Anticoagulation
Formal Definition
Pharmacological inhibition of the coagulation cascade to prevent or treat thromboembolism; agents include unfractionated heparin (UFH), low molecular weight heparins (LMWH: enoxaparin), direct oral anticoagulants (DOACs: apixaban, rivaroxaban, dabigatran), and warfarin (vitamin K antagonist), each with distinct mechanisms, reversal agents, and monitoring requirements.
How It's Used on the Ward
"Anticoag" or "on blood thinners" — ubiquitous on medicine floors; risk-benefit assessment required before procedures, falls, or discharge.
Example
""Afib patient presenting for knee replacement: INR is 2.8. Surgeon wants INR <1.5. Holding warfarin 5 days pre-op, bridging with lovenox given her high CHA₂DS₂-VASc of 4. Plan to restart warfarin night of surgery.""
Clinical Context
Common indications: AF (stroke prevention), DVT/PE (treatment), mechanical heart valves (warfarin only), ACS (UFH or LMWH acutely). Reversal agents: warfarin → vitamin K ± 4-factor PCC or FFP; UFH → protamine; DOACs → andexanet alfa (factor Xa inhibitors) or idarucizumab (dabigatran). Bridging therapy is now generally NOT recommended for AF patients undergoing procedures per BRIDGE trial — discuss with team. Always assess bleeding vs. clotting risk before holding anticoagulation perioperatively.