Prophylaxis of VTE For surgery w/ moderate thrombogenic risk & in patients not at high risk of thromboembolism: 2000 anti-Xa IU (0.2 mL) SC daily, initiated 2 hr pre-op. For surgery w/ a high thrombogenic risk (hip & knee surgey): 4000 anti-Xa IU (0.4 mL) SC daily, initiated 12 hr pre-op or 2000 anti-Xa IU (0.2 mL) 2 hr pre-op. Duration of treatment must be