ISSN:
1432-1238
Keywords:
Acute respiratory failure
;
Best PEEP
;
Optimum PEEP
;
Total lung and chest wall compliance
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract We assessed hemodynamics, total lung and chest wall compliance (CT) and gas exchange using two different levels of PEEP during controlled ventilation in two different groups of patients with ARF; in the first group (Group 1, 12 patients) chest X-Rays showed a symmetrical pattern of bilateral alveolar infiltrates; in the second group (Group 2, 5 patients) chest X-Rays showed an asymmetrical pattern with unilateral lobar consolidation. A first level of PEEP (best PEEP=9±3 cm H2O) produced an improvement in CT and in gas exchange with a slight decrease in cardiac index in both groups; but improvement in PaO2 (from 64±33 to 122±76 torr, p〈0.001 in Group 1, and from 76±39 to 91±33 torr, p〈0.05 in Group 2) and decrease in QS/QT were not as well marked in Group 2 as in Group 1. A second level of PEEP (high level PEEP: 20±4 cm H2O) produced a sharp decrease in CT and required hemodynamic support in each case (blood volume expansion with or without Dopamine infusion) to maintain cardiac index within a normal range. In Group 1 this high level PEEP produced a greater improvement in gas exchange (PaO2 increased from 122±76 to 194±76, p〈0.01) but in Group 2 it had a deleterious effect, producing a decrease in PaO2 (from 91±33 to 76±41 torr, p〈0.05), and an increase in $$\dot QS/\dot QT$$ ; with this higher PEEP we also noted an increase of alveolar dead space in Group 2. This study demonstrates the efficiency of high levels of PEEP to reduce $$\dot QS/\dot QT$$ in ARF but also shows its limitations: namely reduction in cardiac performance and in efficiency if the damage to one lung is significantly more pronounced than that to the other lung.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01724837
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