Do you mean perioperative? I can't think of a scenario I saw third year where we ever gave thinners pre-op, in fact a lot of surgeries were postponed when PT times hadn't returned to normal by the morning of the surgery. You're trying to find a balance between the patient getting a clot vs bleeding out on the table or after surgery. I don't remember any crazy anticoagulation question on shelves or Step 2 but you might get pimped on stuff like this. The classic scenario is someone taking warfarin which takes a few days to clear the system so usually it is stopped a few days before and replaced with a short acting anticoagulant like heparin which is continued until the day before, that way they will have some level of anticoagulation going until a few hours before surgery. Immediately after surgery they start back on warfarin with a heparin bridge since warfarin takes a few days to accumulate and start working but heparin is almost immediate, once they are at a therapeutic level the heparin is discontinued. In high risk(for a clot) patients they may use perioperative anticoagulation and take some risk of them bleeding but this is probably not something you would be expected to know until residency.
