RESUMEN
OBJECTIVES: Pulse pressure variations are used to assess fluid responsiveness in mechanically ventilated patients. The accuracy of this index in open chest conditions remained unclear. The aim of the study was to evaluate the effect of open chest conditions on pulse pressure variations. STUDY DESIGN: Non-interventional prospective study. METHODS AND PATIENTS: Twenty-eight mechanically ventilated patients scheduled for open-heart surgery were included. Pulse pressure variations, peak aortic velocity, and stroke volume were measured before and after thoracotomy with pericardotomy. Measurements were made at each step and compared. RESULTS: Neither pulse pressure variation nor peak aortic velocity and nor stroke volume variation were modified by open chest conditions (median=5% [interquartile range=6] vs 4% [6], p=NS), (20% [11] vs 17% [12], p=NS and 11% [7] vs 10% [3], p=NS) respectively. Pulse pressure variations were correlated to stroke volume before thoracotomy (r'=-0.432; p=0.02) and after thorocatomy (r'=-0.433, p=0.02). CONCLUSION: In these studied patients, preload dependancy indices were not modified by open chest conditions. Pulse pressure variations remained correlated to stroke volume even after thoracotomy.