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Background: Some neonates with coarctation of the aorta (COA) present with cardiogenic shock and secondary end-organ injury. The management of this subgroup imposes unique challenges. We review our perioperative strategy and outcomes for neonates with COA who presented with cardiogenic shock., Methods: Neonates (younger than 30 days) with isolated COA or COA with aortic arch hypoplasia were identified. Retrospective review was performed to identify and characterize patients who presented with cardiogenic shock, defined as impaired left ventricular (LV) or right ventricular (RV) systolic function, or both, respiratory failure requiring tracheal intubation, and metabolic acidosis., Results: Thirteen neonates presented in cardiogenic shock and underwent surgical repair. No patients required catheter or surgical reintervention for recoarctation. There were no deaths at a mean follow-up of 54 months. Group I neonates (isolated COA, n = 7) underwent end-to-end anastomosis through left thoracotomy. The mean age and pH at presentation were 9 (+/-1.1) days and 7.07 (+/-0.21), respectively. The mean preoperative and postoperative LV myocardial performance indices (MPI) were 0.81 (+/-0.22) and 0.37 (+/-0.16), respectively (p = 0.002). Group II neonates (COA with arch hypoplasia +/- ventricular septal defect, n = 6) underwent aortic arch advancement and ventricular septal defect closure through median sternotomy. The mean time from diagnosis to surgery in group II was 5.5 (+/-1.9) days versus 2.4 (+/-1.5) days in group 1 (p = 0.01). The mean age and pH at presentation were 11.8 (+/-9.3) days and 7.02 (+/-0.21), respectively. The mean preoperative and postoperative LV MPI were 0.46 (+/-0.13) and 0.35 (+/-0.11), respectively (p = 0.02). The total hospital length of stay in group II patients was 18 (+/-6.23) days versus 11.3 (+/-5. 7) days in group I (p = 0.04)., Conclusions: Timely intervention with a strategy individualized to the patient anatomy can be performed with excellent outcomes in neonates with COA and cardiogenic shock. Neonates with isolated COA had worse preoperative LV MPI, which reflects more significant global left ventricular systolic dysfunction in this subgroup. The elapsed time from diagnosis to surgery was decreased in neonates with isolated COA.

The purpose of this study was to ascertain the optimal pharmacokinetic model for milrinone in pediatric patients after cardiac surgery when milrinone was administered as a slow loading dose followed by a constant-rate infusion. The data used for pharmacokinetic analysis were collected in a prospective, randomized, placebo-controlled multi-center trial of milrinone as prophylaxis for the development of low cardiac output syndrome after surgery for repair of complex congenital cardiac defects. Two blood samples were randomly collected from each patient for determination of plasma milrinone concentrations with subsequent population pharmacokinetic modeling. The pharmacokinetics of milrinone in pediatric patients under 6 year's age were best described by a weight-normalized one compartment model after a slow loading dose followed by a constant-rate infusion. The volume of distribution was 482 ml kg(-1) and was independent of age. Clearance was a linear function of age given by Cl = 2.42 ml kg(-1) min(-1) [1 + 0.396*age].

Background: Many pediatric patients undergoing cardiac surgery involving cardiopulmonary bypass have a predictable fall in the cardiac index 6 to 18 hours after surgery, the so-called low cardiac output syndrome (LCOS). Because patients who have LCOS require more monitoring and support and have a prolonged stay in the intensive care unit, the syndrome is associated with a costly morbidity. Milrinone, a phosphodiesterase III inhibitor, improves cardiac muscle contractile force and vascular muscle relaxation through positive inotropic and vasodilatory effects. The purpose of the Prophylactic Intravenous Use of Milrinone After Cardiac Operation in Pediatrics (PRIMACORP) study is to evaluate the safety and efficacy of the prophylactic use of milrinone in pediatric patients at high risk for development of LCOS after undergoing cardiac surgery., Methods: Patients in the multicenter, randomized, double-blind, placebo-controlled, parallel treatment study will be randomized to 1 of 3 treatment arms: (1) low-dose milrinone (25 microg/kg intravenous bolus over 60 minutes followed by a 0.25 microg/kg/min infusion for 35 hours), (2) high-dose milrinone (75 microg/kg intravenous bolus over 60 minutes followed by a 0.75 microg/kg/min infusion for 35 hours), or (3) placebo., Results: The primary end point for efficacy evaluation will be based on a composite variable consisting of death or development of LCOS requiring additional mechanical or pharmacologic support, up to 36 hours after randomization. A 2-sided test with a 0.025 type I error will be used for the primary end point analysis. The PRIMACORP study will enroll a total of 240 patients. Six additional secondary end points will be analyzed., Conclusions: The PRIMACORP study will address several questions regarding the safety and efficacy of prophylactic milrinone use in pediatric patients at high risk for development of LCOS after cardiac surgery.