Thrombotic Complications of Low‐Dose Versus High‐Dose Four‐Factor Prothrombin Complex Concentrate for Massive Bleeding in Pediatric Cardiovascular Surgery

ABSTRACT Introduction Major bleeding is a life‐threatening complication in pediatric cardiovascular surgery, particularly in neonates and infants with immature coagulation systems and congenital heart defects ( CHD ). Cardiopulmonary bypass ( CPB ) exacerbates these risks by depleting coagulation factors and platelets. Four‐factor prothrombin complex concentrates ( 4F ‐ PCC ) provide targeted hemostatic correction but carry potential thrombotic risks. Methods Among 1296 pediatric patients who underwent cardiovascular surgery between January 2018 and April 2024, a retrospective cohort study analyzed 104 patients who received 4F ‐ PCC . Patients were grouped into low‐dose (< 35 U/kg) and high‐dose (≥ 35 U/kg). Thrombotic complications were evaluated within 15 days after use. Results The median age was 1 month ( IQR : 0–7.5), and 69.23% of patients were male. Common diagnoses included hypoplastic left heart syndrome (14.42%), ventricular septal defect (13.46%), and coarctation of the aorta (12.5%). Frequent procedures included Norwood procedure (14.42%) and ventricular septal defect closure (13.46%). Thrombotic complications occurred in 6.73% overall, with no significant differences between high‐dose (5.26%) and low‐dose (8.51%) groups ( p = 0.698). High‐dose 4F ‐ PCC was associated with shorter CPB times ( p = 0.007) (Cohen's d 0.537) but higher reintervention rates (57.89% vs. 34.04%; p = 0.015) (Cramér's V 0.118). Conclusion High‐dose 4F ‐ PCC was not associated with increased thrombotic complications. Thrombotic complications in this study were inferior to all‐cause thrombotic complications in pediatric cardiovascular surgery of 11%. These findings support 4F ‐ PCC as a viable option for managing severe bleeding in pediatric cardiovascular surgery. Further studies should explore dose optimization and preventive applications.