Nitroprusside after open-heart surgery.

The effects of intravenous infusion of sodium nitroprusside were studied in 11 children immediately after open-heart surgery for congenital heart disease. The patients were selected because, following bypass, their cardiac index was below 2,0 L/min/m2 and their systemic vascular resistance exceeded 30 units. In order to eliminate the effects of preload, mean left atrial pressure was maintained at a constant level by blood transfusion. During infusion of nitroprusside the mean decrease of mean arterial pressure was 18.6%, of systemic vascular resistance was 53.7%, and the increase in cardiac index was 76.9%. All children recovered.