Optimization of Anticoagulation Strategy During Cardiopulmonary Bypass in Neonates with Congenital Heart Disease: A Randomized Controlled Trial.

Purpose: Neonatal hemostatic immaturity complicates anticoagulation during cardiopulmonary bypass (CPB). Current practice largely follows the strategy of 400 U/kg from adult protocols, as neonatal-specific guidelines and high-quality evidence remain lacking, which frequently fails to achieve adequate anticoagulation. This single-center randomized controlled trial evaluated the initial heparin dose of 600 U/kg to refine neonatal CPB anticoagulation. Patients and Methods: In this prospective, randomized, controlled, single-blind trial, 76 neonates undergoing CPB were assigned to receive an initial heparin dose of either 600 U/kg (n = 38) or 400 U/kg (n = 38). The primary endpoint was the pre- to post-CPB change in prothrombin fragment 1+2 (ΔF1+2). Secondary endpoints included the proportion of neonates achieving the ACT threshold after the initial heparin bolus, perioperative coagulation measures, postoperative blood loss, transfusion requirements, and adverse clinical outcomes. Results: Mean ΔF1+2 was 0.70 vs 4.08 nmol/L in the 600 and 400 U/kg groups, respectively (treatment-minus-control mean difference, -3.38 nmol/L; 95% confidence interval, -4.58 to -2.18; Conclusion: An initial heparin dose of 600 U/kg in neonatal CPB was associated with a smaller F1+2 increase and greater initial ACT response. Larger studies are needed to establish clinical benefit and safety. Clinical Trial Registry Number: ChiCTR2300069157.