ECHOCARDIOGRAPHIC ANALYSIS OF CARDIAC-FUNCTION DURING HIGH PEEP VENTILATION

Objective: Does positive end-expiratory pressure ventilation (PEEP) deteriorate cardiac contractility? Design: By means of echocardiography nine piglets were studies during ventilation with 0, 15 and 25 cmH2O (PEEP). Recordings were made before and after 500 ml of 6% dextran 70. Measurement and results: Right and left ventricular end-diastolic diameters were plotted against the stroke volume determined by the thermodilution technique. By combining observations made before and after volume expansion during the different ventilation modes, a ventricular function curve was obtained. The slopes of the curves were similar during all three ventilation modes, both on the left and on the right side. Conclusion: This study indicates undisturbed myocardial contractility during PEEP ventilation. We infer that the cardiac output deterioration in the intact animal is caused entirely by impairment of venous return.