A potentially expanded role for enoxaparin in preventing venous thromboembolism in high risk blunt trauma patients

BACKGROUND: Venous thromboembolism (VTE) is a frequent and potentially life -threatening complication after trauma. The purpose of this study is to inv estigate the effectiveness of enoxaparin in preventing deep venous thrombos is (DVT) and pulmonary embolism (PE) after injury in patients who are at hi gh risk for developing VTE. STUDY DESIGN: A prospective single-cohort observational study was initiated for seriously injured blunt trauma patients admitted to a Level I trauma c enter during a 7-month period. Patients were eligible for the study if time hospitalized was greater than or equal to 72 hours, Injury Severity Score (ISS) was greater than or equal to 9, enoxaparin was started within 24 hour s after admission, and one or more of the following high risk criteria were met: age > 50 years, ISS greater than or equal to 16, presence of a femora l vein catheter, Abbreviated Injury Score (AIS) greater than or equal to 3 for any body region, Glasgow Coma Scale (GCS) Score less than or equal to 8 , presence of major pelvic, femur, or tibia fracture, and presence of direc t blunt mechanism venous injury. Patients with closed head injuries and non operatively treated solid abdominal organ injuries were also potential part icipants. The primary outcomes measured were thromboembolic events-either a documented lower extremity DVT by duplex color-flow doppler ultrasonograph y or a PE documented by rapid infusion CT pulmonary angiography or conventi onal pulmonary angiography. RESULTS: There were 118 patients enrolled in the study. Two patients (2%) d eveloped DVT, one of which was proximal to the calf (95% confidence interva l, 0% to 6%). Two of 12 patients (17%) with splenic injuries who received e noxaparin failed initial nonoperative management. There were no other bleed ing complications, and no clinical evidence or documented episodes of PE. O ne patient died from multiple system organ failure. CONCLUSIONS: Enoxaparin is a practical and effective method for reducing th e incidence of VTE in high risk, seriously injured patients. This study sup ports further investigation into the safety of enoxaparin prophylaxis in pa tients with closed head injuries and nonoperatively treated solid abdominal organ injuries. (J Am Coll Surg 2001;192:161-167. (C) 2001 by the American College of Surgeons).