Atelectasis is a major cause of hypoxemia and shunt after cardiopulmonary bypass: an experimental study

Details

Serval ID
serval:BIB_7E2225EECE98
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Atelectasis is a major cause of hypoxemia and shunt after cardiopulmonary bypass: an experimental study
Journal
Anesthesiology
Author(s)
Magnusson  L., Zemgulis  V., Wicky  S., Tyden  H., Thelin  S., Hedenstierna  G.
ISSN
0003-3022 (Print)
Publication state
Published
Issued date
11/1997
Volume
87
Number
5
Pages
1153-63
Notes
Journal Article
Research Support, Non-U.S. Gov't --- Old month value: Nov
Abstract
BACKGROUND: Respiratory failure after cardiopulmonary bypass (CPB) remains a major complication after cardiac surgery. The authors tested the hypothesis that atelectasis is an important factor responsible for the increase in intrapulmonary shunt after CPB. METHODS: Six pigs received standard CPB (bypass group). Six other pigs had the same surgery but without CPB (sternotomy group). Another six pigs were anesthetized for the same duration but without any surgery (control group). The ventilation-perfusion distribution was measured with the inert gases technique, extravascular lung water was quantified by the double-indicator distribution technique, and atelectasis was analyzed by computed tomography. RESULTS: Intrapulmonary shunt increased markedly after bypass but was unchanged over time in the control group (17.9 +/- 6.2% vs. 3.5 +/- 1.2%; P < 0.0001). Shunt also increased in the sternotomy group (10 +/- 2.6%; P < 0.01 compared with baseline) but was significantly lower than in the bypass group (P < 0.01). Extravascular lung water was not significantly altered in any group. The pigs in the bypass group showed extensive atelectasis (32.3 +/- 28.7%), which was significantly larger than in the two other groups. The pigs in the sternotomy group showed less atelectasis (4.1 +/- 1.9%) but still more (P < 0.05) than the controls (1.1 +/- 1.6%). There was good correlation between shunt and atelectasis when all data were pooled (R2 = 0.67; P < 0.0001). CONCLUSIONS: Atelectasis is produced to a much larger extent after CPB than after anesthesia alone or with sternotomy and it explains most of the marked post-CPB increase in shunt and hypoxemia. Surgery per se contributes to a lesser extent to postoperative atelectasis and gas exchange impairment.
Keywords
Animals Anoxemia/*etiology Atelectasis/*complications/etiology Cardiopulmonary Bypass/*adverse effects Hemodynamic Processes Protamines/pharmacology Pulmonary Edema/etiology Pulmonary Gas Exchange Respiration Swine
Pubmed
Web of science
Create date
28/01/2008 10:52
Last modification date
20/08/2019 14:39
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