A total of 50 patients >40 yrs of age with an expected hospital stay in the Medical Intensive Care or Regional Heart Unit at LVH Muhlenberg of 6 days or longer will be enrolled. The patient and study team will be blinded to which drug they are receiving (either Arixtra or Lovenox). Subjects will be examined for any bleeding complications. Subjects will receive drug for a total of 6-14 days while in the hospital. A follow up phone call will be performed by the study team approximately 30 days after discharge from the hospital.

A total of 50 patients will be enrolled in this double-blinded, randomized, controlled trial. Inclusion criteria: subjects>40 yrs of age with an expected hospital stay in the Medical Intensive Care or Regional Heart Unit at LVH Muhlenberg of 6 days or longer (4 days bedridden) will be enrolled. Total drug treatment will be 6-14 days while in the hospital. A follow up phone call will be performed by the study team approximately 30 days after hospital discharge. Primary endpoint: bleeding rate (minor vs major) between study days 1-14. Secondary endpoint: DVT study days 1-14 (confirmed with LE duplex ultrasonogram).

Inclusion Criteria:

• Male or female > 40 years of age.
• Pt with expected stay in hospital 6 days or >, with expectation to be bedridden for > 4 days.
• Pts admitted to the MICU, Regional Heart Units of LV-MHC

Exclusion Criteria:

• Surgical primary admission diagnosis
• Recent surgery within the past 12 weeks
• Planned surgery on the current admission
• Pregnancy
• Vent-dependent respiratory failure requiring intubation for >24 hours.
• Known current DVT or PE prior to enrollment in study.
• Creatinine clearance < 30 mL/min (calculated by the Cockcroft-Gault method) in a well-hydrated patient.
• Hx of prior or current lower upper or lower GI bleed.
• Platelet count < 100,000 per cubic millimeter
• Current or prior anticoagulation within the prior 48 hours, excluding a single dose &lor 24 hour period of prophylactic agent
• Bacterial endocarditis.
• Hemophilia
• Hypersensitivity to aspirin.
• Hypersensitivity to Arixtra or Lovenox
• Hx of hemorrhagic or ischemic stroke < 3 months prior to enrolling
• Hematocrit < 28%.
• SBP >200 mmHg or DBP >120 mmHg
• Positive for occult blood in stool.
• Admission to hospital for > 48 hours prior to randomization
• Documented congenital or acquired bleeding disorder
• Indwelling intrathecal or epidural catheter
• Life expectancy < 30 days
• Inability to have a flu assessment post-discharge from the hospital