Understanding of the hemostatic and complement alterations associated with cardiopulmonary bypass (CPB) in pediatric patients and the impact of these alterations on outcome is limited.

The present study prospectively characterized these alterations and their association with postoperative outcomes in pediatric CPB.

All patients aged <21 years undergoing CPB at the authors’ institution between 2020 and 2021 who weighed >3 kg, were >36 weeks gestational age, and had no known prothrombotic or hemorrhagic disorders were eligible. Blood samples were analyzed for multiple hemostatic and complement biomarkers pre-, intra-, and 24 hours post-CPB. Biomarker levels were compared to clinical outcomes, including chest tube output (CTO).

Fifty consecutive patients were enrolled. CPB resulted in multiple significant alterations in hemostatic and complement components. Lower platelet counts (<80 × 10⁹ platelets/L) at CPB termination were associated with increased postoperative CTO (P = .003). Lower factor (F)VIII levels (<60 IU/dL) at the end of CPB were associated with a longer hospital stay (P < .001) and increased postoperative CTO (P < .001). Patients undergoing staged single ventricle reconstruction were more likely to have lower platelet counts at CPB termination (P = .009) and higher CTO postoperatively (P = .001) than patients undergoing other types of surgical repair. These differences were not due to different preoperative platelet counts, increased incidences of circulatory arrest, or longer CPB times.

These data suggest that intraoperative alterations in hemostatic system components may predict postoperative outcomes in pediatric CPB. Further study is needed to determine if interventions targeting platelets or FVIII could improve outcomes in pediatric CPB.