Unfractioned Heparin for Treatment of Sepsis

Inclusion Criteria: * Patients must have an infection defined by clinical and/or microbiological criteria in accordance with modified CDC definitions for nosocomial infections * Patients must present with one or more of the GENERAL VARIABLES, AND one or more of the INFLAMMATORY VARIABLES within 24 hours before admission to the study GENERAL VARIABLES: * Temperature (oral or axillary) \> 38ºC or \< 36ºC, * Heart rate \> 90 beats/min, * Respiratory rate \> 20 breaths/min, * Altered mental status determined by Glasgow Coma Scale \< 15, * Systolic blood pressure \< 90 mm Hg or a decrease \> 40 mm Hg INFLAMMATORY VARIABLES: * WBC \> 12,000 μL-1 or \< 4,000 μL-1 or with \> 10% immature forms, * Plasma C-reactive protein \> 5 mg/dL. These variables should not be attributable to an underlying disease other than infection or due to the effects of concomitant therapy. Exclusion Criteria: * Pregnant or breastfeeding. * Platelet count \< 60,000/mm3. * Increased risk for bleeding: \* Any patient who has undergone major surgery, defined as surgery that required general or spinal anesthesia, performed within the 12-hour period immediately preceding admission to the hospital; any postoperative patient who demonstrates evidence of active bleeding; or any patient with planned or anticipated major surgery during the first 12 hours after admission to the hospital. \* History of: severe head trauma that required hospitalization, intracranial surgery, or stroke within 3 months of study entry; or any history of intracerebral arteriovenous malformation, cerebral aneurysm, or central nervous system mass lesion. \* History of congenital bleeding diatheses, such as hemophilia. \* Gastrointestinal bleeding within 6 weeks of study entry that required medical intervention unless definitive surgery has been performed. \* Trauma patients at increased risk of bleeding, for example: flail chest; significant contusion to lung, liver, or spleen; retroperitoneal bleed; pelvic fracture; or compartment syndrome. * Patients with a known hypercoagulable condition including activated Protein C resistance; a hereditary deficiency of Protein C, Protein S, or antithrombin; presence of anticardiolipin antibody, antiphospholipid syndrome, lupus anticoagulant or homocysteinemia; or patients with a recently documented (within 3 months of study entry) or highly suspected deep venous thrombosis or pulmonary embolism. * Patients taking or requiring the following medications: \* Therapeutic heparin, defined as UFH dosed to treat an active thrombotic or embolic event within the 12 hours prior to study entry or LMWH used at any dose higher or more frequent than the recommended dose on the product label for prophylaxis within the 12 hours prior to study entry. \* Warfarin, if used within 7 days of study entry. \* Thrombolytic treatment within 3 days of study entry (for example, streptokinase, rtPA, and urokinase). \* Glycoprotein IIb/IIIa antagonists within 7 days of study entry. * Patients with known esophageal varices, chronic jaundice, cirrhosis, or chronic ascites. * Patients not expected to survive 28 days given their preexisting, uncorrectable medical condition. This criterion includes patients with, or suspected to have, poorly controlled neoplasms or other end-stage processes, such as end-stage cardiac disease, prior cardiac arrest, end-stage lung disease, or end-stage liver disease. * Patients with chronic renal failure on either hemodialysis or peritoneal dialysis. * HIV positive patients with most recent CD4 count \< 200/mm3. * Patients who have undergone bone marrow, liver, lung, kidney or pancreas transplantation. * Inability or unwillingness of patients or legal representative to give written informed consent.