Cardiothoracic & vascular anesthesia
Optimising protamine dosing for heparin reversal after cardiopulmonary bypass: a population pharmacokinetic–pharmacodynamic study
Authors' conclusion
A P:H ratio of 0.625:1 provided adequate UFH reversal.
Study context
- Population
- Adults undergoing cardiopulmonary bypass (CPB)-assisted cardiac surgery receiving protamine for unfractionated heparin (UFH) reversal757 blood samples
- Participants
- 68 adults
- Outcome
- Minimal effective P:H ratio for complete reversal (anti-Xa <0.10 IU ml-1)
Methodological detailsprospective, single-centre, nonlinear mixed-effects modelling, Monte Carlo simulations
- Prospective
- Single-centre
- Nonlinear mixed-effects modelling
- Monte Carlo simulations
Main finding
As reported in the abstract
Simulated P:H ratio for complete reversal
- P:H ratio of 0.625:1 predicted to achieve complete reversal in 95% of patients
- Model-based simulations
Observational data: associations, not effects.
Further findings
Measured anti-Xa activity after protamine · within 10 min of protamine initiation
- Anti-Xa <0.10 IU ml-1 in all patients
Doses received
- Mean total UFH dose (IU)
- 30 250
- Mean total protamine dose (mg)
- 200
Activated clotting time (ACT)–anti-Xa relationship
- Positively associated, but ACT varied widely at low anti-Xa concentrations
Original publication
Optimising protamine dosing for heparin reversal after cardiopulmonary bypass: a population pharmacokinetic–pharmacodynamic study. Br J Anaesth. Published 4 February 2026. doi:10.
Composed by AI from the published abstract and checked against it. How Briefs are made →