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CO2 elimination at varying inspiratory pause in acute lung injury

Aboab, J.; Niklason, Lisbet LU ; Uttman, Leif LU ; Kouatchet, A.; Brochard, L. and Jonson, Björn LU (2007) In Clinical Physiology and Functional Imaging 27(1). p.2-6
Abstract
Previous studies have indicated that, during mechanical ventilation, an inspiratory pause enhances gas exchange. This has been attributed to prolonged time during which fresh gas of the tidal volume is present in the respiratory zone and is available for distribution in the lung periphery. The mean distribution time of inspired gas (MDT) is the mean time during which fractions of fresh gas are present in the respiratory zone. All ventilators allow setting of pause time, T-P, which is a determinant of MDT. The objective of the present study was to test in patients the hypothesis that the volume of CO2 eliminated per breath, VTCO2, is correlated to the logarithm of MDT as previously found in animal models. Eleven patients with acute lung... (More)
Previous studies have indicated that, during mechanical ventilation, an inspiratory pause enhances gas exchange. This has been attributed to prolonged time during which fresh gas of the tidal volume is present in the respiratory zone and is available for distribution in the lung periphery. The mean distribution time of inspired gas (MDT) is the mean time during which fractions of fresh gas are present in the respiratory zone. All ventilators allow setting of pause time, T-P, which is a determinant of MDT. The objective of the present study was to test in patients the hypothesis that the volume of CO2 eliminated per breath, VTCO2, is correlated to the logarithm of MDT as previously found in animal models. Eleven patients with acute lung injury were studied. When T-P increased from 0% to 30%, MDT increased fourfold. A change of T-P from 10% to 0% reduced VTCO2 by 14%, while a change to 30% increased VTCO2 by 19%. The relationship between VTCO2 and MDT was in accordance with the logarithmic hypothesis. The change in VTCO2 reflected to equal extent changes in airway dead space and alveolar PCO2 read from the alveolar plateau of the single breath test for CO2. By varying T-P, effects are observed on VTCO2, airway dead space and alveolar PCO2. These effects depend on perfusion, gas distribution and diffusion in the lung periphery, which need to be further elucidated. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
acute respiratory distress syndrome, dead space, gas exchange, mechanical ventilation
in
Clinical Physiology and Functional Imaging
volume
27
issue
1
pages
2 - 6
publisher
Wiley Online Library
external identifiers
  • wos:000242862200001
  • scopus:33845515684
ISSN
1475-0961
DOI
10.1111/j.1475-097X.2007.00699.x
language
English
LU publication?
yes
id
dbb4bf07-cf6d-41ba-916d-6955ff6f58c1 (old id 681812)
date added to LUP
2007-12-11 09:04:22
date last changed
2017-01-01 04:28:16
@article{dbb4bf07-cf6d-41ba-916d-6955ff6f58c1,
  abstract     = {Previous studies have indicated that, during mechanical ventilation, an inspiratory pause enhances gas exchange. This has been attributed to prolonged time during which fresh gas of the tidal volume is present in the respiratory zone and is available for distribution in the lung periphery. The mean distribution time of inspired gas (MDT) is the mean time during which fractions of fresh gas are present in the respiratory zone. All ventilators allow setting of pause time, T-P, which is a determinant of MDT. The objective of the present study was to test in patients the hypothesis that the volume of CO2 eliminated per breath, VTCO2, is correlated to the logarithm of MDT as previously found in animal models. Eleven patients with acute lung injury were studied. When T-P increased from 0% to 30%, MDT increased fourfold. A change of T-P from 10% to 0% reduced VTCO2 by 14%, while a change to 30% increased VTCO2 by 19%. The relationship between VTCO2 and MDT was in accordance with the logarithmic hypothesis. The change in VTCO2 reflected to equal extent changes in airway dead space and alveolar PCO2 read from the alveolar plateau of the single breath test for CO2. By varying T-P, effects are observed on VTCO2, airway dead space and alveolar PCO2. These effects depend on perfusion, gas distribution and diffusion in the lung periphery, which need to be further elucidated.},
  author       = {Aboab, J. and Niklason, Lisbet and Uttman, Leif and Kouatchet, A. and Brochard, L. and Jonson, Björn},
  issn         = {1475-0961},
  keyword      = {acute respiratory distress syndrome,dead space,gas exchange,mechanical ventilation},
  language     = {eng},
  number       = {1},
  pages        = {2--6},
  publisher    = {Wiley Online Library},
  series       = {Clinical Physiology and Functional Imaging},
  title        = {CO2 elimination at varying inspiratory pause in acute lung injury},
  url          = {http://dx.doi.org/10.1111/j.1475-097X.2007.00699.x},
  volume       = {27},
  year         = {2007},
}