protamine reversal
Pronunciation: PRO-ta-meen
The administration of protamine sulfate to neutralize heparin anticoagulation following cardiopulmonary bypass.
Full Definition
Protamine reversal is a critical step in cardiac surgery that involves administering protamine sulfate to neutralize the heparin anticoagulation required for cardiopulmonary bypass. Protamine is a positively charged protein that binds to negatively charged heparin molecules, forming inactive complexes and restoring normal coagulation function. The typical dose ratio is approximately 1 mg of protamine per 100 units of heparin administered, though this may be adjusted based on ACT values and clinical bleeding assessment. Protamine administration must be carefully managed as it can cause severe adverse reactions including anaphylaxis, pulmonary hypertension, and hemodynamic instability. Successful protamine reversal is confirmed by normalization of ACT values and cessation of abnormal bleeding.
Usage
Usage note: Always specify dose and administration rate; monitor for adverse reactions.
In Context
- "Protamine reversal was accomplished with 350 mg administered slowly over 10 minutes." — anesthesia record
- "The patient developed mild hypotension during protamine reversal, which resolved with fluid administration." — operative report