Inclusion Criteria:  Age > 18 years Traumatic injury of long bones or pelvis requiring surgical intervention Admission to the ICU  Exclusion Criteria:  Age < 18 years Intracranial hemorrhage Direct admit to OR without prior ICU admission Pregnancy Prisoner Chronic Kidney Disease requiring dialysis or a glomerular filtration rate (GFR) or creatinine clearance requiring a decrease in Enoxaparin dosage Presence of DVT prior to study drug dose