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Coronary flow limits right ventricular performance during positive end-expiratory pressure.
D S Schulman1, J W Biondi, S Zohgbi
1Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut.
The American Review of Respiratory Disease
|June 1, 1990
Summary
Positive end-expiratory pressure (PEEP) impairs right ventricular performance and myocardial blood flow, especially when right coronary artery blood flow is limited. This effect is more pronounced at higher PEEP levels.
Area of Science:
- Cardiology
- Physiology
- Critical Care Medicine
Background:
- Positive end-expiratory pressure (PEEP) is commonly used in mechanical ventilation.
- Its effects on right ventricular (RV) function and myocardial perfusion, particularly during compromised coronary flow, require further elucidation.
Purpose of the Study:
- To investigate the impact of PEEP on RV performance and myocardial blood flow.
- To assess these effects before and after right coronary artery (RCA) occlusion in a canine model.
Main Methods:
- Measurements included right ventricular ejection fraction (RVEF), end-diastolic volume (EDV), and end-ejection volume using thermodilution.
- Right ventricular end-ejection pressure-volume relations (RVEEPVR) were determined at varying PEEP levels (0, 10, and 20 cm H2O) before and after RCA occlusion.
- Myocardial blood flow was also assessed.
Main Results:
- With intact RCA flow, PEEP decreased RVEF but did not significantly alter EDV or end-ejection volume, RVEEPVR, or myocardial blood flow.
- After RCA occlusion, PEEP significantly reduced RVEF and increased end-ejection volume.
- RVEEPVR and myocardial blood flow decreased with RCA occlusion and further with 20 cm H2O PEEP, but not with 10 cm H2O PEEP.
Conclusions:
- In this experimental model, PEEP adversely affects right ventricular performance when right coronary blood flow is compromised.
- Higher PEEP levels exacerbate these negative effects, highlighting the importance of monitoring RV function in mechanically ventilated patients with potential coronary ischemia.