Prophylactic and therapeutic inferior vena cava filters to prevent pulmonary emboli in trauma patients.

HYPOTHESIS: Insertion of inferior vena cava filters (IVCFs) can prophylactically reduce pulmonary embolism (PE) in trauma patients.

DESIGN

Retrospective review.

SETTING

Urban, level I trauma center.

PATIENTS: Two hundred blunt trauma patients undergoing IVCF placement.

INTERVENTIONS: In 122 patients who had already been diagnosed as having deep vein thrombosis (DVT) (112 patients) and/or PE (22 patients), the insertion of the IVCF was considered "therapeutic." In 78 patients who had no evidence of DVT or PE but who were considered to be at high risk for a PE, the IVCF was considered "prophylactic."

MAIN OUTCOME MEASURES: Incidence of PE and related mortality and morbidity in therapeutic vs prophylactic IVCFs.

RESULTS

The number of prophylactic IVCFs inserted increased significantly from only 4% (3/68 cases) from 1991 through 1996, up to 57% (75/132 cases) from 1997 to June 2001. Although the mean +/- SD age (51 +/- 20 years vs 41 +/- 15 years; P<.001) was higher in the therapeutic group, there was no difference in the mean +/- SD Injury Severity Scores (20 +/- 12 vs 21 +/- 11). Therapeutic filters were placed much later after injury (mean +/- SD time, 11 +/- 7 vs 3 +/- 2 days; P<.001). The mortality rate was 11% (13/122 patients) in patients having a therapeutic IVCF, as compared with only 3% (2/78 patients) in those placed prophylactically (P =.07). None of the patients who had placement of a prophylactic IVCF developed subsequent PE. The incidence of PE decreased in all blunt trauma patients from 0.29% before 1997 to 0.15% after January 1, 1997, when 57% of the IVCF inserted were prophylactic (P =.06).

CONCLUSIONS

Prophylactic IVCFs should be inserted within 48 hours of injury in specific trauma patients at high risk for PE and with contraindications to anticoagulation.