Surface cooling (20 degrees C) and circulatory arrest in infants undergoing cardiac surgery. Results in ventricular septal defect, complete atrioventricular canal, and total anomalous pulmonary venous connection.

Abstract

During a six-year period, 46 severely symptomatic infants (average age, 5.1 months) underwent correction of ventricular septal defect (22 patients), total anomalous pulmonary venous connection (13 patients), and complete atrioventricular canal (11 patients), with the use of surface cooling to 20 degrees C. Cardiac repair was performed during circulatory arrest, and rewarming was performed with a pump oxygenator. Ten patients undergoing repair of ventricular septal defects were studied hemodynamically at 21 degrees C, before repair and at 37 degrees C after rewarming. Heart rate, left ventricular systolic pressure, maximum dp/dt, cardiac index, stroke work, and oxygen consumption were reduced substantially at 21 degrees C. Systemic vascualr resistance was increased at 21 degrees C. All changes were reversible with repair and rewarming. A protocol for hemodilution and crystalloid volume loading was devised to maintain urine output after early patients were noted to demonstrate renal dysfunction. With this protocol, survival rates were 89% for patients with ventricular septal defects, 67% for those with atrioventricular canal defects, and 85% for those with total anomalous pulmonary-venous connection.