Hospitalized trauma patients frequently suffer from blood clots in the legs or lungs. To minimize the risk of these blood clots developing, patients may be given a blood-thinner drug such as enoxaparin.

Until now, a set dose of enoxaparin has been given to a patient, regardless of his or her weight. However, a recent study suggests that for obese patients, the set dose may be inadequate. The purpose of this study is to evaluate whether or not a dose of enoxaparin that is based on the patient's weight will help to prevent the formation of blood clots.

The information gathered through this study will help doctors to understand the best way to prevent blood clots in future trauma patients. The potential risks of participating in this study include the minor risks of blood draws and ultrasounds, as well as the more significant risks of bleeding as a side effect of the enoxaparin.

Inclusion Criteria:

• 18 years of age or older
• Body Weight >60 kg
• Admitted to the trauma services at Intermountain Medical Center
• Have received 1 standard dose of enoxaparin for VTE prophylaxis during current hospital admission.

Exclusion Criteria:

• Significant bleeding injury such as solid organ laceration or intracranial bleed at discretion of attending physician
• Renal insufficiency (GFR <30)
• Platelet count <100 thousand per cubic ml
• Hypersensitivity to heparin or prior documented heparin induced thrombocytopenia (HIT) by patient report or in medical record
• Pregnant or breast feeding
• Hemorrhagic stroke in proceeding 3 months
• abnormal baseline coagulation characterized by an INR >1.4, obtained at the discretion of the treating clinician
• Required therapeutic anticoagulation for atrial fibrillation, prior VTE, or mechanical heart valve
• Treatment with concomitant antiplatelet agent other than aspirin 326 mg or more daily
• Subjects with a life expectancy less than 1 month
• Subjects hospitalized more than 72 hours prior to randomization.