The Hemodynamic Effects of Protamine in Pediatric Patients Undergoing Pulmonary Artery Reconstruction and Unifocalization Surgery: A Pilot StudyHemodynamic Effects of Protamine in Children.

Objectives: To determine protamine administration increases pulmonary artery pressures (PAPs) in patients undergoing unifocalization or pulmonary artery reconstruction surgeries.

Design: Retrospective database study.

Setting: A large pediatric heart center within an academic quaternary care facility.

Participants: All patients undergoing pulmonary artery reconstruction or a unifocalization procedure identifiable within the data warehouse.

Interventions: We collected data from Stanford University's data repository, formatted it, and analyzed it using RStudio (v 2023.06.1+524).

Measurements and main results: Our primary outcome is the change in PAP after the administration of protamine. Secondary outcomes include changes in the mean arterial pressure, the ratio of systolic pulmonary artery to systemic artery pressure, right-sided filling pressure, and left atrial pressure. After a protamine bolus, we found a difference in PAP (Friedman χ² = 49.46; p < 0.001). When compared with 2 minutes before its administration, the PAP was higher at 2 minutes (29.00 mmHg versus 25.00 mmHg; p < 0.001), 5 minutes (30.00 mmHg versus 25.00 mmHg; p < 0.001) and 10 minutes (31 mmHg versus 25 mmHg; p < 0.001). When coadministered with calcium, there was also a significant increase in PAP (Friedman χ² = 28.11; p < 0.001), with a higher PAP 10 minutes after calcium administration when compared with 2 minutes before (32 mmHg versus 26 mmHg; p < 0.001).

Conclusions: Protamine administration led to a small increase in PAP after separation from cardiopulmonary bypass in patients undergoing pulmonary artery reconstruction or unifocalization surgeries. Calcium coadministration did not lead to a greater increase in PAP.