Permissive hypercapnia impairs pulmonary gas exchange in the acute respiratory distress syndrome

Details

Serval ID
serval:BIB_42CC05E8626B
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Permissive hypercapnia impairs pulmonary gas exchange in the acute respiratory distress syndrome
Journal
American Journal of Respiratory and Critical Care Medicine
Author(s)
Feihl  F., Eckert  P., Brimioulle  S., Jacobs  O., Schaller  M. D., Melot  C., Naeije  R.
ISSN
1073-449X (Print)
Publication state
Published
Issued date
07/2000
Volume
162
Number
1
Pages
209-15
Notes
Journal Article
Research Support, Non-U.S. Gov't --- Old month value: Jul
Abstract
Current recommendations for mechanical ventilation in the acute respiratory distress syndrome (ARDS) include the use of small tidal volumes (VT), even at the cost of respiratory acidosis. We evaluated the effects of this permissive hypercapnia on pulmonary gas exchange with the multiple inert gas elimination technique (MIGET) in eight patients with ARDS. After making baseline measurements, we induced permissive hypercapnia by reducing VT from 10 +/- 2 ml/kg to 6 +/- 1 ml/kg (mean +/- SEM) at constant positive end-expiratory pressure. After restoration of initial VT, we infused dobutamine to increase cardiac output (Q) by the same amount as with hypercapnia. Permissive hypercapnia increased Q by an average of 1.4 L. min(-)(1). m(2), decreased arterial oxygen tension from 109 +/- 10 mm Hg to 92 +/- 11 mm Hg (p < 0.05), markedly increased true shunt (Q S/Q T), from 32 +/- 6% to 48 +/- 5% (p < 0.0001), and had no effect on the dispersion of VA/Q.VA/Q. On reinstatement of baseline V T with maintenance of a high Q, Q S/Q T remained increased, to 38 +/- 6% (p < 0.05), and Pa(O(2 ))remained decreased, to 93 +/- 4 mm Hg (p < 0. 05). These results agreed with effects of changes in VT and Q predicted by the mathematical lung model of the MIGET. We conclude that permissive hypercapnia increases pulmonary shunt, and that deterioration in gas exchange is explained by the combined effects of increased Q and decreased alveolar ventilation.
Keywords
Adolescent Adult Aged Cardiac Output Female Humans Hypercapnia/complications/*physiopathology Male Middle Aged *Pulmonary Gas Exchange Respiratory Distress Syndrome, Adult/complications/*physiopathology
Pubmed
Web of science
Create date
25/01/2008 9:38
Last modification date
20/08/2019 13:45
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