Venous thromboembolism in the high-risk trauma patient: do risks justify aggressive screening and prophylaxis?

Deep venous thrombosis (DVT) and pulmonary embolism (PE) are considered to be a major source of morbidity and mortality among trauma patients. Several reports have identified high-risk patients with recommendations for management ranging from frequent duplex scanning to placement of prophylactic inferior vena cava (IVC) filters. We reviewed our experience with a large trauma population to determine whether such approaches are justified.

We analyzed 2,868 consecutive trauma admissions over 22 months and identified 280 patients (10%) in high-risk groups who survived > or = 48 hours: (1) severe closed head injury with mechanical ventilation > or = 72 hours, (2) closed head injury with lower extremity fractures, (3) spinal column/cord injury, (4) combined pelvic and lower extremity fractures, and (5) major infrarenal venous injuries. The remaining nonthermal injury patients constituted the low-risk group.

There were 280 high-risk patients, 213 of whom (76%) received prophylaxis with compression therapy. There were 12 cases of DVT (5%) with four nonfatal PE (1.4%). Six patients (2%) had therapeutic IVC filters inserted and only one patient had prophylactic placement. There were 38 deaths in this group, attributable primarily to severe closed head injury or spine injuries, and none were caused by PE. In the 2,249 low-risk patients, there were three cases of DVT (0.1%, p < 0.05 vs. high risk) and no PE (p < 0.05 vs. high risk).

Although these patients were at increased risk for thromboembolic events, the overall incidence of DVT was still extremely low with no apparent PE deaths. In our patient population, aggressive screening and prophylactic IVC filters would not have benefited 95% of "high-risk" patients without DVT and would not have prevented any deaths. We could not identify any population, except perhaps venous injuries, where such expensive and potentially harmful maneuvers seemed justified. Our experience with DVT and PE does not support either aggressive screening or prophylactic IVC filters as the standards of care.