Coagulopathies, thrombosis prophylaxis

1. Big picture

This topic has two opposite but connected surgical problems:

1. Bleeding risk: the patient cannot form a stable clot → operative bleeding, hematoma, wound complications, reoperation.
2. Thrombosis risk: surgery creates a hypercoagulable state → deep vein thrombosis (DVT), pulmonary embolism (PE), graft thrombosis, stroke, myocardial infarction.

The exam logic is:

Before surgery:
Is the patient likely to bleed?
Is the patient likely to thrombose?
Is the patient taking anticoagulants or antiplatelets?
Can we correct reversible problems?
What prophylaxis is safest?

After surgery:
Bleeding? Hematoma? Drain output?
DVT? PE? Limb ischemia?
Restart anticoa