Related Experiment Video
Updated: Aug 17, 2025

In Vitro Thrombosis Test for Ventricular Assist Devices
Published on: March 21, 2025
Protamine titration to optimize heparin antagonization after cardiopulmonary bypass
Ruben Foubert1, Geert Van Vaerenbergh2, Guy Cammu1
1Department of Anesthesia, Intensive Care and Emergency Medicine, OLV Hospital Aalst, Aalst, Belgium.
Objectives:
To optimize protamine titration for heparin antagonization after weaning from cardiopulmonary bypass (CPB).
Design:
A prospective, observational trial.
Setting:
Single-center, non-university teaching hospital.
Participants:
Forty patients presenting for elective on-pump coronary artery bypass grafting with or without single valve surgery.
Interventions:
At the end of CPB, the residual amount of heparin in the patient was estimated using a Bull-curve. The total protamine dose was calculated as 1 unit of protamine for 1 unit of heparin. Protamine was administered as 5 aliquots containing 20% of the total protamine dose each, with 2-min intervals.
Measurements And Main Results:
Activated Clotting Time (ACT) values were measured 2 min after administration of each aliquot. ROTEM(®)-analysis was performed after the full dose of protamine had been administered. After 60% of the total protamine dose had been administered, ACT values were normalized in 86.5% of patients. After the complete dose of protamine had been administered, 61.1% of patients displayed signs of protamine overdose on ROTEM(®)-analysis.
Conclusions:
In patients who present for on-pump coronary artery bypass grafting with or without single valve surgery, a 0.6-to-1 ratio of protamine-to-heparin to antagonize heparin may be sufficient and beneficial for patients.
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