Prevention of venous thromboembolism after injury: An evidence-based report - Part I: Analysis of risk fastors and evaluation of the role of vena caval filters

Background: Trauma surgeons use a variety of methods to prevent venous thro mboembolism (VT), The rationale for their use frequently is based on conclu sions from research on nontrauma populations. Existing recommendations are based on expert opinion and consensus statements rather than systematic ana lysis of the existing literature and synthesis of available data. The objec tive is to produce an evidence-based report on the methods of prevention of VT after injury. Methods: A panel of 17 national authorities from the academic, private, and managed care sectors helped design and review the project. We searched thr ee electronic databases (MEDLINE, EMBASE, and Cochrane Controlled Trial Reg ister) to identify articles relevant to four key questions: methods of prop hylaxis, methods of screening, risk factors for VT, and the role of vena ca val filters. The initial 4,093 titles yielded 73 articles for meta-analysis , A random-effects model was used for all pooled results. Study quality was evaluated by previously published quality scores. In this article (part I) , we report on the question ranked by the experts as the most important, i. e., Which is the best method to prevent VT?, and also on the incidence of d eep venous thrombosis and pulmonary embolism in trauma patients. Results:The incidence of deep venous thrombosis and pulmonary embolism repo rted in different studies varies widely. The pooled rates are 11.8% for dee p venous thrombosis and 1.5% for pulmonary embolism. Only a few randomized controlled trials have evaluated the methods of VT prophylaxis among trauma patients, and combining their data is difficult because of different desig ns and preventive methods used. The quality of most studies is low, Meta-an alysis shows no evidence that low-dose heparin, mechanical prophylaxis, or low-molecular-weight heparin are more effective than no prophylaxis or each other. However, the 95% confidence intervals of many of the comparisons ar e wide; therefore, a clinically important difference may exist. Conclusion: The trauma literature on VT prophylaxis provides inconsistent d ata. There is no evidence that any existing method of VT prophylaxis is cle arly superior to the other methods or even to no prophylaxis, Our results c ast serious doubt on the existing policies on VT prophylaxis, and we call f or a large, high-quality, multicenter trial that can provide definitive ans wers.