USE OF LOW-MOLECULAR-WEIGHT HEPARIN IN PREVENTING THROMBOEMBOLISM IN TRAUMA PATIENTS

Objective: To investigate the safety and effectiveness of low molecula r weight heparin (LMWH) in preventing deep venous thrombosis (DVT) in high-risk trauma patients, compared with mechanical methods of prophyl axis. Design: A prospective randomized trial conducted over a 19-month period in an urban, academic trauma center. Methods: All trauma patie nts with the following risk factors for the development of DVT were co nsidered for enrollment in this study: any injury with an Abbreviated Injury Scale score greater than or equal to 3; major head injury (Glas gow Coma Scale score less than or equal to 8); spine, pelvic, or lower extremity fractures; acute venous injury; or age >50 gears, After a s creening venous duplex examination, the patients were assigned to a He parin versus No-Heparin group, depending upon the presence of injuries precluding the use of heparin, In the Heparin group, the patients wer e then randomized to receive either LMWH or optimal mechanical compres sion (defined as bilateral sequential gradient pneumatic compression ( SCD) or, in the presence of lower extremity injuries precluding the us e of the SCD, the arteriovenous impulse (AVI) compression system), All the patients in the No-Heparin group received optimal compression, En rolled patients underwent sequential duplex examinations every 5 to 7 days until discharge. Results: Of the 487 consecutive patients initial ly enrolled in this study, 372 were available for at least the first t wo duplex examinations and comprise the study population, Only nine (2 .4%) patients developed DVT, compared with the predicted 9.1% rate in high-risk trauma patients receiving no prophylaxis (p = 0.037). Of the 120 patients who were randomized to receive LMWH, only one (0.8%) dev eloped DVT. In the SCD group, there were 5 of 199 patients (2.5%) with DVT, and 3 of 53 (5.7%) in the AVI group, One patient with DVT also h ad clinical symptoms of pulmonary embolism, but there were no deaths s econdary to pulmonary embolism, There was one major bleeding complicat ion potentially associated with the use of LMWH. Conclusions: The admi nistration of LMWH is a safe and extremely effective method of prevent ing DVT in high-risk trauma patients, When heparin is contraindicated, aggressive attempts at mechanical compression are warranted.