Cardiovascular effects of positive end-expiratory pressure in dogs

Abstract

The relationship of the fall in cardiac output and blood pressure which occurs during positive end-expiratory pressure (PEEP) to changes in transmural right atrial and left atrial filling pressures was reexamined. Closed-chest dogs, half with pulmonary edema, were studied during spontaneous breathing and inspiratory positive-pressure breathing (IPPB) with 0-15 cmH2O PEEP. Mean esopheageal pressure accurately reflected changes in pericardial pressure and was used to estimate extracardiac pressure. Cardiac output fell approximately 50% and blood pressure fell 20% during 15 cmH2O PEEP in spite of well maintained transmural right atrial and left atrial (or pulmonary artery wedge) pressures suggesting a primary or reflex depression of atrial or ventricular function.