lower tidal volumes and conventional ventilation with higher tidal volumes in anesthetized adults undergoing surgery. We pooled outcomes using a random-effects model. The primary outcome measures were lung injury and pulmonary infection. We included 19 trials (n=1348). Compared with patients in the control group, those who received lung-protective ventilation had a decreased risk of lung injury (risk ratio [RR] 0.36, 95% confidence interval [CI] 0.17 to 0.78; I2=0%) and pulmonary infection (RR 0.46, 95% CI 0.26 to 0.83; I2=8%), and higher levels of arterial partial pressure of carbon dioxide (standardized mean difference 0.47, 95% CI 0.18 to 0.75; I2=65%). No significant differences were observed between the patient groups in atelectasis, mortality, length of hospital stay, length of stay in the intensive care unit or the ratio of arterial partial pressure of oxygen to fraction of inspired oxygen. Anesthetized patients who received ventilation with lower tidal volumes during surgery had a lower risk of lung injury and pulmonary infection than those given conventional ventilation with higher tidal volumes. Implementation of a lung-protective ventilation strategy with lower tidal volumes may lower the incidence of these outcomes. © 2015 Canadian Medical Association or its licensors.

  7. Assessment of Adaptive Rate Response Provided by Accelerometer, Minute Ventilation and Dual Sensor Compared with Normal Sinus Rhythm During Exercise: A Self-controlled Study in Chronotropically Competent Subjects

    Directory of Open Access Journals (Sweden)

    Yuanyuan Cao

    2015-01-01

    Full Text Available Background: Dual sensor (DS for rate adaption was supposed to be more physiological. To evaluate its superiority, the DS (accelerometer [ACC] and minute ventilation [MV] and normal sinus rate response were compared in a self-controlled way during exercise treadmill testing. Methods: This self-controlled study was performed in atrioventricular block patients with normal sinus function who met the indications of pacemaker implant. Twenty-one patients came to the 1-month follow-up visit. Patients performed a treadmill test 1-month post implant while programmed in DDDR and sensor passive mode. For these patients, sensor response factors were left at default settings (ACC = 8, MV = 3 and sensor indicated rates (SIRs for DS, ACC and MV sensor were retrieved from the pacemaker memories, along with measured sinus node (SN rates from the beginning to 1-minute after the end of the treadmill test, and compared among study groups. Repeated measures analysis of variance and profile analysis, as well as variance analysis of randomized block designs, were used for statistical analysis. Results: Fifteen patients (15/21 were determined to be chronotropically competent. The mean differences between DS SIRs and intrinsic sinus rates during treadmill testing were smaller than those for ACC and MV sensor (mean difference between SIR and SN rate: ACC vs. SN, MV vs. SN, DS vs. SN, respectively, 34.84, 17.60, 16.15 beats/min, though no sensors could mimic sinus rates under the default settings for sensor response factor (ACC vs. SN P-adjusted < 0.001; MV vs. SN P-adjusted = 0.002; DS vs. SN P-adjusted = 0.005. However, both in the range of 1 st minute and first 3 minutes of exercise, only the DS SIR profile did not differ from sinus rates (P-adjusted = 0.09, 0.90, respectively. Conclusions: The DS under default settings provides more physiological rate response during physical activity than the corresponding single sensors (ACC or MV sensor. Further study is needed to

  8. Association Between Use of Lung-Protective Ventilation With Lower Tidal Volumes and Clinical Outcomes Among Patients Without Acute Respiratory Distress Syndrome A Meta-analysis

    NARCIS (Netherlands)

    Serpa Neto, Ary; Cardoso, Sérgio Oliveira; Manetta, José Antônio; Pereira, Victor Galvão Moura; Espósito, Daniel Crepaldi; Pasqualucci, Manoela de Oliveira Prado; Damasceno, Maria Cecília Toledo; Schultz, Marcus J.

    2012-01-01

    Context Lung-protective mechanical ventilation with the use of lower tidal volumes has been found to improve outcomes of patients with acute respiratory distress syndrome (ARDS). It has been suggested that use of lower tidal volumes also benefits patients who do not have ARDS. Objective To determine

  9. Breathing circuit compliance and accuracy of displayed tidal volume during pressure-controlled ventilation of infants: A quality improvement project.

    Science.gov (United States)

    Glenski, Todd A; Diehl, Carrie; Clopton, Rachel G; Friesen, Robert H

    2017-09-01

    Anesthesia machines have evolved to deliver desired tidal volumes more accurately by measuring breathing circuit compliance during a preuse self-test and then incorporating the compliance value when calculating expired tidal volume. The initial compliance value is utilized in tidal volume calculation regardless of whether the actual compliance of the breathing circuit changes during a case, as happens when corrugated circuit tubing is manually expanded after the preuse self-test but before patient use. We noticed that the anesthesia machine preuse self-test was usually performed on nonexpanded pediatric circuit tubing, and then the breathing circuit was subsequently expanded for clinical use. We aimed to demonstrate that performing the preuse self-test in that manner could lead to incorrectly displayed tidal volume on the anesthesia machine monitor. The goal of this quality improvement project was to change the usual practice and improve the accuracy of displayed tidal volume in infants undergoing general anesthesia. There were four stages of the project: (i) gathering baseline data about the performance of the preuse self-test and using infant and adult test lungs to measure discrepancies of displayed tidal volumes when breathing circuit compliance was changed after the initial preuse self-test; (ii) gathering clinical data during pressure-controlled ventilation comparing anesthesia machine displayed tidal volume with actual spirometry tidal volume in patients less than 10 kg before (machine preuse self-test performed while the breathing circuit was nonexpanded) and after an intervention (machine preuse self-test performed after the breathing circuit was fully expanded); (iii) performing department-wide education to help implement practice change; (iv) gathering postintervention data to determine the prevalence of proper machine preuse self-test. At constant pressure-controlled ventilation through fully expanded circuit tubing, displayed tidal volume was 83

  10. Comparison of changes in tidal volume associated with expiratory rib cage compression and expiratory abdominal compression in patients on prolonged mechanical ventilation

    OpenAIRE

    Morino, Akira; Shida, Masahiro; Tanaka, Masashi; Sato, Kimihiro; Seko, Toshiaki; Ito, Shunsuke; Ogawa, Shunichi; Takahashi, Naoaki

    2015-01-01

    [Purpose] This study was designed to compare and clarify the relationship between expiratory rib cage compression and expiratory abdominal compression in patients on prolonged mechanical ventilation, with a focus on tidal volume. [Subjects and Methods] The subjects were 18 patients on prolonged mechanical ventilation, who had undergone tracheostomy. Each patient received expiratory rib cage compression and expiratory abdominal compression; the order of implementation was randomized. Subjects ...

  11. Lower tidal volume strategy (?3?ml/kg) combined with extracorporeal CO2 removal versus ?conventional? protective ventilation (6?ml/kg) in severe ARDS

    OpenAIRE

    Bein, Thomas; Weber-Carstens, Steffen; Goldmann, Anton; M?ller, Thomas; Staudinger, Thomas; Brederlau, J?rg; Muellenbach, Ralf; Dembinski, Rolf; Graf, Bernhard M.; Wewalka, Marlene; Philipp, Alois; Wernecke, Klaus-Dieter; Lubnow, Matthias; Slutsky, Arthur S.

    2013-01-01

    Background Acute respiratory distress syndrome is characterized by damage to the lung caused by various insults, including ventilation itself, and tidal hyperinflation can lead to ventilator induced lung injury (VILI). We investigated the effects of a low tidal volume (V T) strategy (V T???3?ml/kg/predicted body weight [PBW]) using pumpless extracorporeal lung assist in established ARDS. Methods Seventy-nine patients were enrolled after a ?stabilization period? (24?h with optimized therapy an...

  12. Increased expression of AQP 1 and AQP 5 in rat lungs ventilated with low tidal volume is time dependent.

    Directory of Open Access Journals (Sweden)

    Gustavo Fabregat

    Full Text Available BACKGROUND AND GOALS: Mechanical ventilation (MV can induce or worsen pulmonary oedema. Aquaporins (AQPs facilitate the selective and rapid bi-directional movement of water. Their role in the development and resolution of pulmonary oedema is controversial. Our objectives are to determine if prolonged MV causes lung oedema and changes in the expression of AQP 1 and AQP 5 in rats. METHODS: 25 male Wistar rats were subjected to MV with a tidal volume of 10 ml/kg, during 2 hours (n = 12 and 4 hours (n = 13. Degree of oedema was compared with a group of non-ventilated rats (n = 5. The expression of AQP 1 and AQP 5 were determined by western immunoblotting, measuring the amount of mRNA (previously amplified by RT-PCR and immunohistochemical staining of AQPs 1 and 5 in lung samples from all groups. RESULTS: Lung oedema and alveolar-capillary membrane permeability did not change during MV. AQP-5 steady state levels in the western blot were increased (p<0.01 at 2 h and 4 h of MV. But in AQP-1 expression these differences were not found. However, the amount of mRNA for AQP-1 was increased at 2 h and 4 h of MV; and for AQP 5 at 4 h of MV. These findings were corroborated by representative immunohistochemical lung samples. CONCLUSION: In lungs from rats ventilated with a low tidal volume the expression of AQP 5 increases gradually with MV duration, but does not cause pulmonary oedema or changes in lung permeability. AQPs may have a protective effect against the oedema induced by MV.

  13. [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.

  14. Comparison of intraoperative volume and pressure-controlled ventilation modes in patients who undergo open heart surgery.

    Science.gov (United States)

    Hoşten, Tülay; Kuş, Alparslan; Gümüş, Esra; Yavuz, Şadan; İrkil, Serhat; Solak, Mine

    2017-02-01

    Respiratory problems occur more frequently in patients who undergo open heart surgery. Intraoperative and postoperative ventilation strategies can prevent these complications and reduce mortality. We hypothesized that PCV would have better effects on gas exchange, lung mechanics and hemodynamics compared to VCV in CABG surgery. Our primary outcome was to compare the PaO 2 /FiO 2 ratio. Patients were randomized into two groups, (VCV, PCV) consisting of 30 individuals each. Two patients were excluded from the study. I/E ratio was adjusted to 1:2 and, RR:10/min fresh air gas flow was set at 3L/min in all patients. In the VCV group TV was set at 8 mL/kg of the predicted body weight. In the PCV group, peak inspiratory pressure was adjusted to the same tidal volume with the VCV group. PaO2/FiO2 was found to be higher with PCV at the end of the surgery. Time to extubation and ICU length of stay was shorter with PCV. Ppeak was similar in both groups. Pplateau was lower and Pmean was higher at the and of the surgery with PCV compared to VCV. The hemodynamic effects of both ventilation modes were found to be similar. PVC may be preferable to VCV in patients who undergo open heart surgery. However, it would be convenient if our findings are supported by similar studies.

  15. Increasing compliance with low tidal volume ventilation in the ICU with two nudge-based interventions: evaluation through intervention time-series analyses.

    Science.gov (United States)

    Bourdeaux, Christopher P; Thomas, Matthew Jc; Gould, Timothy H; Malhotra, Gaurav; Jarvstad, Andreas; Jones, Timothy; Gilchrist, Iain D

    2016-05-26

    Low tidal volume (TVe) ventilation improves outcomes for ventilated patients, and the majority of clinicians state they implement it. Unfortunately, most patients never receive low TVes. 'Nudges' influence decision-making with subtle cognitive mechanisms and are effective in many contexts. There have been few studies examining their impact on clinical decision-making. We investigated the impact of 2 interventions designed using principles from behavioural science on the deployment of low TVe ventilation in the intensive care unit (ICU). University Hospitals Bristol, a tertiary, mixed medical and surgical ICU with 20 beds, admitting over 1300 patients per year. Data were collected from 2144 consecutive patients receiving controlled mechanical ventilation for more than 1 hour between October 2010 and September 2014. Patients on controlled mechanical ventilation for more than 20 hours were included in the final analysis. (1) Default ventilator settings were adjusted to comply with low TVe targets from the initiation of ventilation unless actively changed by a clinician. (2) A large dashboard was deployed displaying TVes in the format mL/kg ideal body weight (IBW) with alerts when TVes were excessive. TVe in mL/kg IBW. TVe was significantly lower in the defaults group. In the dashboard intervention, TVe fell more quickly and by a greater amount after a TVe of 8 mL/kg IBW was breached when compared with controls. This effect improved in each subsequent year for 3 years. This study has demonstrated that adjustment of default ventilator settings and a dashboard with alerts for excessive TVe can significantly influence clinical decision-making. This offers a promising strategy to improve compliance with low TVe ventilation, and suggests that using insights from behavioural science has potential to improve the translation of evidence into practice. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please

  16. The effect of surgery on lung volume and conventional monitoring parameters in ventilated newborn infants.

    Science.gov (United States)

    Proquitté, H; Freiberger, O; Yilmaz, S; Bamberg, C; Degenhardt, P; Roehr, C C; Wauer, R R; Schmalisch, G

    2010-05-01

    In newborn infants, thoraco-abdominal surgery is a serious intervention with respect to gas exchange and lung mechanics. This prospective clinical study compared surgery-induced changes in functional residual capacity (FRC) and ventilation inhomogeneity (VI) indices with changes in conventional monitoring parameters. Of 29 ventilated newborns (mean weight 2,770+/-864 g at surgery), 13, nine and seven underwent thoracic, abdominal or congenital diaphragmatic hernia (CDH) surgery, respectively. The multiple breath washout (MBWO) technique using heptafluoropropane as tracer gas (Babylog 8000; Dräger, Lübeck, Germany) was performed ventilatory monitoring parameters. FRC decreased in non-CDH infants, while FRC increased and VI indices decreased in CDH infants. Despite improvements, the differences in FRC and VI between CDH and non-CDH infants indicated persistent impaired lung function in CHD infants. MBWO can be advantageously used to measure the effect of surgery on the lung. While FRC and VI indices changed following surgery, conventional monitoring parameters did not.

  17. Bench performance of ventilators during simulated paediatric ventilation.

    Science.gov (United States)

    Park, M A J; Freebairn, R C; Gomersall, C D

    2013-05-01

    This study compares the accuracy and capabilities of various ventilators using a paediatric acute respiratory distress syndrome lung model. Various compliance settings and respiratory rate settings were used. The study was done in three parts: tidal volume and FiO2 accuracy; pressure control accuracy and positive end-expiratory pressure (PEEP) accuracy. The parameters set on the ventilator were compared with either or both of the measured parameters by the test lung and the ventilator. The results revealed that none of the ventilators could consistently deliver tidal volumes within 1 ml/kg of the set tidal volume, and the discrepancy between the delivered volume and the volume measured by the ventilator varied greatly. The target tidal volume was 8 ml/kg, but delivered tidal volumes ranged from 3.6-11.4 ml/kg and the volumes measured by the ventilator ranged from 4.1-20.6 ml/kg. All the ventilators maintained pressure within 20% of the set pressure, except one ventilator which delivered pressures of up to 27% higher than the set pressure. Two ventilators maintained PEEP within 10% of the prescribed PEEP. The majority of the readings were also within 10%. However, three ventilators delivered, at times, PEEPs over 20% higher. In conclusion, as lung compliance decreases, especially in paediatric patients, some ventilators perform better than others. This study highlights situations where ventilators may not be able to deliver, nor adequately measure, set tidal volumes, pressure, PEEP or FiO2.

  18. The performances of standard and ResMed masks during bag-valve-mask ventilation.

    Science.gov (United States)

    Lee, Hyoung Youn; Jeung, Kyung Woon; Lee, Byung Kook; Lee, Seung Joon; Jung, Yong Hun; Lee, Geo Sung; Min, Yong Il; Heo, Tag

    2013-01-01

    A tight mask seal is frequently difficult to obtain and maintain during single-rescuer bag-valve-mask (BVM) ventilation. The ResMed mask (Bella Vista, NSW, Australia) is a continuous-positive-airway-pressure mask (CM) designed for noninvasive ventilation. In this study, we compared the ventilation performances of a standard mask (SM) and a ResMed CM using a simulation manikin in an out-of-hospital single-rescuer BVM ventilation scenario. Thirty emergency medical technicians (EMTs) performed two 2-minute attempts to ventilate a simulation manikin using BVM ventilation, alternatively, with the SM or the ResMed CM in a randomized order. Ventilation parameters including tidal volume and peak airway pressure were measured using computer analysis software connected to the simulation manikin. Successful volume delivery was defined as delivery of 440-540 mL of tidal volume in accord with present cardiopulmonary resuscitation guidelines. BVM ventilation using the ResMed CM produced higher mean (± standard deviation) tidal volumes (452 ± 50 mL vs. 394 ± 113 mL, p = 0.014) and had a higher proportion of successful volume deliveries (65.3% vs. 26.7%, p < 0.001) than that using the SM. Peak airway pressure was higher in BVM ventilation using the ResMed CM (p = 0.035). Stomach insufflation did not occur during either method. Twenty-nine of the participants (96.7%) preferred BVM ventilation using the ResMed CM. BVM ventilations using ResMed CM resulted in a significantly higher proportion of successful volume deliveries meeting the currently recommended range of tidal volume. Clinical studies are needed to determine the value of the ResMed CM for BVM ventilation.

  19. Medida da freqüência respiratória e do volume corrente para prever a falha na extubação de recém-nascidos de muito baixo peso em ventilação mecânica Evaluation of respiratory rate and tidal volume to predict extubation failure in mechanically ventilated very low birth weight infants

    Directory of Open Access Journals (Sweden)

    Josy Davidson

    2008-03-01

    Full Text Available OBJETIVO: Verificar se a freqüência respiratória (FR, o volume corrente (VC e a relação FR/VC poderiam prever a falha na extubação em recém-nascidos de muito baixo peso submetidos à ventilação mecânica. MÉTODOS: Estudo prospectivo, observacional, de recém-nascidos com idade gestacional OBJECTIVE: To verify if respiratory rate (RR, tidal volume (TV and respiratory rate and tidal volume ratio (RR/TV could predict extubation failure in very low birth weight infants submitted to mechanical ventilation. METHODS: This prospective observational study enrolled newborn infants with gestational age <37 weeks and birth weight <1,500g, mechanically ventilated from birth during 48 hours to 30 days and thought to be ready for extubation. As soon as the physicians decided for extubation, the neonates received endotracheal continuous positive airway pressure (CPAP for 10 minutes while spontaneous RR, TV and RR/TV were measured using a fixed-orifice pneumotachograph positioned between the endotracheal tube and the ventilator circuit. Thereafter, the neonates were extubated to nasal CPAP. Extubation failure was defined as the need for reintubation within 48 hours. RESULTS: Of the 35 studied infants, 20 (57% were successfully extubated and 15 (43% required reintubation. RR and RR/TV before extubation had a trend to be higher in unsuccessfully extubated infants. TV was similar in both groups. Sensitivity and specificity of these parameters as predictors of extubation failure were 50 and 67% respectively for RR, 40 and 67% for TV and 40 and 73% for RR/TV. CONCLUSIONS: RR, TV and RR/TV showed low sensitivity and specificity to predict extubation failure in mechanically ventilated very low birth weight infants.

  20. Liquid ventilation.

    Science.gov (United States)

    Sarkar, Suman; Paswan, Anil; Prakas, S

    2014-01-01

    Human have lungs to breathe air and they have no gills to breath liquids like fish. When the surface tension at the air-liquid interface of the lung increases as in acute lung injury, scientists started to think about filling the lung with fluid instead of air to reduce the surface tension and facilitate ventilation. Liquid ventilation (LV) is a technique of mechanical ventilation in which the lungs are insufflated with an oxygenated perfluorochemical liquid rather than an oxygen-containing gas mixture. The use of perfluorochemicals, rather than nitrogen as the inert carrier of oxygen and carbon dioxide offers a number of advantages for the treatment of acute lung injury. In addition, there are non-respiratory applications with expanding potential including pulmonary drug delivery and radiographic imaging. It is well-known that respiratory diseases are one of the most common causes of morbidity and mortality in intensive care unit. During the past few years several new modalities of treatment have been introduced. One of them and probably the most fascinating, is of LV. Partial LV, on which much of the existing research has concentrated, requires partial filling of lungs with perfluorocarbons (PFC's) and ventilation with gas tidal volumes using conventional mechanical ventilators. Various physico-chemical properties of PFC's make them the ideal media. It results in a dramatic improvement in lung compliance and oxygenation and decline in mean airway pressure and oxygen requirements. No long-term side-effect reported.

  1. The decrease of cardiac chamber volumes and output during positive-pressure ventilation

    DEFF Research Database (Denmark)

    Kristensen, Kasper Kyhl; Ahtarovski, Kiril Aleksov; Iversen, Kasper

    2013-01-01

    the effect of PPV on the central circulation by studying cardiac chamber volumes with cardiac magnetic resonance imaging (CMR). We hypothesized that PPV lowers cardiac output (CO) mainly via the Frank-Starling relationship. In 18 healthy volunteers, cardiac chamber volumes and flow in aorta and the pulmonary...... artery were measured by CMR during PPV levels of 0, 10, and 20 cmH2O applied via a respirator and a face mask. All cardiac chamber volumes decreased in proportion to the level of PPV. Following 20-cmH2O PPV, the total diastolic and systolic cardiac volumes (±SE) decreased from 605 (±29) ml to 446 (±29......) ml (P volume decreased by 27 (±4) ml/beat; heart rate increased by 7 (±2) beats/min; and CO decreased by 1.0 (±0.4) l/min (P

  2. Heliox Improves Carbon Dioxide Removal during Lung Protective Mechanical Ventilation

    Directory of Open Access Journals (Sweden)

    Charlotte J. Beurskens

    2014-01-01

    Full Text Available Introduction. Helium is a noble gas with low density and increased carbon dioxide (CO2 diffusion capacity. This allows lower driving pressures in mechanical ventilation and increased CO2 diffusion. We hypothesized that heliox facilitates ventilation in patients during lung-protective mechanical ventilation using low tidal volumes. Methods. This is an observational cohort substudy of a single arm intervention study. Twenty-four ICU patients were included, who were admitted after a cardiac arrest and mechanically ventilated for 3 hours with heliox (50% helium; 50% oxygen. A fixed protective ventilation protocol (6 mL/kg was used, with prospective observation for changes in lung mechanics and gas exchange. Statistics was by Bonferroni post-hoc correction with statistical significance set at P<0.017. Results. During heliox ventilation, respiratory rate decreased (25±4 versus 23±5 breaths min−1, P=0.010. Minute volume ventilation showed a trend to decrease compared to baseline (11.1±1.9 versus 9.9±2.1 L min−1, P=0.026, while reducing PaCO2 levels (5.0±0.6 versus 4.5±0.6 kPa, P=0.011 and peak pressures (21.1±3.3 versus 19.8±3.2 cm H2O, P=0.024. Conclusions. Heliox improved CO2 elimination while allowing reduced minute volume ventilation in adult patients during protective mechanical ventilation.

  3. Ventilation with lower tidal volumes for critically ill patients without the acute respiratory distress syndrome: a systematic translational review and meta-analysis

    NARCIS (Netherlands)

    Serpa Neto, Ary; Nagtzaam, Liselotte; Schultz, Marcus J.

    2014-01-01

    There is convincing evidence for benefit from lung-protective mechanical ventilation with lower tidal volumes in patients with the acute respiratory distress syndrome (ARDS). It is uncertain whether this strategy benefits critically ill patients without ARDS as well. This manuscript systematically

  4. Lung-protective ventilation in intensive care unit and operation room : Tidal volume size, level of positive end-expiratory pressure and driving pressure

    NARCIS (Netherlands)

    Serpa Neto, A.

    2017-01-01

    Several investigations have shown independent associations between three ventilator settings – tidal volume size, positive end–expiratory pressure (PEEP) and driving pressure – and outcomes in patients with the acute respiratory distress syndrome (ARDS). There is an increasing notion that similar

  5. Impact of Different Tidal Volume Levels at Low Mechanical Power on Ventilator-Induced Lung Injury in Rats

    Directory of Open Access Journals (Sweden)

    Lillian Moraes

    2018-04-01

    Full Text Available Tidal volume (VT has been considered the main determinant of ventilator-induced lung injury (VILI. Recently, experimental studies have suggested that mechanical power transferred from the ventilator to the lungs is the promoter of VILI. We hypothesized that, as long as mechanical power is kept below a safe threshold, high VT should not be injurious. The present study aimed to investigate the impact of different VT levels and respiratory rates (RR on lung function, diffuse alveolar damage (DAD, alveolar ultrastructure, and expression of genes related to inflammation [interleukin (IL-6], alveolar stretch (amphiregulin, epithelial [club cell secretory protein (CC16] and endothelial [intercellular adhesion molecule (ICAM-1] cell injury, and extracellular matrix damage [syndecan-1, decorin, and metalloproteinase (MMP-9] in experimental acute respiratory distress syndrome (ARDS under low-power mechanical ventilation. Twenty-eight Wistar rats received Escherichia coli lipopolysaccharide intratracheally. After 24 h, 21 animals were randomly assigned to ventilation (2 h with low mechanical power at three different VT levels (n = 7/group: (1 VT = 6 mL/kg and RR adjusted to normocapnia; (2 VT = 13 mL/kg; and 3 VT = 22 mL/kg. In the second and third groups, RR was adjusted to yield low mechanical power comparable to that of the first group. Mechanical power was calculated as [(ΔP,L2/Est,L/2]× RR (ΔP,L = transpulmonary driving pressure, Est,L = static lung elastance. Seven rats were not mechanically ventilated (NV and were used for molecular biology analysis. Mechanical power was comparable among groups, while VT gradually increased. ΔP,L and mechanical energy were higher in VT = 22 mL/kg than VT = 6 mL/kg and VT = 13 mL/kg (p < 0.001 for both. Accordingly, DAD score increased in VT = 22 mL/kg compared to VT = 6 mL/kg and VT = 13 mL/kg [23(18.5–24.75 vs. 16(12–17.75 and 16(13.25–18, p < 0.05, respectively]. VT = 22 mL/kg was associated with higher

  6. Bulbar impairment score predicts noninvasive volume-cycled ventilation failure during an acute lower respiratory tract infection in ALS.

    Science.gov (United States)

    Servera, Emilio; Sancho, Jesús; Bañuls, Pilar; Marín, Julio

    2015-11-15

    Amyotrophic lateral sclerosis (ALS) patients can suffer episodes of lower respiratory tract infections (LRTI) leading to an acute respiratory failure (ARF) requiring noninvasive ventilation (NIV). To determine whether clinical or functional parameters can predict noninvasive management failure during LRTI causing ARF in ALS. A prospective study involving all ALS patients with ARF requiring NIV in a Respiratory Care Unit. NIV was provided with volume-cycled ventilators. 63 ALS patients were included (APACHE II: 14.93±3.56, Norris bulbar subscore (NBS): 18.78±9.68, ALSFRS-R: 19.90±6.98, %FVC: 40.01±18.07%, MIC: 1.62±0.74L, PCF 2.51±1.15L/s, PImax -34.90±19.44cmH2O, PEmax 51.20±28.84cmH2O). In 73.0% of patients NIV was successful in averting death or endotracheal intubation. Differences were found between the success and failure in the NBS (22.08±6.15 vs 8.66±3.39, pNIV failure was the NBS (OR 0.53, 95% CI 0.31-0.92, p 0.002) with a cut-off point of 12 (S 0.93; E 0.97; PPV 0.76; NPV 0.97). NBS can predict noninvasive management failure during LRTI in ALS. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Performance of Portable Ventilators Following Storage at Temperature Extremes.

    Science.gov (United States)

    Blakeman, Thomas C; Rodriquez, Dario; Britton, Tyler J; Johannigman, Jay A; Petro, Michael C; Branson, Richard D

    2016-05-01

    In the current theater of operation, medical devices are often shipped and stored at ambient conditions. The effect of storage at hot and cold temperature extremes on ventilator performance is unknown. We evaluated three portable ventilators currently in use or being evaluated for use by the Department of Defense (731, Impact Instrumentation; T1, Hamilton Medical; and Revel, CareFusion) at temperature extremes in a laboratory setting. The ventilators were stored at temperatures of 60°C and -35°C for 24 hours and were allowed to acclimate to room temperature for 30 minutes before evaluation. The T1 required an extra 15 to 30 minutes of acclimation to room temperature before the ventilator would deliver breaths. All delivered tidal volumes at room temperature and after storage at temperature extremes were less than the ±10% American Society for Testing and Materials standard with the Revel. Delivered tidal volumes at the pediatric settings were less than the ±10% threshold after storage at both temperatures and at room temperature with the 731. Storage at extreme temperature affected the performance of the portable ventilators tested. This study showed that portable ventilators may need an hour or more of acclimation time at room temperature after storage at temperature extremes to operate as intended. Reprint & Copyright © 2016 Association of Military Surgeons of the U.S.

  8. Ventilation systems

    International Nuclear Information System (INIS)

    Gossler

    1980-01-01

    The present paper deals with - controlled area ventilation systems - ventilation systems for switchgear-building and control-room - other ventilation systems for safety equipments - service systems for ventilation systems. (orig./RW)

  9. Mechanical Ventilation

    Science.gov (United States)

    ... ventilation is a life support treatment. A mechanical ventilator is a machine that helps people breathe when ... to breathe enough on their own. The mechanical ventilator is also called a ventilator , respirator, or breathing ...

  10. Effects of a preemptive alveolar recruitment strategy on arterial oxygenation during one-lung ventilation with different tidal volumes in patients with normal pulmonary function test.

    Science.gov (United States)

    Jung, Jong Dal; Kim, Sang Hun; Yu, Byung Sik; Kim, Hye Ji

    2014-08-01

    Hypoxemia during one-lung ventilation (OLV) remains a major concern. The present study compared the effect of alveolar recruitment strategy (ARS) on arterial oxygenation during OLV at varying tidal volumes (Vt) with or without positive end-expiratory pressure (PEEP). In total, 120 patients undergoing wedge resection by video assisted thoracostomy were randomized into four groups comprising 30 patients each: those administered a 10 ml/kg tidal volume with or without preemptive ARS (Group H and Group H-ARS, respectively) and those administered a 6 ml/kg tidal volume and a 8 cmH2O PEEP with or without preemptive ARS (Group L and Group L-ARS, respectively). ARS was performed using pressure-controlled ventilation with a 40 cmH2O plateau airway pressure and a 15 cmH2O PEEP for at least 10 breaths until OLV began. Preemptive ARS significantly improved the PaO2/FiO2 ratio compared to the groups that did not receive ARS (P volume combined with 8 cmH2O PEEP after preemptive ARS may reduce the risk of pulmonary injury caused by high tidal volume during one-lung ventilation in patients with normal pulmonary function.

  11. The role of ventilation. 2 v. Proceedings

    International Nuclear Information System (INIS)

    1994-01-01

    The 78 papers which constitute the proceedings of the conference are presented in two volumes. The papers in the first volume cover sessions dealing with the following broad topics: ventilation strategies; indoor air quality; energy impact of ventilation; building design for optimum ventilation; ventilation and energy. Volume 2 also covers ventilation strategies and ventilation and energy, and in addition: calculation, measurement and design tools; measurement and modelling. Separate abstract have been prepared for 4 papers in Volume 1 which deal with the role of ventilation in mitigating the hazard of radon in buildings. (UK)

  12. Comparison of different inspiratory triggering settings in automated ventilators during cardiopulmonary resuscitation in a porcine model.

    Science.gov (United States)

    Tan, Dingyu; Xu, Jun; Shao, Shihuan; Fu, Yangyang; Sun, Feng; Zhang, Yazhi; Hu, Yingying; Walline, Joseph; Zhu, Huadong; Yu, Xuezhong

    2017-01-01

    Mechanical ventilation via automated in-hospital ventilators is quite common during cardiopulmonary resuscitation. It is not known whether different inspiratory triggering sensitivity settings of ordinary ventilators have different effects on actual ventilation, gas exchange and hemodynamics during resuscitation. 18 pigs enrolled in this study were anaesthetized and intubated. Continuous chest compressions and mechanical ventilation (volume-controlled mode, 100% O2, respiratory rate 10/min, and tidal volumes 10ml/kg) were performed after 3 minutes of ventricular fibrillation. Group trig-4, trig-10 and trig-20 (six pigs each) were characterized by triggering sensitivities of 4, 10 and 20 (cmH2O for pressure-triggering and L/min for flow-triggering), respectively. Additionally, each pig in each group was mechanically ventilated using three types of inspiratory triggering (pressure-triggering, flow-triggering and turned-off triggering) of 5 minutes duration each, and each animal matched with one of six random assortments of the three different triggering settings. Blood gas samples, respiratory and hemodynamic parameters for each period were all collected and analyzed. In each group, significantly lower actual respiratory rate, minute ventilation volume, mean airway pressure, arterial pH, PaO2, and higher end-tidal carbon dioxide, aortic blood pressure, coronary perfusion pressure, PaCO2 and venous oxygen saturation were observed in the ventilation periods with a turned-off triggering setting compared to those with pressure- or flow- triggering (all PVentilation with pressure- or flow-triggering tends to induce hyperventilation and deteriorating gas exchange and hemodynamics during CPR. A turned-off patient triggering or a pressure-triggering of 20 cmH2O is preferred for ventilation when an ordinary inpatient hospital ventilator is used during resuscitation.

  13. A new design for high stability pressure-controlled ventilation for small animal lung imaging

    International Nuclear Information System (INIS)

    Kitchen, M J; Habib, A; Lewis, R A; Fouras, A; Dubsky, S; Wallace, M J; Hooper, S B

    2010-01-01

    We have developed a custom-designed ventilator to deliver a stable pressure to the lungs of small animals for use in imaging experiments. Our ventilator was designed with independent pressure vessels to separately control the Peak Inspiratory Pressure (PIP) and Positive End Expiratory Pressure (PEEP) to minimise pressure fluctuations during the ventilation process. The ventilator was computer controlled through a LabVIEW interface, enabling experimental manipulations to be performed remotely whilst simultaneously imaging the lungs in situ. Mechanical ventilation was successfully performed on newborn rabbit pups to assess the most effective ventilation strategies for aerating the lungs at birth. Highly stable pressures enabled reliable respiratory gated acquisition of projection radiographs and a stable prolonged (15 minute) breath-hold for high-resolution computed tomography of deceased rabbit pups at different lung volumes.

  14. Impact of airflow interaction on inhaled air quality and transport of contaminants in rooms with personalized and total volume ventilation

    DEFF Research Database (Denmark)

    Melikov, Arsen Krikor; Cermak, Radim; Kovar, O.

    2003-01-01

    The impact of airflow interaction on inhaled air quality and transport of contaminants between occupants was studied in regard to pollution from floor covering, human bioeffluents and exhaled air, with combinations of two personalized ventilation systems (PV) with mixing and displacement...... quality with personalized and mixing ventilation was higher or at least similar compared to mixing ventilation alone. In the case of PV combined with displacement ventilation, the interaction caused mixing of the room air, an increase in the transport of bioeffluents and exhaled air between occupants and...... ventilation. In total, 80 L/s of clean air supplied at 20°C was distributed between the ventilation systems at different combinations of personalized airflow rate. Two breathing thermal manikins were used to simulate occupants in a full-scale test room. Regardless of the airflow interaction, the inhaled air...

  15. A comparison of synchronized intermittent mandatory ventilation and pressure-regulated volume control ventilation in elderly patients with acute exacerbations of COPD and respiratory failure

    OpenAIRE

    Chang, Suchi; Shi, Jindong; Fu, Cuiping; Wu, Xu; Li, Shanqun

    2016-01-01

    Suchi Chang,1 Jindong Shi,2 Cuiping Fu,1 Xu Wu,1 Shanqun Li1 1Department of Respiratory Medicine, Zhongshan Hospital, Fudan University, Shanghai, 2Department of Respiratory Medicine, The Fifth People’s Hospital of Shanghai, Fudan University, Shanghai, People’s Republic of China Background: COPD is the third leading cause of death worldwide. Acute exacerbations of COPD may cause respiratory failure, requiring intensive care unit admission and mechanical ventilation. Inten...

  16. Variable effectiveness of stepwise implementation of nudge-type interventions to improve provider compliance with intraoperative low tidal volume ventilation.

    Science.gov (United States)

    O'Reilly-Shah, Vikas N; Easton, George S; Jabaley, Craig S; Lynde, Grant C

    2018-05-18

    Identifying mechanisms to improve provider compliance with quality metrics is a common goal across medical disciplines. Nudge interventions are minimally invasive strategies that can influence behavioural changes and are increasingly used within healthcare settings. We hypothesised that nudge interventions may improve provider compliance with lung-protective ventilation (LPV) strategies during general anaesthesia. We developed an audit and feedback dashboard that included information on both provider-level and department-level compliance with LPV strategies in two academic hospitals, two non-academic hospitals and two academic surgery centres affiliated with a single healthcare system. Dashboards were emailed to providers four times over the course of the 9-month study. Additionally, the default setting on anaesthesia machines for tidal volume was decreased from 700 mL to 400 mL. Data on surgical cases performed between 1 September 2016 and 31 May 2017 were examined for compliance with LPV. The impact of the interventions was assessed via pairwise logistic regression analysis corrected for multiple comparisons. A total of 14 793 anaesthesia records were analysed. Absolute compliance rates increased from 59.3% to 87.8%preintervention to postintervention. Introduction of attending physician dashboards resulted in a 41% increase in the odds of compliance (OR 1.41, 95% CI 1.17 to 1.69, p=0.002). Subsequently, the addition of advanced practice provider and resident dashboards lead to an additional 93% increase in the odds of compliance (OR 1.93, 95% CI 1.52 to 2.46, p<0.001). Lastly, modifying ventilator defaults led to a 376% increase in the odds of compliance (OR 3.76, 95% CI 3.1 to 4.57, p<0.001). Audit and feedback tools in conjunction with default changes improve provider compliance. © 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

  17. Effects of non-invasive ventilation and posture on chest wall volumes and motion in patients with amyotrophic lateral sclerosis: a case series

    OpenAIRE

    Magalh?es, Cristiana M.; Fregonezi, Guilherme A.; Vidigal-Lopes, Mauro; Vieira, Bruna S. P. P.; Vieira, Danielle S. R.; Parreira, Ver?nica F.

    2016-01-01

    ABSTRACT Background The effects of non-invasive ventilation (NIV) on the breathing pattern and thoracoabdominal motion of patients with amyotrophic lateral sclerosis (ALS) are unknown. Objectives 1) To analyze the influence of NIV on chest wall volumes and motion assessed by optoelectronic plethysmography in ALS patients and 2) to compare these parameters in the supine and sitting positions to those of healthy individuals (without NIV). Method Nine ALS patients were evaluated in the supine...

  18. Association between use of lung-protective ventilation with lower tidal volumes and clinical outcomes among patients without acute respiratory distress syndrome: a meta-analysis.

    Science.gov (United States)

    Serpa Neto, Ary; Cardoso, Sérgio Oliveira; Manetta, José Antônio; Pereira, Victor Galvão Moura; Espósito, Daniel Crepaldi; Pasqualucci, Manoela de Oliveira Prado; Damasceno, Maria Cecília Toledo; Schultz, Marcus J

    2012-10-24

    Lung-protective mechanical ventilation with the use of lower tidal volumes has been found to improve outcomes of patients with acute respiratory distress syndrome (ARDS). It has been suggested that use of lower tidal volumes also benefits patients who do not have ARDS. To determine whether use of lower tidal volumes is associated with improved outcomes of patients receiving ventilation who do not have ARDS. MEDLINE, CINAHL, Web of Science, and Cochrane Central Register of Controlled Trials up to August 2012. Eligible studies evaluated use of lower vs higher tidal volumes in patients without ARDS at onset of mechanical ventilation and reported lung injury development, overall mortality, pulmonary infection, atelectasis, and biochemical alterations. Three reviewers extracted data on study characteristics, methods, and outcomes. Disagreement was resolved by consensus. Twenty articles (2822 participants) were included. Meta-analysis using a fixed-effects model showed a decrease in lung injury development (risk ratio [RR], 0.33; 95% CI, 0.23 to 0.47; I2, 0%; number needed to treat [NNT], 11), and mortality (RR, 0.64; 95% CI, 0.46 to 0.89; I2, 0%; NNT, 23) in patients receiving ventilation with lower tidal volumes. The results of lung injury development were similar when stratified by the type of study (randomized vs nonrandomized) and were significant only in randomized trials for pulmonary infection and only in nonrandomized trials for mortality. Meta-analysis using a random-effects model showed, in protective ventilation groups, a lower incidence of pulmonary infection (RR, 0.45; 95% CI, 0.22 to 0.92; I2, 32%; NNT, 26), lower mean (SD) hospital length of stay (6.91 [2.36] vs 8.87 [2.93] days, respectively; standardized mean difference [SMD], 0.51; 95% CI, 0.20 to 0.82; I2, 75%), higher mean (SD) PaCO2 levels (41.05 [3.79] vs 37.90 [4.19] mm Hg, respectively; SMD, -0.51; 95% CI, -0.70 to -0.32; I2, 54%), and lower mean (SD) pH values (7.37 [0.03] vs 7.40 [0

  19. Comparison of changes in tidal volume associated with expiratory rib cage compression and expiratory abdominal compression in patients on prolonged mechanical ventilation.

    Science.gov (United States)

    Morino, Akira; Shida, Masahiro; Tanaka, Masashi; Sato, Kimihiro; Seko, Toshiaki; Ito, Shunsuke; Ogawa, Shunichi; Takahashi, Naoaki

    2015-07-01

    [Purpose] This study was designed to compare and clarify the relationship between expiratory rib cage compression and expiratory abdominal compression in patients on prolonged mechanical ventilation, with a focus on tidal volume. [Subjects and Methods] The subjects were 18 patients on prolonged mechanical ventilation, who had undergone tracheostomy. Each patient received expiratory rib cage compression and expiratory abdominal compression; the order of implementation was randomized. Subjects were positioned in a 30° lateral recumbent position, and a 2-kgf compression was applied. For expiratory rib cage compression, the rib cage was compressed unilaterally; for expiratory abdominal compression, the area directly above the navel was compressed. Tidal volume values were the actual measured values divided by body weight. [Results] Tidal volume values were as follows: at rest, 7.2 ± 1.7 mL/kg; during expiratory rib cage compression, 8.3 ± 2.1 mL/kg; during expiratory abdominal compression, 9.1 ± 2.2 mL/kg. There was a significant difference between the tidal volume during expiratory abdominal compression and that at rest. The tidal volume in expiratory rib cage compression was strongly correlated with that in expiratory abdominal compression. [Conclusion] These results indicate that expiratory abdominal compression may be an effective alternative to the manual breathing assist procedure.

  20. Effects of short-term pressure-controlled ventilation on gas exchange, airway pressures, and gas distribution in patients with acute lung injury/ARDS: comparison with volume-controlled ventilation.

    Science.gov (United States)

    Prella, Maura; Feihl, François; Domenighetti, Guido

    2002-10-01

    The potential clinical benefits of pressure-controlled ventilation (PCV) over volume-controlled ventilation (VCV) in patients with acute lung injury (ALI) or ARDS still remain debated. We compared PCV with VCV in patients with ALI/ARDS with respect to the following physiologic end points: (1) gas exchange and airway pressures, and (2) CT scan intrapulmonary gas distribution at end-expiration. Prospective, observational study. A multidisciplinary ICU in a nonuniversity, acute-care hospital. Ten patients with ALI or ARDS (9 men and 1 woman; age range, 17 to 80 years). Sequential ventilation in PCV and VCV with a constant inspiratory/expiratory ratio, tidal volume, respiratory rate, and total positive end-expiratory pressure; measurement of gas exchange and airway pressures; and achievement of CT sections at lung base, hilum, and apex for the quantitative analysis of lung densities and of aerated vs nonaerated zones. PaO(2), PaCO(2), and PaO(2)/fraction of inspired oxygen ratio levels did not differ between PCV and VCV. Peak airway pressure (Ppeak) was significantly lower in PCV compared with VCV (26 +/- 2 cm H(2)O vs 31 +/- 2 cm H(2)O; p mean +/- SEM). The surface areas of the nonaerated zones as well as the total areas at each section level were unchanged in PCV compared with VCV, except at the apex level, where there was a significantly greater nonaerated area in VCV (11 +/- 2 cm(2) vs 9 +/- 2 cm(2); p mean CT number of each lung (20 lungs from 10 patients) was similar in the two modes, as were the density values at the basal and apical levels; the hilum mean CT number was - 442 +/- 28 Hounsfield units (HU) in VCV and - 430 +/- 26 HU in PCV (p lower Ppeaks through the precise titration of the lung distending pressure, and might be applied to avoid regional overdistension by means of a more homogeneous gas distribution.

  1. Effect of flashlight guidance on manual ventilation performance in cardiopulmonary resuscitation: A randomized controlled simulation study.

    Science.gov (United States)

    Kim, Ji Hoon; Beom, Jin Ho; You, Je Sung; Cho, Junho; Min, In Kyung; Chung, Hyun Soo

    2018-01-01

    Several auditory-based feedback devices have been developed to improve the quality of ventilation performance during cardiopulmonary resuscitation (CPR), but their effectiveness has not been proven in actual CPR situations. In the present study, we investigated the effectiveness of visual flashlight guidance in maintaining high-quality ventilation performance. We conducted a simulation-based, randomized, parallel trial including 121 senior medical students. All participants were randomized to perform ventilation during 2 minutes of CPR with or without flashlight guidance. For each participant, we measured mean ventilation rate as a primary outcome and ventilation volume, inspiration velocity, and ventilation interval as secondary outcomes using a computerized device system. Mean ventilation rate did not significantly differ between flashlight guidance and control groups (P = 0.159), but participants in the flashlight guidance group exhibited significantly less variation in ventilation rate than participants in the control group (Pguidance group. Our results demonstrate that flashlight guidance is effective in maintaining a constant ventilation rate and interval. If confirmed by further studies in clinical practice, flashlight guidance could be expected to improve the quality of ventilation performed during CPR.

  2. Anaesthesia ventilators

    OpenAIRE

    Jain, Rajnish K; Swaminathan, Srinivasan

    2013-01-01

    Anaesthesia ventilators are an integral part of all modern anaesthesia workstations. Automatic ventilators in the operating rooms, which were very simple with few modes of ventilation when introduced, have become very sophisticated with many advanced ventilation modes. Several systems of classification of anaesthesia ventilators exist based upon various parameters. Modern anaesthesia ventilators have either a double circuit, bellow design or a single circuit piston configuration. In the bello...

  3. Very low tidal volume ventilation with associated hypercapnia--effects on lung injury in a model for acute respiratory distress syndrome.

    Directory of Open Access Journals (Sweden)

    Hans Fuchs

    Full Text Available BACKGROUND: Ventilation using low tidal volumes with permission of hypercapnia is recommended to protect the lung in acute respiratory distress syndrome. However, the most lung protective tidal volume in association with hypercapnia is unknown. The aim of this study was to assess the effects of different tidal volumes with associated hypercapnia on lung injury and gas exchange in a model for acute respiratory distress syndrome. METHODOLOGY/PRINCIPAL FINDINGS: In this randomized controlled experiment sixty-four surfactant-depleted rabbits were exposed to 6 hours of mechanical ventilation with the following targets: Group 1: tidal volume = 8-10 ml/kg/PaCO(2 = 40 mm Hg; Group 2: tidal volume = 4-5 ml/kg/PaCO(2 = 80 mm Hg; Group 3: tidal volume = 3-4 ml/kg/PaCO(2 = 120 mm Hg; Group 4: tidal volume = 2-3 ml/kg/PaCO(2 = 160 mm Hg. Decreased wet-dry weight ratios of the lungs, lower histological lung injury scores and higher PaO(2 were found in all low tidal volume/hypercapnia groups (group 2, 3, 4 as compared to the group with conventional tidal volume/normocapnia (group 1. The reduction of the tidal volume below 4-5 ml/kg did not enhance lung protection. However, oxygenation and lung protection were maintained at extremely low tidal volumes in association with very severe hypercapnia and no adverse hemodynamic effects were observed with this strategy. CONCLUSION: Ventilation with low tidal volumes and associated hypercapnia was lung protective. A tidal volume below 4-5 ml/kg/PaCO(2 80 mm Hg with concomitant more severe hypercapnic acidosis did not increase lung protection in this surfactant deficiency model. However, even at extremely low tidal volumes in association with severe hypercapnia lung protection and oxygenation were maintained.

  4. Actual performance of mechanical ventilators in ICU: a multicentric quality control study.

    Science.gov (United States)

    Govoni, Leonardo; Dellaca', Raffaele L; Peñuelas, Oscar; Bellani, Giacomo; Artigas, Antonio; Ferrer, Miquel; Navajas, Daniel; Pedotti, Antonio; Farré, Ramon

    2012-01-01

    Even if the performance of a given ventilator has been evaluated in the laboratory under very well controlled conditions, inappropriate maintenance and lack of long-term stability and accuracy of the ventilator sensors may lead to ventilation errors in actual clinical practice. The aim of this study was to evaluate the actual performances of ventilators during clinical routines. A resistance (7.69 cmH(2)O/L/s) - elastance (100 mL/cmH(2)O) test lung equipped with pressure, flow, and oxygen concentration sensors was connected to the Y-piece of all the mechanical ventilators available for patients in four intensive care units (ICUs; n = 66). Ventilators were set to volume-controlled ventilation with tidal volume = 600 mL, respiratory rate = 20 breaths/minute, positive end-expiratory pressure (PEEP) = 8 cmH(2)O, and oxygen fraction = 0.5. The signals from the sensors were recorded to compute the ventilation parameters. The average ± standard deviation and range (min-max) of the ventilatory parameters were the following: inspired tidal volume = 607 ± 36 (530-723) mL, expired tidal volume = 608 ± 36 (530-728) mL, peak pressure = 20.8 ± 2.3 (17.2-25.9) cmH(2)O, respiratory rate = 20.09 ± 0.35 (19.5-21.6) breaths/minute, PEEP = 8.43 ± 0.57 (7.26-10.8) cmH(2)O, oxygen fraction = 0.49 ± 0.014 (0.41-0.53). The more error-prone parameters were the ones related to the measure of flow. In several cases, the actual delivered mechanical ventilation was considerably different from the set one, suggesting the need for improving quality control procedures for these machines.

  5. Effect of tidal volume on extravascular lung water content during one-lung ventilation for video-assisted thoracoscopic surgery: a randomised, controlled trial.

    Science.gov (United States)

    Qutub, Hatem; El-Tahan, Mohamed R; Mowafi, Hany A; El Ghoneimy, Yasser F; Regal, Mohamed A; Al Saflan, AbdulHadi A

    2014-09-01

    The use of low tidal volume during one-lung ventilation (OLV) has been shown to attenuate the incidence of acute lung injury after thoracic surgery. To test the effect of tidal volume during OLV for video-assisted thoracoscopic surgery on the extravascular lung water content index (EVLWI). A randomised, double-blind, controlled study. Single university hospital. Thirty-nine patients scheduled for elective video-assisted thoracoscopic surgery. Patients were randomly assigned to one of three groups (n = 13 per group) to ventilate the dependent lung with a tidal volume of 4, 6 or 8 ml  kg(-1) predicted body weight with I:E ratio of 1:2.5 and PEEP of 5 cm H2O. The primary outcomes were perioperative changes in EVLWI and EVLWI to intrathoracic blood volume index (ITBVI) ratio. Secondary outcomes included haemodynamics, oxygenation indices, incidences of postoperative acute lung injury, atelectasis, pneumonia, morbidity and 30-day mortality. A tidal volume of 4 compared with 6 and 8 ml  kg(-1) after 45 min of OLV resulted in an EVLWI of 4.1 [95% confidence interval (CI) 3.5 to 4.7] compared with 7.7 (95% CI 6.7 to 8.6) and 8.6 (95% CI 7.5 to 9.7) ml  kg(-1), respectively (P tidal volume of 4 ml kg during OLV was associated with less lung water content than with larger tidal volumes of 6 to 8 ml kg(-1), although no patient developed acute lung injury. Further studies are required to address the usefulness of EVLWI as a marker for the development of postoperative acute lung injury after the use of a low tidal volume during OLV in patients undergoing pulmonary resection. Clinicaltrials.gov identifier: NCT01762709.

  6. Ventilation and ventilation/perfusion ratios

    International Nuclear Information System (INIS)

    Valind, S.O.

    1989-01-01

    The thesis is based on five different papers. The labelling of specific tracer compounds with positron emitting radionuclides enables a range of structural, physiological and biochemical parameters in the lung to be measured non-invasively, using positron emission tomography. This concept affords a unique opportunity for in vivo studies of different expressions of pulmonary pathophysiology at the regional level. The present thesis describes the application of positron emission tomography to the measurements of ventilation and ventilation/perfusion ratios using inert gas tracers, neon-19 and nitrogen-13 respectively. The validity of the methods applied was investigated with respect to the transport of inert gas tracers in the human lung. Both ventilation and the ventilation/perfusion ratio may be obtained with errors less than 10 % in the normal lung. In disease, however, errors may increase in those instances where the regional ventilation is very low or the intra-regional gas flow distribution is markedly nonuniform. A 2-3 fold increase in ventilation was demonstrated in normal nonsmoking subjects going from ventral to dorsal regions in the supine posture. These large regional differences could be well explained by the intrinsic elastic properties of lung tissue, considering the gravitational gradient in transpulmonary pressure. In asymptomatic smokers substantial regional ventilatroy abnormalities were found whilst the regional gas volume was similar in smokers and nonsmokers. The uncoupling between ventilation and gas volume probably reflects inflammatory changes in the airways. The regional differences in dV/dt/dQ/dt were relatively small and blood flow was largely matched to ventilation in the supine posture. However, small regions of lung with very low ventilation, unmatched by blood flow commonly exists in the most dependent parts of the lung in both smokers and nonsmokers. (29 illustrations, 7 tables, 113 references)

  7. Combining "open-lung" ventilation and arteriovenous extracorporeal lung assist: influence of different tidal volumes on gas exchange in experimental lung failure.

    Science.gov (United States)

    Muellenbach, Ralf M; Kredel, Markus; Kuestermann, Julian; Klingelhoefer, Michael; Schuster, Frank; Wunder, Christian; Kranke, Peter; Roewer, Norbert; Brederlau, Jörg

    2009-08-01

    Although low-tidal ventilation may reduce mortality in acute respiratory distress syndrome (ARDS), it can also result in severe respiratory acidosis and lung derecruitment. This study tested the hypothesis that combining "open-lung" ventilation and arteriovenous extracorporeal lung assist (av-ECLA) allows for maximal tidal volume (VT) reduction without the development of decompensated respiratory acidosis and impairment of oxygenation. After induction of ARDS in eight female pigs (56.1+/-3.2 kg), lung recruitment was performed and positive end-expiratory pressure was set 3 cmH2O above the lower inflection point of the pressure-volume curve. All animals were ventilated in the pressure-controlled ventilation mode (PCV) with VTs ranging from 0-8 ml/kg. At each VT, gas exchange and hemodynamic measurements were obtained with the av-ECLA circuit clamped and declamped. With each declamping, the gas flow through the membrane lung was set to 10 l of oxygen/min. The respiratory rate was adjusted to maintain normocapnia, but limited to 40/min. After lung recruitment, oxygenation remained significantly improved although VTs were minimized to 0 ml/kg (p<0.05). PaO2 was significantly improved during PCV and av-ECLA compared with PCV alone at VTs <4 ml/kg (p<0.05). With VT <6 ml/kg, severe acidosis could only be avoided if PCV was combined with av-ECLA. Due to sufficient CO2 elimination during av-ECLA, the VTs could be reduced to 0-2 ml/kg without the risk of decompensated respiratory acidosis. It was also shown that the "open-lung" strategy chosen was associated with sustained improvements in oxygenation, even though VTs were minimized.

  8. Ventilação mecânica volume-controlada versus pressão controlada em modelo canino de lesão pulmonar aguda: efeitos cardiorrespiratórios e sobre o custo de oxigênio da respiração Volume controlled ventilation versus pressure controlled ventilation in a canine acute lung injury model: effects on cardiorespiratory parameters and oxygen cost of breathing

    Directory of Open Access Journals (Sweden)

    BRUNO DO VALLE PINHEIRO

    2002-01-01

    Full Text Available Introdução: Persiste a questão sobre se há vantagens mecânicas ou de trocas gasosas no uso da ventilação pressão-controlada (VPC sobre a ciclada a volume (VCV. Objetivos: Comparar, de forma randômica, a VPC com a VCV com fluxo desacelerado nos modos assistido e controlado em modelo experimental de lesão pulmonar aguda. Métodos: Sete cães com lesão pulmonar aguda grave (PaO2/FIO2 Background: It is questionable whether pressure-controlled ventilation (PCV has advantages over volume-cycled ventilation (VCV. Objectives: To compare PCV to VCV with decelerating flow profile during assisted and controlled modes in an acute lung injury experimental model. Methods: Severe acute lung injury (PaO2/FIO2 < 100 mmHg was induced by oleic acid IV infusion (0.05 mg/kg in seven dogs. The animals were submitted to PCV and VCV in a randomized sequence. After 40 minutes in the assisted mode, ventilation was changed to the controlled mode after neuromuscular blockade. The tidal volume and the inspiratory time were kept constant throughout the experiment. Results: There were no differences in gas exchange (PaO2 and PaCO2, cardiac output or oxygen delivery (DO2 between VCV and PCV. The same was observed regarding maximum airway and plateau pressures, and also to the static compliance. Oxygen consumption (VO2 after neuromuscular blockade was 124 ± 48 in VCV versus 143 ± 50 ml/min in PCV, p = 0.42. In the assisted mode, there was a statistical trend of a higher VO2 in PCV (219 ± 72 versus 154 ± 67 ml/min in VCV, p = 0.06, that was associated with a statistical trend of a higher oxygen cost of breathing (OCB during assisted PCV, although without statistical significance (31 ± 77 in VCV versus 75 ± 96 ml/min in PCV, p = 0.23, and also in a lower PvO2 (34 ± 7 in PCV versus 42 ± 6 ml/min in VCV, p = 0.02. These occurred despite a higher maximum inspiratory flow in the assisted mode in PCV (58 ± 9 versus 48 ± 4 L/min in VCV, p = 0.01. In both VCV and

  9. Mechanical Ventilation and Bronchopulmonary Dysplasia.

    Science.gov (United States)

    Keszler, Martin; Sant'Anna, Guilherme

    2015-12-01

    Mechanical ventilation is an important potentially modifiable risk factor for the development of bronchopulmonary dysplasia. Effective use of noninvasive respiratory support reduces the risk of lung injury. Lung volume recruitment and avoidance of excessive tidal volume are key elements of lung-protective ventilation strategies. Avoidance of oxidative stress, less invasive methods of surfactant administration, and high-frequency ventilation are also important factors in lung injury prevention. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Battery life of portable home ventilators: effects of ventilator settings.

    Science.gov (United States)

    Falaize, Line; Leroux, Karl; Prigent, Hélène; Louis, Bruno; Khirani, Sonia; Orlikowski, David; Fauroux, Brigitte; Lofaso, Frédéric

    2014-07-01

    The battery life (BL) of portable home ventilator batteries is reported by manufacturers. The aim of this study was to evaluate the effects of ventilator mode, breathing frequency, PEEP, and leaks on the BL of 5 commercially available portable ventilators. The effects of the ventilator mode (volume controlled-continuous mandatory ventilation [VC-CMV] vs pressure support ventilation [PSV]), PEEP 5 cm H2O, breathing frequency (10, 15, and 20 breaths/min), and leaks during both volume-targeted ventilation and PSV on the BL of 5 ventilators (Elisée 150, Monnal T50, PB560, Vivo 50, and Trilogy 100) were evaluated. Each ventilator was ventilated with a test lung at a tidal volume of 700 ml and an inspiratory time of 1.2 s in the absence of leaks. Switching from PSV to VC-CMV or the addition of PEEP did not significantly change ventilator BL. The increase in breathing frequency from 10 to 20 breaths/min decreased the BL by 18 ± 11% (P = .005). Leaks were associated with an increase in BL during the VC-CMV mode (18 ± 20%, P = .04) but a decrease in BL during the PSV mode (-13 ± 15%, P = .04). The BL of home ventilators depends on the ventilator settings. BL is not affected by the ventilator mode (VC-CMV or PSV) or the addition of PEEP. BL decreases with an increase in breathing frequency and during leaks with a PSV mode, whereas leaks increase the duration of ventilator BL during VC-CMV. Copyright © 2014 by Daedalus Enterprises.

  11. Are there benefits or harm from pressure targeting during lung-protective ventilation?

    Science.gov (United States)

    MacIntyre, Neil R; Sessler, Curtis N

    2010-02-01

    Mechanically, breath design is usually either flow/volume-targeted or pressure-targeted. Both approaches can effectively provide lung-protective ventilation, but they prioritize different ventilation parameters, so their responses to changing respiratory-system mechanics and patient effort are different. These different response behaviors have advantages and disadvantages that can be important in specific circumstances. Flow/volume targeting guarantees a set minute ventilation but sometimes may be difficult to synchronize with patient effort, and it will not limit inspiratory pressure. In contrast, pressure targeting, with its variable flow, may be easier to synchronize and will limit inspiratory pressure, but it provides no control over delivered volume. Skilled clinicians can maximize benefits and minimize problems with either flow/volume targeting or pressure targeting. Indeed, as is often the case in managing complex life-support devices, it is operator expertise rather than the device design features that most impacts patient outcomes.

  12. Goal-directed fluid optimization based on stroke volume variation and cardiac index during one-lung ventilation in patients undergoing thoracoscopy lobectomy operations: a pilot study

    Directory of Open Access Journals (Sweden)

    Jian Zhang

    2013-07-01

    Full Text Available OBJECTIVES: This pilot study was designed to utilize stroke volume variation and cardiac index to ensure fluid optimization during one-lung ventilation in patients undergoing thoracoscopic lobectomies. METHODS: Eighty patients undergoing thoracoscopic lobectomy were randomized into either a goal-directed therapy group or a control group. In the goal-directed therapy group, the stroke volume variation was controlled at 10%±1%, and the cardiac index was controlled at a minimum of 2.5 L.min-1.m-2. In the control group, the MAP was maintained at between 65 mm Hg and 90 mm Hg, heart rate was maintained at between 60 BPM and 100 BPM, and urinary output was greater than 0.5 mL/kg-1/h-1. The hemodynamic variables, arterial blood gas analyses, total administered fluid volume and side effects were recorded. RESULTS: The PaO2/FiO2-ratio before the end of one-lung ventilation in the goal-directed therapy group was significantly higher than that of the control group, but there were no differences between the goal-directed therapy group and the control group for the PaO2/FiO2-ratio or other arterial blood gas analysis indices prior to anesthesia. The extubation time was significantly earlier in the goal-directed therapy group, but there was no difference in the length of hospital stay. Patients in the control group had greater urine volumes, and they were given greater colloid and overall fluid volumes. Nausea and vomiting were significantly reduced in the goal-directed therapy group. CONCLUSION: The results of this study demonstrated that an optimization protocol, based on stroke volume variation and cardiac index obtained with a FloTrac/Vigileo device, increased the PaO2/FiO2-ratio and reduced the overall fluid volume, intubation time and postoperative complications (nausea and vomiting in thoracic surgery patients requiring one-lung ventilation.

  13. Ventilatory protective strategies during thoracic surgery: effects of alveolar recruitment maneuver and low-tidal volume ventilation on lung density distribution.

    Science.gov (United States)

    Kozian, Alf; Schilling, Thomas; Schütze, Hartmut; Senturk, Mert; Hachenberg, Thomas; Hedenstierna, Göran

    2011-05-01

    The increased tidal volume (V(T)) applied to the ventilated lung during one-lung ventilation (OLV) enhances cyclic alveolar recruitment and mechanical stress. It is unknown whether alveolar recruitment maneuvers (ARMs) and reduced V(T) may influence tidal recruitment and lung density. Therefore, the effects of ARM and OLV with different V(T) on pulmonary gas/tissue distribution are examined. Eight anesthetized piglets were mechanically ventilated (V(T) = 10 ml/kg). A defined ARM was applied to the whole lung (40 cm H(2)O for 10 s). Spiral computed tomographic lung scans were acquired before and after ARM. Thereafter, the lungs were separated with an endobronchial blocker. The pigs were randomized to receive OLV in the dependent lung with a V(T) of either 5 or 10 ml/kg. Computed tomography was repeated during and after OLV. The voxels were categorized by density intervals (i.e., atelectasis, poorly aerated, normally aerated, or overaerated). Tidal recruitment was defined as the addition of gas to collapsed lung regions. The dependent lung contained atelectatic (56 ± 10 ml), poorly aerated (183 ± 10 ml), and normally aerated (187 ± 29 ml) regions before ARM. After ARM, lung volume and aeration increased (426 ± 35 vs. 526 ± 69 ml). Respiratory compliance enhanced, and tidal recruitment decreased (95% vs. 79% of the whole end-expiratory lung volume). OLV with 10 ml/kg further increased aeration (atelectasis, 15 ± 2 ml; poorly aerated, 94 ± 24 ml; normally aerated, 580 ± 98 ml) and tidal recruitment (81% of the dependent lung). OLV with 5 ml/kg did not affect tidal recruitment or lung density distribution. (Data are given as mean ± SD.) The ARM improves aeration and respiratory mechanics. In contrast to OLV with high V(T), OLV with reduced V(T) does not reinforce tidal recruitment, indicating decreased mechanical stress.

  14. A bench evaluation of fraction of oxygen in air delivery and tidal volume accuracy in home care ventilators available for hospital use

    Science.gov (United States)

    Baboi, Loredana; Subtil, Fabien

    2016-01-01

    Background Turbine-powered ventilators are not only designed for long-term ventilation at home but also for hospital use. It is important to verify their capabilities in delivering fraction of oxygen in air (FIO2) and tidal volume (VT). Methods We assessed the FIO2 accuracy and the VT delivery in four home care ventilators (HCV) on the bench. The four HCV were Astral 150, Elisée 150, Monnal T50 and Trilogy 200 HCV, which were connected to a lung model (ASL 5000). For assessing FIO2 accuracy, lung model was set to mimic an obstructive lung and HCV were set in volume controlled mode (VC). They supplied with air, 3 or 15 L/min oxygen and FIO2 was measured by using a ventilator tester (Citrex H4TM). For the VT accuracy, the lung model was set in a way to mimic three adult configurations (normal, obstructive, or restrictive respiratory disorder) and one pediatric configuration. Each HCV was set in VC. Two VT (300 and 500 mL) in adult lung configuration and one 50 mL VT in pediatric lung configuration, at two positive end expiratory pressures 5 and 10 cmH2O, were tested. VT accuracy was measured as volume error (the relative difference between set and measured VT). Statistical analysis was performed by suing one-factor ANOVA with a Bonferroni correction for multiple tests. Results For Astral 150, Elisée 150, Monnal T50 and Trilogy 200, FIO2 averaged 99.2%, 93.7%, 86.3%, and 62.1%, respectively, at 15 L/min oxygen supplementation rate (P<0.001). Volume error was 0.5%±0%, −38%±0%, −9%±0%, −29%±0% and −36%±0% for pediatric lung condition (P<0.001). In adult lung configurations, Monnal T50 systematically over delivered VT and Trilogy 150 was sensitive to lung configuration when VT was set to 300 mL at either positive end-expiratory pressure (PEEP). Conclusions HCV are different in terms of FIO2 efficiency and VT delivery. PMID:28149559

  15. Comparative evaluation of hemodynamic and respiratory parameters during mechanical ventilation with two tidal volumes calculated by demi-span based height and measured height in normal lungs

    Directory of Open Access Journals (Sweden)

    L Mousavi Seresht

    2014-01-01

    Full Text Available Background : Appropriate determination of tidal volume (VT is important for preventing ventilation induced lung injury. We compared hemodynamic and respiratory parameters in two conditions of receiving VTs calculated by using body weight (BW, which was estimated by measured height (HBW or demi-span based body weight (DBW. Materials and Methods : This controlled-trial was conducted in St. Alzahra Hospital in 2009 on American Society of Anesthesiologists (ASA I and II, 18-65-years-old patients. Standing height and weight were measured and then height was calculated using demi-span method. BW and VT were calculated with acute respiratory distress syndrome-net formula. Patients were randomized and then crossed to receive ventilation with both calculated VTs for 20 min. Hemodynamic and respiratory parameters were analyzed with SPSS version 20.0 using univariate and multivariate analyses. Results : Forty nine patients were studied. Demi-span based body weight and thus VT (DTV were lower than Height based body weight and VT (HTV (P = 0.028, in male patients (P = 0.005. Difference was observed in peak airway pressure (PAP and airway resistance (AR changes with higher PAP and AR at 20 min after receiving HTV compared with DTV. Conclusions : Estimated VT based on measured height is higher than that based on demi-span and this difference exists only in females, and this higher VT results higher airway pressures during mechanical ventilation.

  16. Adjusting tidal volume to stress index in an open lung condition optimizes ventilation and prevents overdistension in an experimental model of lung injury and reduced chest wall compliance.

    Science.gov (United States)

    Ferrando, Carlos; Suárez-Sipmann, Fernando; Gutierrez, Andrea; Tusman, Gerardo; Carbonell, Jose; García, Marisa; Piqueras, Laura; Compañ, Desamparados; Flores, Susanie; Soro, Marina; Llombart, Alicia; Belda, Francisco Javier

    2015-01-13

    The stress index (SI), a parameter derived from the shape of the pressure-time curve, can identify injurious mechanical ventilation. We tested the hypothesis that adjusting tidal volume (VT) to a non-injurious SI in an open lung condition avoids hypoventilation while preventing overdistension in an experimental model of combined lung injury and low chest-wall compliance (Ccw). Lung injury was induced by repeated lung lavages using warm saline solution, and Ccw was reduced by controlled intra-abdominal air-insufflation in 22 anesthetized, paralyzed and mechanically ventilated pigs. After injury animals were recruited and submitted to a positive end-expiratory pressure (PEEP) titration trial to find the PEEP level resulting in maximum compliance. During a subsequent four hours of mechanical ventilation, VT was adjusted to keep a plateau pressure (Pplat) of 30 cmH2O (Pplat-group, n = 11) or to a SI between 0.95 and 1.05 (SI-group, n = 11). Respiratory rate was adjusted to maintain a 'normal' PaCO2 (35 to 65 mmHg). SI, lung mechanics, arterial-blood gases haemodynamics pro-inflammatory cytokines and histopathology were analyzed. In addition Computed Tomography (CT) data were acquired at end expiration and end inspiration in six animals. PaCO2 was significantly higher in the Pplat-group (82 versus 53 mmHg, P = 0.01), with a resulting lower pH (7.19 versus 7.34, P = 0.01). We observed significant differences in VT (7.3 versus 5.4 mlKg(-1), P = 0.002) and Pplat values (30 versus 35 cmH2O, P = 0.001) between the Pplat-group and SI-group respectively. SI (1.03 versus 0.99, P = 0.42) and end-inspiratory transpulmonary pressure (PTP) (17 versus 18 cmH2O, P = 0.42) were similar in the Pplat- and SI-groups respectively, without differences in overinflated lung areas at end- inspiration in both groups. Cytokines and histopathology showed no differences. Setting tidal volume to a non-injurious stress index in an open lung condition improves

  17. Effects of acetazolamide and furosemide on ventilation and cerebral blood volume in normocapnic and hypercapnic patients with COPD.

    NARCIS (Netherlands)

    Ven, M.J.T. van de; Colier, W.N.J.M.; Sluijs, M.C. van der; Oeseburg, B.; Vis, P.; Folgering, H.T.M.

    2002-01-01

    STUDY OBJECTIVES: Effects of chronic metabolic alkalosis and acidosis and their relation to central chemoregulation may differ between normocapnic and chronic hypercapnic patients with COPD. The relationship between responses of inspired ventilation (VI), mouth occlusion pressure (P(0.1)), and

  18. Lung-Protective Ventilation With Low Tidal Volumes and the Occurrence of Pulmonary Complications in Patients Without Acute Respiratory Distress Syndrome: A Systematic Review and Individual Patient Data Analysis

    NARCIS (Netherlands)

    Neto, Ary Serpa; Simonis, Fabienne D.; Barbas, Carmen S. V.; Biehl, Michelle; Determann, Rogier M.; Elmer, Jonathan; Friedman, Gilberto; Gajic, Ognjen; Goldstein, Joshua N.; Linko, Rita; Pinheiro de Oliveira, Roselaine; Sundar, Sugantha; Talmor, Daniel; Wolthuis, Esther K.; Gama de Abreu, Marcelo; Pelosi, Paolo; Schultz, Marcus J.

    2015-01-01

    Protective mechanical ventilation with low tidal volumes is standard of care for patients with acute respiratory distress syndrome. The aim of this individual patient data analysis was to determine the association between tidal volume and the occurrence of pulmonary complications in ICU patients

  19. Effect of metronome rates on the quality of bag-mask ventilation during metronome-guided 30:2 cardiopulmonary resuscitation: A randomized simulation study.

    Science.gov (United States)

    Na, Ji Ung; Han, Sang Kuk; Choi, Pil Cho; Shin, Dong Hyuk

    2017-01-01

    Metronome guidance is a feasible and effective feedback technique to improve the quality of cardiopulmonary resuscitation (CPR). The rate of the metronome should be set between 100 to 120 ticks/minute and the speed of ventilation may have crucial effect on the quality of ventilation. We compared three different metronome rates (100, 110, 120 ticks/minute) to investigate its effect on the quality of ventilation during metronome-guided 30:2 CPR. This is a prospective, randomized, crossover observational study using a RespiTrainer○ r . To simulate 30 chest compressions, one investigator counted from 1 to 30 in cadence with the metronome rate (1 count for every 1 tick), and the participant performed 2 consecutive ventilations immediately following the counting of 30. Thirty physicians performed 5 sets of 2 consecutive (total 10) bag-mask ventilations for each metronome rate. Participants were instructed to squeeze the bag over 2 ticks (1.0 to 1.2 seconds depending on the rate of metronome) and deflate the bag over 2 ticks. The sequence of three different metronome rates was randomized. Mean tidal volume significantly decreased as the metronome rate was increased from 110 ticks/minute to 120 ticks/minute (343±84 mL vs. 294±90 mL, P =0.004). Peak airway pressure significantly increased as metronome rate increased from 100 ticks/minute to 110 ticks/minute (18.7 vs. 21.6 mmHg, P =0.006). In metronome-guided 30:2 CPR, a higher metronome rate may adversely affect the quality of bag-mask ventilations. In cases of cardiac arrest where adequate ventilation support is necessary, 100 ticks/minute may be better than 110 or 120 ticks/minute to deliver adequate tidal volume during audio tone guided 30:2 CPR.

  20. Intraoperative and postoperative evaluation of low tidal volume combined with low-level positive end-expiratory pressure ventilation in laparoscopic surgery in elderly patients

    Directory of Open Access Journals (Sweden)

    Ye-Qiu Li

    2016-01-01

    Full Text Available Objective: To evaluate intraoperative and postoperative condition of low tidal volume combined with low-level positive end-expiratory pressure ventilation in laparoscopic surgery in elderly patients. Methods: A total of 176 cases of elderly patients (more than 60 years old receiving laparoscopic surgery in our hospital from July 2013 to July 2015 were selected as research subjects and randomly divided into observation group and control group, each group included 88 cases, control group received conventional ventilation strategy, observation group received low tidal volume combined with low-level positive end-expiratory pressure ventilation strategy, and then levels of hemodynamic indexes, respiratory mechanical indexes, serology indexes and cerebral vessel related indexes, etc of two groups were compared. Results: Intraoperative and postoperative heart rate and mean arterial pressure levels of observation group were lower than those of control group, arterial partial pressure of oxygen and oxygenation index levels were higher than those of control group and differences had statistical significance (P<0.05; intraoperative APIP and Pplat values of observation group were lower than those of control group, Cs value was higher than that of control group and differences had statistical significance (P<0.05; intraoperative and postoperative serum IL-8 and TNF-α levels of observation group were lower than those of control group, IL-10 level was higher than that of control group and differences had statistical significance (P<0.05; intraoperative and postoperative PjvO2, SjvO2 and CjvO2 levels of observation group were higher than those of control group, Da-jvO2 level was lower than that of control group and differences had statistical significance (P<0.05. Conclusions: When elderly patients receive laparoscopic surgery, the use of low tidal volume combined with low-level positive end-expiratory pressure ventilation strategy can stabilize hemodynamic

  1. 3 Level Ventilation: the First Clinical Experience

    Directory of Open Access Journals (Sweden)

    P. Torok

    2008-01-01

    Full Text Available Considering the issues of artificial ventilation (AV in non-homogenous pathological lung processes (acute lung injury (ALI, acute respiratory distress syndrome (ARDS, pneumonia, etc., the authors applied the three-level lung ventilation to a group of 12 patients with non-homogenous lung injury. Three-level ventilation was defined as a type (modification of AV whose basic ventilation level was produced by the modes CMV, PCV or PS (ASB and add-on level, the so-called background ventilation was generated by two levels of PEEP. PEEP (constant and PEEPh (PEEP high with varying frequency and duration of transition between the individual levels of PEEP. Objective: to elucidate whether in cases of considerably non-homogenous gas distribution in acute pathological disorders, three-level ventilation (3LV can correct gas distribution into the so-called slow bronchoalveolar compartments, by decreasing the volume load of the so-called fast compartments and to improve lung gas exchange, by following the principles of safe ventilation. Results. 3LV was applied to 12 patients with severe non-homogenous lung injury/disorder (atypic pneumonia and ARDS/ALI and low-success PCV ventilation after recruitment manoeuvre (PaO2 (kPA /FiO2 = 5—6. There were pronounced positive changes in pulmonary gas exchange within 1—4 hours after initiation of 3LV at a fPCV of 26±4 breaths/min-1 and PEEPh at a fPEEPH of 7±2 breaths/min-1 with a minute ventilation of 12±4 l/min. 3LV reduced a intrapulmonary shunt fraction 50±5 to 30±5%, increased CO2 elimination, with PaCO2 falling to the values below 6±0.3 kPa, and PaO2 to 7.5±1.2 kPa, with FiO2 being decreased to 0.8—0.4. Lung recruitment also improved gas exchange: with PEEP=1.2±0.4 kPa, static tho-racopulmonary compliance (Cst elevated from 0.18±0.02 l/kPa to 0.3±0.02 l/kPa and then to 0.38±0.05 l/kPa. Airways resistance (Raw decreased by more than 30%. Improved lung aeration was also estimated as a manifestation of

  2. Mechanical ventilation with high tidal volumes attenuates myocardial dysfunction by decreasing cardiac edema in a rat model of LPS-induced peritonitis

    Directory of Open Access Journals (Sweden)

    Smeding Lonneke

    2012-03-01

    Full Text Available Abstract Background Injurious mechanical ventilation (MV may augment organ injury remote from the lungs. During sepsis, myocardial dysfunction is common and increased endothelial activation and permeability can cause myocardial edema, which may, among other factors, hamper myocardial function. We investigated the effects of MV with injuriously high tidal volumes on the myocardium in an animal model of sepsis. Methods Normal rats and intraperitoneal (i.p. lipopolysaccharide (LPS-treated rats were ventilated with low (6 ml/kg and high (19 ml/kg tidal volumes (Vt under general anesthesia. Non-ventilated animals served as controls. Mean arterial pressure (MAP, central venous pressure (CVP, cardiac output (CO and pulmonary plateau pressure (Pplat were measured. Ex vivo myocardial function was measured in isolated Langendorff-perfused hearts. Cardiac expression of endothelial vascular cell adhesion molecule (VCAM-1 and edema were measured to evaluate endothelial inflammation and leakage. Results MAP decreased after LPS-treatment and Vt-dependently, both independent of each other and with interaction. MV Vt-dependently increased CVP and Pplat and decreased CO. LPS-induced peritonitis decreased myocardial function ex vivo but MV attenuated systolic dysfunction Vt-dependently. Cardiac endothelial VCAM-1 expression was increased by LPS treatment independent of MV. Cardiac edema was lowered Vt-dependently by MV, particularly after LPS, and correlated inversely with systolic myocardial function parameters ex vivo. Conclusion MV attenuated LPS-induced systolic myocardial dysfunction in a Vt-dependent manner. This was associated with a reduction in cardiac edema following a lower transmural coronary venous outflow pressure during LPS-induced coronary inflammation.

  3. Improved regression models for ventilation estimation based on chest and abdomen movements

    International Nuclear Information System (INIS)

    Liu, Shaopeng; Gao, Robert; He, Qingbo; Staudenmayer, John; Freedson, Patty

    2012-01-01

    Non-invasive estimation of minute ventilation is important for quantifying the intensity of physical activity of individuals. In this paper, several improved regression models are presented, based on the measurement of chest and abdomen movements from sensor belts worn by subjects (n = 50) engaged in 14 types of physical activity. Five linear models involving a combination of 11 features were developed, and the effects of different model training approaches and window sizes for computing the features were investigated. The performance of the models was evaluated using experimental data collected during the physical activity protocol. The predicted minute ventilation was compared to the criterion ventilation measured using a bidirectional digital volume transducer housed in a respiratory gas exchange system. The results indicate that the inclusion of breathing frequency and the use of percentile points instead of interdecile ranges over a 60 s window size reduced error by about 43%, when applied to the classical two-degrees-of-freedom model. The mean percentage error of the minute ventilation estimated for all the activities was below 7.5%, verifying reasonably good performance of the models and the applicability of the wearable sensing system for minute ventilation estimation during physical activity. (paper)

  4. What does built-in software of home ventilators tell us? An observational study of 150 patients on home ventilation.

    Science.gov (United States)

    Pasquina, Patrick; Adler, Dan; Farr, Pamela; Bourqui, Pascale; Bridevaux, Pierre Olivier; Janssens, Jean-Paul

    2012-01-01

    Recent home ventilators are equipped with built-in software which provides data such as compliance, estimations of leaks, tidal volume, minute ventilation, respiratory rate, apnea and apnea-hypopnea indexes, and percentage of inspirations triggered by the patient (or ventilator). However, for many of these variables, there is neither consensus nor documentation as to what is to be expected in a population of stable patients under noninvasive ventilation (NIV). To document the values and distribution of specific items downloaded from ventilator monitoring software, by diagnostic category. Analysis of data downloaded from home ventilators in clinically stable patients under long-term NIV, during elective home visits by specialized nurses. Data were collected from home ventilators of 150 patients with chronic obstructive pulmonary disease (n = 32), overlap syndrome (n = 29), obesity-hypoventilation (n = 38), neuromuscular disorders (n = 19), restrictive disorders (n = 21), and central sleep apnea syndrome (n = 11). On average, leaks were low, being lowest in patients with facial masks (vs. nasal masks), and increased with older age. Compliance was excellent in all groups. Patients with neuromuscular diseases triggered their ventilators less and tended to be 'captured', while other groups triggered at least half of inspiratory cycles. Most patients had a respiratory rate just slightly above the back-up rate. Residual apneas and hypopneas were highest in patients with central apneas. Built-in software of home ventilators provides the clinician with new parameters, some of which are a useful adjunct to recommended tools for monitoring NIV and may contribute to a better understanding of residual hypoventilation and/or desaturations. However, an independent validation of the accuracy of this information is mandatory. Copyright © 2011 S. Karger AG, Basel.

  5. Lung-Protective Ventilation With Low Tidal Volumes and the Occurrence of Pulmonary Complications in Patients Without Acute Respiratory Distress Syndrome: A Systematic Review and Individual Patient Data Analysis.

    Science.gov (United States)

    Neto, Ary Serpa; Simonis, Fabienne D; Barbas, Carmen S V; Biehl, Michelle; Determann, Rogier M; Elmer, Jonathan; Friedman, Gilberto; Gajic, Ognjen; Goldstein, Joshua N; Linko, Rita; Pinheiro de Oliveira, Roselaine; Sundar, Sugantha; Talmor, Daniel; Wolthuis, Esther K; Gama de Abreu, Marcelo; Pelosi, Paolo; Schultz, Marcus J

    2015-10-01

    Protective mechanical ventilation with low tidal volumes is standard of care for patients with acute respiratory distress syndrome. The aim of this individual patient data analysis was to determine the association between tidal volume and the occurrence of pulmonary complications in ICU patients without acute respiratory distress syndrome and the association between occurrence of pulmonary complications and outcome in these patients. Individual patient data analysis. ICU patients not fulfilling the consensus criteria for acute respiratory distress syndrome at the onset of ventilation. Mechanical ventilation with low tidal volume. The primary endpoint was development of a composite of acute respiratory distress syndrome and pneumonia during hospital stay. Based on the tertiles of tidal volume size in the first 2 days of ventilation, patients were assigned to a "low tidal volume group" (tidal volumes ≤ 7 mL/kg predicted body weight), an "intermediate tidal volume group" (> 7 and volume group" (≥ 10 mL/kg predicted body weight). Seven investigations (2,184 patients) were included. Acute respiratory distress syndrome or pneumonia occurred in 23% of patients in the low tidal volume group, in 28% of patients in the intermediate tidal volume group, and in 31% of the patients in the high tidal volume group (adjusted odds ratio [low vs high tidal volume group], 0.72; 95% CI, 0.52-0.98; p = 0.042). Occurrence of pulmonary complications was associated with a lower number of ICU-free and hospital-free days and alive at day 28 (10.0 ± 10.9 vs 13.8 ± 11.6 d; p volumes is associated with a lower risk of development of pulmonary complications in patients without acute respiratory distress syndrome.

  6. VENTILATION MODEL

    International Nuclear Information System (INIS)

    V. Chipman

    2002-01-01

    The purpose of the Ventilation Model is to simulate the heat transfer processes in and around waste emplacement drifts during periods of forced ventilation. The model evaluates the effects of emplacement drift ventilation on the thermal conditions in the emplacement drifts and surrounding rock mass, and calculates the heat removal by ventilation as a measure of the viability of ventilation to delay the onset of peak repository temperature and reduce its magnitude. The heat removal by ventilation is temporally and spatially dependent, and is expressed as the fraction of heat carried away by the ventilation air compared to the fraction of heat produced by radionuclide decay. One minus the heat removal is called the wall heat fraction, or the remaining amount of heat that is transferred via conduction to the surrounding rock mass. Downstream models, such as the ''Multiscale Thermohydrologic Model'' (BSC 2001), use the wall heat fractions as outputted from the Ventilation Model to initialize their postclosure analyses

  7. Ventilation models

    Science.gov (United States)

    Skaaret, Eimund

    Calculation procedures, used in the design of ventilating systems, which are especially suited for displacement ventilation in addition to linking it to mixing ventilation, are addressed. The two zone flow model is considered and the steady state and transient solutions are addressed. Different methods of supplying air are discussed, and different types of air flow are considered: piston flow, plane flow and radial flow. An evaluation model for ventilation systems is presented.

  8. Tidal ventilation distribution during pressure-controlled ventilation and pressure support ventilation in post-cardiac surgery patients.

    Science.gov (United States)

    Blankman, P; VAN DER Kreeft, S M; Gommers, D

    2014-09-01

    Inhomogeneous ventilation is an important contributor to ventilator-induced lung injury. Therefore, this study examines homogeneity of lung ventilation by means of electrical impedance tomography (EIT) measurements during pressure-controlled ventilation (PCV) and pressure support ventilation (PSV) using the same ventilation pressures. Twenty mechanically ventilated patients were studied after cardiac surgery. On arrival at the intensive care unit, ventilation distribution was measured with EIT just above the diaphragm for 15 min. After awakening, PCV was switched to PSV and EIT measurements were again recorded. Tidal impedance variation, a measure of tidal volume, increased during PSV compared with PCV, despite using the same ventilation pressures (P = 0.045). The distribution of tidal ventilation to the dependent lung region was more pronounced during PSV compared with PCV, especially during the first half of the inspiration. An even distribution of tidal ventilation between the dependent and non-dependent lung regions was seen during PCV at lower tidal volumes (tidal volumes (≥ 8 ml/kg). In addition, the distribution of tidal ventilation was predominantly distributed to the dependent lung during PSV at low tidal volumes. In post-cardiac surgery patients, PSV showed improved ventilation of the dependent lung region due to the contribution of the diaphragm activity, which is even more pronounced during lower assist levels. © 2014 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  9. Industrial ventilation

    Science.gov (United States)

    Goodfellow, H. D.

    Industrial ventilation design methodology, using computers and using fluid dynamic models, is considered. It is noted that the design of a ventilation system must be incorporated into the plant design and layout at the earliest conceptual stage of the project. A checklist of activities concerning the methodology for the design of a ventilation system for a new facility is given. A flow diagram of the computer ventilation model shows a typical input, the initialization and iteration loop, and the output. The application of the fluid dynamic modeling techniques include external and internal flow fields, and individual sources of heat and contaminants. Major activities for a ventilation field test program are also addressed.

  10. An evaluation of peak inspiratory pressure, tidal volume, and ventilatory frequency during ventilation with a neonatal self-inflating bag resuscitator.

    Science.gov (United States)

    Bassani, Mariana Almada; Filho, Francisco Mezzacappa; de Carvalho Coppo, Maria Regina; Martins Marba, Sérgio Tadeu

    2012-04-01

    Although the self-inflating bag is widely used in the hospital setting, variability of delivered ventilatory parameters is usually high, which might result in both hypoventilation and lung injury. The aims of this study were to assess possible sources of the high variability and to evaluate the adequacy of obtained values in relation to the recommended values for neonatal resuscitation. This was an experimental study in which 172 health professionals (physicians, resident physicians, physiotherapists, nurses, and nursing technicians) who work with neonatal intensive care manually ventilated a test lung (adjusted to simulate the lungs of an intubated term newborn) with a self-inflating bag in 5 different handling techniques, using 10, 5, 4, 3, and 2 fingers. Delivered values of peak inspiratory pressure (PIP), tidal volume (V(T)), and ventilatory frequency (f) were compared, taking into account the different handling modalities and professions by analysis of variance for repeated measures. Chi-square, the Friedman test and the Fisher exact tests were performed to compare the delivered and standard values. PIP and V(T) were significantly affected by the handling technique, with higher values for a greater number of fingers used for ventilation. Profession also influenced V(T) and f significantly: physiotherapists tended to deliver higher volumes and lower rates. Nevertheless, we observed high variability of all studied ventilatory parameters and overall inadequacy of obtained values. Most volunteers delivered excessive pressures and volumes at insufficient ventilatory frequency. Delivered values seem to depend on operators' individual and professional differences, as well as on the number of fingers used to compress the bag. However, from the clinical point of view, it is important to point out the high occurrence of inadequate delivered values, regardless of handling technique and profession.

  11. Effects of Dexmedetomidine Infusion on Inflammatory Responses and Injury of Lung Tidal Volume Changes during One-Lung Ventilation in Thoracoscopic Surgery: A Randomized Controlled Trial

    Directory of Open Access Journals (Sweden)

    Chun-Yu Wu

    2018-01-01

    Full Text Available One-lung ventilation in thoracic surgery provokes profound systemic inflammatory responses and injury related to lung tidal volume changes. We hypothesized that the highly selective a2-adrenergic agonist dexmedetomidine attenuates these injurious responses. Sixty patients were randomly assigned to receive dexmedetomidine or saline during thoracoscopic surgery. There is a trend of less postoperative medical complication including that no patients in the dexmedetomidine group developed postoperative medical complications, whereas four patients in the saline group did (0% versus 13.3%, p=0.1124. Plasma inflammatory and injurious biomarkers between the baseline and after resumption of two-lung ventilation were particularly notable. The plasma high-mobility group box 1 level decreased significantly from 51.7 (58.1 to 33.9 (45.0 ng.ml−1 (p<0.05 in the dexmedetomidine group, which was not observed in the saline group. Plasma monocyte chemoattractant protein 1 [151.8 (115.1 to 235.2 (186.9 pg.ml−1, p<0.05] and neutrophil elastase [350.8 (154.5 to 421.9 (106.1 ng.ml−1, p<0.05] increased significantly only in the saline group. In addition, plasma interleukin-6 was higher in the saline group than in the dexmedetomidine group at postoperative day 1 [118.8 (68.8 versus 78.5 (58.8 pg.ml−1, p=0.0271]. We conclude that dexmedetomidine attenuates one-lung ventilation-associated inflammatory and injurious responses by inhibiting alveolar neutrophil recruitment in thoracoscopic surgery.

  12. Comparison of a Constant Air Volume (CAV) and a Demand Controlled Ventilation (DCV) System in a Residential Building

    DEFF Research Database (Denmark)

    Mortensen, Dorthe Kragsig; Nielsen, Toke Rammer; Topp, Claus

    2008-01-01

    hygroscopic properties on indoor climate and energy consumption was investigated for the two systems. Dynamic simulations of the studio apartment were carried out in the program WUFI+ with weather data from Copenhagen including outside temperature end relative humidity. For the non-hygroscopic case...... it was found that the energy consumption for heating and operating the ventilation system could be reduced by respectively 8.0% and 10.6 % in the case of DCV without negative impact on the indoor climate. Including the hygroscopic properties of the materials resulted in a reduction of the energy consumption...

  13. Work of breathing during lung-protective ventilation in patients with acute lung injury and acute respiratory distress syndrome: a comparison between volume and pressure-regulated breathing modes.

    Science.gov (United States)

    Kallet, Richard H; Campbell, Andre R; Dicker, Rochelle A; Katz, Jeffrey A; Mackersie, Robert C

    2005-12-01

    Pressure-control ventilation (PCV) and pressure-regulated volume-control (PRVC) ventilation are used during lung-protective ventilation because the high, variable, peak inspiratory flow rate (V (I)) may reduce patient work of breathing (WOB) more than the fixed V (I) of volume-control ventilation (VCV). Patient-triggered breaths during PCV and PRVC may result in excessive tidal volume (V(T)) delivery unless the inspiratory pressure is reduced, which in turn may decrease the peak V (I). We tested whether PCV and PRVC reduce WOB better than VCV with a high, fixed peak V (I) (75 L/min) while also maintaining a low V(T) target. Fourteen nonconsecutive patients with acute lung injury or acute respiratory distress syndrome were studied prospectively, using a random presentation of ventilator modes in a crossover, repeated-measures design. A target V(T) of 6.4 + 0.5 mL/kg was set during VCV and PRVC. During PCV the inspiratory pressure was set to achieve the same V(T). WOB and other variables were measured with a pulmonary mechanics monitor (Bicore CP-100). There was a nonsignificant trend toward higher WOB (in J/L) during PCV (1.27 + 0.58 J/L) and PRVC (1.35 + 0.60 J/L), compared to VCV (1.09 + 0.59 J/L). While mean V(T) was not statistically different between modes, in 40% of patients, V(T) markedly exceeded the lung-protective ventilation target during PRVC and PCV. During lung-protective ventilation, PCV and PRVC offer no advantage in reducing WOB, compared to VCV with a high flow rate, and in some patients did not allow control of V(T) to be as precise.

  14. Trigger performance of mid-level ICU mechanical ventilators during assisted ventilation: a bench study.

    Science.gov (United States)

    Ferreira, Juliana C; Chipman, Daniel W; Kacmarek, Robert M

    2008-09-01

    To compare the triggering performance of mid-level ICU mechanical ventilators with a standard ICU mechanical ventilator. Experimental bench study. The respiratory care laboratory of a university-affiliated teaching hospital. A computerized mechanical lung model, the IngMar ASL5000. Ten mid-level ICU ventilators were compared to an ICU ventilator at two levels of lung model effort, three combinations of respiratory mechanics (normal, COPD and ARDS) and two modes of ventilation, volume and pressure assist/control. A total of 12 conditions were compared. Performance varied widely among ventilators. Mean inspiratory trigger time was ventilators. The mean inspiratory delay time (time from initiation of the breath to return of airway pressure to baseline) was longer than that for the ICU ventilator for all tested ventilators except one. The pressure drop during triggering (Ptrig) was comparable with that of the ICU ventilator for only two ventilators. Expiratory Settling Time (time for pressure to return to baseline) had the greatest variability among ventilators. Triggering differences among these mid-level ICU ventilators and with the ICU ventilator were identified. Some of these ventilators had a much poorer triggering response with high inspiratory effort than the ICU ventilator. These ventilators do not perform as well as ICU ventilators in patients with high ventilatory demand.

  15. Mine ventilation engineering

    Energy Technology Data Exchange (ETDEWEB)

    Hall, C.J.

    1981-01-01

    This book on mine ventilation covers psychometrics, airflow through roadways and ducts, natural ventilation, fans, instruments, ventilation surveys, auxiliary ventilation, air quality, and planning and economics.

  16. Functional evaluation of lung by Xe-133 lung ventilation scintigraphy before and after lung volume reduction surgery (LVRS) in patients with pulmonary emphysema

    International Nuclear Information System (INIS)

    Kurose, Taichi; Okumura, Yoshihiro; Sato, Shuhei

    2004-01-01

    We evaluated the respiratory functions of patients with pulmonary emphysema who underwent lung volume reduction surgery (LVRS) by the mean transit time (MTT) with Xe-133 lung ventilation scintigraphy, forced expiration volume in 1 sec (FEV1.0), residual volume (RV), distance walked in 6 min (6-min walk), and the Hugh-Jones classification (H-J classification) before and after LVRS. In 69 patients with pulmonary emphysema (62 men, 7 women; age range, 47-75 years; mean age, 65.4 years±6.1, preoperative H-J classification, III (two were II)-V) who underwent LVRS, all preoperative and postoperative parameters (MTT 3 weeks after LVRS and the others 3 months after LVRS) were judged statistically by the Wilcoxon signed-ranks test and Odds ratio. Every postoperative parameter was improved with a significant difference (P<0.05) compared to preoperative parameters. MTT at 3 weeks after LVRS was not associated with %FEV1.0 and the H-J classification at 3 months after LVRS, but was associated with RV and a 6-min walk at 3 months after LVRS. MTT was useful for the clinical evaluation of aerobic capability after LVRS. (author)

  17. Taking minutes of meetings

    CERN Document Server

    Gutmann, Joanna

    2016-01-01

    aking Minutes of Meetings guides you through the entire process behind minute taking: arranging the meeting; writing the agenda; creating the optimum environment; structuring the meeting and writing notes up accurately. The minute-taker is one of the most important and powerful people in a meeting and you can use this opportunity to develop your knowledge, broaden your horizons and build credibility within the organization. Taking Minutes of Meetings is an easy to read 'dip-in, dip-out' guide which shows you how to confidently arrange meetings and produce minutes. It provides hands-on advice about the sections of a meeting as well as tips on how to create an agenda, personal preparation, best practice advice on taking notes and how to improve your accuracy. Brand new chapters of this 4th edition include guidance on using technology to maximize effectiveness and practical help with taking minutes for a variety of different types of meetings. The creating success series of books... With over one million copi...

  18. Ventilation effectiveness

    CERN Document Server

    Mathisen, Hans Martin; Nielsen, Peter V; Moser, Alfred

    2004-01-01

    Improving the ventilation effectiveness allows the indoor air quality to be significantly enhanced without the need for higher air changes in the building, thereby avoiding the higher costs and energy consumption associated with increasing the ventilation rates. This Guidebook provides easy-to-understand descriptions of the indices used to mesure the performance of a ventilation system and which indices to use in different cases.

  19. Displacement Ventilation

    DEFF Research Database (Denmark)

    Nielsen, Peter Vilhelm

    Displacement ventilation is an interesting new type of air distribution principle which should be considered in connection with design of comfort ventilation in both smal1 and large spaces. Research activities on displacement ventilation are large all over the world and new knowledge of design...... methods appears continuously. This book gives an easy introduction to the basis of displacement ventilation and the chapters are written in the order which is used in a design procedure. The main text is extended by five appendices which show some of the new research activities taking place at Aalborg...

  20. Demand Controlled Ventilation and Classroom Ventilation

    Energy Technology Data Exchange (ETDEWEB)

    Fisk, William J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Mendell, Mark J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Davies, Molly [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Eliseeva, Ekaterina [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Faulkner, David [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Hong, Tienzen [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sullivan, Douglas P. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2012-05-01

    This document summarizes a research effort on demand controlled ventilation and classroom ventilation. The research on demand controlled ventilation included field studies and building energy modeling.

  1. Demand controlled ventilation and classroom ventilation

    Energy Technology Data Exchange (ETDEWEB)

    Fisk, William J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Mendell, Mark J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Davies, Molly [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Eliseeva, Ekaterina [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Faulkner, David [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Hong, Tienzen [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sullivan, Douglas P. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2014-01-06

    This document summarizes a research effort on demand controlled ventilation and classroom ventilation. The research on demand controlled ventilation included field studies and building energy modeling.

  2. [Lung protective ventilation. Ventilatory modes and ventilator parameters].

    Science.gov (United States)

    Schädler, Dirk; Weiler, Norbert

    2008-06-01

    Mechanical ventilation has a considerable potential for injuring the lung tissue. Therefore, attention has to be paid to the proper choice of ventilatory mode and settings to secure lung-protective ventilation whenever possible. Such ventilator strategy should account for low tidal volume ventilation (6 ml/kg PBW), limited plateau pressure (30 to 35 cm H2O) and positive end-expiratory pressure (PEEP). It is unclear whether pressure controlled or volume controlled ventilation with square flow profile is beneficial. The adjustment of inspiration and expiration time should consider the actual breathing mechanics and anticipate the generation of intrinsic PEEP. Ventilatory modes with the possibility of supporting spontaneous breathing should be used as soon as possible.

  3. Demand controlled ventilation in a bathroom

    DEFF Research Database (Denmark)

    Mortensen, Dorthe Kragsig; Nielsen, Toke Rammer; Topp, Claus

    2008-01-01

    consumption during periods where the demand for ventilation is low and poor indoor climate during periods where the demand for ventilation is high. Controlling the ventilation rate by demand can improve the energy performance of the ventilation system and the indoor climate. This paper compares the indoor...... climate and energy consumption of a Constant Air Volume (CAV) system and a Demand Controlled Ventilation (DCV) system for two different bathroom designs. The air change rate of the CAV system corresponded to 0.5h-1. The ventilation rate of the DCV system was controlled by occupancy and by the relative...

  4. Ventilation Effectiveness

    DEFF Research Database (Denmark)

    Mundt, M.; Mathisen, H. M.; Moser, M.

    Improving the ventilation effectiveness allows the indoor air quality to be significantly enhanced without the need for higher air changes in the building, thereby avoiding the higher costs and energy consumption associated with increasing the ventilation rates. This Guidebook provides easy-to-un...

  5. Behovstyret ventilation

    DEFF Research Database (Denmark)

    Afshari, Alireza; Heiselberg, Per; Reinhold, Claus

    2010-01-01

    I en nylig afsluttet undersøgelse er der udført en række målinger på otte udvalgte børneinstitutioner. Fire af disse med mekanisk ventilation og fire med naturlig ventilation. Formålet er at udvide den erfaringsbaserede viden om funktionen af naturlige og mekaniske ventilationsløsninger i...

  6. Ventilation Model

    International Nuclear Information System (INIS)

    Yang, H.

    1999-01-01

    The purpose of this analysis and model report (AMR) for the Ventilation Model is to analyze the effects of pre-closure continuous ventilation in the Engineered Barrier System (EBS) emplacement drifts and provide heat removal data to support EBS design. It will also provide input data (initial conditions, and time varying boundary conditions) for the EBS post-closure performance assessment and the EBS Water Distribution and Removal Process Model. The objective of the analysis is to develop, describe, and apply calculation methods and models that can be used to predict thermal conditions within emplacement drifts under forced ventilation during the pre-closure period. The scope of this analysis includes: (1) Provide a general description of effects and heat transfer process of emplacement drift ventilation. (2) Develop a modeling approach to simulate the impacts of pre-closure ventilation on the thermal conditions in emplacement drifts. (3) Identify and document inputs to be used for modeling emplacement ventilation. (4) Perform calculations of temperatures and heat removal in the emplacement drift. (5) Address general considerations of the effect of water/moisture removal by ventilation on the repository thermal conditions. The numerical modeling in this document will be limited to heat-only modeling and calculations. Only a preliminary assessment of the heat/moisture ventilation effects and modeling method will be performed in this revision. Modeling of moisture effects on heat removal and emplacement drift temperature may be performed in the future

  7. Initial ventilator settings for critically ill patients

    OpenAIRE

    Kilickaya, Oguz; Gajic, Ognjen

    2013-01-01

    The lung-protective mechanical ventilation strategy has been standard practice for management of acute respiratory distress syndrome (ARDS) for more than a decade. Observational data, small randomized studies and two recent systematic reviews suggest that lung protective ventilation is both safe and potentially beneficial in patients who do not have ARDS at the onset of mechanical ventilation. Principles of lung-protective ventilation include: a) prevention of volutrauma (tidal volume 4 to 8 ...

  8. Effects of non-invasive ventilation and posture on chest wall volumes and motion in patients with amyotrophic lateral sclerosis: a case series.

    Science.gov (United States)

    Magalhães, Cristiana M; Fregonezi, Guilherme A; Vidigal-Lopes, Mauro; Vieira, Bruna S P P; Vieira, Danielle S R; Parreira, Verônica F

    2016-01-01

    The effects of non-invasive ventilation (NIV) on the breathing pattern and thoracoabdominal motion of patients with amyotrophic lateral sclerosis (ALS) are unknown. 1) To analyze the influence of NIV on chest wall volumes and motion assessed by optoelectronic plethysmography in ALS patients and 2) to compare these parameters in the supine and sitting positions to those of healthy individuals (without NIV). Nine ALS patients were evaluated in the supine position using NIV. In addition, the ALS patients and nine healthy individuals were evaluated in both sitting and supine positions. Statistical analysis was performed using the paired Student t-test or Wilcoxon test and the Student t-test for independent samples or Mann-Whitney U test. Chest wall volume increased significantly with NIV, mean volume=0.43 (SD=0.16)L versus 0.57 (SD=0.19)L (p=0.04). No significant changes were observed for the pulmonary rib cage, abdominal rib cage, or abdominal contribution. The index of the shortening velocity of the diaphragmatic muscle, mean=0.15 (SD=0.05)L/s versus 0.21 (SD=0.05)L/s (pNIV. Comparisons between the supine and sitting positions showed similar changes in chest wall motion in both groups. However, the ALS patients presented a significantly lower contribution of the abdomen in the supine position compared with the controls, mean=56 (SD=13) versus 69 (SD=10) (p=0.02). NIV improved chest wall volumes without changing the contribution of the chest wall compartment in ALS patients. In the supine position, ALS patients had a lower contribution of the abdomen, which may indicate early diaphragmatic dysfunction.

  9. Effects of non-invasive ventilation and posture on chest wall volumes and motion in patients with amyotrophic lateral sclerosis: a case series

    Directory of Open Access Journals (Sweden)

    Cristiana M. Magalhães

    2016-01-01

    Full Text Available ABSTRACT Background The effects of non-invasive ventilation (NIV on the breathing pattern and thoracoabdominal motion of patients with amyotrophic lateral sclerosis (ALS are unknown. Objectives 1 To analyze the influence of NIV on chest wall volumes and motion assessed by optoelectronic plethysmography in ALS patients and 2 to compare these parameters in the supine and sitting positions to those of healthy individuals (without NIV. Method Nine ALS patients were evaluated in the supine position using NIV. In addition, the ALS patients and nine healthy individuals were evaluated in both sitting and supine positions. Statistical analysis was performed using the paired Student t-test or Wilcoxon test and the Student t-test for independent samples or Mann-Whitney U test. Results Chest wall volume increased significantly with NIV, mean volume=0.43 (SD=0.16L versus 0.57 (SD=0.19L (p=0.04. No significant changes were observed for the pulmonary rib cage, abdominal rib cage, or abdominal contribution. The index of the shortening velocity of the diaphragmatic muscle, mean=0.15 (SD=0.05L/s versus 0.21 (SD=0.05L/s (p<0.01, and abdominal muscles, mean=0.09 (SD=0.02L/s versus 0.14 (SD=0.06L/s (p<0.01, increased during NIV. Comparisons between the supine and sitting positions showed similar changes in chest wall motion in both groups. However, the ALS patients presented a significantly lower contribution of the abdomen in the supine position compared with the controls, mean=56 (SD=13 versus 69 (SD=10 (p=0.02. Conclusions NIV improved chest wall volumes without changing the contribution of the chest wall compartment in ALS patients. In the supine position, ALS patients had a lower contribution of the abdomen, which may indicate early diaphragmatic dysfunction.

  10. Liquid Ventilation

    Directory of Open Access Journals (Sweden)

    Qutaiba A. Tawfic

    2011-01-01

    Full Text Available Mammals have lungs to breathe air and they have no gills to breath liquids. When the surface tension at the air-liquid interface of the lung increases, as in acute lung injury, scientists started to think about filling the lung with fluid instead of air to reduce the surface tension and facilitate ventilation. Liquid ventilation (LV is a technique of mechanical ventilation in which the lungs are insufflated with an oxygenated perfluorochemical liquid rather than an oxygen-containing gas mixture. The use of perfluorochemicals, rather than nitrogen, as the inert carrier of oxygen and carbon dioxide offers a number of theoretical advantages for the treatment of acute lung injury. In addition, there are non-respiratory applications with expanding potential including pulmonary drug delivery and radiographic imaging. The potential for multiple clinical applications for liquid-assisted ventilation will be clarified and optimized in future. Keywords: Liquid ventilation; perfluorochemicals; perfluorocarbon; respiratory distress; surfactant.

  11. Ventilative Cooling

    DEFF Research Database (Denmark)

    Heiselberg, Per Kvols; Kolokotroni, Maria

    This report, by venticool, summarises the outcome of the work of the initial working phase of IEA ECB Annex 62 Ventilative Cooling and is based on the findings in the participating countries. It presents a summary of the first official Annex 62 report that describes the state-of-the-art of ventil......This report, by venticool, summarises the outcome of the work of the initial working phase of IEA ECB Annex 62 Ventilative Cooling and is based on the findings in the participating countries. It presents a summary of the first official Annex 62 report that describes the state......-of-the-art of ventilative cooling potentials and limitations, its consideration in current energy performance regulations, available building components and control strategies and analysis methods and tools. In addition, the report provides twenty six examples of operational buildings using ventilative cooling ranging from...

  12. One minute paper

    African Journals Online (AJOL)

    Arun Kumar Agnihotri

    One-Minute Paper: A thinking centered assessment tool. Ashakiran ... achievement of objectives and learning ability of the students, to analyze the questioning pattern of ... factual information, rote memory and critical thinking. The aim of every teacher while teaching ... question prompts another higher order cognitive skill ...

  13. Effectiveness of mask ventilation performed by hospital doctors in an Irish tertiary referral teaching hospital.

    LENUS (Irish Health Repository)

    Walsh, K

    2012-02-03

    The objective of this study was to assess the effectiveness of mask ventilation performed by 112 doctors with clinical responsibilities at a tertiary referral teaching hospital. Participant doctors were asked to perform mask ventilation for three minutes on a Resusci Anne mannequin using a facemask and a two litre self inflating bag. The tidal volumes generated were quantified using a Laerdal skillmeter computer as grades 0-5, corresponding to 0, 334, 434, 561, 673 and > 800 ml respectively. The effectiveness of mask ventilation (i.e. the proportion of ventilation attempts which achieved a volume delivery of > 434 mls) was greater for anaesthetists [78.0 (29.5)%] than for non anaesthetists [54.6 (40.0)%] (P = 0.012). Doctors who had attended one or more resuscitation courses where no more effective at mask ventilation than their colleagues who had not undertaken such courses. It is likely that first responders to in-hospital cardiac arrests are commonly unable to perform adequate mask ventilation.

  14. Effect of a clinical decision support system on adherence to a lower tidal volume mechanical ventilation strategy

    NARCIS (Netherlands)

    Eslami, Saeid; de Keizer, Nicolette F.; Abu-Hanna, Ameen; de Jonge, Evert; Schultz, Marcus J.

    2009-01-01

    PURPOSE: The purpose of the study was to measure the effect of a computerized decision support system (CDSS) on adherence to tidal volume (V(T)) recommendations. MATERIALS AND METHODS: We performed a prospective before-after evaluation study on applied V(T) to examine the impact of a CDSS on

  15. Carbon dioxide production during mechanical ventilation

    DEFF Research Database (Denmark)

    Henneberg, S; Söderberg, D; Groth, T

    1987-01-01

    studied CO2 production (VCO2) and oxygen consumption (VO2) in mechanically ventilated ICU patients, where CO2 stores were altered by: a) changing minute ventilation by 15%, b) reducing body temperature, and c) changing the level of sedation. Expired gases went through a mixing chamber and were analyzed...

  16. Application of mid-frequency ventilation in an animal model of lung injury: a pilot study.

    Science.gov (United States)

    Mireles-Cabodevila, Eduardo; Chatburn, Robert L; Thurman, Tracy L; Zabala, Luis M; Holt, Shirley J; Swearingen, Christopher J; Heulitt, Mark J

    2014-11-01

    Mid-frequency ventilation (MFV) is a mode of pressure control ventilation based on an optimal targeting scheme that maximizes alveolar ventilation and minimizes tidal volume (VT). This study was designed to compare the effects of conventional mechanical ventilation using a lung-protective strategy with MFV in a porcine model of lung injury. Our hypothesis was that MFV can maximize ventilation at higher frequencies without adverse consequences. We compared ventilation and hemodynamic outcomes between conventional ventilation and MFV. This was a prospective study of 6 live Yorkshire pigs (10 ± 0.5 kg). The animals were subjected to lung injury induced by saline lavage and injurious conventional mechanical ventilation. Baseline conventional pressure control continuous mandatory ventilation was applied with V(T) = 6 mL/kg and PEEP determined using a decremental PEEP trial. A manual decision support algorithm was used to implement MFV using the same conventional ventilator. We measured P(aCO2), P(aO2), end-tidal carbon dioxide, cardiac output, arterial and venous blood oxygen saturation, pulmonary and systemic vascular pressures, and lactic acid. The MFV algorithm produced the same minute ventilation as conventional ventilation but with lower V(T) (-1 ± 0.7 mL/kg) and higher frequency (32.1 ± 6.8 vs 55.7 ± 15.8 breaths/min, P ventilation and MFV for mean airway pressures (16.1 ± 1.3 vs 16.4 ± 2 cm H2O, P = .75) even when auto-PEEP was higher (0.6 ± 0.9 vs 2.4 ± 1.1 cm H2O, P = .02). There were no significant differences in any hemodynamic measurements, although heart rate was higher during MFV. In this pilot study, we demonstrate that MFV allows the use of higher breathing frequencies and lower V(T) than conventional ventilation to maximize alveolar ventilation. We describe the ventilatory or hemodynamic effects of MFV. We also demonstrate that the application of a decision support algorithm to manage MFV is feasible. Copyright © 2014 by Daedalus Enterprises.

  17. Comparative analysis of parameters of oxygenation, ventilation and acid-base status during intraoperative application of conventional and protective lung ventilation

    Directory of Open Access Journals (Sweden)

    Videnović N.

    2015-01-01

    Full Text Available The aim of this study was to perform a comparative analysis applied conventional (traditional and protective mechanical lung ventilation in clinical conditions with regard to intraoperative parameters changes of oxygenation, ventilation and acid-base status. This was a prospective study that included 240 patients. All patients underwent the same elective surgery (classic cholecystectomy. Patients were divided into two groups of 120 patients, A and B. In group A during the operation had received conventional lung ventilation with tidal volume of 10-15 ml/kg body weight, respiratory rate 12/min. and a PEEP zero. In group B was applied protective lung ventilation with a tidal volume of 6-8 ml/kg body weight, respiratory rate 12/min. and a PEEP of 7 mbar. Monitoring of oxygenation included the monitoring SaO2 and PaO2. Monitoring of ventilation included the determination of the value of tidal volume and minute volume ventilation, peak inspiratory pressure (Ppeak, medium pressure in the airway (Paw.mean, PEEP, PaCO2 and EtCO2. Monitoring of acid-base status was performed via determination of the pH values of arterial blood. Monitoring was carried out in four intervals: T1 - 5-10 minutes after the establishment of the airway, T2 - after opening peritoneum, T3 - after removal of the gallbladder, T4 - after the closure of the abdominal wall. All monitoring results are presented as mean. The statistical significance of differences in mean values was tested by t - test mean values in the case of two independent samples. As a statistical significance test taken as standard values p <0.01 and p <0.001. Comparative analysis of the value of SaO2, PaO2, Ppeak did not reach statistical significance. Statistical significance there is in the analysis of values of tidal volume and Paw.mean (p <0.001. Analysis of PaCO2 and pH of arterial blood showed no statistical significance in the first interval measurements but did interval T2-T4 (p <0.001. Based on the

  18. Ventilation of radioactive enclosures

    International Nuclear Information System (INIS)

    Caminade, F.; Laurent, H.

    1957-01-01

    Mechanical, physical and chemical manipulations on radioactive products must be carried out in properly ventilated enclosed places. The air extracted can only be discharged into the atmosphere after a correct filtration. The power of the ventilation systems is a function of the dimensions and purpose of the enclosure? The choice of types of filter is determined by the physical state and chemical nature of the radioactive materials to be manipulated. This study deals with the individual equipment of small installations: glove boxes, manipulation boxes with outside control and, if necessary, production chambers (maximum useful volume: 5 m 3 ). The performances of three types of 'ventilators', and the modifications provided by the addition of filters, are measured and compared. (author) [fr

  19. Mechanical ventilation in abdominal surgery.

    Science.gov (United States)

    Futier, E; Godet, T; Millot, A; Constantin, J-M; Jaber, S

    2014-01-01

    One of the key challenges in perioperative care is to reduce postoperative morbidity and mortality. Patients who develop postoperative morbidity but survive to leave hospital have often reduced functional independence and long-term survival. Mechanical ventilation provides a specific example that may help us to shift thinking from treatment to prevention of postoperative complications. Mechanical ventilation in patients undergoing surgery has long been considered only as a modality to ensure gas exchange while allowing maintenance of anesthesia with delivery of inhaled anesthetics. Evidence is accumulating, however, suggesting an association between intraoperative mechanical ventilation strategy and postoperative pulmonary function and clinical outcome in patients undergoing abdominal surgery. Non-protective ventilator settings, especially high tidal volume (VT) (>10-12mL/kg) and the use of very low level of positive end-expiratory pressure (PEEP) (PEEPventilator-associated lung injury in patients with healthy lungs. Stimulated by previous findings in patients with acute respiratory distress syndrome, the use of lower tidal volume ventilation is becoming increasingly more common in the operating room. However, lowering tidal volume, though important, is only part of the overall multifaceted approach of lung protective mechanical ventilation. In this review, we aimed at providing the most recent and relevant clinical evidence regarding the use of mechanical ventilation in patients undergoing abdominal surgery. Copyright © 2014 Société française d’anesthésie et de réanimation (Sfar). Published by Elsevier SAS. All rights reserved.

  20. Injurious mechanical ventilation in the normal lung causes a progressive pathologic change in dynamic alveolar mechanics.

    Science.gov (United States)

    Pavone, Lucio A; Albert, Scott; Carney, David; Gatto, Louis A; Halter, Jeffrey M; Nieman, Gary F

    2007-01-01

    Acute respiratory distress syndrome causes a heterogeneous lung injury, and without protective mechanical ventilation a secondary ventilator-induced lung injury can occur. To ventilate noncompliant lung regions, high inflation pressures are required to 'pop open' the injured alveoli. The temporal impact, however, of these elevated pressures on normal alveolar mechanics (that is, the dynamic change in alveolar size and shape during ventilation) is unknown. In the present study we found that ventilating the normal lung with high peak pressure (45 cmH(2)0) and low positive end-expiratory pressure (PEEP of 3 cmH(2)O) did not initially result in altered alveolar mechanics, but alveolar instability developed over time. Anesthetized rats underwent tracheostomy, were placed on pressure control ventilation, and underwent sternotomy. Rats were then assigned to one of three ventilation strategies: control group (n = 3, P control = 14 cmH(2)O, PEEP = 3 cmH(2)O), high pressure/low PEEP group (n = 6, P control = 45 cmH(2)O, PEEP = 3 cmH(2)O), and high pressure/high PEEP group (n = 5, P control = 45 cmH(2)O, PEEP = 10 cmH(2)O). In vivo microscopic footage of subpleural alveolar stability (that is, recruitment/derecruitment) was taken at baseline and than every 15 minutes for 90 minutes following ventilator adjustments. Alveolar recruitment/derecruitment was determined by measuring the area of individual alveoli at peak inspiration (I) and end expiration (E) by computer image analysis. Alveolar recruitment/derecruitment was quantified by the percentage change in alveolar area during tidal ventilation (%I - E Delta). Alveoli were stable in the control group for the entire experiment (low %I - E Delta). Alveoli in the high pressure/low PEEP group were initially stable (low %I - E Delta), but with time alveolar recruitment/derecruitment developed. The development of alveolar instability in the high pressure/low PEEP group was associated with histologic lung injury. A large change in

  1. Ventilation of an hydrofoil wake

    Science.gov (United States)

    Arndt, Roger; Lee, Seung Jae; Monson, Garrett

    2013-11-01

    Ventilation physics plays a role in a variety of important engineering applications. For example, hydroturbine ventilation is used for control of vibration and cavitation erosion and more recently for improving the dissolved oxygen content of the flow through the turbine. The latter technology has been the focus of an ongoing study involving the ventilation of an hydrofoil wake to determine the velocity and size distribution of bubbles in a bubbly wake. This was carried out by utilizing particle shadow velocimetry (PSV). This technique is a non-scattering approach that relies on direct in-line volume illumination by a pulsed source such as a light-emitting diode (LED). The data are compared with previous studies of ventilated flow. The theoretical results of Hinze suggest that a scaling relationship is possible that can lead to developing appropriate design parameters for a ventilation system. Sponsored by ONR and DOE.

  2. Differential Effects of Endotracheal Suctioning on Gas Exchanges in Patients with Acute Respiratory Failure under Pressure-Controlled and Volume-Controlled Ventilation

    Directory of Open Access Journals (Sweden)

    Xiao-Wei Liu

    2015-01-01

    Full Text Available This study was conducted to evaluate the effects of open endotracheal suctioning on gas exchange and respiratory mechanics in ARF patients under the modes of PCV or VCV. Ninety-six ARF patients were treated with open endotracheal suctioning and their variations in respiratory mechanics and gas exchange after the suctions were compared. Under PCV mode, compared with the initial level of tidal volume (VT, ARF patients showed 30.0% and 27.8% decrease at 1 min and 10 min, respectively. Furthermore, the initial respiratory system compliance (Crs decreased by 29.6% and 28.5% at 1 min and 10 min, respectively. Under VCV mode, compared with the initial level, 38.6% and 37.5% increase in peak airway pressure (PAP were found at 1 min and 10 min, respectively. Under PCV mode, the initial PaO2 increased by 6.4% and 10.2 % at 3 min and 10 min, respectively, while 18.9% and 30.6% increase of the initial PaO2 were observed under VCV mode. Summarily, endotracheal suctioning may impair gas exchange and decrease lung compliance in ARF patients receiving mechanical ventilation under both PCV and VCV modes, but endotracheal suctioning effects on gas exchange were more severe and longer-lasting under PCV mode than VCV.

  3. The influence of the cigarette smoke pollution and ventilation rate on alpha-activities per unit volume due to radon and its progeny

    International Nuclear Information System (INIS)

    Misdaq, M.A.; Flata, K.

    2003-01-01

    Alpha and beta activities per unit volume air due to radon, thoron and their decay products were evaluated in the air of various cafe rooms polluted by cigarette smoke. Both CR-39 and LR-115 type II solid state nuclear track detectors (SSNTD) were used. Equilibrium factors between radon and its progeny and thoron and its daughters have been evaluated in the air of the studied cafe rooms. The committed equivalent doses due to short-lived radon decay products were determined in different regions of the respiratory tract of non-smoker members of the public. The influence of cigarette smoke pollution, ventilation rate and exposure time on committed equivalent dose in the respiratory systems of non-smokers was investigated. Committed equivalent doses ranged from 1.15x10 -11 -2.7x10 -7 Sv.y -1 /h of exposure in the extrathoracic region and from 0.8x10 -12 -1.7x10 -8 Sv.y -1 /h of exposure in the thoracic region of the respiratory tract of non-smokers

  4. High Frequency Oscillatory Ventilation

    Directory of Open Access Journals (Sweden)

    AC Bryan

    1996-01-01

    Full Text Available High frequency oscillatory (HFO ventilation using low tidal volume and peak airway pressures is extremely efficient at eliminating carbon dioxide and raising pH in the newborn infant with acute respiratory failure. Improvement in oxygenation requires a strategy of sustained or repetitive inflations to 25 to 30 cm H2O in order to place the lung on the deflation limb of the pressure-volume curve. This strategy has also been shown to decrease the amount of secondary lung injury in animal models. Experience of the use of HFO ventilation as a rescue therapy as well as several published controlled trials have shown improved outcomes and a decrease in the use of extracorporeal membrane oxygenation when it has been used in newborns.

  5. CSEWG 2017 Minutes

    Energy Technology Data Exchange (ETDEWEB)

    Brown, D. [Brookhaven National Lab. (BNL), Upton, NY (United States); Sonzogni, A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Chadwick, M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Trkov, Andrej [Intl Atomic Energy Agency (IAEA), Vienna (Austria); Dunn, M. [SprectraTech, Oak Ridge, TN (United States); Danon, Y. [Rensselaer Polytechnic Inst., Troy, NY (United States); Neudecker, D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-11-28

    These are the minutes of the 2017 Cross Section Evaluation Working Group (CSEWG). This meeting corresponds to the 50±1th anniversary of CSEWG. The uncertainty on the anniversary reflects the fact that CSEWG was formed in 1966 yet the first ENDF library was published in 1968. Despite the uncertainty on the date of the anniversary, this meeting is an especially auspicious one: this is the last meeting before the release of ENDF/B-VIII.0. This meeting is devoted both to closing out the last open issues before releasing the library and to looking toward the future. The careful reader should note that there are no closing statements in this meeting. This is in a way symbolic of the fact that since ENDF/B is always improving, our work here will never truly be done.

  6. Theoretical study of inspiratory flow waveforms during mechanical ventilation on pulmonary blood flow and gas exchange.

    Science.gov (United States)

    Niranjan, S C; Bidani, A; Ghorbel, F; Zwischenberger, J B; Clark, J W

    1999-08-01

    A lumped two-compartment mathematical model of respiratory mechanics incorporating gas exchange and pulmonary circulation is utilized to analyze the effects of square, descending and ascending inspiratory flow waveforms during mechanical ventilation. The effects on alveolar volume variation, alveolar pressure, airway pressure, gas exchange rate, and expired gas species concentration are evaluated. Advantages in ventilation employing a certain inspiratory flow profile are offset by corresponding reduction in perfusion rates, leading to marginal effects on net gas exchange rates. The descending profile provides better CO2 exchange, whereas the ascending profile is more advantageous for O2 exchange. Regional disparities in airway/lung properties create maldistribution of ventilation and a concomitant inequality in regional alveolar gas composition and gas exchange rates. When minute ventilation is maintained constant, for identical time constant disparities, inequalities in compliance yield pronounced effects on net gas exchange rates at low frequencies, whereas the adverse effects of inequalities in resistance are more pronounced at higher frequencies. Reduction in expiratory air flow (via increased airway resistance) reduces the magnitude of upstroke slope of capnogram and oxigram time courses without significantly affecting end-tidal expired gas compositions, whereas alterations in mechanical factors that result in increased gas exchanges rates yield increases in CO2 and decreases in O2 end-tidal composition values. The model provides a template for assessing the dynamics of cardiopulmonary interactions during mechanical ventilation by combining concurrent descriptions of ventilation, capillary perfusion, and gas exchange. Copyright 1999 Academic Press.

  7. Continuous use of an adaptive lung ventilation controller in critically ...

    African Journals Online (AJOL)

    1995-05-05

    May 5, 1995 ... Adaptive lung ventilation (ALV) refers to closed-loop mechanical ventilation designed to work ... optimise the controller performance, the volume controller .... PawEE), vital capacity IYC), an index of airway resistance relative to ...

  8. APRV Mode in Ventilator Induced Lung Injury (VILI

    Directory of Open Access Journals (Sweden)

    Ata Mahmoodpoor

    2014-01-01

    Full Text Available Ventilator-Induced Lung Injury (VILI, being a significant iatrogenic complication in the ICU patients, is associated with high morbidity and mortality. Numerous approaches, protocols and ventilation modes have been introduced and examined to decrease the incidence of VILI in the ICU patients. Airway pressure release ventilation (APRV, firstly introduced by Stock and Downs in 1987, applies higher Continuous Positive Airway Pressure (CPAP levels in prolonged periods (P and T high in order to preserve satisfactory lung volume and consequently alveolar recruitment. This mode benefits a time-cycled release phase to a lower set of pressure for a short period of time (P and T low i.e. release time (1,2. While some advantages have been introduced for APRV such as efficiently recruited alveoli over time, more homogeneous ventilation, less volutrauma, probable stabilization of patent alveoli and reduction in atelectrauma, protective effects of APRV on lung damage only seem to be substantial if spontaneous breathing responds to more than 30% of total minute ventilation (3. APRV in ARDS patients should be administered cautiously; T low<0.6 seconds, for recruiting collapsed alveoli; however overstretching of alveoli especially during P high should not be neglected and appropriate sedation considered. The proposed advantages for APRV give the impression of being outstanding; however, APRV, as a non-physiologic inverse ratio mode of ventilation, might result in inflammation mainly due to impaired patient-ventilator interaction explaining the negative or minimally desirable effects of APRV on inflammation (4. Consequently, continuous infusion of neuromuscular blocking drugs during ARDS has been reported to reduce mortality (5. There are insufficient confirming data on the superiority of APRV above other ventilatory methods in regard to oxygenation, hemodynamics, regional blood flow, patient comfort and length of mechanical ventilation. Based on current findings

  9. Personalized ventilation

    DEFF Research Database (Denmark)

    Melikov, Arsen Krikor

    2004-01-01

    microenvironment. Furthermore, HVAC systems should be designed to protect occupants from airborne transmission of infectious agents that may be present in exhaled air. Personalized ventilation is a new development in the field of HVAC and has the potential to fulfill the above requirements. This paper reviews...... existing knowledge on performance of personalized ventilation (PV) and on human response to it. The airflow interaction in the vicinity of the human body is analyzed and its impact on thermal comfort and inhaled air quality is discussed together with control strategies and the application of PV in practice...

  10. Effect of PEEP and inhaled nitric oxide on pulmonary gas exchange during gaseous and partial liquid ventilation with small volumes of perfluorocarbon.

    Science.gov (United States)

    Max, M; Kuhlen, R; Falter, F; Reyle-Hahn, M; Dembinski, R; Rossaint, R

    2000-04-01

    Partial liquid ventilation, positive end-expiratory pressure (PEEP) and inhaled nitric oxide (NO) can improve ventilation/perfusion mismatch in acute lung injury (ALI). The aim of the present study was to compare gas exchange and hemodynamics in experimental ALI during gaseous and partial liquid ventilation at two different levels of PEEP, with and without the inhalation of nitric oxide. Seven pigs (24+/-2 kg BW) were surfactant-depleted by repeated lung lavage with saline. Gas exchange and hemodynamic parameters were assessed in all animals during gaseous and subsequent partial liquid ventilation at two levels of PEEP (5 and 15 cmH2O) and intermittent inhalation of 10 ppm NO. Arterial oxygenation increased significantly with a simultaneous decrease in cardiac output when PEEP 15 cmH2O was applied during gaseous and partial liquid ventilation. All other hemodynamic parameters revealed no relevant changes. Inhalation of NO and instillation of perfluorocarbon had no additive effects on pulmonary gas exchange when compared to PEEP 15 cmH2O alone. In experimental lung injury, improvements in gas exchange are most distinct during mechanical ventilation with PEEP 15 cmH2O without significantly impairing hemodynamics. Partial liquid ventilation and inhaled NO did not cause an additive increase of PaO2.

  11. Can mechanical ventilation strategies reduce chronic lung disease?

    Science.gov (United States)

    Donn, Steven M; Sinha, Sunil K

    2003-12-01

    Chronic lung disease (CLD) continues to be a significant complication in newborn infants undergoing mechanical ventilation for respiratory failure. Although the aetiology of CLD is multifactorial, specific factors related to mechanical ventilation, including barotrauma, volutrauma and atelectrauma, have been implicated as important aetiologic mechanisms. This article discusses the ways in which these factors might be manipulated by various mechanical ventilatory strategies to reduce ventilator-induced lung injury. These include continuous positive airway pressure, permissive hypercapnia, patient-triggered ventilation, volume-targeted ventilation, proportional assist ventilation, high-frequency ventilation and real-time monitoring.

  12. Alterações hemodinâmicas durante o pneumoperitônio em cães ventilados com volume e pressão controlados Alteraciones hemodinámicas durante el pneumoperitoneo en canes ventilados con volumen y presión controlados Hemodynamic changes during pneumoperitoneum in volume and pressure controlled ventilated dogs

    Directory of Open Access Journals (Sweden)

    Armando Vieira de Almeida

    2003-12-01

    por el pneumoperitoneo en canes con ventilación por volumen y presión controlados. MÉTODO: Diez y seis canes anestesiados con tiopental sódico y fentanil fueron divididos en grupo 1, volumen controlado, y grupo 2, presión controlada, y sometidos al pneumoperitoneo de 10 y 15 mmHg. Se estudió la frecuencia cardíaca, presión arterial media, presión del atrio derecho, presión de la arteria pulmonar ocluida, índice cardíaco, índice de resistencia vascular sistémica y vasopresina plasmática. Los datos fueron colectados en 4 momentos. M1 - antes del pneumoperitoneo, M2 - 30 minutos después del pneumoperitoneo con 10 mmHg, M3 - 30 minutos después del pneumoperitoneo con 15 mmHg, M4 - 30 minutos después de la deflación del pneumoperitoneo. RESULTADOS: Los resultados mostraron aumento en el índice cardíaco, en las presiones del atrio derecho y de la arteria pulmonar ocluida en M2 y M3, en ambos grupos. La vasopresina no varió durante el procedimiento y el índice de resistencia vascular sistémica no aumentó, proporcionando estabilidad de la presión arterial media en ambos grupos. CONCLUSIONES: Las modalidades ventilatorias no determinaron diferencias en la respuesta hemodinámica entre los grupos estudiados. La técnica anestésica utilizada y las presiones intra-abdominales alcanzadas determinaron estabilidad de la presión arterial media, probablemente resultante de la ausencia del aumento en el índice de la resistencia vascular sistémica.BACKGROUND AND OBJECTIVES: There are no studies associating ventilation-induced effects and hemodynamic changes during pneumoperitoneum. This study aimed at evaluating hemodynamic changes determined by pneumoperitoneum in dogs under volume and pressure controlled ventilation. METHODS: The study involved 16 dogs anesthetized with sodium thiopental and fentanyl, divided in group 1: volume controlled; and group 2: pressure controlled; submitted to 10 and 15 mmHg pneumoperitoneum. The following parameters were

  13. Displacement Ventilation

    DEFF Research Database (Denmark)

    Bjørn, Erik; Mattsson, Magnus; Sandberg, Mats

    Full-scale experiments were made in a displacement ventilated room with two breathing thermal manikins to study the effect of movements and breathing on the vertical contaminant distribution, and on the personal exposure of occupants. Concentrations were measured with tracer gas equipment...

  14. Mixing Ventilation

    DEFF Research Database (Denmark)

    Kandzia, Claudia; Kosonen, Risto; Melikov, Arsen Krikor

    In this guidebook most of the known and used in practice methods for achieving mixing air distribution are discussed. Mixing ventilation has been applied to many different spaces providing fresh air and thermal comfort to the occupants. Today, a design engineer can choose from large selection...

  15. Prehospital tidal volume influences hospital tidal volume: A cohort study.

    Science.gov (United States)

    Stoltze, Andrew J; Wong, Terrence S; Harland, Karisa K; Ahmed, Azeemuddin; Fuller, Brian M; Mohr, Nicholas M

    2015-06-01

    The purposes of the study are to describe current practice of ventilation in a modern air medical system and to measure the association of ventilation strategy with subsequent ventilator care and acute respiratory distress syndrome (ARDS). Retrospective observational cohort study of intubated adult patients (n = 235) transported by a university-affiliated air medical transport service to a 711-bed tertiary academic center between July 2011 and May 2013. Low tidal volume ventilation was defined as tidal volumes less than or equal to 8 mL/kg predicted body weight. Multivariable regression was used to measure the association between prehospital tidal volume, hospital ventilation strategy, and ARDS. Most patients (57%) were ventilated solely with bag valve ventilation during transport. Mean tidal volume of mechanically ventilated patients was 8.6 mL/kg predicted body weight (SD, 0.2 mL/kg). Low tidal volume ventilation was used in 13% of patients. Patients receiving low tidal volume ventilation during air medical transport were more likely to receive low tidal volume ventilation in the emergency department (P tidal volume (P = .840). Low tidal volume ventilation was rare during air medical transport. Air transport ventilation strategy influenced subsequent ventilation but was not associated with ARDS. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Intraoperative Protective Mechanical Ventilation for Prevention of Postoperative Pulmonary Complications A Comprehensive Review of the Role of Tidal Volume, Positive End-expiratory Pressure, and Lung Recruitment Maneuvers

    NARCIS (Netherlands)

    Güldner, Andreas; Kiss, Thomas; Serpa Neto, Ary; Hemmes, Sabrine N. T.; Canet, Jaume; Spieth, Peter M.; Rocco, Patricia R. M.; Schultz, Marcus J.; Pelosi, Paolo; Gama de Abreu, Marcelo

    2015-01-01

    Postoperative pulmonary complications are associated with increased morbidity, length of hospital stay, and mortality after major surgery. Intraoperative lung-protective mechanical ventilation has the potential to reduce the incidence of postoperative pulmonary complications. This review discusses

  17. No change in the regional distribution of tidal volume during lateral posture in mechanically ventilated patients assessed by electrical impedance tomography

    OpenAIRE

    Bein, Thomas; Ploner, Franz; Ritzka, Markus; Pfeifer, Michael; Schlitt, Hans J; Graf, Bernhard M

    2010-01-01

    We assessed the distribution of regional lung ventilation during moderate and steep lateral posture using electrical impedance tomography (EIT) in mechanically ventilated patients. Seven patients were placed on a kinetic treatment table. An elastic belt containing 16 electrodes was placed around the chest and was connected to the EIT device. Patients were moved to left and right lateral positions in a stepwise (10?) mode up to 60?. EIT images [arbitrary units (AU)] were generated and scanned ...

  18. Lower tidal volume strategy (≈3 ml/kg) combined with extracorporeal CO2 removal versus 'conventional' protective ventilation (6 ml/kg) in severe ARDS: the prospective randomized Xtravent-study.

    Science.gov (United States)

    Bein, Thomas; Weber-Carstens, Steffen; Goldmann, Anton; Müller, Thomas; Staudinger, Thomas; Brederlau, Jörg; Muellenbach, Ralf; Dembinski, Rolf; Graf, Bernhard M; Wewalka, Marlene; Philipp, Alois; Wernecke, Klaus-Dieter; Lubnow, Matthias; Slutsky, Arthur S

    2013-05-01

    Acute respiratory distress syndrome is characterized by damage to the lung caused by various insults, including ventilation itself, and tidal hyperinflation can lead to ventilator induced lung injury (VILI). We investigated the effects of a low tidal volume (V(T)) strategy (V(T) ≈ 3 ml/kg/predicted body weight [PBW]) using pumpless extracorporeal lung assist in established ARDS. Seventy-nine patients were enrolled after a 'stabilization period' (24 h with optimized therapy and high PEEP). They were randomly assigned to receive a low V(T) ventilation (≈3 ml/kg) combined with extracorporeal CO2 elimination, or to a ARDSNet strategy (≈6 ml/kg) without the extracorporeal device. The primary outcome was the 28-days and 60-days ventilator-free days (VFD). Secondary outcome parameters were respiratory mechanics, gas exchange, analgesic/sedation use, complications and hospital mortality. Ventilation with very low V(T)'s was easy to implement with extracorporeal CO2-removal. VFD's within 60 days were not different between the study group (33.2 ± 20) and the control group (29.2 ± 21, p = 0.469), but in more hypoxemic patients (PaO2/FIO2 ≤150) a post hoc analysis demonstrated significant improved VFD-60 in study patients (40.9 ± 12.8) compared to control (28.2 ± 16.4, p = 0.033). The mortality rate was low (16.5%) and did not differ between groups. The use of very low V(T) combined with extracorporeal CO2 removal has the potential to further reduce VILI compared with a 'normal' lung protective management. Whether this strategy will improve survival in ARDS patients remains to be determined (Clinical trials NCT 00538928).

  19. Oral mask ventilation is more effective than face mask ventilation after nasal surgery.

    Science.gov (United States)

    Yazicioğlu, Dilek; Baran, Ilkay; Uzumcugil, Filiz; Ozturk, Ibrahim; Utebey, Gulten; Sayın, M Murat

    2016-06-01

    To evaluate and compare the face mask (FM) and oral mask (OM) ventilation techniques during anesthesia emergence regarding tidal volume, leak volume, and difficult mask ventilation (DMV) incidence. Prospective, randomized, crossover study. Operating room, training and research hospital. American Society of Anesthesiologists physical status I and II adult patients scheduled for nasal surgery. Patients in group FM-OM received FM ventilation first, followed by OM ventilation, and patients in group OM-FM received OM ventilation first, followed by FM ventilation, with spontaneous ventilation after deep extubation. The FM ventilation was applied with the 1-handed EC-clamp technique. The OM was placed only over the mouth, and the 1-handed EC-clamp technique was used again. A child's size FM was used for the OM ventilation technique, the mask was rotated, and the inferior part of the mask was placed toward the nose. The leak volume (MVleak), mean airway pressure (Pmean), and expired tidal volume (TVe) were assessed with each mask technique for 3 consecutive breaths. A mask ventilation grade ≥3 was considered DMV. DMV occurred more frequently during FM ventilation (75% with FM vs 8% with OM). In the FM-first sequence, the mean TVe was 249±61mL with the FM and 455±35mL with the OM (P=.0001), whereas in the OM-first sequence, it was 276±81mL with the FM and 409±37mL with the OM (P=.0001). Regardless of the order used, the OM technique significantly decreased the MVleak and increased the TVe when compared to the FM technique. During anesthesia emergence after nasal surgery the OM may offer an effective ventilation method as it decreases the incidence of DMV and the gas leak around the mask and provides higher tidal volume delivery compared with FM ventilation. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Lung-protective ventilation in abdominal surgery.

    Science.gov (United States)

    Futier, Emmanuel; Jaber, Samir

    2014-08-01

    To provide the most recent and relevant clinical evidence regarding the use of prophylactic lung-protective mechanical ventilation in abdominal surgery. Evidence is accumulating, suggesting an association between intraoperative mechanical ventilation strategy and postoperative pulmonary complications in patients undergoing abdominal surgery. Nonprotective ventilator settings, especially high tidal volume (>10-12 ml/kg), very low level of positive end-expiratory pressure (PEEP, ventilator-associated lung injury in patients with healthy lungs. Stimulated by the previous findings in patients with acute respiratory distress syndrome, the use of lower tidal volume ventilation is becoming increasingly more common in the operating room. However, lowering tidal volume, though important, is only part of the overall multifaceted approach of lung-protective mechanical ventilation. Recent data provide compelling evidence that prophylactic lung-protective mechanical ventilation using lower tidal volume (6-8 ml/kg of predicted body weight), moderate PEEP (6-8 cm H2O), and recruitment maneuvers is associated with improved functional or physiological and clinical postoperative outcome in patients undergoing abdominal surgery. The use of prophylactic lung-protective ventilation can help in improving the postoperative outcome.

  1. Variable versus conventional lung protective mechanical ventilation during open abdominal surgery: study protocol for a randomized controlled trial

    NARCIS (Netherlands)

    Spieth, Peter M.; Güldner, Andreas; Uhlig, Christopher; Bluth, Thomas; Kiss, Thomas; Schultz, Marcus J.; Pelosi, Paolo; Koch, Thea; Gama de Abreu, Marcelo

    2014-01-01

    General anesthesia usually requires mechanical ventilation, which is traditionally accomplished with constant tidal volumes in volume- or pressure-controlled modes. Experimental studies suggest that the use of variable tidal volumes (variable ventilation) recruits lung tissue, improves pulmonary

  2. Methodology for ventilation/perfusion SPECT

    DEFF Research Database (Denmark)

    Bajc, Marika; Neilly, Brian; Miniati, Massimo

    2010-01-01

    radiolabeled liquid aerosols are not restricted to the presence of obstructive lung disease. Radiolabeled macroaggregated human albumin is the imaging agent of choice for perfusion scintigraphy. An optimal combination of nuclide activities and acquisition times for ventilation and perfusion, collimators......Ventilation/perfusion single-photon emission computed tomography (V/Q SPECT) is the scintigraphic technique of choice for the diagnosis of pulmonary embolism and many other disorders that affect lung function. Data from recent ventilation studies show that the theoretic advantages of Technegas over......, and imaging matrix yields an adequate V/Q SPECT study in approximately 20 minutes of imaging time. The recommended protocol based on the patient remaining in an unchanged position during the initial ventilation study and the perfusion study allows presentation of matching ventilation and perfusion slices...

  3. Air compressor battery duration with mechanical ventilation in a field anesthesia machine.

    Science.gov (United States)

    Szpisjak, Dale F; Giberman, Anthony A

    2015-05-01

    Compressed air to power field anesthesia machine ventilators may be supplied by air compressor with battery backup. This study determined the battery duration when the compPAC ventilator's air compressor was powered by NiCd battery to ventilate the Vent Aid Training Test Lung modeling high (HC = 0.100 L/cm H2O) and low (LC = 0.020 L/cm H2O) pulmonary compliance. Target tidal volumes (VT) were 500, 750, and 1,000 mL. Respiratory rate = 10 bpm, inspiratory-to-expiratory time ratio = 1:2, and fresh gas flow = 1 L/min air. N = 5 in each group. Control limits were determined from the first 150 minutes of battery power for each run and lower control limit = mean VT - 3SD. Battery depletion occurred when VT was below the lower control limit. Battery duration ranged from 185.8 (±3.2) minutes in the LC-1000 group to 233.3 (±3.6) minutes in the HC-750 group. Battery duration of the LC-1000 group was less than all others (p = 0.027). The differences among the non-LC-1000 groups were not clinically significant. Reprint & Copyright © 2015 Association of Military Surgeons of the U.S.

  4. Ventilator induced lung injury (VILI) in acute respiratory distress ...

    African Journals Online (AJOL)

    The lung protective ventilation strategy- Low tidal volume ventilation has shown some reduction in mortality in patients with ARDS but mortality is still high in patient with severe ARDS secondary to Pneumocystis jiroveci pneumonia (PJP) despite of lung protective ventilation strategy. In patients with Severe ARDS due to PJP ...

  5. Mechanical ventilation strategies for the surgical patient

    NARCIS (Netherlands)

    Schultz, Marcus J.; Abreu, Marcelo Gama de; Pelosi, Paolo

    2015-01-01

    Purpose of review To summarize clinical evidence for intraoperative ventilation settings, which could protect against postoperative pulmonary complications (PPCs) in surgical patients with uninjured lungs. Recent findings There is convincing evidence for protection against PPCs by low tidal volumes:

  6. Adaptive Intelligent Ventilation Noise Control, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — To address NASA needs for quiet crew volumes in a space habitat, Physical Optics Corporation (POC) proposes to develop a new Adaptive Intelligent Ventilation Noise...

  7. Nasal mask ventilation is better than face mask ventilation in edentulous patients.

    Science.gov (United States)

    Kapoor, Mukul Chandra; Rana, Sandeep; Singh, Arvind Kumar; Vishal, Vindhya; Sikdar, Indranil

    2016-01-01

    Face mask ventilation of the edentulous patient is often difficult as ineffective seating of the standard mask to the face prevents attainment of an adequate air seal. The efficacy of nasal ventilation in edentulous patients has been cited in case reports but has never been investigated. Consecutive edentulous adult patients scheduled for surgery under general anesthesia with endotracheal intubation, during a 17-month period, were prospectively evaluated. After induction of anesthesia and administration of neuromuscular blocker, lungs were ventilated with a standard anatomical face mask of appropriate size, using a volume controlled anesthesia ventilator with tidal volume set at 10 ml/kg. In case of inadequate ventilation, the mask position was adjusted to achieve best-fit. Inspired and expired tidal volumes were measured. Thereafter, the face mask was replaced by a nasal mask and after achieving best-fit, the inspired and expired tidal volumes were recorded. The difference in expired tidal volumes and airway pressures at best-fit with the use of the two masks and number of patients with inadequate ventilation with use of the masks were statistically analyzed. A total of 79 edentulous patients were recruited for the study. The difference in expiratory tidal volumes with the use of the two masks at best-fit was statistically significant (P = 0.0017). Despite the best-fit mask placement, adequacy of ventilation could not be achieved in 24.1% patients during face mask ventilation, and 12.7% patients during nasal mask ventilation and the difference was statistically significant. Nasal mask ventilation is more efficient than standard face mask ventilation in edentulous patients.

  8. Comparative performances analysis of neonatal ventilators.

    Science.gov (United States)

    Baldoli, Ilaria; Tognarelli, Selene; Scaramuzzo, Rosa T; Ciantelli, Massimiliano; Cecchi, Francesca; Gentile, Marzia; Sigali, Emilio; Ghirri, Paolo; Boldrini, Antonio; Menciassi, Arianna; Laschi, Cecilia; Cuttano, Armando

    2015-02-08

    Mechanical ventilation is a therapeutic action for newborns with respiratory diseases but may have side effects. Correct equipment knowledge and training may limit human errors. We aimed to test different neonatal mechanical ventilators' performances by an acquisition module (a commercial pressure sensor plus an isolated chamber and a dedicated software). The differences (ΔP) between peak pressure values and end-expiration pressure were investigated for each ventilator. We focused on discrepancies among measured and imposed pressure data. A statistical analysis was performed. We investigated the measured/imposed ΔP relation. The ΔP do not reveal univocal trends related to ventilation setting parameters and the data distributions were non-Gaussian. Measured ΔP represent a significant parameter in newborns' ventilation, due to the typical small volumes. The investigated ventilators showed different tendencies. Therefore, a deep specific knowledge of the intensive care devices is mandatory for caregivers to correctly exploit their operating principles.

  9. Creating a Positive Classroom Culture: Minute by Minute

    Science.gov (United States)

    Wright, Ali

    2014-01-01

    This article offers a peek into high school math teacher Ali Wright's typical school day, which includes time-tested strategies that she uses to build a positive culture in her classroom. Scheduled timeframes and activities include before school starts, five minutes before class, during announcements, during class, last five minutes of class,…

  10. Comparison of Ventilation With One-Handed Mask Seal With an Intraoral Mask Versus Conventional Cuffed Face Mask in a Cadaver Model: A Randomized Crossover Trial.

    Science.gov (United States)

    Amack, Andrew J; Barber, Gary A; Ng, Patrick C; Smith, Thomas B; April, Michael D

    2017-01-01

    We compare received minute volume with an intraoral mask versus conventional cuffed face mask among medics obtaining a 1-handed mask seal on a cadaver model. This study comprised a randomized crossover trial of adult US Army combat medic volunteers participating in a cadaver laboratory as part of their training. We randomized participants to obtain a 1-handed mask seal during ventilation of a fresh unembalmed cadaver, first using either an intraoral airway device or conventional cuffed face mask. Participants obtained a 1-handed mask seal while a ventilator delivered 10 standardized 750-mL breaths during 1 minute. After a 5-minute rest period, they repeated the study with the alternative mask. The primary outcome measure was received minute volume as measured by a respirometer. Of 27 recruited participants, all completed the study. Median received minute volume was higher with the intraoral mask compared with conventional cuffed mask by 1.7 L (95% confidence interval 1.0 to 1.9 L; Pcadaver model. The intraoral mask may prove a useful airway adjunct for ventilation. Copyright © 2016 American College of Emergency Physicians. Published by Elsevier Inc. All rights reserved.

  11. Bilevel vs ICU ventilators providing noninvasive ventilation: effect of system leaks: a COPD lung model comparison.

    Science.gov (United States)

    Ferreira, Juliana C; Chipman, Daniel W; Hill, Nicholas S; Kacmarek, Robert M

    2009-08-01

    Noninvasive positive-pressure ventilation (NPPV) modes are currently available on bilevel and ICU ventilators. However, little data comparing the performance of the NPPV modes on these ventilators are available. In an experimental bench study, the ability of nine ICU ventilators to function in the presence of leaks was compared with a bilevel ventilator using the IngMar ASL5000 lung simulator (IngMar Medical; Pittsburgh, PA) set at a compliance of 60 mL/cm H(2)O, an inspiratory resistance of 10 cm H(2)O/L/s, an expiratory resistance of 20 cm H(2)O/ L/s, and a respiratory rate of 15 breaths/min. All of the ventilators were set at 12 cm H(2)O pressure support and 5 cm H(2)O positive end-expiratory pressure. The data were collected at baseline and at three customized leaks. At baseline, all of the ventilators were able to deliver adequate tidal volumes, to maintain airway pressure, and to synchronize with the simulator, without missed efforts or auto-triggering. As the leak was increased, all of the ventilators (except the Vision [Respironics; Murrysville, PA] and Servo I [Maquet; Solna, Sweden]) needed adjustment of sensitivity or cycling criteria to maintain adequate ventilation, and some transitioned to backup ventilation. Significant differences in triggering and cycling were observed between the Servo I and the Vision ventilators. The Vision and Servo I were the only ventilators that required no adjustments as they adapted to increasing leaks. There were differences in performance between these two ventilators, although the clinical significance of these differences is unclear. Clinicians should be aware that in the presence of leaks, most ICU ventilators require adjustments to maintain an adequate tidal volume.

  12. Spirolit-2 instrument used to test pulmonary ventilation

    Science.gov (United States)

    Zhuravlev, V. V.

    1985-02-01

    At the present time, the Spirolit-2 automatic analyzer of main respiratory gases, of the Junkalor Dessau firm, is used to examine parameters of gas exchange, levels of energy expended by man and animals with different degrees of activity. However, the capabilities of this model of the instrument are limited. A method of determining pulmonary ventilation with use of the Spirolit-2 is described. An additional exhalation valve is built into a valve box to which an anesthesia machine rubber bag is attached. Samples are collected into another bag concurrently with the usual tests on the Spirolit-2 instrument. Four to five minutes are sufficient to obtain stable parameters at relative rest of oxygen uptake, determine carbon dioxide output per minute and collect samples in for analysis of exhaled air. The proposed method can furnish information about the dynamics of development of respiratory function of the lungs at virtually any moment with a constant physical load. For this, there must be spare bags to collect samples. Stage-by-stage data can be obtained analogously as to ventilation volume during a step test while determining maximum oxygen uptake.

  13. Assessment of dynamic mechanical properties of the respiratory system during high-frequency oscillatory ventilation*.

    Science.gov (United States)

    Dellacà, Raffaele L; Zannin, Emanuela; Ventura, Maria L; Sancini, Giulio; Pedotti, Antonio; Tagliabue, Paolo; Miserocchi, Giuseppe

    2013-11-01

    1) To investigate the possibility of estimating respiratory system impedance (Zrs, forced oscillation technique) by using high-amplitude pressure oscillations delivered during high-frequency oscillatory ventilation; 2) to characterize the relationship between Zrs and continuous distending pressure during an increasing/decreasing continuous distending pressure trial; 3) to evaluate how the optimal continuous distending pressure identified by Zrs relates to the point of maximal curvature of the deflation limb of the quasi-static pressure-volume curve. Prospective laboratory animal investigation. Experimental medicine laboratory. Eight New Zealand rabbits. The rabbits were ventilated with high-frequency oscillatory ventilation. Zrs was measured while continuous distending pressure was increased and decreased between 2 and 26 cm H2O in 1-minute steps of 4 cm H2O. At each step, a low-amplitude (6 cm H2O) sinusoidal signal was alternated with a high-amplitude (18 cm H2O) asymmetric high-frequency oscillatory ventilation square pressure waveform. Pressure-volume curves were determined at the end of the continuous distending pressure trial. All measurements were repeated after bronchoalveolar lavage. Zrs was estimated from flow and pressure measured at the inlet of the tracheal tube and expressed as resistance (Rrs) and reactance (Xrs). Linear correlation between the values, measured by applying the small-amplitude sinusoidal signal and the ventilator waveform, was good for Xrs (r = 0.95 ± 0.04) but not for Rrs (r = 0.60 ± 0.34). Following lavage, the Xrs-continuous distending pressure curves presented a maximum on the deflation limb, identifying an optimal continuous distending pressure that was, on average, 1.1 ± 1.7 cm H2O below the point of maximal curvature of the deflation limb of the pressure-volume curves. Xrs can be accurately measured during high-frequency oscillatory ventilation without interrupting ventilation and/or connecting additional devices. An optimal

  14. Effects of Pressure Support Ventilation May Be Lost at High Exercise Intensities in People with COPD.

    Science.gov (United States)

    Anekwe, David; de Marchie, Michel; Spahija, Jadranka

    2017-06-01

    Pressure support ventilation (PSV) may be used for exercise training in chronic obstructive pulmonary disease (COPD), but its acute effect on maximum exercise capacity is not fully known. The objective of this study was to evaluate the effect of 10 cm H 2 O PSV and a fixed PSV level titrated to patient comfort at rest on maximum exercise workload (WLmax), breathing pattern and metabolic parameters during a symptom-limited incremental bicycle test in individuals with COPD. Eleven individuals with COPD (forced expiratory volume in one second: 49 ± 16%; age: 64 ± 7 years) performed three exercise tests: without a ventilator, with 10 cm H 2 O of PSV and with a fixed level titrated to comfort at rest, using a SERVO-i ventilator. Tests were performed in randomized order and at least 48 hours apart. The WLmax, breathing pattern, metabolic parameters, and mouth pressure (Pmo) were compared using repeated measures analysis of variance. Mean PSV during titration was 8.2 ± 4.5 cm H 2 O. There was no difference in the WLmax achieved during the three tests. At rest, PSV increased the tidal volume, minute ventilation, and mean inspiratory flow with a lower end-tidal CO 2 ; this was not sustained at peak exercise. Pmo decreased progressively (decreased unloading) with PSV at workloads close to peak, suggesting the ventilator was unable to keep up with the increased ventilatory demand at high workloads. In conclusion, with a Servo-i ventilator, 10 cm H 2 O of PSV and a fixed level of PSV established by titration to comfort at rest, is ineffective for the purpose of achieving higher exercise workloads as the acute physiological effects may not be sustained at peak exercise.

  15. Cellular phone interference with the operation of mechanical ventilators.

    Science.gov (United States)

    Shaw, Cheryl I; Kacmarek, Robert M; Hampton, Rickey L; Riggi, Vincent; El Masry, Ashraf; Cooper, Jeffrey B; Hurford, William E

    2004-04-01

    To determine whether a cellular phone would interfere with the operation of mechanical ventilators. Laboratory study. University medical center. Fourteen mechanical ventilators. We evaluated change in operation and malfunction of the mechanical ventilators. The cellular phone (Nokia 6120i) was computer controlled, operating at 828.750 MHz analog modulation. It was operated at 16, 40, 100, 250, and 600 mW, 30 cm from the floor and 30, 15, and ventilator. Six of the 14 ventilators tested malfunctioned when a cellular phone at maximum power output was placed ventilating when the cellular phone at maximum power output was placed ventilator. One ventilator doubled the ventilatory rate and another increased the displayed tidal volume from 350 to 1033 mL. In one of the infant ventilators, displayed tidal volume increased from 21 to 100 mL. In another ventilator, the high respiratory rate alarm sounded but the rate had not changed. In a controlled laboratory setting, cellular phones placed in close proximity to some commercially available intensive care ventilators can cause malfunctions, including irrecoverable cessation of ventilation. This is most likely to occur if the cellular phone is or =3 feet from all medical devices. The current electromagnetic compatibility standards for mechanical ventilators are inadequate to prevent malfunction. Manufacturers should ensure that their products are not affected by wireless technology even when placed immediately next to the device.

  16. Intraoperative mechanical ventilation for the pediatric patient.

    Science.gov (United States)

    Kneyber, Martin C J

    2015-09-01

    Invasive mechanical ventilation is required when children undergo general anesthesia for any procedure. It is remarkable that one of the most practiced interventions such as pediatric mechanical ventilation is hardly supported by any scientific evidence but rather based on personal experience and data from adults, especially as ventilation itself is increasingly recognized as a harmful intervention that causes ventilator-induced lung injury. The use of low tidal volume and higher levels of positive end-expiratory pressure became an integral part of lung-protective ventilation following the outcomes of clinical trials in critically ill adults. This approach has been readily adopted in pediatric ventilation. However, a clear association between tidal volume and mortality has not been ascertained in pediatrics. In fact, experimental studies have suggested that young children might be less susceptible to ventilator-induced lung injury. As such, no recommendations on optimal lung-protective ventilation strategy in children with or without lung injury can be made. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Ventilation-perfused studies using SPECT

    International Nuclear Information System (INIS)

    Zwijnenburg, A.

    1989-01-01

    A method for the quantitative analysis of ventilation-perfusion SPECT studies is decribed and an effort is made to evaluate its usefullness. The technical details of the emthod are described. In the the transaxial reconstructions of the tomographic studies the contour of the lungs is detected and regional values of lung volume, ventilation, perfusion and ventilation-perfusion ratios are calculated. The method is operator independent. The lung volume calculations from the SPECT studies are validated by comparing them with lung volume measurements using the helium dilution technique. A good correlation (r=0.91) was found between the two volumes. SPECT volume was greater than the volume measured with helium dilution, which was attributed to non-gas-containing structures in the. lungs. The use of ventilation-perfusion ratio SPECT is described to evaluate the effect of ionizing radiation on the lungs in patients treated with mantle field irradiation for Hodgkin's disease. Perfusion changes appear as early as 2 months after the start of irradiation. Ventilation changes appear later and relatively minor. No changes are seen outside the radiation portals. The ventilation-perfusion inequality in pulmonary sarcoidosis is treated. It is suggested that the decrease D LCO in these patients may be partly due to an even distribution of ventilation perfusion ratios. An effort is made to establish the properties of a new tracer used for the assessment of the metabolic function of the pulmonary endothelium. The lung uptake of I-123 IMP mimics the distribution of a perfusion tracer and it is suggested that this tracer may be useful for the early detection of pulmonary vascular damage, even when blood flow is still intact. Some aspects of the use of Kr-81m as a ventilation tracer are discussed as well as the effect of noise on Kr-81m SPECT reconstructions. (author). 146 refs.; 39 figs.; 8 tabs

  18. Actual performance of mechanical ventilators in ICU: a multicentric quality control study

    Directory of Open Access Journals (Sweden)

    Govoni L

    2012-12-01

    Full Text Available Leonardo Govoni,1 Raffaele L Dellaca,1 Oscar Peñuelas,2,3 Giacomo Bellani,4,5 Antonio Artigas,3,6 Miquel Ferrer,3,7 Daniel Navajas,3,8,9 Antonio Pedotti,1 Ramon Farré3,81TBM-Lab, Dipartimento di Bioingegneria, Politecnico di Milano University, Milano, Italy; 2Hospital Universitario de Getafe – CIBERES, Madrid, Spain; 3CIBER de Enfermedades Respiratorias, Bunyola, Spain; 4Department of Experimental Medicine, University of Milan, Bicocca, Italy; 5Department of Perioperative Medicine and Intensive Care, San Gerardo Hospital, Monza (MI, Italy; 6Critical Care Center, Sabadell Hospital, Corporació Sanitaria Universitaria Parc Tauli, Universitat Autonoma de Barcelona, CIBERES, Spain; 7Department of Pneumology, Hospital Clinic, IDIBAPS, Barcelona, Spain; 8Unitat de Biofísica i Bioenginyeria, Facultat de Medicina, Universidad de Barcelona-IDIBAPS, Barcelona, Spain; 9Institut de Bioenginyeria de Catalunya, Barcelona, SpainAbstract: Even if the performance of a given ventilator has been evaluated in the laboratory under very well controlled conditions, inappropriate maintenance and lack of long-term stability and accuracy of the ventilator sensors may lead to ventilation errors in actual clinical practice. The aim of this study was to evaluate the actual performances of ventilators during clinical routines. A resistance (7.69 cmH2O/L/s – elastance (100 mL/cmH2O test lung equipped with pressure, flow, and oxygen concentration sensors was connected to the Y-piece of all the mechanical ventilators available for patients in four intensive care units (ICUs; n = 66. Ventilators were set to volume-controlled ventilation with tidal volume = 600 mL, respiratory rate = 20 breaths/minute, positive end-expiratory pressure (PEEP = 8 cmH2O, and oxygen fraction = 0.5. The signals from the sensors were recorded to compute the ventilation parameters. The average ± standard deviation and range (min–max of the ventilatory parameters were the following: inspired

  19. Diffuse Ceiling Ventilation

    DEFF Research Database (Denmark)

    Zhang, Chen; Yu, Tao; Heiselberg, Per Kvols

    with conventional ventilation systems (mixing or displacement ventilation), diffuse ceiling ventilation can significantly reduce or even eliminate draught risk in the occupied zone. Moreover, this ventilation system presents a promising opportunity for energy saving, because of the low pressure loss, extended free...

  20. Diffuse ceiling ventilation

    DEFF Research Database (Denmark)

    Zhang, Chen

    Diffuse ceiling ventilation is an innovative ventilation concept where the suspended ceiling serves as air diffuser to supply fresh air into the room. Compared with conventional ventilation systems, diffuse ceiling ventilation can significantly reduce or even eliminate draught risk due to the low...

  1. Ventilation of radioactive enclosures; Ventilation des enceintes radioactives

    Energy Technology Data Exchange (ETDEWEB)

    Caminade, F; Laurent, H [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1957-07-01

    Mechanical, physical and chemical manipulations on radioactive products must be carried out in properly ventilated enclosed places. The air extracted can only be discharged into the atmosphere after a correct filtration. The power of the ventilation systems is a function of the dimensions and purpose of the enclosure? The choice of types of filter is determined by the physical state and chemical nature of the radioactive materials to be manipulated. This study deals with the individual equipment of small installations: glove boxes, manipulation boxes with outside control and, if necessary, production chambers (maximum useful volume: 5 m{sup 3}). The performances of three types of 'ventilators', and the modifications provided by the addition of filters, are measured and compared. (author) [French] Les manipulations oceaniques, physiques et chimiques sur des produits radioactifs doivent s'effectuer dans des enceintes convenablement ventilees. L'air extrait ne peut etre rejete dans l'atmosphere qu'apres une filtration correcte. La puissance des installations de ventilation est fonction des dimensions de l'enceinte et de son utilisation. Le choix des types de filtres est determine par l'etat physique et la nature ehimique des corps radioactifs manipules. Notre etude porte sur l'equipement individuel d'installations de petites dimensions: boites a gants, boites a pinces et, a la rigueur, enceintes de production (volume maximum utilisable 5 m{sup 3}). Nous mesurons et comparons les performances de trois types de 'ventilateurs' et les modifications apportees par l'adjonction de filtres. (auteur)

  2. Early biomarkers and potential mediators of ventilation-induced lung injury in very preterm lambs

    Directory of Open Access Journals (Sweden)

    Davis Peter G

    2009-03-01

    Full Text Available Abstract Background Bronchopulmonary dysplasia (BPD is closely associated with ventilator-induced lung injury (VILI in very preterm infants. The greatest risk of VILI may be in the immediate period after birth, when the lungs are surfactant deficient, still partially filled with liquid and not uniformly aerated. However, there have been very few studies that have examined this immediate post-birth period and identified the initial injury-related pathways that are activated. We aimed to determine if the early response genes; connective tissue growth factor (CTGF, cysteine rich-61 (CYR61 and early growth response 1 (EGR1, were rapidly induced by VILI in preterm lambs and whether ventilation with different tidal volumes caused different inflammatory cytokine and early response gene expression. Methods To identify early markers of VILI, preterm lambs (132 d gestational age; GA, term ~147 d were resuscitated with an injurious ventilation strategy (VT 20 mL/kg for 15 min then gently ventilated (5 mL/kg for 15, 30, 60 or 120 min (n = 4 in each. To determine if early response genes and inflammatory cytokines were differentially regulated by different ventilation strategies, separate groups of preterm lambs (125 d GA; n = 5 in each were ventilated from birth with a VT of 5 (VG5 or 10 mL/kg (VG10 for 135 minutes. Lung gene expression levels were compared to levels prior to ventilation in age-matched control fetuses. Results CTGF, CYR61 and EGR1 lung mRNA levels were increased ~25, 50 and 120-fold respectively (p CTGF, CYR61, EGR1, IL1-β, IL-6 and IL-8 mRNA levels compared to control levels. CTGF, CYR61, IL-6 and IL-8 expression levels were higher in VG10 than VG5 lambs; although only the IL-6 and CYR61 mRNA levels reached significance. Conclusion CTGF, CYR61 and EGR1 may be novel early markers of lung injury and mechanical ventilation from birth using relatively low tidal volumes may be less injurious than using higher tidal volumes.

  3. Variable mechanical ventilation.

    Science.gov (United States)

    Fontela, Paula Caitano; Prestes, Renata Bernardy; Forgiarini, Luiz Alberto; Friedman, Gilberto

    2017-01-01

    To review the literature on the use of variable mechanical ventilation and the main outcomes of this technique. Search, selection, and analysis of all original articles on variable ventilation, without restriction on the period of publication and language, available in the electronic databases LILACS, MEDLINE®, and PubMed, by searching the terms "variable ventilation" OR "noisy ventilation" OR "biologically variable ventilation". A total of 36 studies were selected. Of these, 24 were original studies, including 21 experimental studies and three clinical studies. Several experimental studies reported the beneficial effects of distinct variable ventilation strategies on lung function using different models of lung injury and healthy lungs. Variable ventilation seems to be a viable strategy for improving gas exchange and respiratory mechanics and preventing lung injury associated with mechanical ventilation. However, further clinical studies are necessary to assess the potential of variable ventilation strategies for the clinical improvement of patients undergoing mechanical ventilation.

  4. VENTILATION NEEDS DURING CONSTRUCTION

    International Nuclear Information System (INIS)

    C.R. Gorrell

    1998-01-01

    The purpose of this analysis is to determine ventilation needs during construction and development of the subsurface repository and develop systems to satisfy those needs. For this analysis, construction is defined as pre-emplacement excavation and development is excavation that takes place simultaneously with emplacement. The three options presented in the ''Overall Development and Emplacement Ventilation Systems'' analysis (Reference 5.5) for development ventilation will be applied to construction ventilation in this analysis as well as adding new and updated ventilation factors to each option for both construction and development. The objective of this analysis is to develop a preferred ventilation system to support License Application Design. The scope of this analysis includes: (1) Description of ventilation conditions; (2) Ventilation factors (fire hazards, dust control, construction logistics, and monitoring and control systems); (3) Local ventilation alternatives; (4) Global ventilation options; and (5) Evaluation of options

  5. Intensive care unit ventilation for the non-intensivist

    African Journals Online (AJOL)

    Mode classification: volume versus pressure targeting. There is no evidence to ... and so most modern ventilators can be set up by the technician to directly display the .... mechanics: transpulmonary pressure and lung volume. Crit Care. 2013 ...

  6. Evaluation of Mechanical Ventilator Use with Liquid Oxygen Systems

    Science.gov (United States)

    2017-02-22

    Endotracheal tubes, high-volume, low-pressure, tracheal wall injury 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT SAR 18. NUMBER OF...ventilators to the LOX devices. Ventilator settings were as follows : respiratory rate 35 breaths/min, inspiratory time 0.8 seconds, tidal volume 450 mL

  7. [Lung protective ventilation - pathophysiology and diagnostics].

    Science.gov (United States)

    Uhlig, Stefan; Frerichs, Inéz

    2008-06-01

    Mechanical ventilation may lead to lung injury depending on the ventilatory settings (e.g. pressure amplitudes, endexpiratory pressures, frequency) and the length of mechanical ventilation. Particularly in the inhomogeneously injured lungs of ARDS patients, alveolar overextension results in volutrauma, cyclic opening and closure of alveolar units in atelectrauma. Particularly important appears to be the fact that these processes may also cause biotrauma, i.e. the ventilator-induced hyperactivation of inflammatory responses in the lung. These side effects are reduced, but not eliminated with the currently recommended ventilation strategy with a tidal volume of 6 ml/kg idealized body weight. It is our hope that in the future optimization of ventilator settings will be facilated by bedside monitoring of novel indices of respiratory mechanics such as the stress index or the Slice technique, and by innovative real-time imaging technologies such as electrical impedance tomography.

  8. [Pressure support ventilation and proportional assist ventilation during weaning from mechanical ventilation].

    Science.gov (United States)

    Aguirre-Bermeo, H; Bottiroli, M; Italiano, S; Roche-Campo, F; Santos, J A; Alonso, M; Mancebo, J

    2014-01-01

    To compare tolerance, duration of mechanical ventilation (MV) and clinical outcomes during weaning from MV in patients subjected to either pressure support ventilation (PSV) or proportional assist ventilation (PAV). A prospective, observational study was carried out. Intensive Care Unit. A total of 40 consecutive subjects were allocated to either the PSV or the PAV group until each group contained 20 patients. Patients were included in the study when they met the criteria to begin weaning and the attending physician decided to initiate the weaning process. The physician selected the modality and set the ventilatory parameters. None. Demographic data, respiratory mechanics, ventilatory parameters, duration of MV, and clinical outcomes (reintubation, tracheostomy, mortality). Baseline characteristics were similar in both groups. No significant differences were observed between the PSV and PAV groups in terms of the total duration of MV (10 [5-18] vs. 9 [7-19] days; P=.85), reintubation (5 [31%] vs. 3 [19%]; P=.69), or mortality (4 [20%] vs. 5 [25%] deaths; P=1). Eight patients (40%) in the PSV group and 6 patients (30%) in the PAV group (P=.74) required a return to volume assist-control ventilation due to clinical deterioration. Tolerance, duration of MV and clinical outcomes during weaning from mechanical ventilation were similar in PSV and PAV. Copyright © 2013 Elsevier España, S.L. and SEMICYUC. All rights reserved.

  9. International Energy Agency Building Energy Simulation Test and Diagnostic Method for Heating, Ventilating, and Air-Conditioning Equipment Models (HVAC BESTEST); Volume 1: Cases E100-E200

    Energy Technology Data Exchange (ETDEWEB)

    Neymark, J.; Judkoff, R.

    2002-01-01

    This report describes the Building Energy Simulation Test for Heating, Ventilating, and Air-Conditioning Equipment Models (HVAC BESTEST) project conducted by the Tool Evaluation and Improvement International Energy Agency (IEA) Experts Group. The group was composed of experts from the Solar Heating and Cooling (SHC) Programme, Task 22, Subtask A. The current test cases, E100-E200, represent the beginning of work on mechanical equipment test cases; additional cases that would expand the current test suite have been proposed for future development.

  10. Energy and IAQ Implications of Residential Ventilation Cooling

    Energy Technology Data Exchange (ETDEWEB)

    Turner, William [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Walker, Iain [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2014-08-01

    This study evaluates the energy, humidity and indoor air quality (IAQ) implications of residential ventilation cooling in all U.S. IECC climate zones. A computer modeling approach was adopted, using an advanced residential building simulation tool with airflow, energy and humidity models. An economizer (large supply fan) was simulated to provide ventilation cooling while outdoor air temperatures were lower than indoor air temperatures (typically at night). The simulations were performed for a full year using one-minute time steps to allow for scheduling of ventilation systems and to account for interactions between ventilation and heating/cooling systems.

  11. Performance of portable ventilators for mass-casualty care.

    Science.gov (United States)

    Blakeman, Thomas C; Rodriquez, Dario; Dorlac, Warren C; Hanseman, Dennis J; Hattery, Ellie; Branson, Richard D

    2011-10-01

    Disasters and mass-casualty scenarios may overwhelm medical resources regardless of the level of preparation. Disaster response requires medical equipment, such as ventilators, that can be operated under adverse circumstances and should be able to provide respiratory support for a variety of patient populations. The objective of this study was to evaluate the performance of three portable ventilators designed to provide ventilatory support outside the hospital setting and in mass-casualty incidents, and their adherence to the Task Force for Mass Critical Care recommendations for mass-casualty care ventilators. Each device was evaluated at minimum and maximum respiratory rate and tidal volume settings to determine the accuracy of set versus delivered VT at lung compliance settings of 0.02, 0.08 and 0.1 L/cm H20 with corresponding resistance settings of 10, 25, and 5 cm H2O/L/sec, to simulate patients with ARDS, severe asthma, and normal lungs. Additionally, different FIO2 settings with each device (if applicable) were evaluated to determine accuracy of FIO2 delivery and evaluate the effect on delivered VT. Ventilators also were tested for duration of battery life. VT decreased with all three devices as compliance decreased. The decrease was more pronounced when the internal compressor was activated. At the 0.65 FIO2 setting on the MCV 200, the measured FIO2 varied widely depending on the set VT. Battery life range was 311-582 minutes with the 73X having the longest battery life. Delivered VT decreased toward the end of battery life with the SAVe having the largest decrease. The respiratory rate on the SAVe also decreased approaching the end of battery life. The 73X and MCV 200 were the closest to satisfying the Task Force for Mass Critical Care requirements for mass casualty ventilators, although neither had the capability to provide PEEP. The 73X provided the most consistent tidal volume delivery across all compliances, had the longest battery duration and the

  12. Leakage Characteristics of Dual-Cannula Fenestrated Tracheostomy Tubes during Positive Pressure Ventilation: A Bench Study

    Directory of Open Access Journals (Sweden)

    Thomas Berlet

    2016-01-01

    Full Text Available This study compared the leakage characteristics of different types of dual-cannula fenestrated tracheostomy tubes during positive pressure ventilation. Fenestrated Portex® Blue Line Ultra®, TRACOE® twist, or Rüsch® Traceofix® tracheostomy tubes equipped with nonfenestrated inner cannulas were tested in a tracheostomy-lung simulator. Transfenestration pressures and transfenestration leakage rates were measured during positive pressure ventilation. The impact of different ventilation modes, airway pressures, temperatures, and simulated static lung compliance settings on leakage characteristics was assessed. We observed substantial differences in transfenestration pressures and transfenestration leakage rates. The leakage rates of the best performing tubes were <3.5% of the delivered minute volume. At body temperature, the leakage rates of these tracheostomy tubes were <1%. The tracheal tube design was the main factor that determined the leakage characteristics. Careful tracheostomy tube selection permits the use of fenestrated tracheostomy tubes in patients receiving positive pressure ventilation immediately after stoma formation and minimises the risk of complications caused by transfenestration gas leakage, for example, subcutaneous emphysema.

  13. Constant flow ventilation as a novel approach to elimination of respiratory artifact in MR imaging

    International Nuclear Information System (INIS)

    Shtern, F.; Kersh, R.; Lee, A.; Venegas, J.; Brady, T.J.

    1988-01-01

    This pilot study was performed to evaluate constant flow ventilation (CFV) as a method of respiratory artifact suppression in magnetic resonance (MR) imaging. In contrast to currently used methods of respiratory artifact suppression, CFV is able to provide adequate ventilation in the absence of any chest wall motion and thus obviates the need for respiratory gating. High-velocity jets of fresh gas delivered through two narrow (2-mm) intrabronchial cannulas promote gas exchange through airway turbulence and enhanced molecular diffusion. One mongrel dog (8.5 kg) was anesthetized with pentobarbital (35 mg/kg). For CFV, endobronchial cannulas were inserted with the aid of bronchoscopy and connected to a flow meter (flow rate, 500 mL/sec). Intrathoracic pressure was monitored via a pressure transducer connected to an air-filled intraesophageal balloon. Conventional ventilation (CV), with a tidal volume of 85 mL and ten breaths per minute, was provided through a cuffed endotracheal tube. After establishment of adequate ventilation (carbon dioxide pressure, 39), muscle paralysis was induced by succinylcholine at 0.1 mg/kg. T2-weighted [1,500/50 (repetition time msec/echo time msec), two excitations] gradient-echo and spin-echo images were obtained at 0.6T with both CV and CFV. MR images with CFV were free of respiratory motion artifact, which was present on all MR images with CV. This pilot study indicates that implementation of CFV results in elimination of respiratory motion artifact

  14. Aerosolized gadolinium-DTPA for demonstration of pulmonary ventilation in MR imaging of the lung

    International Nuclear Information System (INIS)

    Haage, P.; Adam, G.; Karaagac, S.; Pfeffer, J.G.; Glowinski, A.; Doehmen, S.; Guenther, R.W.; Misselwitz, B.; Tacke, J.

    2000-01-01

    Purpose: Magnetic resonance assessment of lung ventilation with aerosolized Gd-DTPA. Methods: Eleven experimental procedures were carried out in a domestic pig model. The intubated pigs were aerosolized for 30 minutes with an aqueous formulation of Gd-DTPA. The contrast agent aerosol was generated by a small particle aerosol generator. Imaging was performed on a 1.5 T MR imager using a T 1 -weighted turbo spin echo sequence with respiratory gating (T R 141 ms, T E 8.5 ms, 6 averages, slice thickness 10 mm). Pulmonary signal intensities before and after ventilation were measured in peripheral portions of both lungs. Results: Immediately after ventilation with aerosolized Gd-DTPA, the signal intensity in both lungs increased significantly in all animals with values up to 237% above baseline (mean 139%±48%), but within some cases considerable regional intra- and interindividual intensity differences. Distinctive parenchymal enhancement was readily visualized in all eleven cases with good spatial resolution. Conclusion: The presented data indicate that Gd-DTPA in aerosolized form can be used to demonstrate pulmonary ventilation in large animals with lung volumes comparable to man. Further experimental trials are necessary to improve reproducibility and to define the scope of this method for depicting lung disease. (orig.) [de

  15. Effect of endobronchial valve therapy on pulmonary perfusion and ventilation distribution.

    Directory of Open Access Journals (Sweden)

    Carmen Pizarro

    Full Text Available Endoscopic lung volume reduction (ELVR is an emerging therapy for emphysematous COPD. However, any resulting changes in lung perfusion and ventilation remain undetermined. Here, we report ELVR-mediated adaptations in lung perfusion and ventilation, as investigated by means of pulmonary scintigraphy.In this observational study, we enrolled 26 patients (64.9 ± 9.4 yrs, 57.7% male with COPD heterogeneous emphysema undergoing ELVR with endobronchial valves (Zephyr, Pulmonx, Inc.. Mean baseline FEV1 and RV were 32.9% and 253.8% predicted, respectively. Lung scintigraphy was conducted prior to ELVR and eight weeks thereafter. Analyses of perfusion and ventilation shifts were performed and complemented by correlation analyses between paired zones.After ELVR, target zone perfusion showed a mean relative reduction of 43.32% (p<0.001, which was associated with a significant decrease in target zone ventilation (p<0.001. Perfusion of the contralateral untreated zone and of the contralateral total lung exhibited significant increases post-ELVR (p = 0.002 and p = 0.005, respectively; both correlated significantly with the corresponding target zone perfusion adaptations. Likewise, changes in target zone ventilation correlated significantly with ventilatory changes in the contralateral untreated zone and the total contralateral lung (Pearson's r: -0.42, p = 0.04 and Pearson's r: -0.42, p = 0.03, respectively. These effects were observed in case of clinical responsiveness to ELVR, as assessed by changes in the six-minute walk test distance.ELVR induces a relevant decrease in perfusion and ventilation of the treated zone with compensatory perfusional and ventilatory redistribution to the contralateral lung, primarily to the non-concordant, contralateral zone.

  16. A historical perspective on ventilator management.

    Science.gov (United States)

    Shapiro, B A

    1994-02-01

    Paralysis via neuromuscular blockade in ICU patients requires mechanical ventilation. This review historically addresses the technological advances and scientific information upon which ventilatory management concepts are based, with special emphasis on the influence such concepts have had on the use of neuromuscular blocking agents. Specific reference is made to the scientific information and technological advances leading to the newer concepts of ventilatory management. Information from > 100 major studies in the peer-reviewed medical literature, along with the author's 25 yrs of clinical experience and academic involvement in acute respiratory care is presented. Nomenclature related to ventilatory management is specifically defined and consistently utilized to present and interpret the data. Pre-1970 ventilatory management is traced from the clinically unacceptable pressure-limited devices to the reliable performance of volume-limited ventilators. The scientific data and rationale that led to the concept of relatively large tidal volume delivery are reviewed in the light of today's concerns regarding alveolar overdistention, control-mode dyssynchrony, and auto-positive end-expiratory pressure. Also presented are the post-1970 scientific rationales for continuous positive airway pressure/positive end-expiratory pressure therapy, avoidance of alveolar hyperxia, and partial ventilatory support techniques (intermittent mandatory ventilation/synchronized intermittent mandatory ventilation). The development of pressure-support devices is discussed and the capability of pressure-control techniques is presented. The rationale for more recent concepts of total ventilatory support to avoid ventilator-induced lung injury is presented. The traditional techniques utilizing volume-preset ventilators with relatively large tidal volumes remain valid and desirable for the vast majority of patients requiring mechanical ventilation. Neuromuscular blockade is best avoided in these

  17. Cardiac gated ventilation

    International Nuclear Information System (INIS)

    Hanson, C.W. III; Hoffman, E.A.

    1995-01-01

    There are several theoretic advantages to synchronizing positive pressure breaths with the cardiac cycle, including the potential for improving distribution of pulmonary and myocardial blood flow and enhancing cardiac output. The authors evaluated the effects of synchronizing respiration to the cardiac cycle using a programmable ventilator and electron beam CT (EBCT) scanning. The hearts of anesthetized dogs were imaged during cardiac gated respiration with a 50 msec scan aperture. Multi slice, short axis, dynamic image data sets spanning the apex to base of the left ventricle were evaluated to determine the volume of the left ventricular chamber at end-diastole and end-systole during apnea, systolic and diastolic cardiac gating. The authors observed an increase in cardiac output of up to 30% with inspiration gated to the systolic phase of the cardiac cycle in a non-failing model of the heart

  18. Development of energy-efficient comfortable ventilation systems with air quality guided volume flow control and continuous monitoring of the window opening status. Part 1. Use of the LuQaS triple sensor for air quality guided volume flow control of mechanical ventilation systems in domestic buildings. Research project; Entwicklung energieeffizienter Komfortlueftungsanlagen mit luftqualitaetsgefuehrter Volumenstromregelung und kontinuierlicher Erfassung des Fensteroeffnungszustandes. Teilbericht 1. Einsatz des LuQaS-Triple-Sensors zur luftqualitaetsgefuehrten Volumenstromregelung von mechanischen Lueftungsanlagen in Wohngebaeuden. Forschungsprojekt

    Energy Technology Data Exchange (ETDEWEB)

    Grossklos, Marc; Ebel, Witta; Knissel, Jens

    2011-05-15

    The report presents the preparatory work on the research project of the above title. The first chapter presents a status report on air quality monitoring inside rooms and evaluates the projects so far in which the LuQaS air quality sensor was used. The second chapter is a documentation of preliminary measurements using the LuQaS sensor in two passive residential buildings and several individual measurements for sensor calibration. It was found that in apartments with mechanical ventilation, the sensor reflects the user activities; further, the measured values indicate signal changes also in the off-air of the building, so that control via central sensors in the ventilation and off-air systems appears feasible. The third chapter discusses control strategies for air quality control. Apart from a discussion of control unit types, operating regimes, methods to determine rated values, and additional control functions, the effects of threshold value control with different threshold limit values and volume flow changes on the air quality of a model building was simulated. The results prove the expectation that the air quality inside a building will be influenced positively by air quality control. Theoretical investigations of the DrD method will be presented in another part-report of the project.

  19. Cross-sectional changes in lung volume measured by electrical impedance tomography are representative for the whole lung in ventilated preterm infants

    NARCIS (Netherlands)

    van der Burg, Pauline S.; Miedema, Martijn; de Jongh, Franciscus H.C.; Frerichs, Inez; van Kaam, Anton H.

    2014-01-01

    Objective: Electrical impedance tomography measures lung volume in a cross-sectional slice of the lung. Whether these cross-sectional volume changes are representative of the whole lung has only been investigated in adults, showing conflicting results. This study aimed to compare cross-sectional and

  20. Cross-sectional changes in lung volume measured by electrical impedance tomography are representative for the whole lung in ventilated preterm infants

    NARCIS (Netherlands)

    van der Burg, Pauline S.; Miedema, Martijn; de Jongh, Frans H.; Frerichs, Inez; van Kaam, Anton H.

    2014-01-01

    Electrical impedance tomography measures lung volume in a cross-sectional slice of the lung. Whether these cross-sectional volume changes are representative of the whole lung has only been investigated in adults, showing conflicting results. This study aimed to compare cross-sectional and whole lung

  1. [Neurally adjusted ventilatory assist (NAVA). A new mode of assisted mechanical ventilation].

    Science.gov (United States)

    Moerer, O; Barwing, J; Quintel, M

    2008-10-01

    The aim of mechanical ventilation is to assure gas exchange while efficiently unloading the respiratory muscles and mechanical ventilation is an integral part of the care of patients with acute respiratory failure. Modern lung protective strategies of mechanical ventilation include low-tidal-volume ventilation and the continuation of spontaneous breathing which has been shown to be beneficial in reducing atelectasis and improving oxygenation. Poor patient-ventilator interaction is a major issue during conventional assisted ventilation. Neurally adjusted ventilator assist (NAVA) is a new mode of mechanical ventilation that uses the electrical activity of the diaphragm (EAdi) to control the ventilator. First experimental studies showed an improved patient-ventilator synchrony and an efficient unloading of the respiratory muscles. Future clinical studies will have to show that NAVA is of clinical advantage when compared to conventional modes of assisted mechanical ventilation. This review characterizes NAVA according to current publications on this topic.

  2. Estimation of Lung Ventilation

    Science.gov (United States)

    Ding, Kai; Cao, Kunlin; Du, Kaifang; Amelon, Ryan; Christensen, Gary E.; Raghavan, Madhavan; Reinhardt, Joseph M.

    Since the primary function of the lung is gas exchange, ventilation can be interpreted as an index of lung function in addition to perfusion. Injury and disease processes can alter lung function on a global and/or a local level. MDCT can be used to acquire multiple static breath-hold CT images of the lung taken at different lung volumes, or with proper respiratory control, 4DCT images of the lung reconstructed at different respiratory phases. Image registration can be applied to this data to estimate a deformation field that transforms the lung from one volume configuration to the other. This deformation field can be analyzed to estimate local lung tissue expansion, calculate voxel-by-voxel intensity change, and make biomechanical measurements. The physiologic significance of the registration-based measures of respiratory function can be established by comparing to more conventional measurements, such as nuclear medicine or contrast wash-in/wash-out studies with CT or MR. An important emerging application of these methods is the detection of pulmonary function change in subjects undergoing radiation therapy (RT) for lung cancer. During RT, treatment is commonly limited to sub-therapeutic doses due to unintended toxicity to normal lung tissue. Measurement of pulmonary function may be useful as a planning tool during RT planning, may be useful for tracking the progression of toxicity to nearby normal tissue during RT, and can be used to evaluate the effectiveness of a treatment post-therapy. This chapter reviews the basic measures to estimate regional ventilation from image registration of CT images, the comparison of them to the existing golden standard and the application in radiation therapy.

  3. Ventilation practices in subarachnoid hemorrhage: a cohort study exploring the use of lung protective ventilation.

    Science.gov (United States)

    Marhong, Jonathan D; Ferguson, Niall D; Singh, Jeffrey M

    2014-10-01

    Acute respiratory distress syndrome (ARDS) is common following aneurysmal subarachnoid hemorrhage (SAH), but the influence of mechanical ventilator settings on its development is unclear. We sought to determine adherence to lung protective thresholds in ventilated patients with SAH and describe the association between ventilator settings and subsequent development of ARDS. We conducted a retrospective cohort study of consecutive patients receiving mechanical ventilation within 72 h of SAH at a single academic center. Ventilator settings and blood gas data were collected twice daily for the first 7 days of ventilation along with ICU and hospital outcomes. Lung protective ventilation was defined as follows: tidal volume ≤8 mL/kg of predicted body weight, positive end-expiratory pressure (PEEP) ≥5 cm H(2)O, and peak or plateau pressure ≤30 cm H(2)O. The development of ARDS was ascertained retrospectively by PaO(2)/FiO(2) ≤300 with new bilateral lung opacities on chest X-ray within one day of hypoxemia. We identified 62 patients who underwent early mechanical ventilation following SAH. PS and Continuous Positive Airway Pressure were common ventilator modes with a median tidal volume of 7.8 mL/kg [interquartile range 6.8-8.8], median peak pressure of 14 cm H(2)O [IQR 12-17], and median PEEP of 5 cm H(2)O [IQR 5-6]. Adherence to tidal volumes ≤8 mL/kg was seen in 64 % of all observations and peak pressures protective criteria were seen in 58 % of all observations. Thirty-one patients (50 %) were determined to have ARDS. ARDS patients were more frequently ventilated with a peak pressure >30 cm H(2)O (11.3 % of ARDS ventilation days vs. 0 % of non-ARDS ventilation days; p mechanical ventilation frequently breathe spontaneously, generating tidal volumes above usual protective thresholds regardless of meeting ARDS criteria. In patients with SAH, the presence of an additional ARDS risk factor should prompt close screening for the development of ARDS and

  4. A comparison of leak compensation in acute care ventilators during noninvasive and invasive ventilation: a lung model study.

    Science.gov (United States)

    Oto, Jun; Chenelle, Christopher T; Marchese, Andrew D; Kacmarek, Robert M

    2013-12-01

    Although leak compensation has been widely introduced to acute care ventilators to improve patient-ventilator synchronization in the presence of system leaks, there are no data on these ventilators' ability to prevent triggering and cycling asynchrony. The goal of this study was to evaluate the ability of leak compensation in acute care ventilators during invasive and noninvasive ventilation (NIV). Using a lung simulator, the impact of system leaks was compared on 7 ICU ventilators and 1 dedicated NIV ventilator during triggering and cycling at 2 respiratory mechanics (COPD and ARDS models) settings, various modes of ventilation (NIV mode [pressure support ventilation], and invasive mode [pressure support and continuous mandatory ventilation]), and 2 PEEP levels (5 and 10 cm H(2)O). Leak levels used were up to 35-36 L/min in NIV mode and 26-27 L/min in invasive mode. Although all of the ventilators were able to synchronize with the simulator at baseline, only 4 of the 8 ventilators synchronized to all leaks in NIV mode, and 2 of the 8 ventilators in invasive mode. The number of breaths to synchronization was higher during increasing than during decreasing leak. In the COPD model, miss-triggering occurred more frequently and required a longer time to stabilize tidal volume than in the ARDS model. The PB840 required fewer breaths to synchronize in both invasive and noninvasive modes, compared with the other ventilators (P ventilators. The PB840 and the V60 were the only ventilators to acclimate to all leaks, but there were differences in performance between these 2 ventilators. It is not clear if these differences have clinical importance.

  5. Patient-Ventilator Dyssynchrony

    Directory of Open Access Journals (Sweden)

    Elvira-Markela Antonogiannaki

    2017-11-01

    Full Text Available In mechanically ventilated patients, assisted mechanical ventilation (MV is employed early, following the acute phase of critical illness, in order to eliminate the detrimental effects of controlled MV, most notably the development of ventilator-induced diaphragmatic dysfunction. Nevertheless, the benefits of assisted MV are often counteracted by the development of patient-ventilator dyssynchrony. Patient-ventilator dyssynchrony occurs when either the initiation and/or termination of mechanical breath is not in time agreement with the initiation and termination of neural inspiration, respectively, or if the magnitude of mechanical assist does not respond to the patient’s respiratory demand. As patient-ventilator dyssynchrony has been associated with several adverse effects and can adversely influence patient outcome, every effort should be made to recognize and correct this occurrence at bedside. To detect patient-ventilator dyssynchronies, the physician should assess patient comfort and carefully inspect the pressure- and flow-time waveforms, available on the ventilator screen of all modern ventilators. Modern ventilators offer several modifiable settings to improve patient-ventilator interaction. New proportional modes of ventilation are also very helpful in improving patient-ventilator interaction.

  6. Automatic control of arterial carbon dioxide tension in mechanically ventilated patients.

    Science.gov (United States)

    Fernando, Tyrone; Cade, John; Packer, John

    2002-12-01

    This paper presents a method of controlling the arterial carbon dioxide tension of patients receiving mechanical ventilation. Controlling of the CO2 tension is achieved by regulating the ventilator initiated breath frequency and also volume per breath.

  7. Practice of mechanical ventilation in cardiac arrest patients and effects of targeted temperature management: A substudy of the targeted temperature management trial.

    Science.gov (United States)

    Harmon, Matthew B A; van Meenen, David M P; van der Veen, Annelou L I P; Binnekade, Jan M; Dankiewicz, Josef; Ebner, Florian; Nielsen, Niklas; Pelosi, Paolo; Schultz, Marcus J; Horn, Janneke; Friberg, Hans; Juffermans, Nicole P

    2018-05-12

    Mechanical ventilation practices in patients with cardiac arrest are not well described. Also, the effect of temperature on mechanical ventilation settings is not known. The aims of this study were 1) to describe practice of mechanical ventilation and its relation with outcome 2) to determine effects of different target temperatures strategies (33 °C versus 36 °C) on mechanical ventilation settings. This is a substudy of the TTM-trial in which unconscious survivors of a cardiac arrest due to a cardiac cause were randomized to two TTM strategies, 33 °C (TTM33) and 36 °C (TTM36). Mechanical ventilation data were obtained at three time points: 1) before TTM; 2) at the end of TTM (before rewarming) and 3) after rewarming. Logistic regression was used to determine an association between mechanical ventilation variables and outcome. Repeated-measures mixed modelling was performed to determine the effect of TTM on ventilation settings. Mechanical ventilation data was available for 567 of the 950 TTM patients. Of these, 81% was male with a mean (SD) age of 64 (12) years. At the end of TTM median tidal volume was 7.7 ml/kg predicted body weight (PBW)(6.4-8.7) and 60% of patients were ventilated with a tidal volume ≤ 8 ml/kg PBW. Median PEEP was 7.7cmH 2 O (6.4-8.7) and mean driving pressure was 14.6 cmH 2 O (±4.3). The median FiO 2 fraction was 0.35 (0.30-0.45). Multivariate analysis showed an independent relationship between increased respiratory rate and 28-day mortality. TTM33 resulted in lower end-tidal CO 2 (Pgroup = 0.0003) and higher alveolar dead space fraction (Pgroup = 0.003) compared to TTM36, while PCO 2 levels and respiratory minute volume were similar between groups. In the majority of the cardiac arrest patients, protective ventilation settings are applied, including low tidal volumes and driving pressures. High respiratory rate was associated with mortality. TTM33 results in lower end-tidal CO 2 levels and a higher alveolar dead

  8. Mechanical ventilator - infants

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/007240.htm Mechanical ventilator - infants To use the sharing features on this page, please enable JavaScript. A mechanical ventilator is a machine that assists with breathing. ...

  9. Learning about ventilators

    Science.gov (United States)

    ... medlineplus.gov/ency/patientinstructions/000458.htm Learning about ventilators To use the sharing features on this page, ... fixed or changed. How Does Being on a Ventilator Feel? A person receives medicine to remain comfortable ...

  10. The DECam Minute Cadence Survey

    Science.gov (United States)

    Belardi, C.; Kilic, M.; Munn, J. A.; Gianninas, A.; Barber, S. D.; Dey, A.; Stetson, P. B.

    2017-03-01

    We present the first results from a minute cadence survey of a 3 deg2 field obtained with the Dark Energy Camera. We imaged part of the Canada- France-Hawaii Telescope Legacy Survey area over eight half-nights. We use the stacked images to identify 111 high proper motion white dwarf candidates with g≤ 24.5 mag and search for eclipse-like events and other sources of variability. We find a new g=20.64 mag pulsating ZZ Ceti star with pulsation periods of 11-13 min. However, we do not find any transiting planetary companions in the habitable zone of our target white dwarfs. Given the probability of eclipses of 1% and our observing window from the ground, the non-detection of such companions in this first field is not surprising. Minute cadence DECam observations of additional fields will provide stringent constraints on the frequency of planets in the white dwarf habitable zone.

  11. Comparison between conventional and protective one-lung ventilation for ventilator-assisted thoracic surgery.

    Science.gov (United States)

    Ahn, H J; Kim, J A; Yang, M; Shim, W S; Park, K J; Lee, J J

    2012-09-01

    Recent papers suggest protective ventilation (PV) as a primary ventilation strategy during one-lung ventilation (OLV) to reduce postoperative pulmonary morbidity. However, data regarding the advantage of the PV strategy in patients with normal preoperative pulmonary function are inconsistent, especially in the case of minimally invasive thoracic surgery. Therefore we compared conventional OLV (VT 10 ml/kg, FiO2 1.0, zero PEEP) to protective OLV (VT 6 ml/kg, FiO2 0.5, PEEP 5 cmH2O) in patients with normal preoperative pulmonary function tests undergoing video-assisted thoracic surgery. Oxygenation, respiratory mechanics, plasma interleukin-6 and malondialdehyde levels were measured at baseline, 15 and 60 minutes after OLV and 15 minutes after restoration of two-lung ventilation. PaO2 and PaO2/FiO2 were higher in conventional OLV than in protective OLV (PProtective ventilation did not provide advantages over conventional ventilation for video-assisted thoracic surgery in this group of patients with normal lung function.

  12. Dangerous Pressurization and Inappropriate Alarms during Water Occlusion of the Expiratory Circuit of Commonly Used Infant Ventilators.

    Directory of Open Access Journals (Sweden)

    Murray Hinder

    Full Text Available Non-invasive continuous positive airways pressure is commonly a primary respiratory therapy delivered via multi-purpose ventilators in premature newborns. Expiratory limb occlusion due to water accumulation or 'rainout' from gas humidification is a frequent issue. A case of expiratory limb occlusion due to rainout causing unexpected and excessive repetitive airway pressurisation in a Draeger VN500 prompted a systematic bench test examination of currently available ventilators.To assess neonatal ventilator response to partial or complete expiratory limb occlusion when set to non-invasive continuous positive airway pressure mode.Seven commercially available neonatal ventilators connected to a test lung using a standard infant humidifier circuit with partial and/or complete expiratory limb occlusion were examined in a bench test study. Each ventilator was set to deliver 6 cmH2O in non-invasive mode and respiratory mechanics data for 75%, 80% and 100% occlusion were collected.Several ventilators responded inappropriately with complete occlusion by cyclical pressurisation/depressurisation to peak pressures of between 19·4 and 64·6 cm H2O at rates varying between 2 to 77 inflations per minute. Tidal volumes varied between 10·1 and 24·3mL. Alarm responses varied from 'specific' (tube occluded to 'ambiguous' (Safety valve open. Carefusion Avea responded by continuing to provide the set distending pressure and displaying an appropriate alarm message. Draeger Babylog 8000 did not alarm with partial occlusions and incorrectly displayed airways pressure at 6·1cmH2O compared to the measured values of 13cmH2O.This study found a potential for significant adverse ventilator response due to complete or near complete expiratory limb occlusion in CPAP mode.

  13. 5 experiments in 5 minutes

    Science.gov (United States)

    Hut, Rolf

    2015-04-01

    Show, don't tell. When kids ask about your research, show, don't tell. We, the ambassadors of science, shouldn't be boring our nieces and nephews at family dinners with parameter distributions, we should make them excited about science. Getting people excited: show, don't tell. In 5 minutes, I will perform 5 experiments that anyone can do using everyday household items to get kids interested in science. Bring safety glasses.

  14. VENTILATION TECHNOLOGY SYSTEMS ANALYSIS

    Science.gov (United States)

    The report gives results of a project to develop a systems analysis of ventilation technology and provide a state-of-the-art assessment of ventilation and indoor air quality (IAQ) research needs. (NOTE: Ventilation technology is defined as the hardware necessary to bring outdoor ...

  15. Ventilation of nuclear facilities

    International Nuclear Information System (INIS)

    1982-01-01

    In this work an examination is made of ventilation problems in nuclear installations, of the fuel cycle or the handling of radioactive compounds. The study covers the detection of radioactive aerosols, purification, iodine trapping, ventilation equipment and its maintenance, engineering, safety of ventilation, fire efficiency, operation, regulations and normalization [fr

  16. High-Frequency Jet Ventilation for Complete Target Immobilization and Reduction of Planning Target Volume in Stereotactic High Single-Dose Irradiation of Stage I Non-Small Cell Lung Cancer and Lung Metastases

    International Nuclear Information System (INIS)

    Fritz, Peter; Kraus, Hans-Joerg; Muehlnickel, Werner; Sassmann, Volker; Hering, Werner; Strauch, Konstantin

    2010-01-01

    Purpose: To demonstrate the feasibility of complete target immobilization by means of high-frequency jet ventilation (HFJV); and to show that the saving of planning target volume (PTV) on the stereotactic body radiation therapy (SBRT) under HFJV, compared with SBRT with respiratory motion, can be predicted with reliable accuracy by computed tomography (CT) scans at peak inspiration phase. Methods and Materials: A comparison regarding different methods for defining the PTV was carried out in 22 patients with tumors that clearly moved with respiration. A movement span of the gross tumor volume (GTV) was defined by fusing respiration-correlated CT scans. The PTV enclosed the GTV positions with a safety margin throughout the breathing cycle. To create a PTV from CT scans acquired under HFJV, the same margins were drawn around the immobilized target. In addition, peak inspiration phase CT images (PIP-CTs) were used to approximate a target immobilized by HFJV. Results: The resulting HFJV-PTVs were between 11.6% and 45.4% smaller than the baseline values calculated as respiration-correlated CT-PTVs (median volume reduction, 25.4%). Tentative planning by means of PIP-CT PTVs predicted that in 19 of 22 patients, use of HFJV would lead to a reduction in volume of ≥20%. Using this threshold yielded a positive predictive value of 0.89, as well as a sensitivity of 0.94 and a specificity of 0.5. Conclusions: In all patients, SBRT under HFJV provided a reliable immobilization of the GTVs and achieved a reduction in PTVs, regardless of patient compliance. Tentative planning facilitated the selection of patients who could better undergo radiation in respiratory standstill, both with greater accuracy and lung protection.

  17. Early application of airway pressure release ventilation may reduce the duration of mechanical ventilation in acute respiratory distress syndrome.

    Science.gov (United States)

    Zhou, Yongfang; Jin, Xiaodong; Lv, Yinxia; Wang, Peng; Yang, Yunqing; Liang, Guopeng; Wang, Bo; Kang, Yan

    2017-11-01

    Experimental animal models of acute respiratory distress syndrome (ARDS) have shown that the updated airway pressure release ventilation (APRV) methodologies may significantly improve oxygenation, maximize lung recruitment, and attenuate lung injury, without circulatory depression. This led us to hypothesize that early application of APRV in patients with ARDS would allow pulmonary function to recover faster and would reduce the duration of mechanical ventilation as compared with low tidal volume lung protective ventilation (LTV). A total of 138 patients with ARDS who received mechanical ventilation for mechanical ventilation from enrollment to day 28. The secondary endpoints included oxygenation, P plat , respiratory system compliance, and patient outcomes. Compared with the LTV group, patients in the APRV group had a higher median number of ventilator-free days {19 [interquartile range (IQR) 8-22] vs. 2 (IQR 0-15); P mechanical ventilation and ICU stay.

  18. International Energy Agency Building Energy Simulation Test and Diagnostic Method for Heating, Ventilating, and Air-Conditioning Equipment Models (HVAC BESTEST): Volume 2: Cases E300-E545.

    Energy Technology Data Exchange (ETDEWEB)

    Neymark J.; Judkoff, R.

    2004-12-01

    This report documents an additional set of mechanical system test cases that are planned for inclusion in ANSI/ASHRAE STANDARD 140. The cases test a program's modeling capabilities on the working-fluid side of the coil, but in an hourly dynamic context over an expanded range of performance conditions. These cases help to scale the significance of disagreements that are less obvious in the steady-state cases. The report is Vol. 2 of HVAC BESTEST Volume 1. Volume 1 was limited to steady-state test cases that could be solved with analytical solutions. Volume 2 includes hourly dynamic effects, and other cases that cannot be solved analytically. NREL conducted this work in collaboration with the Tool Evaluation and Improvement Experts Group under the International Energy Agency (IEA) Solar Heating and Cooling Programme Task 22.

  19. Conservative fluid management prevents age-associated ventilator induced mortality.

    Science.gov (United States)

    Herbert, Joseph A; Valentine, Michael S; Saravanan, Nivi; Schneck, Matthew B; Pidaparti, Ramana; Fowler, Alpha A; Reynolds, Angela M; Heise, Rebecca L

    2016-08-01

    Approximately 800 thousand patients require mechanical ventilation in the United States annually with an in-hospital mortality rate of over 30%. The majority of patients requiring mechanical ventilation are over the age of 65 and advanced age is known to increase the severity of ventilator-induced lung injury (VILI) and in-hospital mortality rates. However, the mechanisms which predispose aging ventilator patients to increased mortality rates are not fully understood. Ventilation with conservative fluid management decreases mortality rates in acute respiratory distress patients, but to date there has been no investigation of the effect of conservative fluid management on VILI and ventilator associated mortality rates. We hypothesized that age-associated increases in susceptibility and incidence of pulmonary edema strongly promote age-related increases in ventilator associated mortality. 2month old and 20month old male C57BL6 mice were mechanically ventilated with either high tidal volume (HVT) or low tidal volume (LVT) for up to 4h with either liberal or conservative fluid support. During ventilation, lung compliance, total lung capacity, and hysteresis curves were quantified. Following ventilation, bronchoalveolar lavage fluid was analyzed for total protein content and inflammatory cell infiltration. Wet to dry ratios were used to directly measure edema in excised lungs. Lung histology was performed to quantify alveolar barrier damage/destruction. Age matched non-ventilated mice were used as controls. At 4h, both advanced age and HVT ventilation significantly increased markers of inflammation and injury, degraded pulmonary mechanics, and decreased survival rates. Conservative fluid support significantly diminished pulmonary edema and improved pulmonary mechanics by 1h in advanced age HVT subjects. In 4h ventilations, conservative fluid support significantly diminished pulmonary edema, improved lung mechanics, and resulted in significantly lower mortality rates in

  20. Mechanical ventilation using non-injurious ventilation settings causes lung injury in the absence of pre-existing lung injury in healthy mice

    NARCIS (Netherlands)

    Wolthuis, Esther K; Vlaar, Alexander P J; Choi, Goda; Roelofs, Joris J T H; Juffermans, Nicole P; Schultz, Marcus J

    2009-01-01

    INTRODUCTION: Mechanical ventilation (MV) may cause ventilator-induced lung injury (VILI). Present models of VILI use exceptionally large tidal volumes, causing gross lung injury and haemodynamic shock. In addition, animals are ventilated for a relative short period of time and only after a

  1. Mechanical ventilation using non-injurious ventilation settings causes lung injury in the absence of pre-existing lung injury in healthy mice

    NARCIS (Netherlands)

    Wolthuis, Esther K.; Vlaar, Alexander Pj; Choi, Goda; Roelofs, Joris J. T. H.; Juffermans, Nicole P.; Schultz, Marcus J.

    2009-01-01

    Introduction Mechanical ventilation (MV) may cause ventilator-induced lung injury (VILI). Present models of VILI use exceptionally large tidal volumes, causing gross lung injury and haemodynamic shock. In addition, animals are ventilated for a relative short period of time and only after a 'priming'

  2. Ventilator-induced mediator release: role of PEEP and surfactant

    OpenAIRE

    Haitsma, Jack

    2002-01-01

    textabstractLung protective ventilation such as the ARDSnet low tidal volumes strategy can reduce mortality in ARDS patients. The lmowledge that an essential therapy such as mechanical ventilation on the intensive care influences patient outcome has given rise to the re-evaluation of current ventilation practices. This review addresses the current state of lung protective strategies and their physiological rationale. Latest knowledge on the instigation and progression of lung injury by mechan...

  3. Heliox Improves Carbon Dioxide Removal during Lung Protective Mechanical Ventilation

    OpenAIRE

    Beurskens, Charlotte J; Brevoord, Daniel; Lagrand, Wim K; van den Bergh, Walter M; Vroom, Margreeth B; Preckel, Benedikt; Horn, Janneke; Juffermans, Nicole P

    2014-01-01

    Introduction. Helium is a noble gas with low density and increased carbon dioxide (CO2) diffusion capacity. This allows lower driving pressures in mechanical ventilation and increased CO2 diffusion. We hypothesized that heliox facilitates ventilation in patients during lung-protective mechanical ventilation using low tidal volumes. Methods. This is an observational cohort substudy of a single arm intervention study. Twenty-four ICU patients were included, who were admitted after a cardiac arr...

  4. Personalizing mechanical ventilation for acute respiratory distress syndrome.

    Science.gov (United States)

    Berngard, S Clark; Beitler, Jeremy R; Malhotra, Atul

    2016-03-01

    Lung-protective ventilation with low tidal volumes remains the cornerstone for treating patient with acute respiratory distress syndrome (ARDS). Personalizing such an approach to each patient's unique physiology may improve outcomes further. Many factors should be considered when mechanically ventilating a critically ill patient with ARDS. Estimations of transpulmonary pressures as well as individual's hemodynamics and respiratory mechanics should influence PEEP decisions as well as response to therapy (recruitability). This summary will emphasize the potential role of personalized therapy in mechanical ventilation.

  5. 60 minutes/our reply

    International Nuclear Information System (INIS)

    Deakins, H.L.

    1981-01-01

    The prestigious CBS show 60 Minutes visited Illinois Power Company, an investor owned utility company building its first nuclear power plant, to do a story on the economics of nuclear construction. The company opened its doors to the show's producer and was astonished at the program that resulted. Illinois Power had filmed everything CBS filmed and subsequently prepared its own rebutal video tape showing unedited portions of interviews and factual information furnished CBS which they never used in the broadcast. The rebuttal tape has been distributed world wide and received coverage in leading newspapers and magazines. It has also been installed as a class study in major journalism and business schools

  6. A prospective crossover comparison of neurally adjusted ventilatory assist and pressure-support ventilation in a pediatric and neonatal intensive care unit population.

    LENUS (Irish Health Repository)

    Breatnach, Cormac

    2012-02-01

    OBJECTIVE: To compare neurally adjusted ventilatory assist ventilation with pressure-support ventilation. DESIGN: Prospective, crossover comparison study. SETTING: Tertiary care pediatric and neonatal intensive care unit. PATIENTS: Sixteen ventilated infants and children: mean age = 9.7 months (range = 2 days-4 yrs) and mean weight = 6.2 kg (range = 2.4-13.7kg). INTERVENTIONS: A modified nasogastric tube was inserted and correct positioning was confirmed. Patients were ventilated in pressure-support mode with a pneumatic trigger for a 30-min period and then in neurally adjusted ventilatory assist mode for up to 4 hrs. MEASUREMENTS AND MAIN RESULTS: Data collected for comparison included activating trigger (neural vs. pneumatic), peak and mean airway pressures, expired minute and tidal volumes, heart rate, respiratory rate, pulse oximetry, end-tidal CO2 and arterial blood gases. Synchrony was improved in neurally adjusted ventilatory assist mode with 65% (+\\/-21%) of breaths triggered neurally vs. 35% pneumatically (p < .001) and 85% (+\\/-8%) of breaths cycled-off neurally vs. 15% pneumatically (p = .0001). The peak airway pressure in neurally adjusted ventilatory assist mode was significantly lower than in pressure-support mode with a 28% decrease in pressure after 30 mins (p = .003) and 32% decrease after 3 hrs (p < .001). Mean airway pressure was reduced by 11% at 30 mins (p = .13) and 9% at 3 hrs (p = .31) in neurally adjusted ventilatory assist mode although this did not reach statistical significance. Patient hemodynamics and gas exchange remained stable for the study period. No adverse patient events or device effects were noted. CONCLUSIONS: In a neonatal and pediatric intensive care unit population, ventilation in neurally adjusted ventilatory assist mode was associated with improved patient-ventilator synchrony and lower peak airway pressure when compared with pressure-support ventilation with a pneumatic trigger. Ventilating patients in this new mode

  7. Mechanical ventilation during extracorporeal membrane oxygenation. An international survey.

    Science.gov (United States)

    Marhong, Jonathan D; Telesnicki, Teagan; Munshi, Laveena; Del Sorbo, Lorenzo; Detsky, Michael; Fan, Eddy

    2014-07-01

    In patients with severe, acute respiratory failure undergoing venovenous extracorporeal membrane oxygenation (VV-ECMO), the optimal strategy for mechanical ventilation is unclear. Our objective was to describe ventilation practices used in centers registered with the Extracorporeal Life Support Organization (ELSO). We conducted an international cross-sectional survey of medical directors and ECMO program coordinators from all ELSO-registered centers. The survey was distributed using a commercial website that collected information on center characteristics, the presence of a mechanical ventilator protocol, ventilator settings, and weaning practices. E-mails were sent out to medical directors or coordinators at each ELSO center and their responses were pooled for analysis. We analyzed 141 (50%) individual responses from the 283 centers contacted across 28 countries. Only 27% of centers reported having an explicit mechanical ventilation protocol for ECMO patients. The majority of these centers (77%) reported "lung rest" to be the primary goal of mechanical ventilation, whereas 9% reported "lung recruitment" to be their ventilation strategy. A tidal volume of 6 ml/kg or less was targeted by 76% of respondents, and 58% targeted a positive end-expiratory pressure of 6-10 cm H2O while ventilating patients on VV-ECMO. Centers prioritized weaning VV-ECMO before mechanical ventilation. Although ventilation practices in patients supported by VV-ECMO vary across ELSO centers internationally, the majority of centers used a strategy that targeted lung-protective thresholds and prioritized weaning VV-ECMO over mechanical ventilation.

  8. Comparison of airway pressure release ventilation to conventional mechanical ventilation in the early management of smoke inhalation injury in swine.

    Science.gov (United States)

    Batchinsky, Andriy I; Burkett, Samuel E; Zanders, Thomas B; Chung, Kevin K; Regn, Dara D; Jordan, Bryan S; Necsoiu, Corina; Nguyen, Ruth; Hanson, Margaret A; Morris, Michael J; Cancio, Leopoldo C

    2011-10-01

    The role of airway pressure release ventilation in the management of early smoke inhalation injury has not been studied. We compared the effects of airway pressure release ventilation and conventional mechanical ventilation on oxygenation in a porcine model of acute respiratory distress syndrome induced by wood smoke inhalation. Prospective animal study. Government laboratory animal intensive care unit. Thirty-three Yorkshire pigs. Smoke inhalation injury. Anesthetized female Yorkshire pigs (n = 33) inhaled room-temperature pine-bark smoke. Before injury, the pigs were randomized to receive conventional mechanical ventilation (n = 15) or airway pressure release ventilation (n = 12) for 48 hrs after smoke inhalation. As acute respiratory distress syndrome developed (PaO2/Fio2 ratio conventional mechanical ventilation for 48 hrs and served as time controls. Changes in PaO2/Fio2 ratio, tidal volume, respiratory rate, mean airway pressure, plateau pressure, and hemodynamic variables were recorded. Survival was assessed using Kaplan-Meier analysis. PaO2/Fio2 ratio was lower in airway pressure release ventilation vs. conventional mechanical ventilation pigs at 12, 18, and 24 hrs (p conventional mechanical ventilation animals between 30 and 48 hrs post injury (p animals between 6 and 48 hrs (p conventional mechanical ventilation and airway pressure release ventilation pigs. In this model of acute respiratory distress syndrome caused by severe smoke inhalation in swine, airway pressure release ventilation-treated animals developed acute respiratory distress syndrome faster than conventional mechanical ventilation-treated animals, showing a lower PaO2/Fio2 ratio at 12, 18, and 24 hrs after injury. At other time points, PaO2/Fio2 ratio was not different between conventional mechanical ventilation and airway pressure release ventilation.

  9. The effect of helium on ventilator performance: study of five ventilators and a bedside Pitot tube spirometer.

    Science.gov (United States)

    Oppenheim-Eden, A; Cohen, Y; Weissman, C; Pizov, R

    2001-08-01

    To assess in vitro the performance of five mechanical ventilators-Siemens 300 and 900C (Siemens-Elma; Solna, Sweden), Puritan Bennett 7200 (Nellcor Puritan Bennett; Pleasanton, CA), Evita 4 (Dragerwerk; Lubeck, Germany), and Bear 1000 (Bear Medical Systems; Riverside CA)-and a bedside sidestream spirometer (Datex CS3 Respiratory Module; Datex-Ohmeda; Helsinki, Finland) during ventilation with helium-oxygen mixtures. In vitro study. ICUs of two university-affiliated hospitals. Each ventilator was connected to 100% helium through compressed air inlets and then tested at three to six different tidal volume (VT) settings using various helium-oxygen concentrations (fraction of inspired oxygen [FIO(2)] of 0.2 to 1.0). FIO(2) and VT were measured with the Datex CS3 spirometer, and VT was validated with a water-displacement spirometer. The Puritan Bennett 7200 ventilator did not function with helium. With the other four ventilators, delivered FIO(2) was lower than the set FIO(2). For the Siemens 300 and 900C ventilators, this difference could be explained by the lack of 21% oxygen when helium was connected to the air supply port, while for the other two ventilators, a nonlinear relation was found. The VT of the Siemens 300 ventilator was independent of helium concentration, while for the other three ventilators, delivered VT was greater than the set VT and was dependent on helium concentration. During ventilation with 80% helium and 20% oxygen, VT increased to 125% of set VT for the Siemens 900C ventilator, and more than doubled for the Evita 4 and Bear 1000 ventilators. Under the same conditions, the Datex CS3 spirometer underestimated the delivered VT by about 33%. At present, no mechanical ventilator is calibrated for use with helium. This investigation offers correction factors for four ventilators for ventilation with helium.

  10. Current concepts of protective ventilation during general anaesthesia

    NARCIS (Netherlands)

    Serpa Neto, Ary; Schultz, Marcus J.; Slutsky, Arthur S.

    2015-01-01

    Mechanical ventilation with high tidal volumes (VT) has been common practice in operating theatres because this strategy recruits collapsed lung tissue and improves ventilation-perfusion mismatch, thus decreasing the need for high inspired oxygen concentrations. Positive end-expiratory pressure

  11. Complications of mechanical ventilation

    Directory of Open Access Journals (Sweden)

    Drašković Biljana

    2011-01-01

    Full Text Available Mechanical ventilation of the lungs, as an important therapeutic measure, cannot be avoided in critically ill patients. However, when machines take over some of vital functions there is always a risk of complications and accidents. Complications associated with mechanical ventilation can be divided into: 1 airway-associated complications; 2 complications in the response of patients to mechanical ventilation; and 3 complications related to the patient’s response to the device for mechanical ventilation. Complications of artificial airway may be related to intubation and extubation or the endotracheal tube. Complications of mechanical ventilation, which arise because of the patient’s response to mechanical ventilation, may primarily cause significant side effects to the lungs. During the last two decades it was concluded that mechanical ventilation can worsen or cause acute lung injury. Mechanical ventilation may increase the alveolar/capillary permeability by overdistension of the lungs (volutrauma, it can exacerbate lung damage due to the recruitment/derecruitment of collapsed alveoli (atelectrauma and may cause subtle damages due to the activation of inflammatory processes (biotrauma. Complications caused by mechanical ventilation, beside those involving the lungs, can also have significant effects on other organs and organic systems, and can be a significant factor contributing to the increase of morbidity and mortality in critically ill of mechanically ventilated patients. Complications are fortunately rare and do not occur in every patient, but due to their seriousness and severity they require extensive knowledge, experience and responsibility by health-care workers.

  12. Mechanical Working Group meeting minutes

    Energy Technology Data Exchange (ETDEWEB)

    1992-12-01

    This documents contains the minutes and viewgraphs from the October 27--28, 1992 meeting on the subject of power generation and delivery systems for military applications. Attendees represented the US Air Force and NASA. The thermal management panel reported on the capillary pump loop test facility, thermal control systems and compressors, and the oxygen heat pipe flight experiment. The aerospace power panel reported on the integrated power unit for the more electric airplane, the solar dynamic power system, the modular high temperature gas cooled reactor-gas-turbine program, the multi-megawatt CBC power system, and analytical modeling for heat pipe performance. The terrestrial power panel reported on a free piston stirling engine power generation system, fuel cell vehicles, and the advanced gas turbine project.

  13. Evaluation of ventilators for mouthpiece ventilation in neuromuscular disease.

    Science.gov (United States)

    Khirani, Sonia; Ramirez, Adriana; Delord, Vincent; Leroux, Karl; Lofaso, Frédéric; Hautot, Solène; Toussaint, Michel; Orlikowski, David; Louis, Bruno; Fauroux, Brigitte

    2014-09-01

    Daytime mouthpiece ventilation is a useful adjunct to nocturnal noninvasive ventilation (NIV) in patients with neuromuscular disease. The aims of the study were to analyze the practice of mouthpiece ventilation and to evaluate the performance of ventilators for mouthpiece ventilation. Practice of mouthpiece ventilation was assessed by a questionnaire, and the performance of 6 home ventilators with mouthpiece ventilation was assessed in a bench test using 24 different conditions per ventilator: 3 mouthpieces, a child and an adult patient profile, and 4 ventilatory modes. Questionnaires were obtained from 30 subjects (mean age 33 ± 11 y) using NIV for 12 ± 7 y. Fifteen subjects used NIV for > 20 h/day, and 11 were totally ventilator-dependent. The subject-reported benefits of mouthpiece ventilation were a reduction in dyspnea (73%) and fatigue (93%) and an improvement in speech (43%) and eating (27%). The bench study showed that none of the ventilators, even those with mouthpiece ventilation software, were able to deliver mouthpiece ventilation without alarms and/or autotriggering in each condition. Alarms and/or ineffective triggering or autotriggering were observed in 135 of the 198 conditions. The occurrence of alarms was more common with a large mouthpiece without a filter compared to a small mouthpiece with a filter (P ventilator. Subjects are satisfied with mouthpiece ventilation. Alarms are common with home ventilators, although less common in those with mouthpiece ventilation software. Improvements in home ventilators are needed to facilitate the expansion of mouthpiece ventilation. Copyright © 2014 by Daedalus Enterprises.

  14. Imaging of ventilation/perfusion ratio by gated regional spirometry

    International Nuclear Information System (INIS)

    Touya, J.J.; Jones, J.P.; Price, R.R.; Patton, J.A.; Erickson, J.J.; Rollo, F.D.

    1981-01-01

    Gated 133 Xe images of patients rebreathing into a closed system can provide images of the distribution of lung volumes, ventilation and specific ventilation. These have been shown to be accurate, precise, and do not require unusually sophisticated equipment or skills. A mathematical transformation is used to correct the images for lung movement, which does not alter the total number of counts in the image. Perfusion images are gated to remove motion blurring but not transformed. Ventilation/perfusion images showing the distribution of V/Q ratio are then generated from the individual ventilation and perfusion images. (author)

  15. Protective garment ventilation system

    Science.gov (United States)

    Lang, R. (Inventor)

    1970-01-01

    A method and apparatus for ventilating a protective garment, space suit system, and/or pressure suits to maintain a comfortable and nontoxic atmosphere within is described. The direction of flow of a ventilating and purging gas in portions of the garment may be reversed in order to compensate for changes in environment and activity of the wearer. The entire flow of the ventilating gas can also be directed first to the helmet associated with the garment.

  16. Ventilation rates and health

    DEFF Research Database (Denmark)

    Sundell, Jan; Levin, H; Nazaroff, W W

    2011-01-01

    and health effects to inform the relationship. Consistency was found across multiple investigations and different epidemiologic designs for different populations. Multiple health endpoints show similar relationships with ventilation rate. There is biological plausibility for an association of health outcomes...... studies of the relationship between ventilation rates and health, especially in diverse climates, in locations with polluted outdoor air and in buildings other than offices. PRACTICAL IMPLICATIONS: Ventilation with outdoor air plays an important role influencing human exposures to indoor pollutants...

  17. Ventilation of uranium mines

    International Nuclear Information System (INIS)

    Francois, Y.; Pradel, J.; Zettwoog, P.; Dumas, M.

    1975-01-01

    In the first part of the paper the authors describe the ventilation of French mines in terms of the primary ventilation system, which brings the outside air close to the working places using the overall structure of the mine to form the airways, and the secondary ventilation system, which is for the distribution of the primary air or for the ventilation of the development drifts and blind tunnels. Brief mention is made of the French regulations on the ventilation of mines in general and uranium mines in particular. The authors describe the equipment used and discuss the installed capacities and air flow per man and per working place. The difficulties encountered in properly ventilating various types of working places are mentioned, such as sub-level development drifts, reinforced stopes, and storage chambers with an artificial crown. The second part of the paper is devoted to computer calculations of the primary ventilation system. It is explained why the Commissariat a l'energie atomique has found it necessary to make these calculations. Without restating the mathematical theories underlying the methods employed, the authors demonstrate how simple measuring instruments and a small-size computer can be used to solve the ventilation problems arising in French mines. Emphasis is given to the layout of the ventilation system and to air flow and negative pressure measurements at the base of the mine. The authors show how calculations can be applied to new heading operations, a change in resistance, the replacement or addition of a ventilator, and a new air inlet or outlet. The authors come to the conclusion that since ventilation is at present the most reliable way of avoiding the pollution of mines, a thorough knowledge of the capabilities in this respect can often help improve working conditions. Despite the progress made, however, constant surveillance of the ventilation systems in uranium mines by a separate team with no responsibility for production problems is

  18. Ventilation of uranium mines

    International Nuclear Information System (INIS)

    Francois, Y.; Pradel, J.; Zettwoog, P.; Dumas, M.

    1975-01-01

    In the first part of the paper the authors describe the ventilation of French mines in terms of the primary ventilation system, which brings the outside air close to the working places using the overall structure of the mine to form the airways, and the secondary ventilation system, which is for the distribution of the primary air or for the ventilation of the development drifts and blind tunnels. Brief mention is made of the French regulations on the ventilation of mines in general and uranium mines in particular. The authors describe the equipment used and discuss the installed capacities and air flow per man and per working place. The difficulties encountered in properly ventilating various types of working places are mentioned, such as sublevel development drifts, reinforced stopes, and storage chambers with an artificial crown. The second part of the paper is devoted to computer calculations of the primary ventilation system. It is explained why the Commissariat a l'energie atomique has found it necessary to make these calculations. Without restating the mathematical theories underlying the methods employed, the authors demonstrate how simple measuring instruments and a small-size computer can be used to solve the ventilation problems arising in French mines. Emphasis is given to the layout of the ventilation system and to air flow and negative pressure measurements at the base of the mine. The authors show how calculations can be applied to new heading operations, a change in resistance, the replacement or addition of a ventilator, and a new air inlet or outlet. The authors come to the conclusion that since ventilation is at present the most reliable way of avoiding the pollution of mines, a thorough knowledge of the capabilities in this respect can often help improve working conditions. Despite the progress made, however, constant surveillance of the ventilation systems in uranium mines by a separate team with no responsibility for production problems is

  19. Design Principles for Hybrid Ventilation

    DEFF Research Database (Denmark)

    Heiselberg, Per

    For many years mechanical and natural ventilation systems have developed separately. Naturally, the next step in this development is the development of ventilation concepts that utilize and combine the best features from each system to create a new type of ventilation system -Hybrid Ventilation. ....... The hybrid ventilation concepts, design challenges and - principles are discussed and illustrated by four building examples....

  20. Natural Ventilation in Atria

    DEFF Research Database (Denmark)

    Svidt, Kjeld; Heiselberg, Per; Hendriksen, Ole Juhl

    This case study comprises a monitoring programme as well as a Computational Fluid Dynamics (CFD) analysis of a natural ventilated atrium. The purpose has been to analyse the performance of a typical natural ventilation system in Denmark under both summer and winter conditions.......This case study comprises a monitoring programme as well as a Computational Fluid Dynamics (CFD) analysis of a natural ventilated atrium. The purpose has been to analyse the performance of a typical natural ventilation system in Denmark under both summer and winter conditions....

  1. Weaning newborn infants from mechanical ventilation

    Directory of Open Access Journals (Sweden)

    Paolo Biban

    2013-06-01

    Full Text Available Invasive mechanical ventilation is a life-saving procedure which is largely used in neonatal intensive care units, particularly in very premature newborn infants. However, this essential treatment may increase mortality and cause substantial morbidity, including lung or airway injuries, unplanned extubations, adverse hemodynamic effects, analgosedative dependency and severe infectious complications, such as ventilator-associated pneumonia. Therefore, limiting the duration of airway intubation and mechanical ventilator support is crucial for the neonatologist, who should aim to a shorter process of discontinuing mechanical ventilation as well as an earlier appreciation of readiness for spontaneous breathing trials. Unfortunately, there is scarce information about the best ways to perform an effective weaning process in infants undergoing mechanical ventilation, thus in most cases the weaning course is still based upon the individual judgment of the attending clinician. Nonetheless, some evidence indicate that volume targeted ventilation modes are more effective in reducing the duration of mechanical ventilation than traditional pressure limited ventilation modes, particularly in very preterm babies. Weaning and extubation directly from high frequency ventilation could be another option, even though its effectiveness, when compared to switching and subsequent weaning and extubating from conventional ventilation, is yet to be adequately investigated. Some data suggest the use of weaning protocols could reduce the weaning time and duration of mechanical ventilation, but better designed prospective studies are still needed to confirm these preliminary observations. Finally, the implementation of short spontaneous breathing tests in preterm infants has been shown to be beneficial in some centres, favoring an earlier extubation at higher ventilatory settings compared with historical controls, without worsening the extubation failure rate. Further

  2. Comparison between conventional protective mechanical ventilation and high-frequency oscillatory ventilation associated with the prone position.

    Science.gov (United States)

    Fioretto, José Roberto; Klefens, Susiane Oliveira; Pires, Rafaelle Fernandes; Kurokawa, Cilmery Suemi; Carpi, Mario Ferreira; Bonatto, Rossano César; Moraes, Marcos Aurélio; Ronchi, Carlos Fernando

    2017-01-01

    To compare the effects of high-frequency oscillatory ventilation and conventional protective mechanical ventilation associated with the prone position on oxygenation, histology and pulmonary oxidative damage in an experimental model of acute lung injury. Forty-five rabbits with tracheostomy and vascular access were underwent mechanical ventilation. Acute lung injury was induced by tracheal infusion of warm saline. Three experimental groups were formed: healthy animals + conventional protective mechanical ventilation, supine position (Control Group; n = 15); animals with acute lung injury + conventional protective mechanical ventilation, prone position (CMVG; n = 15); and animals with acute lung injury + high-frequency oscillatory ventilation, prone position (HFOG; n = 15). Ten minutes after the beginning of the specific ventilation of each group, arterial gasometry was collected, with this timepoint being called time zero, after which the animal was placed in prone position and remained in this position for 4 hours. Oxidative stress was evaluated by the total antioxidant performance assay. Pulmonary tissue injury was determined by histopathological score. The level of significance was 5%. Both groups with acute lung injury showed worsening of oxygenation after induction of injury compared with the Control Group. After 4 hours, there was a significant improvement in oxygenation in the HFOG group compared with CMVG. Analysis of total antioxidant performance in plasma showed greater protection in HFOG. HFOG had a lower histopathological lesion score in lung tissue than CMVG. High-frequency oscillatory ventilation, associated with prone position, improves oxygenation and attenuates oxidative damage and histopathological lung injury compared with conventional protective mechanical ventilation.

  3. Lung-protective perioperative mechanical ventilation

    NARCIS (Netherlands)

    Hemmes, S.N.T.

    2015-01-01

    Intraoperative ventilation has the potential to cause lung injury and possibly increase risk of pulmonary complications after surgery. Use of large tidal volumes could cause overdistension of lung tissue, which can be aggravated by too high levels of positive end-expiratory pressure (PEEP). Too low

  4. Ventilation-air conditioning system

    International Nuclear Information System (INIS)

    Kubokoya, Takashi.

    1991-01-01

    Heretofore, in ventilation-air conditioning systems in a nuclear power plant, exhaust gases from each of the ventilation-air conditioning systems of a reactor building, a turbine building, a waste processing building are joined and they are released into atmosphere from the top of a high main exhaustion stack. In order to build such a high main exhaustion stack, a considerable construction cost is required and, in addition, there is a worry of lacking balance with surrounding scenery. Then, in the present invention, exhaust gases are heated by waste heat in a turbine during their introduction from the ventilation-air conditioning facility in the building of a power plant to the main exhaust stack. With such a constitution, since the exhaust gases are heated and their temperature is elevated, they uprise by natural convection when they are released from the top of the main exhaustion stack to the atmosphere. Accordingly, they are released to a level higher than the conventional case in view of the volume of the blower which sends the exhaust gases under pressure, to diffuse them to the atmosphere more sufficiently compared with a conventional case. Further, the height of the main exhaustion stack can be reduced, enabling to minimize the cost for moving the blower. (T.M.)

  5. Recommended Ventilation Strategies for Energy-Efficient Production Homes

    Energy Technology Data Exchange (ETDEWEB)

    Roberson, J.; Brown, R.; Koomey, J.; Warner, J.; Greenberg, S.

    1998-12-01

    This report evaluates residential ventilation systems for the U.S. Environmental Protection Agency's (EPA's) ENERGY STAR{reg_sign} Homes program and recommends mechanical ventilation strategies for new, low-infiltration, energy-efficient, single-family, ENERGY STAR production (site-built tract) homes in four climates: cold, mixed (cold and hot), hot humid, and hot arid. Our group in the Energy Analysis Department at Lawrence Berkeley National Lab compared residential ventilation strategies in four climates according to three criteria: total annualized costs (the sum of annualized capital cost and annual operating cost), predominant indoor pressure induced by the ventilation system, and distribution of ventilation air within the home. The mechanical ventilation systems modeled deliver 0.35 air changes per hour continuously, regardless of actual infiltration or occupant window-opening behavior. Based on the assumptions and analysis described in this report, we recommend independently ducted multi-port supply ventilation in all climates except cold because this strategy provides the safety and health benefits of positive indoor pressure as well as the ability to dehumidify and filter ventilation air. In cold climates, we recommend that multi-port supply ventilation be balanced by a single-port exhaust ventilation fan, and that builders offer balanced heat-recovery ventilation to buyers as an optional upgrade. For builders who continue to install forced-air integrated supply ventilation, we recommend ensuring ducts are airtight or in conditioned space, installing a control that automatically operates the forced-air fan 15-20 minutes during each hour that the fan does not operate for heating or cooling, and offering ICM forced-air fans to home buyers as an upgrade.

  6. Effects of positive end-expiratory pressure and recruitment maneuvers in a ventilator-induced injury mouse model.

    Directory of Open Access Journals (Sweden)

    Laura A Cagle

    Full Text Available Positive-pressure mechanical ventilation is an essential therapeutic intervention, yet it causes the clinical syndrome known as ventilator-induced lung injury. Various lung protective mechanical ventilation strategies have attempted to reduce or prevent ventilator-induced lung injury but few modalities have proven effective. A model that isolates the contribution of mechanical ventilation on the development of acute lung injury is needed to better understand biologic mechanisms that lead to ventilator-induced lung injury.To evaluate the effects of positive end-expiratory pressure and recruitment maneuvers in reducing lung injury in a ventilator-induced lung injury murine model in short- and longer-term ventilation.5-12 week-old female BALB/c mice (n = 85 were anesthetized, placed on mechanical ventilation for either 2 hrs or 4 hrs with either low tidal volume (8 ml/kg or high tidal volume (15 ml/kg with or without positive end-expiratory pressure and recruitment maneuvers.Alteration of the alveolar-capillary barrier was noted at 2 hrs of high tidal volume ventilation. Standardized histology scores, influx of bronchoalveolar lavage albumin, proinflammatory cytokines, and absolute neutrophils were significantly higher in the high-tidal volume ventilation group at 4 hours of ventilation. Application of positive end-expiratory pressure resulted in significantly decreased standardized histology scores and bronchoalveolar absolute neutrophil counts at low- and high-tidal volume ventilation, respectively. Recruitment maneuvers were essential to maintain pulmonary compliance at both 2 and 4 hrs of ventilation.Signs of ventilator-induced lung injury are evident soon after high tidal volume ventilation (as early as 2 hours and lung injury worsens with longer-term ventilation (4 hrs. Application of positive end-expiratory pressure and recruitment maneuvers are protective against worsening VILI across all time points. Dynamic compliance can be used guide

  7. Effects of positive end-expiratory pressure and recruitment maneuvers in a ventilator-induced injury mouse model

    Science.gov (United States)

    Franzi, Lisa M.; Linderholm, Angela L.; Last, Jerold A.; Adams, Jason Y.; Harper, Richart W.

    2017-01-01

    Background Positive-pressure mechanical ventilation is an essential therapeutic intervention, yet it causes the clinical syndrome known as ventilator-induced lung injury. Various lung protective mechanical ventilation strategies have attempted to reduce or prevent ventilator-induced lung injury but few modalities have proven effective. A model that isolates the contribution of mechanical ventilation on the development of acute lung injury is needed to better understand biologic mechanisms that lead to ventilator-induced lung injury. Objectives To evaluate the effects of positive end-expiratory pressure and recruitment maneuvers in reducing lung injury in a ventilator-induced lung injury murine model in short- and longer-term ventilation. Methods 5–12 week-old female BALB/c mice (n = 85) were anesthetized, placed on mechanical ventilation for either 2 hrs or 4 hrs with either low tidal volume (8 ml/kg) or high tidal volume (15 ml/kg) with or without positive end-expiratory pressure and recruitment maneuvers. Results Alteration of the alveolar-capillary barrier was noted at 2 hrs of high tidal volume ventilation. Standardized histology scores, influx of bronchoalveolar lavage albumin, proinflammatory cytokines, and absolute neutrophils were significantly higher in the high-tidal volume ventilation group at 4 hours of ventilation. Application of positive end-expiratory pressure resulted in significantly decreased standardized histology scores and bronchoalveolar absolute neutrophil counts at low- and high-tidal volume ventilation, respectively. Recruitment maneuvers were essential to maintain pulmonary compliance at both 2 and 4 hrs of ventilation. Conclusions Signs of ventilator-induced lung injury are evident soon after high tidal volume ventilation (as early as 2 hours) and lung injury worsens with longer-term ventilation (4 hrs). Application of positive end-expiratory pressure and recruitment maneuvers are protective against worsening VILI across all time points

  8. Effects of positive end-expiratory pressure and recruitment maneuvers in a ventilator-induced injury mouse model.

    Science.gov (United States)

    Cagle, Laura A; Franzi, Lisa M; Linderholm, Angela L; Last, Jerold A; Adams, Jason Y; Harper, Richart W; Kenyon, Nicholas J

    2017-01-01

    Positive-pressure mechanical ventilation is an essential therapeutic intervention, yet it causes the clinical syndrome known as ventilator-induced lung injury. Various lung protective mechanical ventilation strategies have attempted to reduce or prevent ventilator-induced lung injury but few modalities have proven effective. A model that isolates the contribution of mechanical ventilation on the development of acute lung injury is needed to better understand biologic mechanisms that lead to ventilator-induced lung injury. To evaluate the effects of positive end-expiratory pressure and recruitment maneuvers in reducing lung injury in a ventilator-induced lung injury murine model in short- and longer-term ventilation. 5-12 week-old female BALB/c mice (n = 85) were anesthetized, placed on mechanical ventilation for either 2 hrs or 4 hrs with either low tidal volume (8 ml/kg) or high tidal volume (15 ml/kg) with or without positive end-expiratory pressure and recruitment maneuvers. Alteration of the alveolar-capillary barrier was noted at 2 hrs of high tidal volume ventilation. Standardized histology scores, influx of bronchoalveolar lavage albumin, proinflammatory cytokines, and absolute neutrophils were significantly higher in the high-tidal volume ventilation group at 4 hours of ventilation. Application of positive end-expiratory pressure resulted in significantly decreased standardized histology scores and bronchoalveolar absolute neutrophil counts at low- and high-tidal volume ventilation, respectively. Recruitment maneuvers were essential to maintain pulmonary compliance at both 2 and 4 hrs of ventilation. Signs of ventilator-induced lung injury are evident soon after high tidal volume ventilation (as early as 2 hours) and lung injury worsens with longer-term ventilation (4 hrs). Application of positive end-expiratory pressure and recruitment maneuvers are protective against worsening VILI across all time points. Dynamic compliance can be used guide the frequency

  9. Perioperative lung protective ventilation in obese patients.

    Science.gov (United States)

    Fernandez-Bustamante, Ana; Hashimoto, Soshi; Serpa Neto, Ary; Moine, Pierre; Vidal Melo, Marcos F; Repine, John E

    2015-05-06

    The perioperative use and relevance of protective ventilation in surgical patients is being increasingly recognized. Obesity poses particular challenges to adequate mechanical ventilation in addition to surgical constraints, primarily by restricted lung mechanics due to excessive adiposity, frequent respiratory comorbidities (i.e. sleep apnea, asthma), and concerns of postoperative respiratory depression and other pulmonary complications. The number of surgical patients with obesity is increasing, and facing these challenges is common in the operating rooms and critical care units worldwide. In this review we summarize the existing literature which supports the following recommendations for the perioperative ventilation in obese patients: (1) the use of protective ventilation with low tidal volumes (approximately 8 mL/kg, calculated based on predicted -not actual- body weight) to avoid volutrauma; (2) a focus on lung recruitment by utilizing PEEP (8-15 cmH2O) in addition to recruitment maneuvers during the intraoperative period, as well as incentivized deep breathing and noninvasive ventilation early in the postoperative period, to avoid atelectasis, hypoxemia and atelectrauma; and (3) a judicious oxygen use (ideally less than 0.8) to avoid hypoxemia but also possible reabsorption atelectasis. Obesity poses an additional challenge for achieving adequate protective ventilation during one-lung ventilation, but different lung isolation techniques have been adequately performed in obese patients by experienced providers. Postoperative efforts should be directed to avoid hypoventilation, atelectasis and hypoxemia. Further studies are needed to better define optimum protective ventilation strategies and analyze their impact on the perioperative outcomes of surgical patients with obesity.

  10. Intraoperative mechanical ventilation: state of the art.

    Science.gov (United States)

    Ball, Lorenzo; Costantino, Federico; Orefice, Giulia; Chandrapatham, Karthikka; Pelosi, Paolo

    2017-10-01

    Mechanical ventilation is a cornerstone of the intraoperative management of the surgical patient and is still mandatory in several surgical procedures. In the last decades, research focused on preventing postoperative pulmonary complications (PPCs), both improving risk stratification through the use of predictive scores and protecting the lung adopting so-called protective ventilation strategies. The aim of this review was to give an up-to-date overview of the currently suggested intraoperative ventilation strategies, along with their pathophysiologic rationale, with a focus on challenging conditions, such as obesity, one-lung ventilation and cardiopulmonary bypass. While anesthesia and mechanical ventilation are becoming increasingly safe practices, the contribution to surgical mortality attributable to postoperative lung injury is not negligible: for these reasons, the prevention of PPCs, including the use of protective mechanical ventilation is mandatory. Mechanical ventilation should be optimized providing an adequate respiratory support while minimizing unwanted negative effects. Due to the high number of surgical procedures performed daily, the impact on patients' health and healthcare costs can be relevant, even when new strategies result in an apparently small improvement of outcome. A protective intraoperative ventilation should include a low tidal volume of 6-8 mL/kg of predicted body weight, plateau pressures ideally below 16 cmH2O, the lowest possible driving pressure, moderate-low PEEP levels except in obese patients, laparoscopy and long surgical procedures that might benefit of a slightly higher PEEP. The work of the anesthesiologist should start with a careful preoperative visit to assess the risk, and a close postoperative monitoring.

  11. Styret naturlig ventilation

    DEFF Research Database (Denmark)

    Morsing, S.; Strøm, J.S.

    Publikationen præsenterer et generelt dimensioneringsgrundlag for naturlig ventilation i husdyrstalde. Det er kontrolleret ved forsøg i slagtesvinestalde, hvor det ligeledes er undersøgt hvilken temperaturstabilitet, der kan opnås ved naturlig ventilation, samt produktions- og adfærdsmæssige...

  12. Multifamily Ventilation Retrofit Strategies

    Energy Technology Data Exchange (ETDEWEB)

    Ueno, K. [Building Science Corporation (BSC), Somerville, MA (United States); Lstiburek, J. [Building Science Corporation (BSC), Somerville, MA (United States); Bergey, D. [Building Science Corporation (BSC), Somerville, MA (United States)

    2012-12-01

    In multifamily buildings, central ventilation systems often have poor performance, overventilating some portions of the building (causing excess energy use), while simultaneously underventilating other portions (causing diminished indoor air quality). BSC and Innova Services Corporation performed a series of field tests at a mid-rise test building undergoing a major energy audit and retrofit, which included ventilation system upgrades.

  13. Diffuse Ceiling Ventilation

    DEFF Research Database (Denmark)

    Zhang, Chen; Heiselberg, Per; Nielsen, Peter V.

    2014-01-01

    As a novel air distribution system, diffuse ceiling ventilation combines the suspended acoustic ceiling with ventilation supply. Due to the low-impulse supply from the large ceiling area, the system does not generate draught when supplying cold air. However, heat sources play an important role...

  14. Pulmonary perfusion ''without ventilation''

    International Nuclear Information System (INIS)

    Chapman, C.N.; Sziklas, J.J.; Spencer, R.P.; Rosenberg, R.J.

    1983-01-01

    An 88-yr-old man, with prior left upper lobectomy and phrenic nerve injury, had a ventilation/perfusion lung image. Both wash-in and equilibrium ventilation images showed no radioactive gas in the left lung. Nevertheless, the left lung was perfused. A similar result was obtained on a repeat study 8 days later. Delayed images, during washout, showed some radioactive gas in the left lung. Nearly absent ventilation (but continued perfusion) of that lung might have been related to altered gas dynamics brought about by the prior lobectomy, a submucosal bronchial lesion, phrenic nerve damage, and limited motion of the left part of the diaphragm. This case raises the issue of the degree of ventilation (and the phase relationship between the lungs) required for the entry of radioactive gas into a diseased lung, and the production of a ''reversed ventilation/perfusion mismatch.''

  15. Realtime mine ventilation simulation

    International Nuclear Information System (INIS)

    McDaniel, K.H.

    1997-01-01

    This paper describes the development of a Windows based, interactive mine ventilation simulation software program at the Waste Isolation Pilot Plant (WIPP). To enhance the operation of the underground ventilation system, Westinghouse Electric Corporation developed the program called WIPPVENT. While WIPPVENT includes most of the functions of the commercially available simulation program VNETPC and uses the same subroutine to calculate airflow distributions, the user interface has been completely rewritten as a Windows application with screen graphics. WIPPVENT is designed to interact with WIPP ventilation monitoring systems through the sitewise Central monitoring System. Data can be continuously collected from the Underground Ventilation Remote Monitoring and Control System (e.g., air quantity and differential pressure) and the Mine Weather Stations (psychrometric data). Furthermore, WIPPVENT incorporates regulator characteristic curves specific to the site. The program utilizes this data to create and continuously update a REAL-TIME ventilation model. This paper discusses the design, key features, and interactive capabilities of WIPPVENT

  16. Critical evaluation of emergency stockpile ventilators in an in vitro model of pediatric lung injury.

    Science.gov (United States)

    Custer, Jason W; Watson, Christopher M; Dwyer, Joe; Kaczka, David W; Simon, Brett A; Easley, R Blaine

    2011-11-01

    Modern health care systems may be inadequately prepared for mass casualty respiratory failure requiring mechanical ventilation. Current health policy has focused on the "stockpiling" of emergency ventilators, though little is known about the performance of these ventilators under conditions of respiratory failure in adults and children. In this study, we seek to compare emergency ventilator performance characteristics using a test lung simulating pediatric lung injury. Evaluation of ventilator performance using a test lung. Laboratory. None. Six transport/emergency ventilators capable of adult/child application were chosen on the basis of manufacturer specifications, Autovent 3000, Eagle Univent 754, EPV 100, LP-10, LTV 1200, and Parapac 200D. Manufacturer specifications for each ventilator were reviewed and compared with known standards for alarms and functionality for surge capacity ventilators. The delivered tidal volume, gas flow characteristics, and airway pressure waveforms were evaluated in vitro using a mechanical test lung to model pediatric lung injury and integrated software. Test lung and flow meter recordings were analyzed over a range of ventilator settings. Of the six ventilators assessed, only two had the minimum recommended alarm capability. Four of the six ventilators tested were capable of being set to deliver a tidal volume of less than 200 mL. The delivered tidal volume for all ventilators was within 8% of the nominal setting at a positive end expiratory pressure of zero but was reduced significantly with the addition of positive end expiratory pressure (range, ±10% to 30%; p ventilators tested performed comparably at higher set tidal volumes; however, only three of the ventilators tested delivered a tidal volume across the range of ventilator settings that was comparable to that of a standard intensive care unit ventilator. Multiple ventilators are available for the provision of ventilation to children with respiratory failure in a mass

  17. 2 minute Southcentral Alaska Elevation Grid

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The 2-minute Southcentral Alaska Elevation Grid provides bathymetric data in ASCII raster format of 2-minute resolution in geographic coordinates. This grid is...

  18. Neonatal and adult ICU ventilators to provide ventilation in neonates, infants, and children: a bench model study.

    Science.gov (United States)

    Vignaux, Laurence; Piquilloud, Lise; Tourneux, Pierre; Jolliet, Philippe; Rimensberger, Peter C

    2014-10-01

    Using a bench test model, we investigated the hypothesis that neonatal and/or adult ventilators equipped with neonatal/pediatric modes currently do not reliably administer pressure support (PS) in neonatal or pediatric patient groups in either the absence or presence of air leaks. PS was evaluated in 4 neonatal and 6 adult ventilators using a bench model to evaluate triggering, pressurization, and cycling in both the absence and presence of leaks. Delivered tidal volumes were also assessed. Three patients were simulated: a preterm infant (resistance 100 cm H2O/L/s, compliance 2 mL/cm H2O, inspiratory time of the patient [TI] 400 ms, inspiratory effort 1 and 2 cm H2O), a full-term infant (resistance 50 cm H2O/L/s, compliance 5 mL/cm H2O, TI 500 ms, inspiratory effort 2 and 4 cm H2O), and a child (resistance 30 cm H2O/L/s, compliance 10 mL/cm H2O, TI 600 ms, inspiratory effort 5 and 10 cm H2O). Two PS levels were tested (10 and 15 cm H2O) with and without leaks and with and without the leak compensation algorithm activated. Without leaks, only 2 neonatal ventilators and one adult ventilator had trigger delays under a given predefined acceptable limit (1/8 TI). Pressurization showed high variability between ventilators. Most ventilators showed TI in excess high enough to seriously impair patient-ventilator synchronization (> 50% of the TI of the subject). In some ventilators, leaks led to autotriggering and impairment of ventilation performance, but the influence of leaks was generally lower in neonatal ventilators. When a noninvasive ventilation algorithm was available, this was partially corrected. In general, tidal volume was calculated too low by the ventilators in the presence of leaks; the noninvasive ventilation algorithm was able to correct this difference in only 2 adult ventilators. No ventilator performed equally well under all tested conditions for all explored parameters. However, neonatal ventilators tended to perform better in the presence of leaks

  19. Lung-protective mechanical ventilation does not protect against acute kidney injury in patients without lung injury at onset of mechanical ventilation.

    Science.gov (United States)

    Cortjens, Bart; Royakkers, Annick A N M; Determann, Rogier M; van Suijlen, Jeroen D E; Kamphuis, Stephan S; Foppen, Jannetje; de Boer, Anita; Wieland, Cathrien W; Spronk, Peter E; Schultz, Marcus J; Bouman, Catherine S C

    2012-06-01

    Preclinical and clinical studies suggest that mechanical ventilation contributes to the development of acute kidney injury (AKI), particularly in the setting of lung-injurious ventilator strategies. To determine whether ventilator settings in critically ill patients without acute lung injury (ALI) at onset of mechanical ventilation affect the development of AKI. Secondary analysis of a randomized controlled trial (N = 150), comparing conventional tidal volume (V(T), 10 mL/kg) with low tidal volume (V(T), 6 mL/kg) mechanical ventilation in critically ill patients without ALI at randomization. During the first 5 days of mechanical ventilation, the RIFLE class was determined daily, whereas neutrophil gelatinase-associated lipocalin and cystatin C levels were measured in plasma collected on days 0, 2, and 4. Eighty-six patients had no AKI at inclusion, and 18 patients (21%) subsequently developed AKI, but without significant difference between ventilation strategies. (Cumulative hazard, 0.26 vs 0.23; P = .88.) The courses of neutrophil gelatinase-associated lipocalin and cystatin C plasma levels did not differ significantly between randomization groups. In the present study in critically patients without ALI at onset of mechanical ventilation, lower tidal volume ventilation did not reduce the development or worsening of AKI compared with conventional tidal volume ventilation. Copyright © 2012 Elsevier Inc. All rights reserved.

  20. Protective mechanical ventilation in United Kingdom critical care units: A multicentre audit.

    Science.gov (United States)

    Newell, Christopher P; Martin, Matthew J; Richardson, Neil; Bourdeaux, Christopher P

    2017-05-01

    Lung protective ventilation is becoming increasingly used for all critically ill patients being mechanically ventilated on a mandatory ventilator mode. Compliance with the universal application of this ventilation strategy in intensive care units in the United Kingdom is unknown. This 24-h audit of ventilation practice took place in 16 intensive care units in two regions of the United Kingdom. The mean tidal volume for all patients being ventilated on a mandatory ventilator mode was 7.2(±1.4) ml kg -1 predicted body weight and overall compliance with low tidal volume ventilation (≤6.5 ml kg -1 predicted body weight) was 34%. The mean tidal volume for patients ventilated with volume-controlled ventilation was 7.0(±1.2) ml kg -1 predicted body weight and 7.9(±1.8) ml kg -1 predicted body weight for pressure-controlled ventilation ( P  < 0.0001). Overall compliance with recommended levels of positive end-expiratory pressure was 72%. Significant variation in practice existed both at a regional and individual unit level.

  1. The growing role of noninvasive ventilation in patients requiring prolonged mechanical ventilation.

    Science.gov (United States)

    Hess, Dean R

    2012-06-01

    For many patients with chronic respiratory failure requiring ventilator support, noninvasive ventilation (NIV) is preferable to invasive support by tracheostomy. Currently available evidence does not support the use of nocturnal NIV in unselected patients with stable COPD. Several European studies have reported benefit for high intensity NIV, in which setting of inspiratory pressure and respiratory rate are selected to achieve normocapnia. There have also been studies reporting benefit for the use of NIV as an adjunct to exercise training. NIV may be useful as an adjunct to airway clearance techniques in patients with cystic fibrosis. Accumulating evidence supports the use of NIV in patients with obesity hypoventilation syndrome. There is considerable observational evidence supporting the use of NIV in patients with chronic respiratory failure related to neuromuscular disease, and one randomized controlled trial reported that the use of NIV was life-prolonging in patients with amyotrophic lateral sclerosis. A variety of interfaces can be used to provide NIV in patients with stable chronic respiratory failure. The mouthpiece is an interface that is unique in this patient population, and has been used with success in patients with neuromuscular disease. Bi-level pressure ventilators are commonly used for NIV, although there are now a new generation of intermediate ventilators that are portable, have a long battery life, and can be used for NIV and invasive applications. Pressure support ventilation, pressure controlled ventilation, and volume controlled ventilation have been used successfully for chronic applications of NIV. New modes have recently become available, but their benefits await evidence to support their widespread use. The success of NIV in a given patient population depends on selection of an appropriate patient, selection of an appropriate interface, selection of an appropriate ventilator and ventilator settings, the skills of the clinician, the

  2. Interfaces and ventilator settings for long-term noninvasive ventilation in COPD patients

    Directory of Open Access Journals (Sweden)

    Callegari J

    2017-06-01

    Full Text Available Jens Callegari,1 Friederike Sophie Magnet,1 Steven Taubner,1 Melanie Berger,2 Sarah Bettina Schwarz,1 Wolfram Windisch,1 Jan Hendrik Storre3,4 1Department of Pneumology, Cologne-Merheim Hospital, Kliniken der Stadt Koeln, Witten/Herdecke University Hospital, 2Department of Pneumology, Malteser Hospital St Hildegardis, Cologne, 3Department of Pneumology, University Medical Hospital, Freiburg, 4Department of Intensive Care, Sleep Medicine and Mechanical Ventilation, Asklepios Fachkliniken Munich-Gauting, Gauting, Germany Introduction: The establishment of high-intensity (HI noninvasive ventilation (NIV that targets elevated PaCO2 has led to an increase in the use of long-term NIV to treat patients with chronic hypercapnic COPD. However, the role of the ventilation interface, especially in more aggressive ventilation strategies, has not been systematically assessed.Methods: Ventilator settings and NIV compliance were assessed in this prospective cross-sectional monocentric cohort study of COPD patients with pre-existing NIV. Daytime ­arterialized blood gas analyses and lung function testing were also performed. The primary end point was the distribution among study patients of interfaces (full-face masks [FFMs] vs nasal masks [NMs] in a real-life setting.Results: The majority of the 123 patients studied used an FFM (77%, while 23% used an NM. Ventilation settings were as follows: mean ± standard deviation (SD inspiratory positive airway pressure (IPAP was 23.2±4.6 mbar and mean ± SD breathing rate was 16.7±2.4/minute. Pressure support ventilation (PSV mode was used in 52.8% of patients, while assisted pressure-controlled ventilation (aPCV was used in 47.2% of patients. Higher IPAP levels were associated with an increased use of FFMs (IPAP <21 mbar: 73% vs IPAP >25 mbar: 84%. Mean compliance was 6.5 hours/day, with no differences between FFM (6.4 hours/day and NM (6.7 hours/day users. PaCO2 assessment of ventilation quality revealed

  3. Football Equipment Removal Improves Chest Compression and Ventilation Efficacy.

    Science.gov (United States)

    Mihalik, Jason P; Lynall, Robert C; Fraser, Melissa A; Decoster, Laura C; De Maio, Valerie J; Patel, Amar P; Swartz, Erik E

    2016-01-01

    Airway access recommendations in potential catastrophic spine injury scenarios advocate for facemask removal, while keeping the helmet and shoulder pads in place for ensuing emergency transport. The anecdotal evidence to support these recommendations assumes that maintaining the helmet and shoulder pads assists inline cervical stabilization and that facial access guarantees adequate airway access. Our objective was to determine the effect of football equipment interference on performing chest compressions and delivering adequate ventilations on patient simulators. We hypothesized that conditions with more football equipment would decrease chest compression and ventilation efficacy. Thirty-two certified athletic trainers were block randomized to participate in six different compression conditions and six different ventilation conditions using human patient simulators. Data for chest compression (mean compression depth, compression rate, percentage of correctly released compressions, and percentage of adequate compressions) and ventilation (total ventilations, mean ventilation volume, and percentage of ventilations delivering adequate volume) conditions were analyzed across all conditions. The fully equipped athlete resulted in the lowest mean compression depth (F5,154 = 22.82; P Emergency medical personnel should remove the helmet and shoulder pads from all football athletes who require cardiopulmonary resuscitation, while maintaining appropriate cervical spine stabilization when injury is suspected. Further research is needed to confirm our findings supporting full equipment removal for chest compression and ventilation delivery.

  4. Ventilating Air-Conditioner

    Science.gov (United States)

    Dinh, Khanh

    1994-01-01

    Air-conditioner provides ventilation designed to be used alone or incorporated into cooling or heating system operates efficiently only by recirculating stale air within building. Energy needed to operate overall ventilating cooling or heating system slightly greater than operating nonventilating cooling or heating system. Helps to preserve energy efficiency while satisfying need for increased forced ventilation to prevent accumulation of undesired gases like radon and formaldehyde. Provides fresh treated air to variety of confined spaces: hospital surgeries, laboratories, clean rooms, and printing shops and other places where solvents used. In mobile homes and portable classrooms, eliminates irritant chemicals exuded by carpets, panels, and other materials, ensuring healthy indoor environment for occupants.

  5. Flow measurement in mechanical ventilation: a review.

    Science.gov (United States)

    Schena, Emiliano; Massaroni, Carlo; Saccomandi, Paola; Cecchini, Stefano

    2015-03-01

    Accurate monitoring of flow rate and volume exchanges is essential to minimize ventilator-induced lung injury. Mechanical ventilators employ flowmeters to estimate the amount of gases delivered to patients and use the flow signal as a feedback to adjust the desired amount of gas to be delivered. Since flowmeters play a crucial role in this field, they are required to fulfill strict criteria in terms of dynamic and static characteristics. Therefore, mechanical ventilators are equipped with only the following kinds of flowmeters: linear pneumotachographs, fixed and variable orifice meters, hot wire anemometers, and ultrasonic flowmeters. This paper provides an overview of these sensors. Their working principles are described together with their relevant advantages and disadvantages. Furthermore, the most promising emerging approaches for flowmeters design (i.e., fiber optic technology and three dimensional micro-fabrication) are briefly reviewed showing their potential for this application. Copyright © 2015 IPEM. Published by Elsevier Ltd. All rights reserved.

  6. Humidification during invasive and noninvasive mechanical ventilation: 2012.

    Science.gov (United States)

    Restrepo, Ruben D; Walsh, Brian K

    2012-05-01

    We searched the MEDLINE, CINAHL, and Cochrane Library databases for articles published between January 1990 and December 2011. The update of this clinical practice guideline is based on 184 clinical trials and systematic reviews, and 10 articles investigating humidification during invasive and noninvasive mechanical ventilation. The following recommendations are made following the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) scoring system: 1. Humidification is recommended on every patient receiving invasive mechanical ventilation. 2. Active humidification is suggested for noninvasive mechanical ventilation, as it may improve adherence and comfort. 3. When providing active humidification to patients who are invasively ventilated, it is suggested that the device provide a humidity level between 33 mg H(2)O/L and 44 mg H(2)O/L and gas temperature between 34°C and 41°C at the circuit Y-piece, with a relative humidity of 100%. 4. When providing passive humidification to patients undergoing invasive mechanical ventilation, it is suggested that the HME provide a minimum of 30 mg H(2)O/L. 5. Passive humidification is not recommended for noninvasive mechanical ventilation. 6. When providing humidification to patients with low tidal volumes, such as when lung-protective ventilation strategies are used, HMEs are not recommended because they contribute additional dead space, which can increase the ventilation requirement and P(aCO(2)). 7. It is suggested that HMEs are not used as a prevention strategy for ventilator-associated pneumonia.

  7. Meeting Residential Ventilation Standards Through Dynamic Control of Ventilation Systems

    OpenAIRE

    Sherman, Max H.

    2011-01-01

    Existing ventilation standards, including American Society of Heating, Refrigerating, and Air-conditioning Engineers (ASHRAE) Standard 62.2, specify continuous operation of a defined mechanical ventilation system to provide minimum ventilation, with time-based intermittent operation as an option. This requirement ignores several factors and concerns including: other equipment such as household exhaust fans that might incidentally provide ventilation, negative impacts of ventilation when outd...

  8. Intraoperative mechanical ventilation strategies in patients undergoing one-lung ventilation: a meta-analysis.

    Science.gov (United States)

    Liu, Zhen; Liu, Xiaowen; Huang, Yuguang; Zhao, Jing

    2016-01-01

    Postoperative pulmonary complications (PPCs), which are not uncommon in one-lung ventilation, are among the main causes of postoperative death after lung surgery. Intra-operative ventilation strategies can influence the incidence of PPCs. High tidal volume (V T) and increased airway pressure may lead to lung injury, while pressure-controlled ventilation and lung-protective strategies with low V T may have protective effects against lung injury. In this meta-analysis, we aim to investigate the effects of different ventilation strategies, including pressure-controlled ventilation (PCV), volume-controlled ventilation (VCV), protective ventilation (PV) and conventional ventilation (CV), on PPCs in patients undergoing one-lung ventilation. We hypothesize that both PV with low V T and PCV have protective effects against PPCs in one-lung ventilation. A systematic search (PubMed, EMBASE, the Cochrane Library, and Ovid MEDLINE; in May 2015) was performed for randomized trials comparing PCV with VCV or comparing PV with CV in one-lung ventilation. Methodological quality was evaluated using the Cochrane tool for risk. The primary outcome was the incidence of PPCs. The secondary outcomes included the length of hospital stay, intraoperative plateau airway pressure (Pplateau), oxygen index (PaO2/FiO2) and mean arterial pressure (MAP). In this meta-analysis, 11 studies (436 patients) comparing PCV with VCV and 11 studies (657 patients) comparing PV with CV were included. Compared to CV, PV decreased the incidence of PPCs (OR 0.29; 95 % CI 0.15-0.57; P < 0.01) and intraoperative Pplateau (MD -3.75; 95 % CI -5.74 to -1.76; P < 0.01) but had no significant influence on the length of hospital stay or MAP. Compared to VCV, PCV decreased intraoperative Pplateau (MD -1.46; 95 % CI -2.54 to -0.34; P = 0.01) but had no significant influence on PPCs, PaO2/FiO2 or MAP. PV with low V T was associated with the reduced incidence of PPCs compared to CV. However, PCV and VCV had similar

  9. Multifaceted bench comparative evaluation of latest intensive care unit ventilators.

    Science.gov (United States)

    Garnier, M; Quesnel, C; Fulgencio, J-P; Degrain, M; Carteaux, G; Bonnet, F; Similowski, T; Demoule, A

    2015-07-01

    Independent bench studies using specific ventilation scenarios allow testing of the performance of ventilators in conditions similar to clinical settings. The aims of this study were to determine the accuracy of the latest generation ventilators to deliver chosen parameters in various typical conditions and to provide clinicians with a comprehensive report on their performance. Thirteen modern intensive care unit ventilators were evaluated on the ASL5000 test lung with and without leakage for: (i) accuracy to deliver exact tidal volume (VT) and PEEP in assist-control ventilation (ACV); (ii) performance of trigger and pressurization in pressure support ventilation (PSV); and (iii) quality of non-invasive ventilation algorithms. In ACV, only six ventilators delivered an accurate VT and nine an accurate PEEP. Eleven devices failed to compensate VT and four the PEEP in leakage conditions. Inspiratory delays differed significantly among ventilators in invasive PSV (range 75-149 ms, P=0.03) and non-invasive PSV (range 78-165 ms, Pventilation algorithms efficiently prevented the decrease in pressurization capacities and PEEP levels induced by leaks in, respectively, 10 and 12 out of the 13 ventilators. We observed real heterogeneity of performance amongst the latest generation of intensive care unit ventilators. Although non-invasive ventilation algorithms appear to maintain adequate pressurization efficiently in the case of leakage, basic functions, such as delivered VT in ACV and pressurization in PSV, are often less reliable than the values displayed by the device suggest. © The Author 2015. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  10. Effects of Conventional Mechanical Ventilation Performed by Two Neonatal Ventilators on the Lung Functions of Rabbits with Meconium-Induced Acute Lung Injury

    Directory of Open Access Journals (Sweden)

    Mokra D

    2016-12-01

    Full Text Available Severe meconium aspiration syndrome (MAS in the neonates often requires a ventilatory support. As a method of choice, a conventional mechanical ventilation with small tidal volumes (VT<6 ml/kg and appropriate ventilatory pressures is used. The purpose of this study was to assess the short-term effects of the small-volume CMV performed by two neonatal ventilators: Aura V (Chirana Stara Tura a.s., Slovakia and SLE5000 (SLE Ltd., UK on the lung functions of rabbits with experimentally-induced MAS and to estimate whether the newly developed neonatal version of the ventilator Aura V is suitable for ventilation of the animals with MAS.

  11. Protective mechanical ventilation, why use it?

    Science.gov (United States)

    Seiberlich, Emerson; Santana, Jonas Alves; Chaves, Renata de Andrade; Seiberlich, Raquel Carvalho

    2011-01-01

    Mechanical ventilation (MV) strategies have been modified over the last decades with a tendency for increasingly lower tidal volumes (VT). However, in patients without acute lung injury (ALI) or acute respiratory distress syndrome (ARDS) the use of high VTs is still very common. Retrospective studies suggest that this practice can be related to mechanical ventilation-associated ALI. The objective of this review is to search for evidence to guide protective MV in patients with healthy lungs and to suggest strategies to properly ventilate lungs with ALI/ARDS. A review based on the main articles that focus on the use of strategies of mechanical ventilation was performed. Consistent studies to determine which would be the best way to ventilate a patient with healthy lungs are lacking. Expert recommendations and current evidence presented in this article indicate that the use of a VT lower than 10 mL.kg(-1), associated with positive end-expiratory pressure (PEEP) ≥ 5 cmH(2)O without exceeding a pressure plateau of 15 to 20 cmH(2)O could minimize alveolar stretching at the end of inspiration and avoid possible inflammation or alveolar collapse. Copyright © 2011 Elsevier Editora Ltda. All rights reserved.

  12. Why We Ventilate

    Energy Technology Data Exchange (ETDEWEB)

    Logue, Jennifer M.; Sherman, Max H.; Price, Phil N.; Singer, Brett C.

    2011-09-01

    It is widely accepted that ventilation is critical for providing good indoor air quality (IAQ) in homes. However, the definition of"good" IAQ, and the most effective, energy efficient methods for delivering it are still matters of research and debate. This paper presents the results of work done at the Lawrence Berkeley National Lab to identify the air pollutants that drive the need for ventilation as part of a larger effort to develop a health-based ventilation standard. First, we present results of a hazard analysis that identified the pollutants that most commonly reach concentrations in homes that exceed health-based standards or guidelines for chronic or acute exposures. Second, we present results of an impact assessment that identified the air pollutants that cause the most harm to the U.S. population from chronic inhalation in residences. Lastly, we describe the implications of our findings for developing effective ventilation standards.

  13. What Is a Ventilator?

    Science.gov (United States)

    ... who are on ventilators for shorter periods. The advantage of this tube is that it can be ... other disease or condition. VAP is treated with antibiotics. You may need special antibiotics if the VAP ...

  14. Fire, safety and ventilation

    Energy Technology Data Exchange (ETDEWEB)

    Hindle, D.

    1999-02-01

    Correct ventilation in tunnel environments is vital for the comfort and safety of the people passing through. This article gives details of products from several manufacturers of safety rescue and fire fighting equipment, fire and fume detection equipment, special fire resistant materials, fire resistant hydraulic oils and fire dampers, and ventilation systems. Company addresses and fax numbers are supplied. 4 refs., 5 tabs., 10 photos.

  15. Pleural liquid and kinetic friction coefficient of mesothelium after mechanical ventilation.

    Science.gov (United States)

    Bodega, Francesca; Sironi, Chiara; Porta, Cristina; Zocchi, Luciano; Agostoni, Emilio

    2015-01-15

    Volume and protein concentration of pleural liquid in anesthetized rabbits after 1 or 3h of mechanical ventilation, with alveolar pressure equal to atmospheric at end expiration, were compared to those occurring after spontaneous breathing. Moreover, coefficient of kinetic friction between samples of visceral and parietal pleura, obtained after spontaneous or mechanical ventilation, sliding in vitro at physiological velocity under physiological load, was determined. Volume of pleural liquid after mechanical ventilation was similar to that previously found during spontaneous ventilation. This finding is contrary to expectation of Moriondo et al. (2005), based on measurement of lymphatic and interstitial pressure. Protein concentration of pleural liquid after mechanical ventilation was also similar to that occurring after spontaneous ventilation. Coefficient of kinetic friction after mechanical ventilation was 0.023±0.001, similar to that obtained after spontaneous breathing. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Protective ventilation of preterm lambs exposed to acute chorioamnionitis does not reduce ventilation-induced lung or brain injury.

    Science.gov (United States)

    Barton, Samantha K; Moss, Timothy J M; Hooper, Stuart B; Crossley, Kelly J; Gill, Andrew W; Kluckow, Martin; Zahra, Valerie; Wong, Flora Y; Pichler, Gerhard; Galinsky, Robert; Miller, Suzanne L; Tolcos, Mary; Polglase, Graeme R

    2014-01-01

    The onset of mechanical ventilation is a critical time for the initiation of cerebral white matter (WM) injury in preterm neonates, particularly if they are inadvertently exposed to high tidal volumes (VT) in the delivery room. Protective ventilation strategies at birth reduce ventilation-induced lung and brain inflammation and injury, however its efficacy in a compromised newborn is not known. Chorioamnionitis is a common antecedent of preterm birth, and increases the risk and severity of WM injury. We investigated the effects of high VT ventilation, after chorioamnionitis, on preterm lung and WM inflammation and injury, and whether a protective ventilation strategy could mitigate the response. Pregnant ewes (n = 18) received intra-amniotic lipopolysaccharide (LPS) 2 days before delivery, instrumentation and ventilation at 127±1 days gestation. Lambs were either immediately euthanased and used as unventilated controls (LPSUVC; n = 6), or were ventilated using an injurious high VT strategy (LPSINJ; n = 5) or a protective ventilation strategy (LPSPROT; n = 7) for a total of 90 min. Mean arterial pressure, heart rate and cerebral haemodynamics and oxygenation were measured continuously. Lungs and brains underwent molecular and histological assessment of inflammation and injury. LPSINJ lambs had poorer oxygenation than LPSPROT lambs. Ventilation requirements and cardiopulmonary and systemic haemodynamics were not different between ventilation strategies. Compared to unventilated lambs, LPSINJ and LPSPROT lambs had increases in pro-inflammatory cytokine expression within the lungs and brain, and increased astrogliosis (pVentilation after acute chorioamnionitis, irrespective of strategy used, increases haemodynamic instability and lung and cerebral inflammation and injury. Mechanical ventilation is a potential contributor to WM injury in infants exposed to chorioamnionitis.

  17. Influences of Duration of Inspiratory Effort, Respiratory Mechanics, and Ventilator Type on Asynchrony With Pressure Support and Proportional Assist Ventilation.

    Science.gov (United States)

    Vasconcelos, Renata S; Sales, Raquel P; Melo, Luíz H de P; Marinho, Liégina S; Bastos, Vasco Pd; Nogueira, Andréa da Nc; Ferreira, Juliana C; Holanda, Marcelo A

    2017-05-01

    Pressure support ventilation (PSV) is often associated with patient-ventilator asynchrony. Proportional assist ventilation (PAV) offers inspiratory assistance proportional to patient effort, minimizing patient-ventilator asynchrony. The objective of this study was to evaluate the influence of respiratory mechanics and patient effort on patient-ventilator asynchrony during PSV and PAV plus (PAV+). We used a mechanical lung simulator and studied 3 respiratory mechanics profiles (normal, obstructive, and restrictive), with variations in the duration of inspiratory effort: 0.5, 1.0, 1.5, and 2.0 s. The Auto-Trak system was studied in ventilators when available. Outcome measures included inspiratory trigger delay, expiratory trigger asynchrony, and tidal volume (V T ). Inspiratory trigger delay was greater in the obstructive respiratory mechanics profile and greatest with a effort of 2.0 s (160 ms); cycling asynchrony, particularly delayed cycling, was common in the obstructive profile, whereas the restrictive profile was associated with premature cycling. In comparison with PSV, PAV+ improved patient-ventilator synchrony, with a shorter triggering delay (28 ms vs 116 ms) and no cycling asynchrony in the restrictive profile. V T was lower with PAV+ than with PSV (630 mL vs 837 mL), as it was with the single-limb circuit ventilator (570 mL vs 837 mL). PAV+ mode was associated with longer cycling delays than were the other ventilation modes, especially for the obstructive profile and higher effort values. Auto-Trak eliminated automatic triggering. Mechanical ventilation asynchrony was influenced by effort, respiratory mechanics, ventilator type, and ventilation mode. In PSV mode, delayed cycling was associated with shorter effort in obstructive respiratory mechanics profiles, whereas premature cycling was more common with longer effort and a restrictive profile. PAV+ prevented premature cycling but not delayed cycling, especially in obstructive respiratory mechanics

  18. [Alveolar ventilation and recruitment under lung protective ventilation].

    Science.gov (United States)

    Putensen, Christian; Muders, Thomas; Kreyer, Stefan; Wrigge, Hermann

    2008-11-01

    Goal of mechanical ventilation is to improve gas exchange and reduce work of breathing without contributing to further lung injury. Besides providing adequate EELV and thereby arterial oxygenation PEEP in addition to a reduction in tidal volume is required to prevent cyclic alveolar collapse and tidal recruitment and hence protective mechanical ventilation. Currently, there is no consensus if and if yes at which price alveolar recruitment with high airway pressures should be intended ("open up the lung"), or if it is more important to reduce the mechanical stress and strain to the lungs as much as possible ("keep the lung closed"). Potential of alveolar recruitment differs from patient to patient but also between lung regions. Potential for recruitment depends probably more on regional lung mechanics - especially on lung elastance - than on the underlying disease. Based on available data neither high PEEP nor other methods used for alveolar recruitment could demonstrate a survival benefit in patients with ARDS. These results may support an individualized titration of PEEP or other manoeuvres used for recruitment taking into consideration the regional effects. Bedside imaging techniques allowing titration of PEEP or other manoeuvres to prevent end-expiratory alveolar collapse (tidal recruitment) and inspiratory overinflation may be a promising development.

  19. Modes of mechanical ventilation for the operating room.

    Science.gov (United States)

    Ball, Lorenzo; Dameri, Maddalena; Pelosi, Paolo

    2015-09-01

    Most patients undergoing surgical procedures need to be mechanically ventilated, because of the impact of several drugs administered at induction and during maintenance of general anaesthesia on respiratory function. Optimization of intraoperative mechanical ventilation can reduce the incidence of post-operative pulmonary complications and improve the patient's outcome. Preoxygenation at induction of general anaesthesia prolongs the time window for safe intubation, reducing the risk of hypoxia and overweighs the potential risk of reabsorption atelectasis. Non-invasive positive pressure ventilation delivered through different interfaces should be considered at the induction of anaesthesia morbidly obese patients. Anaesthesia ventilators are becoming increasingly sophisticated, integrating many functions that were once exclusive to intensive care. Modern anaesthesia machines provide high performances in delivering the desired volumes and pressures accurately and precisely, including assisted ventilation modes. Therefore, the physicians should be familiar with the potential and pitfalls of the most commonly used intraoperative ventilation modes: volume-controlled, pressure-controlled, dual-controlled and assisted ventilation. Although there is no clear evidence to support the advantage of any one of these ventilation modes over the others, protective mechanical ventilation with low tidal volume and low levels of positive end-expiratory pressure (PEEP) should be considered in patients undergoing surgery. The target tidal volume should be calculated based on the predicted or ideal body weight rather than on the actual body weight. To optimize ventilation monitoring, anaesthesia machines should include end-inspiratory and end-expiratory pause as well as flow-volume loop curves. The routine administration of high PEEP levels should be avoided, as this may lead to haemodynamic impairment and fluid overload. Higher PEEP might be considered during surgery longer than 3 h

  20. The performance of Dräger Oxylog ventilators at simulated altitude.

    Science.gov (United States)

    Flynn, J G; Singh, B

    2008-07-01

    Ventilated patients frequently require transport by air in a hypobaric environment. Previous studies have demonstrated significant changes in the performance of ventilators with changes in cabin pressure (altitude) but no studies have been published on the function of modem ventilators at altitude. This experiment set out to evaluate ventilatory parameters (tidal volume and respiratory rate) of three commonly used transport ventilators (the Dräger Oxylog 1000, 2000 and 3000) in a simulated hypobaric environment. Ventilators were assessed using either air-mix (60% oxygen) or 100% oxygen and tested against models simulating a normal lung, a low compliance (Acute Respiratory Distress Syndrome) lung and a high-resistance (asthma) lung. Ventilators were tested at a range of simulated altitudes between sea level and 3048 m. Over this range, tidal volume delivered by the Oxylog 1000 increased by 68% and respiratory rate decreased by 28%. Tidal volume delivered by the Oxylog 2000 ventilator increased by 29% over the same range of altitudes but there was no significant change in respiratory rate. Tidal volume and respiratory rate remained constant with the Oxylog 3000 over the same range of altitudes. Changes were consistent with each ventilator regardless of oxygen content or lung model. It is important that clinicians involved in critical care transport in a hypobaric environment are aware that individual ventilators perform differently at altitude and that they are aware of the characteristics of the particular ventilator that they are using.

  1. DSCOVR Magnetometer Level 2 One Minute Averages

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Interplanetary magnetic field observations collected from magnetometer on DSCOVR satellite - 1-minute average of Level 1 data

  2. Monitoring of noninvasive ventilation by built-in software of home bilevel ventilators: a bench study.

    Science.gov (United States)

    Contal, Olivier; Vignaux, Laurence; Combescure, Christophe; Pepin, Jean-Louis; Jolliet, Philippe; Janssens, Jean-Paul

    2012-02-01

    Current bilevel positive-pressure ventilators for home noninvasive ventilation (NIV) provide physicians with software that records items important for patient monitoring, such as compliance, tidal volume (Vt), and leaks. However, to our knowledge, the validity of this information has not yet been independently assessed. Testing was done for seven home ventilators on a bench model adapted to simulate NIV and generate unintentional leaks (ie, other than of the mask exhalation valve). Five levels of leaks were simulated using a computer-driven solenoid valve (0-60 L/min) at different levels of inspiratory pressure (15 and 25 cm H(2)O) and at a fixed expiratory pressure (5 cm H(2)O), for a total of 10 conditions. Bench data were compared with results retrieved from ventilator software for leaks and Vt. For assessing leaks, three of the devices tested were highly reliable, with a small bias (0.3-0.9 L/min), narrow limits of agreement (LA), and high correlations (R(2), 0.993-0.997) when comparing ventilator software and bench results; conversely, for four ventilators, bias ranged from -6.0 L/min to -25.9 L/min, exceeding -10 L/min for two devices, with wide LA and lower correlations (R(2), 0.70-0.98). Bias for leaks increased markedly with the importance of leaks in three devices. Vt was underestimated by all devices, and bias (range, 66-236 mL) increased with higher insufflation pressures. Only two devices had a bias ventilation must be aware of differences in the estimation of leaks and Vt by ventilator software. Also, leaks are reported in different ways according to the device used.

  3. Demand Controlled Ventilation in a Combined Ventilation and Radiator System

    OpenAIRE

    Hesaraki, Arefeh; Holmberg, Sture

    2013-01-01

    With growing concerns for efficient and sustainable energy treatment in buildings there is a need for balanced and intelligent ventilation solutions. This paper presents a strategy for demand controlled ventilation with ventilation radiators, a combined heating and ventilation system. The ventilation rate was decreased from normal requirements (per floor area) of 0.375 l·s-1·m-2 to 0.100 l·s-1·m-2 when the residence building was un-occupied. The energy saving potential due to decreased ventil...

  4. Clinical challenges in mechanical ventilation.

    Science.gov (United States)

    Goligher, Ewan C; Ferguson, Niall D; Brochard, Laurent J

    2016-04-30

    Mechanical ventilation supports gas exchange and alleviates the work of breathing when the respiratory muscles are overwhelmed by an acute pulmonary or systemic insult. Although mechanical ventilation is not generally considered a treatment for acute respiratory failure per se, ventilator management warrants close attention because inappropriate ventilation can result in injury to the lungs or respiratory muscles and worsen morbidity and mortality. Key clinical challenges include averting intubation in patients with respiratory failure with non-invasive techniques for respiratory support; delivering lung-protective ventilation to prevent ventilator-induced lung injury; maintaining adequate gas exchange in severely hypoxaemic patients; avoiding the development of ventilator-induced diaphragm dysfunction; and diagnosing and treating the many pathophysiological mechanisms that impair liberation from mechanical ventilation. Personalisation of mechanical ventilation based on individual physiological characteristics and responses to therapy can further improve outcomes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Protective lung ventilation in operating room: a systematic review.

    Science.gov (United States)

    Futier, E; Constantin, J M; Jaber, S

    2014-06-01

    Postoperative pulmonary and extrapulmonary complications adversely affect clinical outcomes and healthcare utilization, so that prevention has become a measure of the quality of perioperative care. Mechanical ventilation is an essential support therapy to maintain adequate gas exchange during general anesthesia for surgery. Mechanical ventilation using high tidal volume (VT) (between 10 and 15 mL/kg) has been historically encouraged to prevent hypoxemia and atelectasis formation in anesthetized patients undergoing abdominal and thoracic surgery. However, there is accumulating evidence from both experimental and clinical studies that mechanical ventilation, especially the use of high VT and plateau pressure, may potentially aggravate or even initiate lung injury. Ventilator-associated lung injury can result from cyclic alveolar overdistension of non-dependent lung tissue, and repetitive opening and closing of dependent lung tissue resulting in ultrastructural damage at the junction of closed and open alveoli. Lung-protective ventilation, which refers to the use of lower VT and limited plateau pressure to minimize overdistension, and positive end-expiratory pressure to prevent alveolar collapse at end-expiration, was shown to improve outcome in critically ill patients with acute respiratory distress syndrome (ARDS). It has been recently suggested that this approach might also be beneficial in a broader population, especially in critically ill patients without ARDS at the onset of mechanical ventilation. There is, however, little evidence regarding a potential beneficial effect of lung protective ventilation during surgery, especially in patients with healthy lungs. Although surgical patients are frequently exposed to much shorter periods of mechanical ventilation, this is an important gap in knowledge given the number of patients receiving mechanical ventilation in the operating room. This review developed the benefits of lung protective ventilation during surgery

  6. Jet Ventilation during Rigid Bronchoscopy in Adults: A Focused Review

    Directory of Open Access Journals (Sweden)

    Laurie Putz

    2016-01-01

    Full Text Available The indications for rigid bronchoscopy for interventional pulmonology have increased and include stent placements and transbronchial cryobiopsy procedures. The shared airway between anesthesiologist and pulmonologist and the open airway system, requiring specific ventilation techniques such as jet ventilation, need a good understanding of the procedure to reduce potentially harmful complications. Appropriate adjustment of the ventilator settings including pause pressure and peak inspiratory pressure reduces the risk of barotrauma. High frequency jet ventilation allows adequate oxygenation and carbon dioxide removal even in cases of tracheal stenosis up to frequencies of around 150 min−1; however, in an in vivo animal model, high frequency jet ventilation along with normal frequency jet ventilation (superimposed high frequency jet ventilation has been shown to improve oxygenation by increasing lung volume and carbon dioxide removal by increasing tidal volume across a large spectrum of frequencies without increasing barotrauma. General anesthesia with a continuous, intravenous, short-acting agent is safe and effective during rigid bronchoscopy procedures.

  7. Controlled invasive mechanical ventilation strategies in obese patients undergoing surgery.

    Science.gov (United States)

    Maia, Lígia de Albuquerque; Silva, Pedro Leme; Pelosi, Paolo; Rocco, Patricia Rieken Macedo

    2017-06-01

    The obesity prevalence is increasing in surgical population. As the number of obese surgical patients increases, so does the demand for mechanical ventilation. Nevertheless, ventilatory strategies in this population are challenging, since obesity results in pathophysiological changes in respiratory function. Areas covered: We reviewed the impact of obesity on respiratory system and the effects of controlled invasive mechanical ventilation strategies in obese patients undergoing surgery. To date, there is no consensus regarding the optimal invasive mechanical ventilation strategy for obese surgical patients, and no evidence that possible intraoperative beneficial effects on oxygenation and mechanics translate into better postoperative pulmonary function or improved outcomes. Expert commentary: Before determining the ideal intraoperative ventilation strategy, it is important to analyze the pathophysiology and comorbidities of each obese patient. Protective ventilation with low tidal volume, driving pressure, energy, and mechanical power should be employed during surgery; however, further studies are required to clarify the most effective ventilation strategies, such as the optimal positive end-expiratory pressure and whether recruitment maneuvers minimize lung injury. In this context, an ongoing trial of intraoperative ventilation in obese patients (PROBESE) should help determine the mechanical ventilation strategy that best improves clinical outcome in patients with body mass index≥35kg/m 2 .

  8. Personalizing mechanical ventilation for acute respiratory distress syndrome

    OpenAIRE

    Berngard, S. Clark; Beitler, Jeremy R.; Malhotra, Atul

    2016-01-01

    Lung-protective ventilation with low tidal volumes remains the cornerstone for treating patient with acute respiratory distress syndrome (ARDS). Personalizing such an approach to each patient's unique physiology may improve outcomes further. Many factors should be considered when mechanically ventilating a critically ill patient with ARDS. Estimations of transpulmonary pressures as well as individual's hemodynamics and respiratory mechanics should influence PEEP decisions as well as response ...

  9. Improvenet of The Broiler House Ventilation Using The CFD Simulation

    Czech Academy of Sciences Publication Activity Database

    Zajíček, Milan; Kic, P.

    Volume 10, Spec. 1 (2012), s. 235-242 ISSN 1406-894X. [Biosystems Engineering 2012. Tartu, 10.05.2012-11.05.2012] Institutional support: RVO:67985556 Keywords : broiler house * ventilation * fluid dynamics Subject RIV: GB - Machines ; Buildings for Agriculture http://library.utia.cas.cz/separaty/2012/VS/zajicek-improvenet of the broiler house ventilation using the cfd simulation.pdf

  10. Evaluation of respiratory dynamics by volumetric capnography during submaximal exercise protocol of six minutes on treadmill in cystic fibrosis patients.

    Science.gov (United States)

    Parazzi, Paloma L F; Marson, Fernando A L; Ribeiro, Maria A G O; Schivinski, Camila I S; Ribeiro, José D

    2017-11-29

    Volumetric capnography provides the standard CO 2 elimination by the volume expired per respiratory cycle and is a measure to assess pulmonary involvement. Thus, the objective of this study was to evaluate the respiratory dynamics of healthy control subjects and those with cystic fibrosis in a submaximal exercise protocol for six minutes on the treadmill, using volumetric capnography parameters (slope 3 [Slp3], Slp3/tidal volume [Slp3/TV], and slope 2 [Slp2]). This was a cross-sectional study with 128 subjects (cystic fibrosis, 64 subjects; controls, 64 subjects]. Participants underwent volumetric capnography before, during, and after six minutes on the treadmill. Statistical analysis was performed using the Friedman, Mann-Whitney, and Kruskal-Wallis tests, considering age and sex. An alpha=0.05 was considered. Six minutes on the treadmill evaluation: in cystic fibrosis, volumetric capnography parameters were different before, during, and after six minutes on the treadmill; the same was observed for the controls, except for Slp2. Regarding age, an Slp3 difference was observed in cystic fibrosis patients regardless of age, at all moments, and in controls for age≥12 years; a difference in Slp3/TV was observed in cystic fibrosis and controls, regardless of age; and an Slp2 difference in the cystic fibrosis, regardless of age. Regarding sex, Slp3 and Slp3/TV differences were observed in cystic fibrosis regardless of sex, and in controls in male participants; an Slp2 difference was observed in the cystic fibrosis and female participants. The analysis between groups (cystic fibrosis and controls) indicated that Slp3 and Slp3/TV has identified the CF, regardless of age and sex, while the Slp2 showed the CF considering age. Cystic fibrosis showed greater values of the parameters before, during, and after exercise, even when stratified by age and sex, which may indicate ventilation inhomogeneity in the peripheral pathways in the cystic fibrosis. Copyright © 2017

  11. Efeitos do pneumoperitônio sobre a hemodinâmica e função renais de cães ventilados com volume e pressão controlados Efectos del pneumoperitonio sobre la hemodinámica y función renal de perros ventilados con volumen y presión controlados Effects of pneumoperitoneum on renal hemodynamics and function of dogs under volume and pressure-controlled ventilation

    Directory of Open Access Journals (Sweden)

    Armando Vieira de Almeida

    2004-06-01

    hemodynamics and function changes in dogs under volume and pressure controlled ventilation. METHODS: This study involved 16 dogs anesthetized with sodium thiopental and fentanyl, which were divided in two groups: Group 1: volume controlled; and Group 2: pressure controlled, both submitted to 10 and 15 mmHg pneumoperitoneum. The following parameters were evaluated: renal blood flow, renal vascular resistance, sodium para-aminohippurate clearance, plasma sodium, plasma potassium, plasma osmolality, creatinine clearance, filtration fraction, urinary volume, urinary clearance, osmolar clearance, free water clearance, sodium clearance, sodium urinary excretion, sodium fractional excretion, potassium clearance, potassium urinary excretion and potassium fractional excretion. Data were collected in 4 moments: M1 before pneumoperitoneum, M2, 30 minutes after 10 mmHg pneumoperitoneum, M3, 30 minutes after 15 mmHg pneumoperitoneum, M4, 30 minutes after pneumoperitoneum deflation. RESULTS: Sodium para-aminohippurate and creatinine clearance remained constant for both groups throughout the experiment. Plasma sodium and potassium were not changed. There has been potassium clearance and fractional excretion decrease as from M2 in both groups. CONCLUSIONS: Ventilatory modes have not promoted renal hemodynamic differences between groups. Pneumoperitoneum, by compressing renal parenchyma, may have determined changes in potassium reabsorption and/or secretion.

  12. Spatial distribution of sequential ventilation during mechanical ventilation of the uninjured lung: an argument for cyclical airway collapse and expansion

    Directory of Open Access Journals (Sweden)

    Altemeier William A

    2010-05-01

    Full Text Available Abstract Background Ventilator-induced lung injury (VILI is a recognized complication of mechanical ventilation. Although the specific mechanism by which mechanical ventilation causes lung injury remains an active area of study, the application of positive end expiratory pressure (PEEP reduces its severity. We have previously reported that VILI is spatially heterogeneous with the most severe injury in the dorsal-caudal lung. This regional injury heterogeneity was abolished by the application of PEEP = 8 cm H2O. We hypothesized that the spatial distribution of lung injury correlates with areas in which cyclical airway collapse and recruitment occurs. Methods To test this hypothesis, rabbits were mechanically ventilated in the supine posture, and regional ventilation distribution was measured under four conditions: tidal volumes (VT of 6 and 12 ml/kg with PEEP levels of 0 and 8 cm H2O. Results We found that relative ventilation was sequentially redistributed towards dorsal-caudal lung with increasing tidal volume. This sequential ventilation redistribution was abolished with the addition of PEEP. Conclusions These results suggest that cyclical airway collapse and recruitment is regionally heterogeneous and spatially correlated with areas most susceptible to VILI.

  13. Mechanical ventilation strategies.

    Science.gov (United States)

    Keszler, Martin

    2017-08-01

    Although only a small proportion of full term and late preterm infants require invasive respiratory support, they are not immune from ventilator-associated lung injury. The process of lung damage from mechanical ventilation is multifactorial and cannot be linked to any single variable. Atelectrauma and volutrauma have been identified as the most important and potentially preventable elements of lung injury. Respiratory support strategies for full term and late preterm infants have not been as thoroughly studied as those for preterm infants; consequently, a strong evidence base on which to make recommendations is lacking. The choice of modalities of support and ventilation strategies should be guided by the specific underlying pathophysiologic considerations and the ventilatory approach must be individualized for each patient based on the predominant pathophysiology at the time. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. [Ventilator associated pneumonia].

    Science.gov (United States)

    Bellani, S; Nesci, M; Celotto, S; Lampati, L; Lucchini, A

    2003-04-01

    Ventilator associated pneumonia (VAP) is a nosocomial lower respiratory tract infection that ensues in critically ill patients undergoing mechanical ventilation. The reported incidence of VAP varies between 9% and 68% with a mortality ranging between 33% and 71%. Two key factors are implicated in the pathogenesis of VAP: bacterial colonization of the upper digestive-respiratory tract and aspiration of oral secretions into the trachea. Preventive measurements are advocated to reduce the incidence of VAP, such as selective decontamination of the digestive tract (SDD), supraglottic aspiration and positioning. Prompt recognition and treatment of established VAP has also been demostrated to affect outcome. Therefore, the knowledge of risk factors associated with the development of VAP and the implementation of strategies to prevent, diagnose and treat VAP are mainstems in the nursing of mechanically ventilated patients.

  15. CFD and Ventilation Research

    DEFF Research Database (Denmark)

    Li, Y.; Nielsen, Peter V.

    2011-01-01

    There has been a rapid growth of scientific literature on the application of computational fluid dynamics (CFD) in the research of ventilation and indoor air science. With a 1000–10,000 times increase in computer hardware capability in the past 20 years, CFD has become an integral part...... of scientific research and engineering development of complex air distribution and ventilation systems in buildings. This review discusses the major and specific challenges of CFD in terms of turbulence modelling, numerical approximation, and boundary conditions relevant to building ventilation. We emphasize...... the growing need for CFD verification and validation, suggest on-going needs for analytical and experimental methods to support the numerical solutions, and discuss the growing capacity of CFD in opening up new research areas. We suggest that CFD has not become a replacement for experiment and theoretical...

  16. Auxiliary mine ventilation manual

    International Nuclear Information System (INIS)

    Workplace Safety North

    2010-01-01

    An adequate ventilation system is needed for air quality and handling in a mine and is comprised of many different pieces of equipment for removing contaminated air and supplying fresh air and thereby provide a satisfactory working environment. This manual highlights auxiliary ventilation systems made up of small fans, ducts, tubes, air movers, deflectors and additional air flow controls which distribute fresh air delivered by the primary system to all areas. A review of auxiliary ventilation is provided. Design, operation and management issues are discussed and guidelines are furnished. This manual is limited to underground hard rock operations and does not address directly other, specific auxiliary systems, either in underground coal mines or uranium mines.

  17. Auxiliary mine ventilation manual

    Energy Technology Data Exchange (ETDEWEB)

    Workplace Safety North

    2010-07-01

    An adequate ventilation system is needed for air quality and handling in a mine and is comprised of many different pieces of equipment for removing contaminated air and supplying fresh air and thereby provide a satisfactory working environment. This manual highlights auxiliary ventilation systems made up of small fans, ducts, tubes, air movers, deflectors and additional air flow controls which distribute fresh air delivered by the primary system to all areas. A review of auxiliary ventilation is provided. Design, operation and management issues are discussed and guidelines are furnished. This manual is limited to underground hard rock operations and does not address directly other, specific auxiliary systems, either in underground coal mines or uranium mines.

  18. Performance of ICU ventilators during noninvasive ventilation with large leaks in a total face mask: a bench study.

    Science.gov (United States)

    Nakamura, Maria Aparecida Miyuki; Costa, Eduardo Leite Vieira; Carvalho, Carlos Roberto Ribeiro; Tucci, Mauro Roberto

    2014-01-01

    Discomfort and noncompliance with noninvasive ventilation (NIV) interfaces are obstacles to NIV success. Total face masks (TFMs) are considered to be a very comfortable NIV interface. However, due to their large internal volume and consequent increased CO2 rebreathing, their orifices allow proximal leaks to enhance CO2 elimination. The ventilators used in the ICU might not adequately compensate for such leakage. In this study, we attempted to determine whether ICU ventilators in NIV mode are suitable for use with a leaky TFM. This was a bench study carried out in a university research laboratory. Eight ICU ventilators equipped with NIV mode and one NIV ventilator were connected to a TFM with major leaks. All were tested at two positive end-expiratory pressure (PEEP) levels and three pressure support levels. The variables analyzed were ventilation trigger, cycling off, total leak, and pressurization. Of the eight ICU ventilators tested, four did not work (autotriggering or inappropriate turning off due to misdetection of disconnection); three worked with some problems (low PEEP or high cycling delay); and one worked properly. The majority of the ICU ventilators tested were not suitable for NIV with a leaky TFM.

  19. Performance of ICU ventilators during noninvasive ventilation with large leaks in a total face mask: a bench study* **

    Science.gov (United States)

    Nakamura, Maria Aparecida Miyuki; Costa, Eduardo Leite Vieira; Carvalho, Carlos Roberto Ribeiro; Tucci, Mauro Roberto

    2014-01-01

    Objective: Discomfort and noncompliance with noninvasive ventilation (NIV) interfaces are obstacles to NIV success. Total face masks (TFMs) are considered to be a very comfortable NIV interface. However, due to their large internal volume and consequent increased CO2 rebreathing, their orifices allow proximal leaks to enhance CO2 elimination. The ventilators used in the ICU might not adequately compensate for such leakage. In this study, we attempted to determine whether ICU ventilators in NIV mode are suitable for use with a leaky TFM. Methods: This was a bench study carried out in a university research laboratory. Eight ICU ventilators equipped with NIV mode and one NIV ventilator were connected to a TFM with major leaks. All were tested at two positive end-expiratory pressure (PEEP) levels and three pressure support levels. The variables analyzed were ventilation trigger, cycling off, total leak, and pressurization. Results: Of the eight ICU ventilators tested, four did not work (autotriggering or inappropriate turning off due to misdetection of disconnection); three worked with some problems (low PEEP or high cycling delay); and one worked properly. Conclusions: The majority of the ICU ventilators tested were not suitable for NIV with a leaky TFM. PMID:25029653

  20. Cardiopulmonary function and oxygen delivery during total liquid ventilation.

    Science.gov (United States)

    Tsagogiorgas, Charalambos; Alb, Markus; Herrmann, Peter; Quintel, Michael; Meinhardt, Juergen P

    2011-10-01

    Total liquid ventilation (TLV) with perfluorocarbons has shown to improve cardiopulmonary function in the injured and immature lung; however there remains controversy over the normal lung. Hemodynamic effects of TLV in the normal lung currently remain undetermined. This study compared changes in cardiopulmonary and circulatory function caused by either liquid or gas tidal volume ventilation. In a prospective, controlled study, 12 non-injured anesthetized, adult New Zealand rabbits were primarily conventionally gas-ventilated (CGV). After instrumentation for continuous recording of arterial (AP), central venous (CVP), left artrial (LAP), pulmonary arterial pressures (PAP), and cardiac output (CO) animals were randomized into (1) CGV group and (2) TLV group. In the TLV group partial liquid ventilation was initiated with instillation of perfluoroctylbromide (12 ml/kg). After 15 min, TLV was established for 3 hr applying a volume-controlled, pressure-limited, time-cycled ventilation mode using a double-piston configured TLV. Controls (CGV) remained gas-ventilated throughout the experiment. During TLV, heart rate, CO, PAP, MAP, CVP, and LAP as well as derived hemodynamic variables, arterial and mixed venous blood gases, oxygen delivery, PVR, and SVR did not differ significantly compared to CGV. Liquid tidal volumes suitable for long-term TLV in non-injured rabbits do not significantly impair CO, blood pressure, and oxygen dynamics when compared to CGV. Copyright © 2011 Wiley-Liss, Inc.

  1. Correlation between alveolar ventilation and electrical properties of lung parenchyma.

    Science.gov (United States)

    Roth, Christian J; Ehrl, Andreas; Becher, Tobias; Frerichs, Inéz; Schittny, Johannes C; Weiler, Norbert; Wall, Wolfgang A

    2015-06-01

    One key problem in modern medical imaging is linking measured data and actual physiological quantities. In this article we derive such a link between the electrical bioimpedance of lung parenchyma, which can be measured by electrical impedance tomography (EIT), and the magnitude of regional ventilation, a key to understanding lung mechanics and developing novel protective ventilation strategies. Two rat-derived three-dimensional alveolar microstructures obtained from synchrotron-based x-ray tomography are each exposed to a constant potential difference for different states of ventilation in a finite element simulation. While the alveolar wall volume remains constant during stretch, the enclosed air volume varies, similar to the lung volume during ventilation. The enclosed air, serving as insulator in the alveolar ensemble, determines the resulting current and accordingly local tissue bioimpedance. From this we can derive a relationship between lung tissue bioimpedance and regional alveolar ventilation. The derived relationship shows a linear dependence between air content and tissue impedance and matches clinical data determined from a ventilated patient at the bedside.

  2. Comparing the effects of rise time and inspiratory cycling criteria on 6 different mechanical ventilators.

    Science.gov (United States)

    Gonzales, Joshua F; Russian, Christopher J; Gregg Marshall, S; Collins, Kevin P

    2013-03-01

    Inspiratory rise time and cycling criteria are important settings in pressure support ventilation. The purpose of this study was to investigate the impact of minimum and maximum rise time and inspiratory cycling criteria settings on 6 new generation ventilators. Our hypothesis was there would be a difference in the exhaled tidal volume, inspiratory time, and peak flow among 6 different ventilators, based, on change in rise time and cycling criteria. The research utilized a breathing simulator and 4 different ventilator models. All mechanical ventilators were set to a spontaneous mode of ventilation with settings of pressure support 8 cm H2O and PEEP of 5 cm H2O. A minimum and maximum setting for rise time and cycling criteria were examined. Exhaled tidal volume, inspiratory time, and peak flow measurements were recorded for each simulation. Significant (P ventilator. Significant differences in exhaled tidal volume, inspiratory time, and peak flow were observed by adjusting rise time and cycling criteria. This research demonstrates that during pressure support ventilation strategy, adjustments in rise time and/or cycling criteria can produce changes in inspiratory parameters. Obviously, this finding has important implications for practitioners who utilize a similar pressure support strategy when conducting a ventilator wean. Additionally, this study outlines major differences among ventilator manufacturers when considering inspiratory rise time and cycling criteria.

  3. Ventilation with heat recovery

    DEFF Research Database (Denmark)

    Tommerup, Henrik M.; Svendsen, Svend

    2005-01-01

    This paper presents the experiences from the use of ventilation with heat recovery in several experimental single-family houses developed and built within the last four years to meet the new Danish energy requirements of 2005. Included are descriptions of the ventilation system components...... and the main functional demands as well as measurements of the thermal efficiency, electricity consumptions and building air tightness. The paper addresses the aspects of minimizing the heat loss from the duct system and the heat recovery unit (when placed in an unheated attic space) in order to obtain...

  4. Behovstyret ventilation til enfamiliehuse

    DEFF Research Database (Denmark)

    Nielsen, Toke Rammer; Drivsholm, Christian; Hansen, Mads Peter Rudolph

    Muligheden for behovsstyret ventilation i enfamiliehuse er undersøgt. To strategier er afprøvet i praksis: En relativ simpel og billig strategi og en relativ avanceret og dyr strategi. Den simple strategi regulerer luftskiftet ensartet for alle rum mellem et lavt eller højt niveau. Den avancerede...... ventilation efter gældende krav. Desuden kræver den simple regulering kun få sensorer og er således væsentlig billigere og enklere at implementere end den avancerede strategi....

  5. 1-3-7 minute intravenous urography

    International Nuclear Information System (INIS)

    Bahk, Yong Whee; Yoon, Sei Chul; Lee, Myung Hee

    1980-01-01

    Intravenous urography (IVU) as it is used widely today was probably started in early 1950's after the introduction of triiodobenzoic acid compounds as contrast media. This long cherished traditional method consists of taking radiograms at 5, 15 and 25 minutes after the injection of contrast medium. There are a few modifications of this standard urographic examination such as five minute IVU (Woodruff, 1959), minute-sequence pyelogram (Maxwell et al., 1964), drip infusion pyelography (Schencker, 1964) and nephrotomography (Evans et al., 1955). The present study has been undertaken to test if the conventional standard IVU can be more rapidly performed without losing essential informational contents of urograms. In this new clinical trial, urograms were taken at the end of 1, 3 and 7 minutes instead of 5, 15 and 25 minutes after the intravenous injection of contrast medium. We injected 40 ml of meglumine diatrizoate solution within 30 seconds using an 18G iv needle. (The amount of injected contrast medium has been reduced recently to ordinary single dose of 20 ml for subjects weighing less than 8 kg). Upon viewing the 7 minute film in front of an automatic processor, the examination was terminated after obtaining an upright view unless any further radiogram was indicated. As shown in Tables and Figures, our new 1-3-7 minute method has been proven to provide us with as much essential and useful information as conventional 5-15-25 minute urography. Thus, we were able to finish one examination within 10 minutes without losing any necessary diagnostic information. In some of patients with obstructive uropathy such as stone the examination was extended as long as it was desired. Side reactions were occasional nausea, flushing and rare mild vomiting which never prevented the examination

  6. Development of analog watch with minute repeater

    Science.gov (United States)

    Okigami, Tomio; Aoyama, Shigeru; Osa, Takashi; Igarashi, Kiyotaka; Ikegami, Tomomi

    A complementary metal oxide semiconductor with large scale integration was developed for an electronic minute repeater. It is equipped with the synthetic struck sound circuit to generate natural struck sound necessary for the minute repeater. This circuit consists of an envelope curve drawing circuit, frequency mixer, polyphonic mixer, and booster circuit made by using analog circuit technology. This large scale integration is a single chip microcomputer with motor drivers and input ports in addition to the synthetic struck sound circuit, and it is possible to make an electronic system of minute repeater at a very low cost in comparison with the conventional type.

  7. Development of energy-efficient comfort ventilation plants with air quality controlled volume flow rate and continuous detection of the status of the windows aperture. Part 3. Final report with documentation of the field test; Entwicklung energieeffizienter Komfortlueftungsanlagen mit luftqualitaetsgefuehrter Volumenstromregelung und kontinuierlicher Erfassung des Fensteroeffnungszustandes. Teilbericht 3. Endbericht mit Dokumentation des Feldtests

    Energy Technology Data Exchange (ETDEWEB)

    Grossklos, Marc; Hacke, Ulrike [Institut Wohnen und Umwelt GmbH, Darmstadt (Germany)

    2012-10-25

    Residential ventilation systems with a heat recovery contribute to the improvement of the air quality and to the reduction of heat losses caused by ventilation. An additional opening of the windows in residential buildings results in a clearly increasing consumption of thermal heat because the thermal heat of the out coming air cannot be utilized furthermore. Continuous information on the energetic effects of the opening of windows is helpful. Under this aspect, the authors of the contribution under consideration report on the development of energy efficient comfort ventilation systems with an air quality controlled volume flow rate and continuous detection of the status of the windows aperture. The contribution under consideration is the third part of a project concerning to this theme. This part encompasses a field test with four single-family houses in which the air quality control as well as the detection of the status of the windows aperture is tested and optimized for a long period. This contribution also contains the results of the second part of the project. The second project investigate the technical implementation of a air quality regulation at prototypes and test facilities.

  8. Krypton for computed tomography lung ventilation imaging: preliminary animal data.

    Science.gov (United States)

    Mahnken, Andreas H; Jost, Gregor; Pietsch, Hubertus

    2015-05-01

    The objective of this study was to assess the feasibility and safety of krypton ventilation imaging with intraindividual comparison to xenon ventilation computed tomography (CT). In a first step, attenuation of different concentrations of xenon and krypton was analyzed in a phantom setting. Thereafter, 7 male New Zealand white rabbits (4.4-6.0 kg) were included in an animal study. After orotracheal intubation, an unenhanced CT scan was obtained in end-inspiratory breath-hold. Thereafter, xenon- (30%) and krypton-enhanced (70%) ventilation CT was performed in random order. After a 2-minute wash-in of gas A, CT imaging was performed. After a 45-minute wash-out period and another 2-minute wash-in of gas B, another CT scan was performed using the same scan protocol. Heart rate and oxygen saturation were measured. Unenhanced and krypton or xenon data were registered and subtracted using a nonrigid image registration tool. Enhancement was quantified and statistically analyzed. One animal had to be excluded from data analysis owing to problems during intubation. The CT scans in the remaining 6 animals were completed without complications. There were no relevant differences in oxygen saturation or heart rate between the scans. Xenon resulted in a mean increase of enhancement of 35.3 ± 5.5 HU, whereas krypton achieved a mean increase of 21.9 ± 1.8 HU in enhancement (P = 0.0055). The use of krypton for lung ventilation imaging appears to be feasible and safe. Despite the use of a markedly higher concentration of krypton, enhancement is significantly worse when compared with xenon CT ventilation imaging, but sufficiently high for CT ventilation imaging studies.

  9. Demand controlled ventilation; Behovsstyrt ventilasjon

    Energy Technology Data Exchange (ETDEWEB)

    Soerensen, Henning Holm

    2006-07-01

    The terms CAV and VAV have been known terms for many years in the ventilation business. The terms are also included in building regulations, but the time is now right to focus on demand controlled ventilation (DCV). The new building regulations and the accompanying energy framework underline the need for a more nuanced thinking when it comes to controlling ventilation systems. Descriptions and further details of the ventilation systems are provided (ml)

  10. Assessment of tidal volume and thoracoabdominal motion using volume and flow-oriented incentive spirometers in healthy subjects

    Directory of Open Access Journals (Sweden)

    V.F. Parreira

    2005-07-01

    Full Text Available The objective of the present study was to evaluate incentive spirometers using volume- (Coach and Voldyne and flow-oriented (Triflo II and Respirex devices. Sixteen healthy subjects, 24 ± 4 years, 62 ± 12 kg, were studied. Respiratory variables were obtained by respiratory inductive plethysmography, with subjects in a semi-reclined position (45º. Tidal volume, respiratory frequency, minute ventilation, inspiratory duty cycle, mean inspiratory flow, and thoracoabdominal motion were measured. Statistical analysis was performed with Kolmogorov-Smirnov test, t-test and ANOVA. Comparison between the Coach and Voldyne devices showed that larger values of tidal volume (1035 ± 268 vs 947 ± 268 ml, P = 0.02 and minute ventilation (9.07 ± 3.61 vs 7.49 ± 2.58 l/min, P = 0.01 were reached with Voldyne, whereas no significant differences in respiratory frequency were observed (7.85 ± 1.24 vs 8.57 ± 1.89 bpm. Comparison between flow-oriented devices showed larger values of inspiratory duty cycle and lower mean inspiratory flow with Triflo II (0.35 ± 0.05 vs 0.32 ± 0.05 ml/s, P = 0.00, and 531 ± 137 vs 606 ± 167 ml/s, P = 0.00, respectively. Abdominal motion was larger (P < 0.05 during the use of volume-oriented devices compared to flow-oriented devices (52 ± 11% for Coach and 50 ± 9% for Voldyne; 43 ± 13% for Triflo II and 44 ± 14% for Respirex. We observed that significantly higher tidal volume associated with low respiratory frequency was reached with Voldyne, and that there was a larger abdominal displacement with volume-oriented devices.

  11. [Six-minute walk test in children with neuromuscular disease.

    Science.gov (United States)

    Cruz-Anleu, Israel Didier; Baños-Mejía, Benjamín Omar; Galicia-Amor, Susana

    2013-01-01

    Background: neuromuscular diseases affect the motor unit. When they evolve, respiratory complications are common; the six-minute walk test plays an important role in the assessment of functional capacity. Methods: prospective, transversal, descriptive and observational study. We studied seven children with a variety of neuromuscular diseases and spontaneous ambulation. We tested their lung function, and administered a six-minute walk test and a test of respiratory muscle strength to these children. Results: the age was 9.8 ± 2.4 years. All patients were males. Forced vital capacity decreased in three patients (42.8 %), forced expiratory volume during the first second (2.04 ± 1.4 L) and peak expiratory flow (4.33 ± 3.3 L/s) were normal. The maximum strength of respiratory muscles was less than 60 % of predicted values. The distance covered in the six-minute walk test was lower when compared with healthy controls (29.9 %). Conclusions: the six-minute walk test can be a useful tool in early stages of this disease, since it is easy to perform and well tolerated by the patients.

  12. U.S. 15 Minute Precipitation Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — U.S. 15 Minute Precipitation Data is digital data set DSI-3260, archived at the National Climatic Data Center (NCDC). This is precipitation data. The primary source...

  13. Hybrid Ventilation Air Flow Process

    DEFF Research Database (Denmark)

    Heiselberg, Per Kvols

    The scope of this annex is therefore to obtain better knowledge of the use of hybrid ventilation technologies. The annex focus on development of control strategies for hybrid ventilation, on development of methods to predict hybrid ventilation performance in office buildings and on implementation...

  14. Ventilator and viral induced inflammation

    NARCIS (Netherlands)

    Hennus, M.P.

    2013-01-01

    This thesis expands current knowledge on ventilator induced lung injury and provides insights on the immunological effects of mechanical ventilation during viral respiratory infections. The experimental studies in the first part of this thesis improve our understanding of how mechanical ventilation

  15. How to Plan Ventilation Systems.

    Science.gov (United States)

    Clarke, John H.

    1963-01-01

    Ventilation systems for factory safety demand careful planning. The increased heat loads and new processes of industry have introduced complex ventilation problems in--(1) ventilation supply, (2) duct work design, (3) space requirements, (4) hood face velocities, (5) discharge stacks, and (6) building eddies. This article describes and diagrams…

  16. Thermal Plumes in Ventilated Rooms

    DEFF Research Database (Denmark)

    Kofoed, P.; Nielsen, Peter Vilhelm

    The main objective of ventilation is to provide good air quality for the occupants. For this purpose the necessary ventilating air change rate must be determined. Within displacement ventilation the estimation is closely related to the air flow rate in the thermal plumes when an air quality based...

  17. Management of critically ill patients receiving noninvasive and invasive mechanical ventilation in the emergency department

    Directory of Open Access Journals (Sweden)

    Rose L

    2012-03-01

    Full Text Available Louise RoseLawrence S Bloomberg Faculty of Nursing, University of Toronto, Toronto, Ontario, CanadaAbstract: Patients requiring noninvasive and invasive ventilation frequently present to emergency departments, and may remain for prolonged periods due to constrained critical care services. Emergency clinicians often do not receive the same education on management of mechanical ventilation or have similar exposure to these patients as do their critical care colleagues. The aim of this review was to synthesize the evidence on management of patients requiring noninvasive and invasive ventilation in the emergency department including indications, clinical applications, monitoring priorities, and potential complications. Noninvasive ventilation is recommended for patients with acute exacerbation of chronic obstructive pulmonary disease or cardiogenic pulmonary edema. Less evidence supports its use in asthma and other causes of acute respiratory failure. Use of noninvasive ventilation in the prehospital setting is relatively new, and some evidence suggests benefit. Monitoring priorities for noninvasive ventilation include response to treatment, respiratory and hemodynamic stability, noninvasive ventilation tolerance, detection of noninvasive ventilation failure, and identification of air leaks around the interface. Application of injurious ventilation increases patient morbidity and mortality. Lung-protective ventilation with low tidal volumes based on determination of predicted body weight and control of plateau pressure has been shown to reduce mortality in patients with acute respiratory distress syndrome, and some evidence exists to suggest this strategy should be used in patients without lung injury. Monitoring of the invasively ventilated patient should focus on assessing response to mechanical ventilation and other interventions, and avoiding complications, such as ventilator-associated pneumonia. Several key aspects of management of noninvasive

  18. Algebra success in 20 minutes a day

    CERN Document Server

    LearningExpress, LLC

    2014-01-01

    Stripped of unnecessary math jargon but bursting with algebra essentials, this handy guide covers vital algebra skills that apply to real-world scenarios. Whether you're new to algebra or just looking for a refresher, Algebra Success in 20 Minutes a Day offers a lesson plan that provides quick and thorough instruction in practical, critical skills. All lessons can be completed in just 20 minutes a day, for a manageable and non-intimidating learning experience.

  19. Measurements of pulmonary ventilation following inhalation of Isovist trademark -300

    International Nuclear Information System (INIS)

    Thiele, J.; Kloeppel, R.

    1995-01-01

    A self-experiment was performed, in which representative planar images of the lungs were obtained using computerized tomography following inhalation of highly atomized isoosmolar contrast medium (Isovist-300 produced by the firm Schering). The administration of 2 ml contrast medium over 15 minutes was well tolerated by a healthy volunteer and caused no discomfort. The pattern of the contrast medium distribution was in accordance with that of regional ventilation. An increased density of peripheral vascular structures was not observed. The procedure can thus be regarded as an addition to the range of methods used in computerized tomography for measurements of pulmonary ventilation. (orig.) [de

  20. The amazing Minivent ventilator

    African Journals Online (AJOL)

    Southern African Journal of Anaesthesia and Analgesia is co-published by Medpharm Publications, NISC (Pty) Ltd and Cogent, ... Respiratory rate was obtained by counting the clicking noise ... was appointed as a part-time lecturer to the University of the ... The Minivent became the first of three miniature ventilators that.

  1. Omnidirectional ventilated acoustic barrier

    Science.gov (United States)

    Zhang, Hai-long; Zhu, Yi-fan; Liang, Bin; Yang, Jing; Yang, Jun; Cheng, Jian-chun

    2017-11-01

    As an important problem in acoustics, sound insulation finds applications in a great variety of situations. In the existing schemes, however, there has always been a trade-off between the thinness of sound-insulating devices and their ventilating capabilities, limiting their potentials in the control of low-frequency sound in high ventilation environments. Here, we design and experimentally implement an omnidirectional acoustic barrier with a planar profile, subwavelength thickness ( 0.18 λ ), yet high ventilation. The proposed mechanism is based on the interference between the resonant scattering of discrete states and the background scattering of continuous states which induces a Fano-like asymmetric transmission profile. Benefitting from the binary-structured design of the coiled unit and hollow pipe, it maximally simplifies the design and fabrication while ensuring the ventilation for all the non-resonant units with open tubes. The simulated and measured results agree well, showing the effectiveness of our proposed mechanism to block low frequency sound coming from various directions while allowing 63% of the air flow to pass. We anticipate our design to open routes to design sound insulators and to enable applications in traditionally unattainable cases such as those calling for noise reduction and cooling simultaneously.

  2. Mechanical ventilation of mice

    NARCIS (Netherlands)

    Schwarte, L. A.; Zuurbier, C. J.; Ince, C.

    2000-01-01

    Due to growing interest in murine functional genomics research, there is an increasing need for physiological stable in vivo murine models. Of special importance is support and control of ventilation by artificial respiration, which is difficult to execute as a consequence of the small size of the

  3. Lavt elforbrug til ventilation

    DEFF Research Database (Denmark)

    Jagemar, L.; Bergsøe, Niels Christian

    Rapporten giver gode råd om mulige energibesparelser og praktiske projekteringshensyn, som er forbundet med udformning af energieffektiv ventilation i ikke blot kontorbygninger, men i alle bygninger med komfortventilationsanlæg. I forbindelse med projektering af ventilationsanlæg har interessen...

  4. Understanding mechanical ventilators.

    Science.gov (United States)

    Chatburn, Robert L

    2010-12-01

    The respiratory care academic community has not yet adopted a standardized system for classifying and describing modes of ventilation. As a result, there is enough confusion that patient care, clinician education and even ventilator sales are all put at risk. This article summarizes a ventilator mode taxonomy that has been extensively published over the last 15 years. Specifically, the classification system has three components: a description of the control variables within breath; a description of the sequence of mandatory and spontaneous breaths; and a specification for the targeting scheme. This three-level specification provides scalability of detail to make the mode description appropriate for the particular need. At the bedside, we need only refer to a mode briefly using the first or perhaps first and second components. To distinguish between similar modes and brand names, we would need to include all components. This taxonomy uses the equation of motion for the respiratory system as the underlying theoretical framework. All terms relevant to describing modes of mechanical ventilation are defined in an extensive appendix.

  5. Positional effects on distribution of ventilation in chronic obstructive pulmonary disease

    International Nuclear Information System (INIS)

    Shim, C.; Chun, K.J.; Williams, M.H. Jr.; Blaufox, M.D.

    1986-01-01

    Ventilation is distributed predominantly to the dependent lung in normal persons in the decubitus position. We evaluated the distribution of ventilation in four patients with mild-to-moderate chronic obstructive pulmonary disease using 81mKr gas. Patients were tested in the sitting and right and left decubitus positions with and without the application of positive end expiratory pressure (PEEP). In contrast to findings in controls, ventilation was predominantly distributed to the nondependent lung in patients in the decubitus position. Mean ventilation in the right lung decreased from 51% of the total in the sitting position to 31% in the right decubitus position; it increased with the application of 10 cm PEEP. Reduced ventilation in the dependent lung most likely is caused by closure of the airways after a decrease in volume. Application of PEEP resulted in increased lung volume and preferential distribution of ventilation to the dependent lung

  6. Human response to ductless personalized ventilation coupled with displacement ventilation

    DEFF Research Database (Denmark)

    Dalewski, Mariusz; Veselý, Michal; Melikov, Arsen K.

    2012-01-01

    A human subject experiment was carried out to investigate the extent to which ductless personalized ventilation (DPV) in conjunction with displacement ventilation can improve perceived air quality (PAQ) and thermal comfort at elevated room air temperature in comparison with displacement ventilation...... alone. The experimental conditions comprised displacement ventilation alone (room air temperature of 23 °C, 26 °C, 29 °C) and DPV with displacement ventilation (26 °C, 29 °C), both operating at supply air temperatures 3, 5 or 6K lower than room air temperature, as well as mixing ventilation (23 °C, 3 K......). During one hour exposure participants answered questionnaires regarding PAQ and thermal comfort. PAQ was significantly better with DPV than without DPV at the same background conditions. Thermal comfort improved when DPV was used. Combining DPV with displacement ventilation showed the potential...

  7. The effects of aminophylline infusion in the treatment of children with acute asthma exacerbation. Evaluation with 81mKr ventilation scintigraphy

    International Nuclear Information System (INIS)

    Matsubara, Yasuko; Shimada, Takao

    1998-01-01

    The use of intravenous aminophylline in the treatment of children with acute asthma remains controversial. Most authors suggest that aminophylline be used with caution because of its poor efficacy with adverse reactions and instead recommend other drugs, such as β 2 -adrenergic agonists and glucocorticoids. However other studies have reported the benefits of aminophylline, and current Japanese guidelines for the management of asthma recommend its use. Here, we have evaluated the efficacy of aminophylline infusion in children with acute asthma exacerbations. Twenty children with acute asthma exacerbations were given an infusion of 5 mg/kg of aminophylline over 5 minutes, 30 minutes after the same volume of normal saline had been infused as a control. 81m Kr ventilation scintigraphy was done sequentially, and lung function was measured with spirometry before and after each infusion. Side effects were also evaluated with a questionnaire. Ventilation images obtained with 81m Kr scintigraphy, which initially showed widespread ventilatory defects caused by bronchoconstriction, decreased 54.9% after aminophylline infusion (p 81m Kr bolus inhalation procedure, also showed significant improvement (p<0.0001). These improvement were accompanied by improvements in lung function as assessed with forced expiratory volume in 1 second (p<0.01) and maximum expiratory flow rates at 25% (p<0.001) and 50% (p<0.001). No serious adverse reactions were recognized in any subjects. Our results show that aminophylline is a useful bronchodilator which decreased ventilatory imbalance and improves lung function in both central and peripheral airways. (author)

  8. Estimation of tidal ventilation in preterm and term newborn infants using electromagnetic inductance plethysmography

    International Nuclear Information System (INIS)

    Williams, E M; Pickerd, N; Kotecha, S; Eriksen, M; Øygarden, K

    2011-01-01

    Tidal volume (VT) measurements in newborn infants remain largely a research tool. Tidal ventilation and breathing pattern were measured using a new device, FloRight, which uses electromagnetic inductive plethysmography, and compared simultaneously with pneumotachography in 43 infants either receiving no respiratory support or continuous positive airway pressure (CPAP). Twenty-three infants were receiving CPAP (gestational age 28 ± 2 weeks, mean ± SD) and 20 were breathing spontaneously (gestational age 34 ± 4 weeks). The two methods were in reasonable agreement, with VT (r 2 = 0.69) ranging from 5 to 23 ml (4–11 ml kg −1 ) with a mean difference of 0.4 ml and limit of agreement of −4.7 to + 5.5 ml. For respiratory rate, minute ventilation, peak flow and breathing pattern indices, the mean difference between the two methods ranged between 0.7% and 5.8%. The facemask increased the respiratory rate (P < 0.001) in both groups with the change in VT being more pronounced in the infants receiving no respiratory support. Thus, FloRight provides an easy to use technique to measure term and preterm infants in the clinical environment without altering the infant's breathing pattern

  9. Humidification during high-frequency oscillation ventilation is affected by ventilator circuit and ventilatory setting.

    Science.gov (United States)

    Chikata, Yusuke; Imanaka, Hideaki; Onishi, Yoshiaki; Ueta, Masahiko; Nishimura, Masaji

    2009-08-01

    High-frequency oscillation ventilation (HFOV) is an accepted ventilatory mode for acute respiratory failure in neonates. As conventional mechanical ventilation, inspiratory gas humidification is essential. However, humidification during HFOV has not been clarified. In this bench study, we evaluated humidification during HFOV in the open circumstance of ICU. Our hypothesis is that humidification during HFOV is affected by circuit design and ventilatory settings. We connected a ventilator with HFOV mode to a neonatal lung model that was placed in an infant incubator set at 37 degrees C. We set a heated humidifier (Fisher & Paykel) to obtain 37 degrees C at the chamber outlet and 40 degrees C at the distal temperature probe. We measured absolute humidity and temperature at the Y-piece using a rapid-response hygrometer. We evaluated two types of ventilator circuit: a circuit with inner heating wire and another with embedded heating element. In addition, we evaluated three lengths of the inspiratory limb, three stroke volumes, three frequencies, and three mean airway pressures. The circuit with embedded heating element provided significantly higher absolute humidity and temperature than one with inner heating wire. As an extended tube lacking a heating wire was shorter, absolute humidity and temperature became higher. In the circuit with inner heating wire, absolute humidity and temperature increased as stroke volume increased. Humidification during HFOV is affected by circuit design and ventilatory settings.

  10. Comparison of two modes of ventilation after fast-track cardiac surgery: Adaptive support ventilation versus synchronized intermittent mandatory ventilation

    International Nuclear Information System (INIS)

    Aghadavoudi, O.

    2012-01-01

    Objective: There is substantial debate regarding the appropriate protocol for ventilatory management in fast-track cardiac anesthesia (FTCA). This study was carried out to assess and compare the risks and benefits of respiratory weaning based on adaptive support ventilation (ASV) and synchronized intermittent mandatory ventilation (SIMV) after uncomplicated cardiac surgery. Methodology: In a randomized clinical trial, after receiving approval of the Department Research Committee and informed consent from study subjects, 100 patients undergoing elective coronary artery bypass graft (CABG) surgery with cardiopulmonary bypass (CPB) were enrolled during a 4-month period at a university-based hospital. After surgery and admission to the intensive care unit (ICU), patients were randomized to ASV and SIMV groups. Arterial blood gas (ABG) and hemodynamic variables, respiratory and ventilator characteristics including lung compliance, rapid shallow breathing index (RSBI), tidal volume (TV), respiratory rate (RR), peak inspiratory pressure (P peak), mean airway pressure (p mean), Pao2/FIo2, duration of mechanical ventilation and tracheal intubation, and length of ICU stay were recorded and compared between the two groups. The data were analyzed in 82 patients after considering the exclusion criteria. Results: There were no differences between ASV and SIMV groups in demographics and preoperative characteristics. The duration of tracheal intubation and the length of ICU stay were similar in both groups. There were no statistically and clinically relevant differences between the two groups in ABG, hemodynamic changes, and respiratory and ventilator characteristics during ICU stay. Conclusion: Although ASV may facilitate postoperative respiratory management in FTCA, both ASV and SIMV provide similarly safe and practicable respiratory weaning in the cardiac ICU. The evaluation of potential advantages in patient outcomes and resource utilization of respiratory weaning based on ASV

  11. Poor Adherence to Lung-Protective Mechanical Ventilation in Pediatric Acute Respiratory Distress Syndrome.

    Science.gov (United States)

    Ward, Shan L; Quinn, Carson M; Valentine, Stacey L; Sapru, Anil; Curley, Martha A Q; Willson, Douglas F; Liu, Kathleen D; Matthay, Michael A; Flori, Heidi R

    2016-10-01

    To determine the frequency of low-tidal volume ventilation in pediatric acute respiratory distress syndrome and assess if any demographic or clinical factors improve low-tidal volume ventilation adherence. Descriptive post hoc analysis of four multicenter pediatric acute respiratory distress syndrome studies. Twenty-six academic PICU. Three hundred fifteen pediatric acute respiratory distress syndrome patients. All patients who received conventional mechanical ventilation at hours 0 and 24 of pediatric acute respiratory distress syndrome who had data to calculate ideal body weight were included. Two cutoff points for low-tidal volume ventilation were assessed: less than or equal to 6.5 mL/kg of ideal body weight and less than or equal to 8 mL/kg of ideal body weight. Of 555 patients, we excluded 240 for other respiratory support modes or missing data. The remaining 315 patients had a median PaO2-to-FIO2 ratio of 140 (interquartile range, 90-201), and there were no differences in demographics between those who did and did not receive low-tidal volume ventilation. With tidal volume cutoff of less than or equal to 6.5 mL/kg of ideal body weight, the adherence rate was 32% at hour 0 and 33% at hour 24. A low-tidal volume ventilation cutoff of tidal volume less than or equal to 8 mL/kg of ideal body weight resulted in an adherence rate of 58% at hour 0 and 60% at hour 24. Low-tidal volume ventilation use was no different by severity of pediatric acute respiratory distress syndrome nor did adherence improve over time. At hour 0, overweight children were less likely to receive low-tidal volume ventilation less than or equal to 6.5 mL/kg ideal body weight (11% overweight vs 38% nonoverweight; p = 0.02); no difference was noted by hour 24. Furthermore, in the overweight group, using admission weight instead of ideal body weight resulted in misclassification of up to 14% of patients as receiving low-tidal volume ventilation when they actually were not. Low

  12. Ventilation of nuclear power plants

    International Nuclear Information System (INIS)

    Madoyan, A.A.; Vlasik, V.F.

    1984-01-01

    Foundations and calculation methods of ventilation of rooms with different degree of heat and gas release with the change of operation mode of NPP main equipment, as well as problems of NPP site and adjoining area aerodynamics, have been presented. Systems of air ventilation and conditioning, cooling equipment, are considered. The main points of designing are described and determination of economic efficiency of the ventilation systems are made. Technical characteristics of the ventilators, conditioners, filters and air heaters used, are presented. Organization of adjustment, tests, operation and maintenance of the ventilation systems of NPP with RBMK and WWER-type reactors, is described

  13. Mathematics of Ventilator-induced Lung Injury.

    Science.gov (United States)

    Rahaman, Ubaidur

    2017-08-01

    Ventilator-induced lung injury (VILI) results from mechanical disruption of blood-gas barrier and consequent edema and releases of inflammatory mediators. A transpulmonary pressure (P L ) of 17 cmH 2 O increases baby lung volume to its anatomical limit, predisposing to VILI. Viscoelastic property of lung makes pulmonary mechanics time dependent so that stress (P L ) increases with respiratory rate. Alveolar inhomogeneity in acute respiratory distress syndrome acts as a stress riser, multiplying global stress at regional level experienced by baby lung. Limitation of stress (P L ) rather than strain (tidal volume [V T ]) is the safe strategy of mechanical ventilation to prevent VILI. Driving pressure is the noninvasive surrogate of lung strain, but its relations to P L is dependent on the chest wall compliance. Determinants of lung stress (V T , driving pressure, positive end-expiratory pressure, and inspiratory flow) can be quantified in terms of mechanical power, and a safe threshold can be determined, which can be used in decision-making between safe mechanical ventilation and extracorporeal lung support.

  14. Metabolic and clinical comparative analysis of treadmill six-minute walking test and cardiopulmonary exercise testing in obese and eutrophic women

    Directory of Open Access Journals (Sweden)

    Luciana Di Thommazo-Luporini

    Full Text Available BACKGROUND: Impaired exercise tolerance is directly linked to decreased functional capacity as a consequence of obesity. OBJECTIVES: To analyze and compare the cardiopulmonary, metabolic, and perceptual responses during a cardiopulmonary exercise test (CPX and a treadmill six-minute walking test (tread6MWT in obese and eutrophic women. METHOD: Twenty-nine female participants, aged 20-45 years were included. Fourteen were allocated to the obese group and 15 to the eutrophic group. Anthropometric measurements and body composition assessment were performed. RESULTS: In both tests, obese women presented with significantly higher absolute oxygen uptake, minute ventilation, and systolic and diastolic blood pressure; they also presented with lower speed, distance walked, and oxygen uptake corrected by the weight compared to eutrophics. During the maximal exercise test, perceived dyspnea was greater and the respiratory exchange ratio was lower in obese subjects compared to eutrophics. During the submaximal test, carbon dioxide production, tidal volume, and heart rate were higher in obese subjects compared to eutrophic women. When analyzing possible correlations between the CPX and the tread6MWT at peak, there was a strong correlation for the variable heart rate and a moderate correlation for the variable oxygen uptake. The heart rate obtained in the submaximal test was able to predict the one obtained in the maximal test. Bland-Altman plots demonstrated the agreement between both tests to identify metabolic and physiological parameters at peak exercise. CONCLUSIONS: The six-minute walking test induced ventilatory, metabolic, and cardiovascular responses in agreement with the maximal testing. Thus, the six-minute walking test proves to be important for functional evaluation in the physical therapy routine.

  15. Control of ventilation system when changing of its topology

    International Nuclear Information System (INIS)

    Koketayev, A.I.

    2009-01-01

    The complex ventilation systems of modern coal and ore mines can be described by multidimensional and highly bound graphs. Because of changes in topology, it is very difficult to control ventilation systems in the event of emergency situations such as rock bumps, roof caving, sudden gas outburst, quicksand intrusion, or mine flooding. Special mathematical tools are needed to consider such changes and to determine the corresponding conditions of a mine's ventilation needs. This paper presented a system to simulate the behaviour of mine ventilation system. The system considered changes in topology as well as timely measures for support of necessary air quantity for safe conditions for miners in underground mine workings. The paper presented the details of the study with particular reference to the calculation of ventilation conditions; graphs and sub-graphs of the ventilation system; and corresponding equations. It was concluded that the simulated system would allow users to simulate the behaviour of the mine ventilation system when changing its topology in a timely manner and to take measures to control the required volume of air to ensure safe working conditions for underground miners. 3 refs., 1 fig.

  16. Design Procedure for Hybrid Ventilation

    DEFF Research Database (Denmark)

    Heiselberg, Per; Tjelflaat, Per Olaf

    Mechanical and natural ventilation systems have developed separately during many years. The natural next step in this development is development of ventilation concepts that utilises and combines the best features from each system into a new type of ventilation system - Hybrid Ventilation....... Buildings with hybrid ventilation often include other sustainable technologies and an energy optimisation requires an integrated approach in the design of the building and its mechanical systems. Therefore, the hybrid ventilation design procedure differs from the design procedure for conventional HVAC....... The first ideas on a design procedure for hybrid ventilation is presented and the different types of design methods, that is needed in different phases of the design process, is discussed....

  17. Closed-loop mechanical ventilation for lung injury: a novel physiological-feedback mode following the principles of the open lung concept.

    Science.gov (United States)

    Schwaiberger, David; Pickerodt, Philipp A; Pomprapa, Anake; Tjarks, Onno; Kork, Felix; Boemke, Willehad; Francis, Roland C E; Leonhardt, Steffen; Lachmann, Burkhard

    2018-06-01

    Adherence to low tidal volume (V T ) ventilation and selected positive end-expiratory pressures are low during mechanical ventilation for treatment of the acute respiratory distress syndrome. Using a pig model of severe lung injury, we tested the feasibility and physiological responses to a novel fully closed-loop mechanical ventilation algorithm based on the "open lung" concept. Lung injury was induced by surfactant washout in pigs (n = 8). Animals were ventilated following the principles of the "open lung approach" (OLA) using a fully closed-loop physiological feedback algorithm for mechanical ventilation. Standard gas exchange, respiratory- and hemodynamic parameters were measured. Electrical impedance tomography was used to quantify regional ventilation distribution during mechanical ventilation. Automatized mechanical ventilation provided strict adherence to low V T -ventilation for 6 h in severely lung injured pigs. Using the "open lung" approach, tidal volume delivery required low lung distending pressures, increased recruitment and ventilation of dorsal lung regions and improved arterial blood oxygenation. Physiological feedback closed-loop mechanical ventilation according to the principles of the open lung concept is feasible and provides low tidal volume ventilation without human intervention. Of importance, the "open lung approach"-ventilation improved gas exchange and reduced lung driving pressures by opening atelectasis and shifting of ventilation to dorsal lung regions.

  18. ASHRAE and residential ventilation

    Energy Technology Data Exchange (ETDEWEB)

    Sherman, Max H.

    2003-10-01

    In the last quarter of a century, the western world has become increasingly aware of environmental threats to health and safety. During this period, people psychologically retreated away from outdoors hazards such as pesticides, smog, lead, oil spills, and dioxin to the seeming security of their homes. However, the indoor environment may not be healthier than the outdoor environment, as has become more apparent over the past few years with issues such as mold, formaldehyde, and sick-building syndrome. While the built human environment has changed substantially over the past 10,000 years, human biology has not; poor indoor air quality creates health risks and can be uncomfortable. The human race has found, over time, that it is essential to manage the indoor environments of their homes. ASHRAE has long been in the business of ventilation, but most of the focus of that effort has been in the area of commercial and institutional buildings. Residential ventilation was traditionally not a major concern because it was felt that, between operable windows and envelope leakage, people were getting enough outside air in their homes. In the quarter of a century since the first oil shock, houses have gotten much more energy efficient. At the same time, the kinds of materials and functions in houses changed in character in response to people's needs. People became more environmentally conscious and aware not only about the resources they were consuming but about the environment in which they lived. All of these factors contributed to an increasing level of public concern about residential indoor air quality and ventilation. Where once there was an easy feeling about the residential indoor environment, there is now a desire to define levels of acceptability and performance. Many institutions--both public and private--have interests in Indoor Air Quality (IAQ), but ASHRAE, as the professional society that has had ventilation as part of its mission for over 100 years, is the

  19. Assessing ventilation system performance in isolation rooms

    Energy Technology Data Exchange (ETDEWEB)

    Balocco, Carla [Department of Energy Engineering ' ' Sergio Stecco' ' , via S. Marta 3, Firenze (Italy); Lio, Pietro [Computer Laboratory, University of Cambridge, 15 JJ Thompson Avenue, CB03FD Cambridge (United Kingdom)

    2011-01-15

    In this paper numerical transient simulations were used to investigate the air flow patterns, distribution and velocity, and the particulate dispersion inside an existing typical hospitalization room equipped with an advanced Heating Ventilation Air Conditioning (HVAC), with Variable Air Volume (VAV) primary air system designed for immune-suppressed patients never modelled before. The three-dimensional models of the room consider different, most typical, positions of the patients. Results indicate the best conditions for the high induction air inlet diffuser and the scheme of pressures imposed in the room to provide the effective means of controlling flows containing virus droplets. We believe that our work exemplifies the usefulness of numerical investigations of HVAC performances in real situations and provides important recommendations towards disease control and careful design and optimization of ventilation in hospital settings. (author)

  20. Diffuse Ceiling Ventilation

    DEFF Research Database (Denmark)

    Zhang, Chen; Yu, Tao; Heiselberg, Per Kvols

    cooling capacity, energy saving, low investment cost and low noise level; while the limitations include condensation risk and the limit on the room geometry. Furthermore, the crucial design parameters are summarized and their effects on the system performance are discussed. In addition to the stand...... is not well structured with this system. These become the motivations in developing the design guide. This design guide aims to establish a systematic understanding of diffuse ceiling ventilation and provide assistance in designing of such a system. The guide is targeted at design engineers, architects...... and manufacturers and the users of diffuse ceiling technology. The design guide introduces the principle and key characteristics of room air distribution with diffuse ceiling ventilation. It provides an overview of potential benefit and limitations of this technology. The benefits include high thermal comfort, high...

  1. Evaluation of 4 new generation portable ventilators.

    Science.gov (United States)

    Blakeman, Thomas C; Branson, Richard D

    2013-02-01

    Portable ventilators are increasingly utilized in the intra- and inter-hospital transport of patients. We evaluated 4 portable ventilators, Impact EMV, CareFusion LTV 1200, Newport HT70, and Hamilton T1, in terms of triggering, delivered tidal volume (V(T)) accuracy, battery duration, delivered F(IO(2)) accuracy, and gas consumption. Triggering was tested using a microprocessor controlled breathing simulator that simulated a weak, normal, and aggressive inspiratory effort using muscle pressures of -2, -4, and -8 cm H2O respectively. Delivered V(T) and F(IO(2)) accuracy were evaluated across a range of operation. To determine gas consumption, the ventilators were attached to an E type oxygen cylinder and operated at an F(IO(2)) of 1.0 until the tank was depleted. Battery duration was tested by operating each ventilator at an F(IO(2)) of 0.21 until the device ceased to operate. Differences remain among devices in several aspects of the testing protocol. Gas consumption ranged from 9.2 to 16 L/min. Battery duration ranged from 101 to 640 min. Triggering performance varied among devices but was consistent breath to breath within the same device, using the fastest and slowest rise time settings. F(IO(2)) accuracy varied at the low range on the 50 mL V(T) setting with one device, and at the high range on both the 50 mL and 500 mL V(T) settings with another. Manufacturers continue to improve the performance of portable ventilators. All the ventilators we tested performed well on V(T) delivery across a range of settings, using both the internal drive mechanism (F(IO(2)) 0.21) and compressed oxygen (F(IO(2)) 1.0). Two of the ventilators were unable to deliver accurate F(IO(2)) across the range of V(T). None of the devices was clearly superior to the others in all aspects of our evaluation. © 2013 Daedalus Enterprises.

  2. Geometry success in 20 minutes a day

    CERN Document Server

    LLC, LearningExpress

    2014-01-01

    Whether you're new to geometry or just looking for a refresher, Geometry Success in 20 Minutes a Day offers a 20-step lesson plan that provides quick and thorough instruction in practical, critical skills. Stripped of unnecessary math jargon but bursting with geometry essentials, Geometry Success in 20 Minutes a Day: Covers all vital geometry skills, from the basic building blocks of geometry to ratio, proportion, and similarity to trigonometry and beyond Provides hundreds of practice exercises in test format Applies geometr

  3. Daytime Mouthpiece for Continuous Noninvasive Ventilation in Individuals With Amyotrophic Lateral Sclerosis.

    Science.gov (United States)

    Bédard, Marie-Eve; McKim, Douglas A

    2016-10-01

    Noninvasive ventilation (NIV) is commonly used to provide ventilatory support for individuals with amyotrophic lateral sclerosis (ALS). Once 24-h ventilation is required, the decision between invasive tracheostomy ventilation and palliation is often faced. This study describes the use and outcomes of daytime mouthpiece ventilation added to nighttime mask ventilation for continuous NIV in subjects with ALS as an effective alternative. This was a retrospective study of 39 subjects with ALS using daytime mouthpiece ventilation over a 17-y period. Thirty-one subjects were successful with mouthpiece ventilation, 2 were excluded, 2 stopped because of lack of motivation, and 4 with bulbar subscores of the Revised Amyotrophic Lateral Sclerosis Functional Rating Scale (b-ALSFRS-R) between 0 and 3 physically failed to use it consistently. No subject in the successful group had a b-ALSFRS-R score of NIV and mouthpiece ventilation were 648 (176-2,188) and 286 (41-1,769) d, respectively. Peak cough flow with lung-volume recruitment >180 L/min at initiation of mouthpiece ventilation was associated with a longer survival (637 ± 468 vs 240 ± 158 d (P = .01). Mouthpiece ventilation provides effective ventilation and prolonged survival for individuals with ALS requiring full-time ventilatory support and maintaining adequate bulbar function. Copyright © 2016 by Daedalus Enterprises.

  4. Harnessing natural ventilation benefits.

    Science.gov (United States)

    O'Leary, John

    2013-04-01

    Making sure that a healthcare establishment has a good supply of clean fresh air is an important factor in keeping patients, staff, and visitors, free from the negative effects of CO2 and other contaminants. John O'Leary of Trend Controls, a major international supplier of building energy management solutions (BEMS), examines the growing use of natural ventilation, and the health, energy-saving, and financial benefits, that it offers.

  5. Purge ventilation operability

    International Nuclear Information System (INIS)

    Marella, J.R.

    1995-01-01

    A determination of minimum requirements for purge exhaust ventilation system operability has been performed. HLWE and HLW Regulatory Program personnel have evaluated the various scenarios of equipment conditions and HLWE has developed the requirements for purge exhaust systems. This report is provided to document operability requirements to assist Tank Farm personnel to determine whether a system is operable/inoperable and to define required compensatory actions

  6. Ventilation i industrien

    DEFF Research Database (Denmark)

    Valbjørn, O.

    I en række afsnit belyses problemer med træk, kulde, varme, og luftforurening på industriens arbejdspladser, og hvordan man ved ventilation og bygningsudformning kan bekæmpe disse gener. Hvert afsnit kan i princippet læses for sig, og anvisningen kan derfor bruges som håndbog, både af de der er...

  7. Criteria for Postoperative Mechanical Ventilation After Thymectomy in Patients With Myasthenia Gravis: A Retrospective Analysis.

    Science.gov (United States)

    Chigurupati, Keerthi; Gadhinglajkar, Shrinivas; Sreedhar, Rupa; Nair, Muraleedharan; Unnikrishnan, Madathipat; Pillai, Manjusha

    2018-02-01

    To determine the criteria for postoperative mechanical ventilation after thymectomy in patients with Myasthenia Gravis. Retrospective study. Teritiary care centre. 77 Myasthenia gravis patients operated for thymectomy were studied. After obtaining clearance from Institutional ethics committee, medical records of 77 patients with MG, who were operated for thymectomy between January 2005 and December 2015 were reviewed in a retrospective manner. Perioperative variables collected from the patient records were demographic data, duration of the disease, Osserman and Genkin classification, Anti-acetylcholine antibody (AChR) positivity, preoperative daily dose of drug, history of preoperative myasthenic crisis, preoperative vital capacity, technique of anesthesia, drugs used for anesthesia, perioperative complications, and duration of postoperative mechanical ventilation. The patients were divided into two groups, group I and group II consisting of those who required postoperative ventilation for 300 minutes, respectively. The determinants of prolonged postoperative ventilation were studied. The requirement of mechanical ventilation was higher in patients with higher Osserman's grade of myasthenia gravis. Duration of the disease had no effect on the duration of mechanical ventilation in myasthenic patients post thymectomy (p = 0.89). The patients with a preoperative history of myasthenic crisis had a requirement for prolonged mechanical ventilation (p=0.03). Patients with preoperative vital capacity mechanical ventilation with p values mechanical ventilation (p=0.026). Preoperative dose of pyridostigmine and the choice of continuation or discontinuation of antcholinesterases on the day of surgery had no influence on the duration of mechanical ventilation (p value of 0.19 and 0.36 respectively). Epidural analgesia intra and postoperatively significantly reduced the requirement of mechanical ventilation (p=0.006). The predictors of postoperative ventilation in myasthenic

  8. Multicenter comparative study of conventional mechanical gas ventilation to tidal liquid ventilation in oleic acid injured sheep.

    Science.gov (United States)

    Wolfson, Marla R; Hirschl, Ronald B; Jackson, J Craig; Gauvin, France; Foley, David S; Lamm, Wayne J E; Gaughan, John; Shaffer, Thomas H

    2008-01-01

    We performed a multicenter study to test the hypothesis that tidal liquid ventilation (TLV) would improve cardiopulmonary, lung histomorphological, and inflammatory profiles compared with conventional mechanical gas ventilation (CMV). Sheep were studied using the same volume-controlled, pressure-limited ventilator systems, protocols, and treatment strategies in three independent laboratories. Following baseline measurements, oleic acid lung injury was induced and animals were randomized to 4 hours of CMV or TLV targeted to "best PaO2" and PaCO2 35 to 60 mm Hg. The following were significantly higher (p ventilation, physiologic shunt, plasma lactate, lung interleukin-6, interleukin-8, myeloperoxidase, and composite total injury score. No significant laboratories by treatment group interactions were found. In summary, TLV resulted in improved cardiopulmonary physiology at lower ventilatory requirements with more favorable histological and inflammatory profiles than CMV. As such, TLV offers a feasible ventilatory alternative as a lung protective strategy in this model of acute lung injury.

  9. Ventilation and perfusion imaging by electrical impedance tomography: a comparison with radionuclide scanning

    NARCIS (Netherlands)

    Kunst, P. W.; Vonk Noordegraaf, A.; Hoekstra, O. S.; Postmus, P. E.; de Vries, P. M.

    1998-01-01

    Electrical impedance tomography (EIT) is a technique that makes it possible to measure ventilation and pulmonary perfusion in a volume that approximates to a 2D plane. The possibility of using EIT for measuring the left-right division of ventilation and perfusion was compared with that of

  10. Noninvasive Ventilation in Premature Neonates.

    Science.gov (United States)

    Flanagan, Keri Ann

    2016-04-01

    The use of noninvasive ventilation is a constantly evolving treatment option for respiratory disease in the premature infant. The goals of these noninvasive ventilation techniques are to improve gas exchange in the premature infant's lungs and to minimize the need for intubation and invasive mechanical ventilation. The goals of this article are to consider various uses of nasal interfaces, discuss skin care and developmental positioning concerns faced by the bedside nurse, and discuss the medical management aimed to reduce morbidity and mortality. This article explores the nursing role, the advances in medical strategies for noninvasive ventilation, and the team approach to noninvasive ventilation use in this population. Search strategy included a literature review on medical databases, such as EBSCOhost, CINAHL, PubMed, and NeoReviews. Innovative products, nursing research on developmental positioning and skin care, and advanced medical management have led to better and safer outcomes for premature infants requiring noninvasive ventilation. The medical focus of avoiding long-term mechanical ventilation would not be possible without the technology to provide noninvasive ventilation to these premature infants and the watchful eye of the nurse in terms of careful positioning, preventing skin breakdown and facial scarring, and a proper seal to maximize ventilation accuracy. This article encourages nursing-based research to quantify some of the knowledge about skin care and positioning as well as research into most appropriate uses for noninvasive ventilation devices.

  11. Performance evaluation of ventilation radiators

    International Nuclear Information System (INIS)

    Myhren, Jonn Are; Holmberg, Sture

    2013-01-01

    A ventilation radiator is a combined ventilation and heat emission unit currently of interest due to its potential for increasing energy efficiency in exhaust-ventilated buildings with warm water heating. This paper presents results of performance tests of several ventilation radiator models conducted under controlled laboratory conditions. The purpose of the study was to validate results achieved by Computational Fluid Dynamics (CFD) in an earlier study and identify possible improvements in the performance of such systems. The main focus was on heat transfer from internal convection fins, but comfort and health aspects related to ventilation rates and air temperatures were also considered. The general results from the CFD simulations were confirmed; the heat output of ventilation radiators may be improved by at least 20% without sacrificing ventilation efficiency or thermal comfort. Improved thermal efficiency of ventilation radiators allows a lower supply water temperature and energy savings both for heating up and distribution of warm water in heat pumps or district heating systems. A secondary benefit is that a high ventilation rate can be maintained all year around without risk for cold draught. -- Highlights: ► Low temperature heat emitters are currently of interest due to their potential for increasing energy efficiency. ► A ventilation radiator is a combined ventilation and heat emission unit which can be adapted to low temperature heating systems. ► We examine how ventilation radiators can be made to be more efficient in terms of energy consumption and thermal comfort. ► Current work focuses on heat transfer mechanisms and convection fin configuration of ventilation radiators

  12. Effects of Modes, Obesity, and Body Position on Non-invasive Positive Pressure Ventilation Success in the Intensive Care Unit: A Randomized Controlled Study.

    Science.gov (United States)

    Türk, Murat; Aydoğdu, Müge; Gürsel, Gül

    2018-01-01

    Different outcomes and success rates of non-invasive positive pressure ventilation (NPPV) in patients with acute hypercapnic respiratory failure (AHRF) still pose a significant problem in intensive care units. Previous studies investigating different modes, body positioning, and obesity-associated hypoventilation in patients with chronic respiratory failure showed that these factors may affect ventilator mechanics to achieve a better minute ventilation. This study tried to compare pressure support (BiPAP-S) and average volume targeted pressure support (AVAPS-S) modes in patients with acute or acute-on-chronic hypercapnic respiratory failure. In addition, short-term effects of body position and obesity within both modes were analyzed. We conducted a randomized controlled study in a 7-bed intensive care unit. The course of blood gas analysis and differences in ventilation variables were compared between BiPAP-S (n=33) and AVAPS-S (n=29), and between semi-recumbent and lateral positions in both modes. No difference was found in the length of hospital stay and the course of PaCO2, pH, and HCO3 levels between the modes. There was a mean reduction of 5.7±4.1 mmHg in the PaCO2 levels in the AVAPS-S mode, and 2.7±2.3 mmHg in the BiPAP-S mode per session (ppositioning had no notable effect in both modes. Although the decrease in the PaCO2 levels in the AVAPS-S mode per session was remarkably high, the course was similar in both modes. Furthermore, obesity and body positioning had no prominent effect on the PaCO2 response and ventilator mechanics. Post hoc power analysis showed that the sample size was not adequate to detect a significant difference between the modes.

  13. Mile-A-Minute (Pest Alert)

    Science.gov (United States)

    Denise Binion; William Jackson

    2009-01-01

    Mile-a-minute weed (Persicaria perfoliata (L.) H. Gross, formerly Polygonum perfoliatum, L.) is an annual vine in the Polygonaceae or Buckwheat family. It is native to eastern Asia including India, Bhutan, Nepal, China, Burma, Japan, Korea, Indonesia, Bangladesh, Siberia, the Philippines, New Guinea, the Malay peninsula and the...

  14. Peripheral Circulatory Features during High-Frequency Jet Ventilation

    Directory of Open Access Journals (Sweden)

    M. B. Kontorovich

    2010-01-01

    Full Text Available The paper gives the results of a study of peripheral circulatory features during high-frequency jet ventilation (HFJV. The main specific features of peripheral circulation and oxygen transport during HFJV are formulated on the basis of a study of cardiac output (impedance cardiography, peripheral vascular resistance, peripheral vascular blood filling (photoplethysmogram analysis, adaptive peripheral blood flow reactions (spectral analysis of peripheral vascular pulsation. HFJV gives rise to the peculiar pattern of peripheral hemodynamics and tissue gas exchange, which is characterized by higher oxygen uptake without a decrease in mixed venous blood saturation, with normal extraction coefficient and preserved low peripheral vascular resistance. During HFJV, unlike traditional ventilation, the main peripheral hemodynamic feature is the increased capillary bed blood volume caused by the blood flow involvement of reserve capillaries under control of volume (parasympathetic regulation of adaptive peripheral hemodynamic reactions. Key words: high-frequency jet ventilation, oxygen transport, peripheral hemodynamics.

  15. Pretest Predictions for Ventilation Tests

    International Nuclear Information System (INIS)

    Y. Sun; H. Yang; H.N. Kalia

    2007-01-01

    The objective of this calculation is to predict the temperatures of the ventilating air, waste package surface, concrete pipe walls, and insulation that will be developed during the ventilation tests involving various test conditions. The results will be used as input to the following three areas: (1) Decisions regarding testing set-up and performance. (2) Assessing how best to scale the test phenomena measured. (3) Validating numerical approach for modeling continuous ventilation. The scope of the calculation is to identify the physical mechanisms and parameters related to thermal response in the ventilation tests, and develop and describe numerical methods that can be used to calculate the effects of continuous ventilation. Sensitivity studies to assess the impact of variation of linear power densities (linear heat loads) and ventilation air flow rates are included. The calculation is limited to thermal effect only

  16. Bench tests of simple, handy ventilators for pandemics: performance, autonomy, and ergonomy.

    Science.gov (United States)

    L'Her, Erwan; Roy, Annie

    2011-06-01

    It has been pointed out that in the wake of a virulent flu strain, patients with survivable illness will die from lack of resources unless more ventilators are made available. Numerous disaster-type ventilators are available, but few evaluations have been performed. To compare simple, lightweight, and handy ventilators that could be used in the initial care of patients with respiratory distress. We bench-tested 4 volume-cycled ventilators (Carevent ALS, EPV100, Pneupac VR1, and Medumat Easy) and 2 pressure-cycled ventilators (Oxylator EMX and VAR-Plus). We studied their general physical characteristics, sonometry, gas consumption, technical performance, ergonomy, and user-friendliness. With a test lung we assessed performance at F(IO(2)) of 0.50 and 1.0, set compliance of 30, 70, and 120 mL/cm H(2)O, and set resistance of 5, 10, and 20 cm H(2)O/L/s. To study user-friendliness and ergonomy we conducted, in randomized order, 7 or 8 objective, quantitative tests and 2 subjective tests. Compliance and resistance strongly affected tidal volume with the pressure-cycled ventilators (from 418 ± 49 mL to 1,377 ± 444 mL with the VAR-Plus, at the lowest pressure level), whereas the volume-cycled ventilators provided a consistent tidal volume in the face of changing test lung characteristics. We are concerned that the pressure-cycled ventilators did not provide a consistent tidal volume, and under certain conditions the volume delivered would be unsafe (too large or too small). Most of the volume-cycled ventilators proved to be technically efficient and reliable. Their reliability, portability, and ease of use could make them valuable in natural disasters and mass-casualty events.

  17. Design Principles for Natural and Hybrid Ventilation

    DEFF Research Database (Denmark)

    Heiselberg, Per

    For many years mechanical and natural ventilation systems have developed separately. Naturally, the next step in this development is the development of ventilation concepts that utilize and combine the best features from each system to create a new type of ventilation system- Hybrid Ventilation. ....... The hybrid ventilation concepts, design challenges and principles are discussed and illustrated by four building examples.......For many years mechanical and natural ventilation systems have developed separately. Naturally, the next step in this development is the development of ventilation concepts that utilize and combine the best features from each system to create a new type of ventilation system- Hybrid Ventilation...

  18. Synchronized mechanical ventilation for respiratory support in newborn infants.

    Science.gov (United States)

    Greenough, Anne; Murthy, Vadivelam; Milner, Anthony D; Rossor, Thomas E; Sundaresan, Adesh

    2016-08-19

    During synchronised mechanical ventilation, positive airway pressure and spontaneous inspiration coincide. If synchronous ventilation is provoked, adequate gas exchange should be achieved at lower peak airway pressures, potentially reducing baro/volutrauma, air leak and bronchopulmonary dysplasia. Synchronous ventilation can potentially be achieved by manipulation of rate and inspiratory time during conventional ventilation and employment of patient-triggered ventilation. To compare the efficacy of:(i) synchronised mechanical ventilation, delivered as high-frequency positive pressure ventilation (HFPPV) or patient-triggered ventilation (assist control ventilation (ACV) and synchronous intermittent mandatory ventilation (SIMV)), with conventional ventilation or high-frequency oscillation (HFO);(ii) different types of triggered ventilation (ACV, SIMV, pressure-regulated volume control ventilation (PRVCV), SIMV with pressure support (PS) and pressure support ventilation (PSV)). We used the standard search strategy of the Cochrane Neonatal Review group to search the Cochrane Central Register of Controlled Trials (CENTRAL 2016, Issue 5), MEDLINE via PubMed (1966 to June 5 2016), EMBASE (1980 to June 5 2016), and CINAHL (1982 to June 5 2016). We also searched clinical trials databases, conference proceedings, and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials. Randomised or quasi-randomised clinical trials comparing synchronised ventilation delivered as HFPPV to CMV, or ACV/SIMV to CMV or HFO in neonates. Randomised trials comparing different triggered ventilation modes (ACV, SIMV, SIMV plus PS, PRVCV and PSV) in neonates. Data were collected regarding clinical outcomes including mortality, air leaks (pneumothorax or pulmonary interstitial emphysema (PIE)), severe intraventricular haemorrhage (grades 3 and 4), bronchopulmonary dysplasia (BPD) (oxygen dependency beyond 28 days), moderate/severe BPD (oxygen

  19. Mechanical ventilation in neurosurgical patients

    Directory of Open Access Journals (Sweden)

    Keshav Goyal

    2013-01-01

    Full Text Available Mechanical ventilation significantly affects cerebral oxygenation and cerebral blood flow through changes in arterial carbon dioxide levels. Neurosurgical patients might require mechanical ventilation for correction and maintenance of changes in the pulmonary system that occur either due to neurosurgical pathology or following surgery during the acute phase. This review discusses the basics of mechanical ventilation relevant to the neurosurgeon in the day-to-day management of neurosurgical patient requiring artificial support of the respiration.

  20. Nasal highflow improves ventilation in patients with COPD

    Directory of Open Access Journals (Sweden)

    Bräunlich J

    2016-05-01

    Full Text Available Jens Bräunlich,* Marcus Köhler,* Hubert WirtzDepartment of Respiratory Medicine, University of Leipzig, Leipzig, Germany *These authors contributed equally to this workBackground: Nasal highflow (NHF provides a warmed and humidified air stream up to 60 L/min. Recent data demonstrated a positive effect in patients with acute hypoxemic respiratory failure, especially when caused by pneumonia. Preliminary data show a decrease in hypercapnia in patients with COPD. Therefore, NHF should be evaluated as a new ventilatory support device. This study was conducted to assess the impact of different flow rates on ventilatory parameters in patients with COPD.Materials and methods: This interventional clinical study was performed with patients suffering from severe COPD. The aim was to characterize flow-dependent changes in mean airway pressure, breathing volumes, breathing frequency, and decrease in partial pressure of CO2 (pCO2. Mean airway pressure was measured in the nasopharyngeal space (19 patients. To evaluate breathing volumes, we used a polysomnographic device (18 patients. All patients received 20 L/min, 30 L/min, 40 L/min, and 50 L/min and – to illustrate the effects – nasal continuous positive airway pressure and nasal bilevel positive airway pressure. Capillary blood gas analyses were performed in 54 patients with hypercapnic COPD before and two hours after the use of NHF. We compared the extent of decrease in pCO2 when using 20 L/min and 30 L/min. Additionally, comfort and dyspnea during the use of NHF were surveyed.Results: NHF resulted in a minor flow dependent increase in mean airway pressure. Tidal volume increased, and breathing rate decreased. The calculated minute volume decreased under NHF breathing. In spite of this fact, hypercapnia decreased with increasing flow (20 L/min vs 30 L/min. Additionally, an improvement in dyspnea was observed. The rapid shallow breathing index shows a decrease when using NHF.Conclusion: NHF

  1. Design Principles for Natural and Hybrid Ventilation

    OpenAIRE

    Heiselberg, Per

    2000-01-01

    For many years mechanical and natural ventilation systems have developed separately. Naturally, the next step in this development is the development of ventilation concepts that utilize and combine the best features from each system to create a new type of ventilation system- Hybrid Ventilation. The hybrid ventilation concepts, design challenges and principles are discussed and illustrated by four building examples.

  2. 46 CFR 42.15-45 - Ventilators.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Ventilators. 42.15-45 Section 42.15-45 Shipping COAST... Conditions of Assignment of Freeboard § 42.15-45 Ventilators. (a) Ventilators in position 1 or 2 to spaces... any ventilator exceeds 351/2 inches in height it shall be specially supported. (b) Ventilators passing...

  3. Feasibility of Protective Ventilation During Elective Supratentorial Neurosurgery: A Randomized, Crossover, Clinical Trial.

    Science.gov (United States)

    Ruggieri, Francesco; Beretta, Luigi; Corno, Laura; Testa, Valentina; Martino, Enrico A; Gemma, Marco

    2017-06-30

    Traditional ventilation approaches, providing high tidal volumes (Vt), produce excessive alveolar distention and lung injury. Protective ventilation, employing lower Vt and positive end-expiratory pressure (PEEP), is an attractive alternative also for neuroanesthesia, when prolonged mechanical ventilation is needed. Nevertheless, protective ventilation during intracranial surgery may exert dangerous effects on intracranial pressure (ICP). We tested the feasibility of a protective ventilation strategy in neurosurgery. Our monocentric, double-blind, 1:1 randomized, 2×2 crossover study aimed at studying the effect size and variability of ICP in patients undergoing elective supratentorial brain tumor removal and alternatively ventilated with Vt 9 mL/kg-PEEP 0 mm Hg and Vt 7 mL/kg-PEEP 5 mm Hg. Respiratory rate was adjusted to maintain comparable end-tidal carbon dioxide between ventilation modes. ICP was measured through a subdural catheter inserted before dural opening. Forty patients were enrolled; 8 (15%) were excluded after enrollment. ICP did not differ between traditional and protective ventilation (11.28±5.37, 11 [7 to 14.5] vs. 11.90±5.86, 11 [8 to 15] mm Hg; P=0.541). End-tidal carbon dioxide (28.91±2.28, 29 [28 to 30] vs. 28.00±2.17, 28 [27 to 29] mm Hg; Pprotective ventilation. Blood pressure, heart rate, and body temperature did not differ between ventilation modes. Dural tension was "acceptable for surgery" in all cases. ICP differences between ventilation modes were not affected by ICP values under traditional ventilation (coefficient=0.067; 95% confidence interval, -0.278 to 0.144; P=0.523). Protective ventilation is a feasible alternative to traditional ventilation during elective neurosurgery.

  4. Performance of portable ventilators at altitude.

    Science.gov (United States)

    Blakeman, Thomas; Britton, Tyler; Rodriquez, Dario; Branson, Richard

    2014-09-01

    Aeromedical transport of critically ill patients requires continued, accurate performance of equipment at altitude. Changes in barometric pressure can affect the performance of mechanical ventilators calibrated for operation at sea level. Deploying ventilators that can maintain a consistent tidal volume (VT) delivery at various altitudes is imperative for lung protection when transporting wounded war fighters to each echelon of care. Three ventilators (Impact 731, Hamilton T1, and CareFusion Revel) were tested at pediatric (50 and 100 mL) and adult (250-750 mL) tidal VTs at 0 and 20 cm H₂O positive end expiratory pressure and at inspired oxygen of 0.21 and 1.0. Airway pressure, volume, and flow were measured at sea level as well as at 8,000, 16,000, and 22,000 ft (corresponding to barometric pressures of 760, 564, 412, and 321 mm Hg) using a calibrated pneumotachograph connected to a training test lung in an altitude chamber. Set VT and delivered VT as well as changes in VT at each altitude were compared by t test. The T1 delivered VT within 10% of set VT at 8,000 ft. The mean VT was less than set VT at sea level as a result of circuit compressible volume with the Revel and the 731. Changes in VT varied widely among the devices at sea level and at altitude. Increasing altitudes resulted in larger VT than set for the Revel and the T1. The 731 compensated for changes in altitude delivered VT within 10% at the adult settings at all altitudes. Altitude compensation is an active software algorithm. Only the 731 actively accounts for changes in barometric pressure to maintain the set VT at all tested altitudes.

  5. Severe bronchopulmonary dysplasia improved by noninvasive positive pressure ventilation: a case report

    Directory of Open Access Journals (Sweden)

    Mann Christian

    2011-09-01

    Full Text Available Abstract Introduction This is the first report to describe the feasibility and effectiveness of noninvasive positive pressure ventilation in the secondary treatment of bronchopulmonary dysplasia. Case presentation A former male preterm of Caucasian ethnicity delivered at 29 weeks gestation developed severe bronchopulmonary dysplasia. At the age of six months he was in permanent tachypnea and dyspnea and in need of 100% oxygen with a flow of 2.0 L/minute via a nasal cannula. Intermittent nocturnal noninvasive positive pressure ventilation was then administered for seven hours daily. The ventilator was set at a positive end-expiratory pressure of 6 cmH2O, with pressure support of 4 cmH2O, trigger at 1.4 mL/second, and a maximum inspiratory time of 0.7 seconds. Over the course of seven weeks, the patient's maximum daytime fraction of inspired oxygen via nasal cannula decreased from 1.0 to 0.75, his respiratory rate from 64 breaths/minute to 50 breaths/minute and carbon dioxide from 58 mmHg to 44 mmHg. Conclusion Noninvasive positive pressure ventilation may be a novel therapeutic option for established severe bronchopulmonary dysplasia. In the case presented, noninvasive positive pressure ventilation achieved sustained improvement in ventilation and thus prepared our patient for safe home oxygen therapy.

  6. Evaluation of Fractional Regional Ventilation Using 4D-CT and Effects of Breathing Maneuvers on Ventilation

    International Nuclear Information System (INIS)

    Mistry, Nilesh N.; Diwanji, Tejan; Shi, Xiutao; Pokharel, Sabin; Feigenberg, Steven; Scharf, Steven M.; D'Souza, Warren D.

    2013-01-01

    Purpose: Current implementations of methods based on Hounsfield units to evaluate regional lung ventilation do not directly incorporate tissue-based mass changes that occur over the respiratory cycle. To overcome this, we developed a 4-dimensional computed tomography (4D-CT)-based technique to evaluate fractional regional ventilation (FRV) that uses an individualized ratio of tidal volume to end-expiratory lung volume for each voxel. We further evaluated the effect of different breathing maneuvers on regional ventilation. The results from this work will help elucidate the relationship between global and regional lung function. Methods and Materials: Eight patients underwent 3 sets of 4D-CT scans during 1 session using free-breathing, audiovisual guidance, and active breathing control. FRV was estimated using a density-based algorithm with mass correction. Internal validation between global and regional ventilation was performed by use of the imaging data collected during the use of active breathing control. The impact of breathing maneuvers on FRV was evaluated comparing the tidal volume from 3 breathing methods. Results: Internal validation through comparison between the global and regional changes in ventilation revealed a strong linear correlation (slope of 1.01, R 2 of 0.97) between the measured global lung volume and the regional lung volume calculated by use of the “mass corrected” FRV. A linear relationship was established between the tidal volume measured with the automated breathing control system and FRV based on 4D-CT imaging. Consistently larger breathing volumes were observed when coached breathing techniques were used. Conclusions: The technique presented improves density-based evaluation of lung ventilation and establishes a link between global and regional lung ventilation volumes. Furthermore, the results obtained are comparable with those of other techniques of functional evaluation such as spirometry and hyperpolarized-gas magnetic resonance

  7. Evaluation of Fractional Regional Ventilation Using 4D-CT and Effects of Breathing Maneuvers on Ventilation

    Energy Technology Data Exchange (ETDEWEB)

    Mistry, Nilesh N., E-mail: nmistry@som.umaryland.edu [Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland (United States); Diwanji, Tejan; Shi, Xiutao [Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland (United States); Pokharel, Sabin [Morgan State University, Baltimore, Maryland (United States); Feigenberg, Steven [Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland (United States); Scharf, Steven M. [Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland (United States); D' Souza, Warren D. [Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland (United States)

    2013-11-15

    Purpose: Current implementations of methods based on Hounsfield units to evaluate regional lung ventilation do not directly incorporate tissue-based mass changes that occur over the respiratory cycle. To overcome this, we developed a 4-dimensional computed tomography (4D-CT)-based technique to evaluate fractional regional ventilation (FRV) that uses an individualized ratio of tidal volume to end-expiratory lung volume for each voxel. We further evaluated the effect of different breathing maneuvers on regional ventilation. The results from this work will help elucidate the relationship between global and regional lung function. Methods and Materials: Eight patients underwent 3 sets of 4D-CT scans during 1 session using free-breathing, audiovisual guidance, and active breathing control. FRV was estimated using a density-based algorithm with mass correction. Internal validation between global and regional ventilation was performed by use of the imaging data collected during the use of active breathing control. The impact of breathing maneuvers on FRV was evaluated comparing the tidal volume from 3 breathing methods. Results: Internal validation through comparison between the global and regional changes in ventilation revealed a strong linear correlation (slope of 1.01, R{sup 2} of 0.97) between the measured global lung volume and the regional lung volume calculated by use of the “mass corrected” FRV. A linear relationship was established between the tidal volume measured with the automated breathing control system and FRV based on 4D-CT imaging. Consistently larger breathing volumes were observed when coached breathing techniques were used. Conclusions: The technique presented improves density-based evaluation of lung ventilation and establishes a link between global and regional lung ventilation volumes. Furthermore, the results obtained are comparable with those of other techniques of functional evaluation such as spirometry and hyperpolarized-gas magnetic

  8. Interagency Advanced Power Group meeting minutes

    Energy Technology Data Exchange (ETDEWEB)

    1991-12-31

    This document contains the minutes and viewgraphs from a meeting of military personnel on the subject of power generation and distribution systems for military applications. Topics include heating and cooling systems for standard shelters, SDIO power programs, solar dynamic space power systems, hybrid solar dynamic/ photovoltaic systems, pulsed power technology, high-{Tc} superconductors, and actuators and other electronic equipment for aerospace vehicles. Attendees represented the US Air Force, Army, Navy, and NASA. (GHH)

  9. Interagency Advanced Power Group meeting minutes

    Energy Technology Data Exchange (ETDEWEB)

    1991-01-01

    This document contains the minutes and viewgraphs from a meeting of military personnel on the subject of power generation and distribution systems for military applications. Topics include heating and cooling systems for standard shelters, SDIO power programs, solar dynamic space power systems, hybrid solar dynamic/ photovoltaic systems, pulsed power technology, high-{Tc} superconductors, and actuators and other electronic equipment for aerospace vehicles. Attendees represented the US Air Force, Army, Navy, and NASA. (GHH)

  10. Mild Wind Series, Minute Steak Event

    Science.gov (United States)

    1992-11-20

    radioactive gas and debris from reaching the atmosphere, thereby complying with the test ban treaty. distance from the source point to the surface was...percent of the active data recorded on film is also important in the event of excessive radioactive release. The weighing of the experiments is arbitrary...in a water-base Polution . S41 ’ The caldera 245 feet In diameter and 17 feet deep formed at +23 minutes (figure 4.2). There was consistent

  11. The elements of grammar in 90 minutes

    CERN Document Server

    Hollander, Robert

    2011-01-01

    An eminent scholar explains the essentials of English grammar to those who never studied the basics as well as those who need a refresher course. Inspired by Strunk & White's classic The Elements of Style, this user-friendly guide focuses exclusively on grammar, explaining the individual parts of speech and their proper arrangement in sentence form. A modest investment of 90 minutes can provide readers of all ages with simple but important tools that will improve their communication skills. Dover (2011) original publication.

  12. Naturlig ventilation i enfamiliehuse

    DEFF Research Database (Denmark)

    Bergsøe, N.C.

    Meddelelsen beskriver resultaterne af en række beregninger foretaget ved anvendelse af et computerprogram. Beregningerne har til formål at belyse forskellige parametres indvirkning på funktionen af et naturligt ventilationssystem. Blandt andet belyses systemets afhængighed af aftrækskanalernes di...... dimension, udeluftventilarealet og placeringen af aftrækskanalernes udmunding i tagfladen. Derudover gengives i kortfattet form de væsentligste konklusioner af udvalgte publikationer, som behandler særlige forhold vedrørende naturlig ventilation i praksis....

  13. Influence of ventilation structure on air flow distribution of large turbo-generator

    Science.gov (United States)

    Zhang, Liying; Ding, Shuye; Zhao, Zhijun; Yang, Jingmo

    2018-04-01

    For the 350 MW air - cooled turbo—generator, the rotor body is ventilated by sub -slots and 94 radial ventilation ducts and the end adopts arc segment and the straight section to acquire the wind. The stator is ventilated with five inlets and eight outlet air branches. In order to analyze the cooling effect of different ventilation schemes, a global physical model including the stator, rotor, casing and fan is established, and the assumptions and boundary conditions of the solution domain are given. the finite volume method is used to solve the problem, and the air flow distribution characteristics of each part of the motor under different ventilation schemes are obtained. The results show that the baffle at the end of the rotor can eliminate the eddy current at the end of the rotor, and make the flow distribution of cooling air more uniform and reasonable. The conclusions can provide reference for the design of motor ventilation structure.

  14. Cost of ventilation and effect of digestive state on the ventilatory response of the tegu lizard.

    Science.gov (United States)

    Skovgaard, Nini; Wang, Tobias

    2004-07-12

    We performed simultaneous measurements of ventilation, oxygen uptake and carbon dioxide production in the South American lizard, Tupinambis merianae, equipped with a mask and maintained at 25 degrees C. Ventilation of resting animals was stimulated by progressive exposure to hypercapnia (2, 4 and 6%) or hypoxia (15, 10, 8 and 6%) in inspired gas mixture. This was carried out in both fasting and digesting animals. The ventilatory response to hypercapnia and hypoxia were affected by digestive state, with a more vigorous ventilatory response in digesting animals compared to fasting animals. Hypoxia doubled total ventilation while hypercapnia led to a four-fold increase in total ventilation both accomplished through an increase in tidal volume. Oxygen uptake remained constant during all hypercapnic exposures while there was an increase during hypoxia. Cost of ventilation was estimated to be 17% during hypoxia but less than 1% during hypercapnia. Our data indicate that ventilation can be greatly elevated at a small energetic cost.

  15. Radioaerosol ventilation imaging in ventilator-dependent patients. Technical considerations

    International Nuclear Information System (INIS)

    Vezina, W.; Chamberlain, M.; Vinitski, S.; King, M.; Nicholson, R.; Morgan, W.K.

    1985-01-01

    The differentiation of pulmonary embolism (PE) from regional ventilatory abnormalities accompanied by reduced perfusion requires contemporary perfusion and ventilation studies. Distinguishing these conditions in ventilator-dependent patients is aided by administering a Tc-99m aerosol to characterize regional ventilation, and by performing a conventional Tc-99m MAA perfusion study. The technique uses a simple in-house constructed apparatus. Simple photographic techniques suffice, but computer subtraction of perfusion from the combined perfusion-ventilation image renders interpretation easier if aerosol administration follows perfusion imaging. Multiple defects can be examined in a single study. Excluding normal or near-normal perfusion studies, PE was thought to be present in eight of 16 patients after perfusion imaging alone, but in only one of eight after added aerosol imaging. Angiography confirmed the diagnosis in that patient. Of the eight patients who had abnormal perfusion but were thought unlikely to have PE from the perfusion study alone, two had normal ventilation, and subsequently were shown to have PE by angiography. Because angiography was only performed on patients who were thought to have a high probability of PE on sequential perfusion-ventilation imaging, the true incidence of PE may have been higher. Aerosol ventilation imaging is a useful adjunct to perfusion imaging in patients on ventilators. It requires an efficient delivery system, particularly if aerosol administration follows perfusion imaging, as it does in this study

  16. Plane Stratified Flow in a Room Ventilated by Displacement Ventilation

    DEFF Research Database (Denmark)

    Nielsen, Peter Vilhelm; Nickel, J.; Baron, D. J. G.

    2004-01-01

    The air movement in the occupied zone of a room ventilated by displacement ventilation exists as a stratified flow along the floor. This flow can be radial or plane according to the number of wall-mounted diffusers and the room geometry. The paper addresses the situations where plane flow...

  17. Ventilator in nuclear power plant

    International Nuclear Information System (INIS)

    Goto, Hiroshi.

    1980-01-01

    Purpose: To fabricate a compact ventilator by arranging separate pipelines communicating the operating stage range and contaminated range in a building, and arranging cleaning means commonly used for these ranges. Constitution: A pipeline to be connected to the operating stage range is connected via an exhaust fan and a damper to the stack, and a pipeline to be connected to the contaminated range is connected via another exhaust fan and another damper to the above described pipeline. The exhaust sides of both exhaust fans are connected by means of separate pipelines, and two dampers are disposed in the intermediate of the pipeline. A pipeline is led out from the intermediate of the dampers, and connected to the terminal end of the pipeline from the contaminated range via a filter train and a booster fan. Since the exhaust volume of the operating stage range is substantially equal to that of the contaminated range, the installation capacity of the filter train is reduced to half. (Sekiya, K.)

  18. Mechanical ventilation in patients subjected to extracorporeal membrane oxygenation (ECMO).

    Science.gov (United States)

    López Sanchez, M

    2017-11-01

    Mechanical ventilation (MV) is a crucial element in the management of acute respiratory distress syndrome (ARDS), because there is high level evidence that a low tidal volume of 6ml/kg (protective ventilation) improves survival. In these patients with refractory respiratory insufficiency, venovenous extracorporeal membrane oxygenation (ECMO) can be used. This salvage technique improves oxygenation, promotes CO 2 clearance, and facilitates protective and ultraprotective MV, potentially minimizing ventilation-induced lung injury. Although numerous trials have investigated different ventilation strategies in patients with ARDS, consensus is lacking on the optimal MV settings during venovenous ECMO. Although the concept of "lung rest" was introduced years ago, there are no evidence-based guidelines on its use in application to MV in patients supported by ECMO. How MV in ECMO patients can promote lung recovery and weaning from ventilation is not clear. The purpose of this review is to describe the ventilation strategies used during venovenous ECMO in clinical practice. Copyright © 2017 Elsevier España, S.L.U. y SEMICYUC. All rights reserved.

  19. Increasing the inspiratory time and I:E ratio during mechanical ventilation aggravates ventilator-induced lung injury in mice.

    Science.gov (United States)

    Müller-Redetzky, Holger C; Felten, Matthias; Hellwig, Katharina; Wienhold, Sandra-Maria; Naujoks, Jan; Opitz, Bastian; Kershaw, Olivia; Gruber, Achim D; Suttorp, Norbert; Witzenrath, Martin

    2015-01-28

    Lung-protective ventilation reduced acute respiratory distress syndrome (ARDS) mortality. To minimize ventilator-induced lung injury (VILI), tidal volume is limited, high plateau pressures are avoided, and positive end-expiratory pressure (PEEP) is applied. However, the impact of specific ventilatory patterns on VILI is not well defined. Increasing inspiratory time and thereby the inspiratory/expiratory ratio (I:E ratio) may improve oxygenation, but may also be harmful as the absolute stress and strain over time increase. We thus hypothesized that increasing inspiratory time and I:E ratio aggravates VILI. VILI was induced in mice by high tidal-volume ventilation (HVT 34 ml/kg). Low tidal-volume ventilation (LVT 9 ml/kg) was used in control groups. PEEP was set to 2 cm H2O, FiO2 was 0.5 in all groups. HVT and LVT mice were ventilated with either I:E of 1:2 (LVT 1:2, HVT 1:2) or 1:1 (LVT 1:1, HVT 1:1) for 4 hours or until an alternative end point, defined as mean arterial blood pressure below 40 mm Hg. Dynamic hyperinflation due to the increased I:E ratio was excluded in a separate group of animals. Survival, lung compliance, oxygenation, pulmonary permeability, markers of pulmonary and systemic inflammation (leukocyte differentiation in lung and blood, analyses of pulmonary interleukin-6, interleukin-1β, keratinocyte-derived chemokine, monocyte chemoattractant protein-1), and histopathologic pulmonary changes were analyzed. LVT 1:2 or LVT 1:1 did not result in VILI, and all individuals survived the ventilation period. HVT 1:2 decreased lung compliance, increased pulmonary neutrophils and cytokine expression, and evoked marked histologic signs of lung injury. All animals survived. HVT 1:1 caused further significant worsening of oxygenation, compliance and increased pulmonary proinflammatory cytokine expression, and pulmonary and blood neutrophils. In the HVT 1:1 group, significant mortality during mechanical ventilation was observed. According to the "baby lung

  20. The Six Minute Walk Test Revisited

    Science.gov (United States)

    Mazumder, M.

    2017-12-01

    Background and Purpose: Heart failure is the leading cause of death and often alters or severely restricts human mobility, an essential life function. Motion capture is an emerging tool for analyzing human movement and extremity articulation, providing quantitative information on gait and range of motion. This study uses BioStamp mechanosensors to identify differences in motion for the duration of the Six Minute Walk Test and signature patterns of muscle contraction and posture in patients with advanced heart failure compared to healthy subjects. Identification and close follow up of these patterns may allow enhanced diagnosis and the possibility for early intervention before disease worsening. Additionally, movement parameters represent a new family of potential biomarkers to track heart failure onset, progression and therapy. Methods: Prior to the Six Minute Walk Test, BioStamps (MC10) were applied to the chest, upper and lower extremities of heart failure and healthy patients and data were streamed and recorded revealing the pattern of movement in three separate axes. Conjointly, before and after the Six Minute Walk Test, the following vitals were measured per subject: heart rate, respiratory rate, blood pressure, oxygen saturation, dyspnea and leg fatigue (self-reported with Borg scale). During the test, patients were encouraged to walk as far as they can in 6 minutes on a 30m course, as we recorded the number of laps completed and oxygen saturation every minute. Results and Conclusions: The sensors captured and quantified whole body and regional motion parameters including: a. motion extent, position, acceleration and angle via incorporated accelerometers and gyroscopes; b. muscle contraction via incorporated electromyogram (EMG). Accelerometry and gyroscopic data for the last five steps of a healthy and heart failure patient are shown. While significant differences in motion for the duration of the test were not found, each category of patients had a distinct

  1. Variability in Usual Care Mechanical Ventilation for Pediatric Acute Respiratory Distress Syndrome: Time for a Decision Support Protocol?

    Science.gov (United States)

    Newth, Christopher J L; Sward, Katherine A; Khemani, Robinder G; Page, Kent; Meert, Kathleen L; Carcillo, Joseph A; Shanley, Thomas P; Moler, Frank W; Pollack, Murray M; Dalton, Heidi J; Wessel, David L; Berger, John T; Berg, Robert A; Harrison, Rick E; Holubkov, Richard; Doctor, Allan; Dean, J Michael; Jenkins, Tammara L; Nicholson, Carol E

    2017-11-01

    Although pediatric intensivists philosophically embrace lung protective ventilation for acute lung injury and acute respiratory distress syndrome, we hypothesized that ventilator management varies. We assessed ventilator management by evaluating changes to ventilator settings in response to blood gases, pulse oximetry, or end-tidal CO2. We also assessed the potential impact that a pediatric mechanical ventilation protocol adapted from National Heart Lung and Blood Institute acute respiratory distress syndrome network protocols could have on reducing variability by comparing actual changes in ventilator settings to those recommended by the protocol. Prospective observational study. Eight tertiary care U.S. PICUs, October 2011 to April 2012. One hundred twenty patients (age range 17 d to 18 yr) with acute lung injury/acute respiratory distress syndrome. Two thousand hundred arterial and capillary blood gases, 3,964 oxygen saturation by pulse oximetry, and 2,757 end-tidal CO2 values were associated with 3,983 ventilator settings. Ventilation mode at study onset was pressure control 60%, volume control 19%, pressure-regulated volume control 18%, and high-frequency oscillatory ventilation 3%. Clinicians changed FIO2 by ±5 or ±10% increments every 8 hours. Positive end-expiratory pressure was limited at ~10 cm H2O as oxygenation worsened, lower than would have been recommended by the protocol. In the first 72 hours of mechanical ventilation, maximum tidal volume/kg using predicted versus actual body weight was 10.3 (8.5-12.9) (median [interquartile range]) versus 9.2 mL/kg (7.6-12.0) (p Ventilator management varies substantially in children with acute respiratory distress syndrome. Opportunities exist to minimize variability and potentially injurious ventilator settings by using a pediatric mechanical ventilation protocol offering adequately explicit instructions for given clinical situations. An accepted protocol could also reduce confounding by mechanical

  2. A bench study of intensive-care-unit ventilators: new versus old and turbine-based versus compressed gas-based ventilators

    Science.gov (United States)

    Thille, Arnaud W.; Lyazidi, Aissam; Richard, Jean-Christophe M.; Galia, Fabrice; Brochard, Laurent

    2009-01-01

    Objective To compare 13 commercially available, new-generation, intensive-care-unit (ICU) ventilators regarding trigger function, pressurization capacity during pressure-support ventilation (PSV), accuracy of pressure measurements and expiratory resistance. Design and Setting Bench study at a research laboratory in a university hospital. Material Four turbine-based ventilators and nine conventional servo-valve compressed-gas ventilators were tested using a two-compartment lung model. Results Three levels of effort were simulated. Each ventilator was evaluated at four PSV levels (5, 10, 15, and 20 cm H2O), with and without positive end-expiratory pressure (5 cm H2O, Trigger function was assessed as the time from effort onset to detectable pressurization. Pressurization capacity was evaluated using the airway pressure-time product computed as the net area under the pressure-time curve over the first 0.3 s after inspiratory effort onset. Expiratory resistance was evaluated by measuring trapped volume in controlled ventilation. Significant differences were found across the ventilators, with a range of triggering-delay from 42 ms to 88 ms for all conditions averaged (Pventilators at PSV5 and three at PSV10, suggesting an inability to unload patient’s effort. On average, turbine-based ventilators performed better than conventional ventilators, which showed no improvement compared to a 2000 bench comparison. Conclusion Technical performances of trigger function, pressurization capacity and expiratory resistance vary considerably across new-generation ICU ventilators. ICU ventilators seem to have reached a technical ceiling in recent years, and some ventilators still perform inadequately. PMID:19352622

  3. The effect of airway pressure and oscillation amplitude on ventilation in pre-term infants

    NARCIS (Netherlands)

    Miedema, M.; de Jongh, Franciscus H.C.; Frerichs, I.; van Veenendaal, M.B.; van Kaam, A.H.

    2012-01-01

    We determined the effect of lung recruitment and oscillation amplitude on regional oscillation volume and functional residual capacity (FRC) in high-frequency oscillatory ventilation (HFOV) used in pre-term infants with respiratory distress syndrome (RDS). Changes in lung volume, oscillation volume

  4. Improved Performance With Ventilation

    Science.gov (United States)

    Kawakami, Ellison; Lee, Seung Jae; Karn, Ashish; Hong, Jiarong; Arndt, Roger

    2013-11-01

    Drag reduction and/or speed augmentation of marine vehicles by means of supercavitation is a topic of great interest. During the initial launch of a supercavitating vehicle, ventilation is required to supply an artificial cavity until conditions at which a natural supercavity can be sustained are reached. Various aspects of the flow physics of a supercavitating vehicle have been under investigation for several years at Saint Anthony Falls Laboratory. Both steady flow and simulated flow below a wave train have been studied. Using a high speed camera and the proper software, it is possible to synchronize cavity dimensions with pressure measurements taken inside the cavity to permit an in-depth study of unsteadiness. It was found that flow unsteadiness caused a decrease in the overall length of the supercavity while having only a minimal effect on the maximum diameter. Results regarding supercavity shape, ventilation demand, cavitation parameters and closure methods are reviewed in light of new studies that focused on various closure mechanisms. Sponsored by ONR.

  5. Ventilator-associated pneumonia.

    Science.gov (United States)

    Shaw, Michael Jan

    2005-05-01

    This review summarises some of the notable papers on ventilator-associated pneumonia (VAP) from January 2003 to October 2004. Ventilator-associated pneumonia remains an important drain on hospital resources. All population groups are affected, but patients with VAP are more likely to be older, sicker, and male, with invasive medical devices in situ. Early VAP diagnosis is desirable to reduce VAP mortality and to retard emergence of multidrug-resistant microbes. This may be possible using preliminary culture results or intracellular organism in polymorphonuclear cells. In most intensive care units, Staphylococcus aureus, Pseudomonas aeruginosa, and Acinetobacter baumannii are the commonest organisms isolated in VAP. However, causative organisms vary between and within hospitals. Consequently, individual intensive care units should develop empirical antibiotic policies to target the pathogenic bacteria prevalent in their patient populations. Preventative strategies aimed at reducing aerodigestive tract colonisation by pathogenic organisms, and also their subsequent aspiration, are becoming increasingly important. Educating medical staff about these simple measures is therefore pertinent. To reduce the occurrence of multidrug-resistant organisms, limiting the duration of antibiotic treatment to 8 days and antimicrobial rotation should be contemplated. Empirical therapy with antipseudomonal penicillins plus beta-lactamase inhibitors should be considered. If methicillin-resistant Staphylococcus aureus VAP is a possibility, linezolid may be better than vancomycin. Prevention remains the key to reducing VAP prevalence.

  6. The Society for Translational Medicine: clinical practice guidelines for mechanical ventilation management for patients undergoing lobectomy.

    Science.gov (United States)

    Gao, Shugeng; Zhang, Zhongheng; Brunelli, Alessandro; Chen, Chang; Chen, Chun; Chen, Gang; Chen, Haiquan; Chen, Jin-Shing; Cassivi, Stephen; Chai, Ying; Downs, John B; Fang, Wentao; Fu, Xiangning; Garutti, Martínez I; He, Jianxing; He, Jie; Hu, Jian; Huang, Yunchao; Jiang, Gening; Jiang, Hongjing; Jiang, Zhongmin; Li, Danqing; Li, Gaofeng; Li, Hui; Li, Qiang; Li, Xiaofei; Li, Yin; Li, Zhijun; Liu, Chia-Chuan; Liu, Deruo; Liu, Lunxu; Liu, Yongyi; Ma, Haitao; Mao, Weimin; Mao, Yousheng; Mou, Juwei; Ng, Calvin Sze Hang; Petersen, René H; Qiao, Guibin; Rocco, Gaetano; Ruffini, Erico; Tan, Lijie; Tan, Qunyou; Tong, Tang; Wang, Haidong; Wang, Qun; Wang, Ruwen; Wang, Shumin; Xie, Deyao; Xue, Qi; Xue, Tao; Xu, Lin; Xu, Shidong; Xu, Songtao; Yan, Tiansheng; Yu, Fenglei; Yu, Zhentao; Zhang, Chunfang; Zhang, Lanjun; Zhang, Tao; Zhang, Xun; Zhao, Xiaojing; Zhao, Xuewei; Zhi, Xiuyi; Zhou, Qinghua

    2017-09-01

    Patients undergoing lobectomy are at significantly increased risk of lung injury. One-lung ventilation is the most commonly used technique to maintain ventilation and oxygenation during the operation. It is a challenge to choose an appropriate mechanical ventilation strategy to minimize the lung injury and other adverse clinical outcomes. In order to understand the available evidence, a systematic review was conducted including the following topics: (I) protective ventilation (PV); (II) mode of mechanical ventilation [e.g., volume controlled (VCV) versus pressure controlled (PCV)]; (III) use of therapeutic hypercapnia; (IV) use of alveolar recruitment (open-lung) strategy; (V) pre-and post-operative application of positive end expiratory pressure (PEEP); (VI) Inspired Oxygen concentration; (VII) Non-intubated thoracoscopic lobectomy; and (VIII) adjuvant pharmacologic options. The recommendations of class II are non-intubated thoracoscopic lobectomy may be an alternative to conventional one-lung ventilation in selected patients. The recommendations of class IIa are: (I) Therapeutic hypercapnia to maintain a partial pressure of carbon dioxide at 50-70 mmHg is reasonable for patients undergoing pulmonary lobectomy with one-lung ventilation; (II) PV with a tidal volume of 6 mL/kg and PEEP of 5 cmH 2 O are reasonable methods, based on current evidence; (III) alveolar recruitment [open lung ventilation (OLV)] may be beneficial in patients undergoing lobectomy with one-lung ventilation; (IV) PCV is recommended over VCV for patients undergoing lung resection; (V) pre- and post-operative CPAP can improve short-term oxygenation in patients undergoing lobectomy with one-lung ventilation; (VI) controlled mechanical ventilation with I:E ratio of 1:1 is reasonable in patients undergoing one-lung ventilation; (VII) use of lowest inspired oxygen concentration to maintain satisfactory arterial oxygen saturation is reasonable based on physiologic principles; (VIII) Adjuvant drugs

  7. The Society for Translational Medicine: clinical practice guidelines for mechanical ventilation management for patients undergoing lobectomy

    Science.gov (United States)

    Zhang, Zhongheng; Brunelli, Alessandro; Chen, Chang; Chen, Chun; Chen, Gang; Chen, Haiquan; Chen, Jin-Shing; Cassivi, Stephen; Chai, Ying; Downs, John B.; Fang, Wentao; Fu, Xiangning; Garutti, Martínez I.; He, Jianxing; Hu, Jian; Huang, Yunchao; Jiang, Gening; Jiang, Hongjing; Jiang, Zhongmin; Li, Danqing; Li, Gaofeng; Li, Hui; Li, Qiang; Li, Xiaofei; Li, Yin; Li, Zhijun; Liu, Chia-Chuan; Liu, Deruo; Liu, Lunxu; Liu, Yongyi; Ma, Haitao; Mao, Weimin; Mao, Yousheng; Mou, Juwei; Ng, Calvin Sze Hang; Petersen, René H.; Qiao, Guibin; Rocco, Gaetano; Ruffini, Erico; Tan, Lijie; Tan, Qunyou; Tong, Tang; Wang, Haidong; Wang, Qun; Wang, Ruwen; Wang, Shumin; Xie, Deyao; Xue, Qi; Xue, Tao; Xu, Lin; Xu, Shidong; Xu, Songtao; Yan, Tiansheng; Yu, Fenglei; Yu, Zhentao; Zhang, Chunfang; Zhang, Lanjun; Zhang, Tao; Zhang, Xun; Zhao, Xiaojing; Zhao, Xuewei; Zhi, Xiuyi; Zhou, Qinghua

    2017-01-01

    Patients undergoing lobectomy are at significantly increased risk of lung injury. One-lung ventilation is the most commonly used technique to maintain ventilation and oxygenation during the operation. It is a challenge to choose an appropriate mechanical ventilation strategy to minimize the lung injury and other adverse clinical outcomes. In order to understand the available evidence, a systematic review was conducted including the following topics: (I) protective ventilation (PV); (II) mode of mechanical ventilation [e.g., volume controlled (VCV) versus pressure controlled (PCV)]; (III) use of therapeutic hypercapnia; (IV) use of alveolar recruitment (open-lung) strategy; (V) pre-and post-operative application of positive end expiratory pressure (PEEP); (VI) Inspired Oxygen concentration; (VII) Non-intubated thoracoscopic lobectomy; and (VIII) adjuvant pharmacologic options. The recommendations of class II are non-intubated thoracoscopic lobectomy may be an alternative to conventional one-lung ventilation in selected patients. The recommendations of class IIa are: (I) Therapeutic hypercapnia to maintain a partial pressure of carbon dioxide at 50–70 mmHg is reasonable for patients undergoing pulmonary lobectomy with one-lung ventilation; (II) PV with a tidal volume of 6 mL/kg and PEEP of 5 cmH2O are reasonable methods, based on current evidence; (III) alveolar recruitment [open lung ventilation (OLV)] may be beneficial in patients undergoing lobectomy with one-lung ventilation; (IV) PCV is recommended over VCV for patients undergoing lung resection; (V) pre- and post-operative CPAP can improve short-term oxygenation in patients undergoing lobectomy with one-lung ventilation; (VI) controlled mechanical ventilation with I:E ratio of 1:1 is reasonable in patients undergoing one-lung ventilation; (VII) use of lowest inspired oxygen concentration to maintain satisfactory arterial oxygen saturation is reasonable based on physiologic principles; (VIII) Adjuvant drugs

  8. Heartbeat synchronized with ventilation

    Science.gov (United States)

    Schäfer, Carsten; Rosenblum, Michael G.; Kurths, Jürgen; Abel, Hans-Henning

    1998-03-01

    It is widely accepted that cardiac and respiratory rhythms in humans are unsynchronised. However, a newly developed data analysis technique allows any interaction that does occur in even weakly coupled complex systems to be observed. Using this technique, we found long periods of hidden cardiorespiratory synchronization, lasting up to 20 minutes, during spontaneous breathing at rest.

  9. Free Convection Personalized Ventilation (FCPV)

    DEFF Research Database (Denmark)

    Nielsen, Peter V.

    Normally we supply fresh air to a room with a diffuser, and this air is distributed in the room according to different principles as: mixing ventilation, displacement ventilation etc. That means we have to supply a very large amount of air to the whole room, although a person in the room totally ...

  10. Innovation in home mechanical ventilation

    NARCIS (Netherlands)

    Hazenberg, Andrea

    2017-01-01

    Patients on home mechanical ventilation (HMV) are ventilator dependent, usually for the rest of their lives. In the past decades, the number of patients on HMV increased to nearly 3,000 in 2016 in the Netherlands. Current indications for HMV are patients diagnosed with either neuromuscular disease,

  11. Reverse ventilation--perfusion mismatch

    International Nuclear Information System (INIS)

    Palmaz, J.C.; Barnett, C.A.; Reich, S.B.; Krumpe, P.E.; Farrer, P.A.

    1984-01-01

    Patients having lobar airway obstruction or consolidation usually have decreases of both ventilation and perfusion on lung scans. We report three patients in whom hypoxic vasoconstriction was apparently incomplete, resulting in a ''reversed'' ventilation-perfusion mismatch. Perfusion of the hypoxic lobe on the radionuclide scan was associated with metabolic alkalosis, pulmonary venous and pulmonary arterial hypertension in these patients

  12. Does Regional Lung Strain Correlate With Regional Inflammation in Acute Respiratory Distress Syndrome During Nonprotective Ventilation? An Experimental Porcine Study.

    Science.gov (United States)

    Retamal, Jaime; Hurtado, Daniel; Villarroel, Nicolás; Bruhn, Alejandro; Bugedo, Guillermo; Amato, Marcelo Britto Passos; Costa, Eduardo Leite Vieira; Hedenstierna, Göran; Larsson, Ander