Prevention of Low Cardiac Output Syndrome After Pediatric Cardiac Surgery: A Double-Blind Randomized Clinical Pilot Study Comparing Dobutamine and Milrinone

Abstract

Objectives: Dobutamine and milrinone are commonly used after open-heart surgery to prevent or treat low cardiac output syndrome. We sought to compare efficacy and safety of these drugs in pediatric patients.

Design: Prospective, single-center, double-blinded, randomized clinical pilot study.

Setting: Tertiary-care university children's hospital postoperative pediatric cardiac ICU.

Patients: After written consent, 50 consecutive patients (age, 0.2-14.2 yr; median, 1.2 yr) undergoing open-heart surgery for congenital malformations were included.

Interventions: After cardiopulmonary bypass, a continuous infusion of either dobutamine or milrinone was administered for the first 36 postoperative hours. Maximum dose: dobutamine 6 µg/kg/min, milrinone 0.75 µg/kg/min.

Measurements and main results: There were no significant differences in demographic data, complexity of surgery, and intraoperative characteristics between the two study groups (dobutamine vs milrinone). Efficacy was defined as need for additional vasoactive support, which did not differ between groups (dobutamine 61% vs milrinone 67%; p = 0.71). Sodium nitroprusside was used more often in the dobutamine group (42% vs 13%; p = 0.019). Systolic blood pressure showed a trend toward higher values in the dobutamine group, whereas both drugs increased heart rate early postoperatively. Echocardiography demonstrated a consistently good cardiac function in both groups. Central venous oxygen saturation, serum lactate levels, urine output, time to chest tube removal, length of mechanical ventilation, ICU, and hospital stay were similar in both groups. Both drugs were well tolerated, no serious adverse events occurred.

Conclusions: Dobutamine and milrinone are safe, well tolerated, and equally effective in prevention of low cardiac output syndrome after pediatric cardiac surgery. The hemodynamic response of the two drugs is comparable. In uncomplicated cases, a trend toward the more cost-saving dobutamine might be anticipated; however, milrinone demonstrated a trend toward higher efficacy in afterload reduction.