[Peritoneal dialysis in the treatment of the low cardiac output after extracorporeal circulation]

Low cardiac output after cardiopulmonary bypass is not uncommon. This per- and postoperative cardiac depression is accompanied by an impairment of renal function, which recovers with the improvement of the low cardiac output. These two correlated failures may become resistant to cardiotonic and diuretic drugs. Indeed the fluid balance is strongly disturbed, although venous pressure is only moderately increased. The only possible treatment could be water withdrawal. Nine patients are reported, all suffering from cardiac and renal failure after cardiopulmonary bypass. They were successfully treated with the method of continuous ambulatory peritoneal dialysis. This method allowed us to stop all intravenous cardiac drugs within 36 h, whilst diuresis reappeared together with a better efficacy of diuretic drugs. This beneficial haemodynamic effect of water withdrawal is discussed. This phenomenon may be related to an influence of right ventricular filling on the left ventricle. Low cardiac output may occur as a result of septal displacement, especially if there is concomitant myocardial suffering. Withdrawing a small volume of water may have modified the septal displacement, and improved cardiac output. Continuous ambulatory peritoneal dialysis was simple and well tolerated; it seemed to have contributed to the haemodynamic recovery of all the nine patients.