Recovery of end-stage organ dysfunction by circulatory assist

To clarify the effectiveness of left ventricular assist on recovery of critical organ dysfunction, 18 patients with ventricular septal rupture or free wall rupture after acute myocardial infarction were retrospectively studied. Fifteen patients were managed with an intraaortic balloon pump (IABP group), and three with a left ventricular assist device (LVAD group) after surgery. In the IABP group, nine patients survived and six died. There were no significant differences between survivors and nonsurvivors with respect to age, cardiopulmonary bypass time, or preoperative renal function. In addition, there were no significant differences in the early postoperative changes in cardiac index. Larger doses of catecholamines were required in nonsurvivors than in survivors, however; blood urea nitrogen and creatinine levels were significantly higher in nonsurvivors than in survivors, and the nonsurvivors' creatinine clearance values stayed under 20 ml/min during the postoperative course, so that all nonsurvivors required renal assist. All in the LVAD group were weaned. Two patients were lost, however, because of cardiac arrythmia and massive gas embolism. Cardiac index in the LVAD was maintained at over 2.1 L/min/m2 with a minimum dose of catecholamines, regardless of poor left ventricular function, and creatinine clearance recovered to over 20 ml/min during circulatory assist. From these data, high doses of catecholamines depressed renal function after surgery. Therefore, it has been concluded that the major role of circulatory assist is to maintain more of the physiologic circulation with minimum doses of drugs.