Heparin Activity Following Titration-Guided Protamine Reversal After Cardiopulmonary Bypass: Impact on Postoperative...

Area of Science:

• Cardiovascular Surgery
• Anesthesiology
• Pharmacology

Background:

• Heparin is crucial for anticoagulation during cardiopulmonary bypass (CPB).
• Protamine sulfate is used to reverse heparin's effects post-CPB.
• Optimizing protamine dosing is essential to prevent residual or rebound heparin activity.

Purpose of the Study:

• To assess residual and reappearing heparin activity post-CPB.
• To evaluate low-dose, titration-guided protamine reversal in elective coronary artery bypass grafting (CABG).

Main Methods:

• Prospective, controlled clinical study at a single university hospital.
• Forty adult patients undergoing elective CABG with CPB.
• Automated titration system guided heparin and protamine dosing.
• Heparin activity measured by anti-factor Xa (anti-FXa), activated partial thromboplastin time (aPTT), and thrombin time (TT).

Main Results:

• Residual heparin activity was detected in 60% of patients on ICU arrival (anti-FXa: 0.14 ± 0.15 U/mL).
• Protamine to heparin (P/H) ratio correlated with TT, aPTT, and endogenous thrombin potential (ETP).
• Heparin activity increased by 3 hours post-ICU arrival (anti-FXa: 0.18 ± 0.10 U/mL, 98% detectable), irrespective of P/H ratio.
• No association found between heparin activity and postoperative bleeding.

Conclusions:

• Low-dose, titration-guided protamine reversal commonly results in residual heparin activity.
• Reappearing heparin activity post-surgery is independent of protamine dosage.
• Observed heparin activity did not correlate with increased postoperative bleeding.