Perioperative administration of angiotensin converting enzyme inhibitors decreases the severity and duration of pleural effusions following bidirectional cavopulmonary anastomosis

Background:. Pleural effusions after bidirectional cavopulmonary anastomosi s remain a significant cause of morbidity. Prolonged effusions in such pati ents have been associated with persistent elevations in plasma renin and an giotensin II. Methods: We conducted a controlled study in 36 patients (medi an age 8 months) undergoing bidirectional cavopulmonary anastomosis. Enalap ril (5 mcg/kg) was administered intravenously within 1 hour of surgery and every 12 hours thereafter in 18 patients; when these patients were tolerati ng feeds, enalapril was switched to enteral captopril(3 mg/kg/day) every 8 hours. The other 18 patients did not receive perioperative angiotensin conv erting enzyme inhibitors. Using standardized criteria for discontinuation o f chest tubes ( < 2 mL/kg/day), volume and duration of pleural drainage wer e compared between groups. Results. There were no differences between group s in demographic, diagnostic, or hemodynamic factors. There was no differen ce in cardiopulmonary bypass time between groups and no difference in posto perative pulmonary arterial pressures. The duration of pleural drainage was shorter (2.2<plus/minus>1.4 vs 5.9 +/-1.4 days, p<0.001) and the volume le ss during the first 24 hours (4.7<plus/minus>1.2 vs 7.7 +/-2.1 mL/kg, p<0.0 01) and overall(10.6<plus/minus>2.4 vs 19.6 +/-4.5 mL/kg, p<0.001) in patie nts who received angiotensin converting enzyme inhibitors than those who di d not. Readmission for persistent effusions was required in 3 patients who did not receive angiotensin converting enzyme inhibitors and none who did ( p=0.11). Conclusions: Perioperative administration of angiotensin convertin g enzyme inhibitors is associated with decreased severity and duration of p leural effusions following bidirectional cavopulmonary anastomosis.