RESUMEN

Overview Venous thromboembolism (VT) is major national health problem, claiming 50,000 lives and resulting in 300,000 to 600,000 hospitalizations annually in the United States. VT presents in two forms: deep venous thrombosis (DVT) and pulmonary embolism (PE). Injured patients are at high risk for VT because of changes in coagulation and thrombolysis mechanisms that are induced by trauma.

Methods of prevention of VT include, among others, sequential compression devices (SCDs), low-dose heparin (LDH), low-molecular-weight heparin (LMWH), vena cava filters (VCFs), and combinations of these. All these methods are associated with contraindications and morbidity. Therefore, selecting the appropriate method for the appropriate trauma patient is important. The difficulty of selecting the appropriate prophylaxis is in part a result of the inconclusiveness of the relevant trauma literature. This allows wide variability among physicians' practices and prevents consistency in quality of care.

With this report, we evaluate and meta-analyze the existing data in the literature to produce scientific answers in controversial areas related to this topic. We also identify research gaps in areas in which the scientific evidence is absent or minimal, and we hope to assist interested organizations in producing relevant guidelines and in directing future research.

EXAMINANDO LA EVIDENCIAe

A panel of 17 technical experts, consisting of national authorities in the field and representing the academic, private, and managed care sectors, was formed to assist in the design and execution of the project. Important questions on the topic were distributed to the experts, who ranked them in order of importance. After two conference calls, four refined key questions were developed:

• (1) What is the best method of VT prophylaxis?
• (2) What groups of patients are at high risk of developing VT?
• (3) What is the best method of screening for VT?
• (4) What is the role of VCFs in preventing PE?

The panel decided to use data restricted to trauma patients only and to avoid extrapolations of conclusions from nontrauma patients to the trauma population. Defining "the trauma patient" was difficult. The panel decided to exclude elderly patients with injuries following low-energy trauma (such as hip fractures after ground-level falls) from consideration. We subsequently developed causal pathways for each key question. We felt it was important to report on the rates of DVT and PE from combined literature data because these rates varied widely among studies. We summarized the existing evidence on all trauma patients included in the available literature as well as that on individual trauma patient groups (orthopedic trauma, neurosurgical