Anaes · Cardiac anaesthesia
Heparin, protamine, and coagulopathy on CPB
Also known as Heparin, protamine, and coagulopathy on CPB · Protamine reaction · Post-CPB bleeding
Exact heparin dosing and ACT targets, protamine dosing and reaction phenotypes, HIT alternatives, and viscoelastic-guided post-CPB bleeding management.
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Target exams
Red flags
- Never initiate full CPB with inadequate ACT.
- Rapid central protamine boluses increase reaction risk.
- Giving more protamine blindly for surgical bleeding worsens some coagulopathies.
- HIT requires planned alternative anticoagulation — not last-minute heparin.
- Catastrophic protamine pulmonary hypertension needs stop-drug and RV support, not more protamine.
Meet the patient
A 68-year-old man is coming off bypass after a three-vessel CABG. The calculated protamine has gone in slowly through a peripheral line, the ACT is back to baseline, and the surgeon is still seeing diffuse ooze from the sternal wires. The perfusionist asks: is this surgical, or is it us?[3]
That single question — surgical or coagulopathic? — is the fork that separates safe candidates from guessers. The ACT and a viscoelastic panel answer it in minutes; viscoelastic tests give rapid point-of-care assessment that allows targeted therapy to be delivered quickly. Reaching blindly for more products or more protamine is the trainee error that bleeds the patient and clouds the diagnosis.[5]
References5ShowHide
- [1]Mazer CD, Whitlock RP, Fergusson DA, et al. Restrictive or Liberal Red-Cell Transfusion for Cardiac Surgery N Engl J Med, 2017.PMID 29130845
- [2]Hahn RT, Abraham T, Adams MS, et al. Guidelines for performing a comprehensive transesophageal echocardiographic examination: recommendations from the American Society of Echocardiography and the Society of Cardiovascular Anesthesiologists J Am Soc Echocardiogr, 2013.PMID 23998692
- [3]Levy JH, Ghadimi K, Kizhakkedathu JN, et al. What's fishy about protamine? Clinical use, adverse reactions, and potential alternatives J Thromb Haemost, 2023.PMID 37062523
- [4]Levy JH, Sniecinski RM, Maier CL, et al. Finding a common definition of heparin resistance in adult cardiac surgery: communication from the ISTH SSC subcommittee on perioperative and critical care thrombosis and hemostasis. J Thromb Haemost, 2024.PMID 38215912
- [5]Agarwal S, Abdelmotieleb M Viscoelastic testing in cardiac surgery. Transfusion, 2020.PMID 32955756