Clinical question: What is the relationship between acute DVT and pulmonary embolism (PE) in trauma patients?
Background: Major trauma is associated with an increased risk of acute DVT and PE. It is assumed that the majority of PEs arise from DVTs in the lower extremities. Definitive evidence demonstrating that PEs form in situ rather than embolize from leg veins could impact indications for inferior vena cava filters.
Study design: Retrospective chart review.
Setting: Academic Level 1 trauma center in Boston.
Synopsis: The medical records of 247 trauma patients with suspected PE who underwent CT angiography of the lungs and simultaneous CT venography of the pelvis and lower extremities from January 2004 to December 2007 were reviewed. High-risk patients also underwent weekly screening with duplex ultrasonagraphy of the legs.
PE was diagnosed in 46 patients (19%) and DVT in 18 patients (7%). Anticoagulant prophylaxis had been administered to 96% and 78% of the patients with PE and DVT, respectively. PE was diagnosed a median of 5.5 days after admission (range 0-40 days) and the majority (61%) were in segmental or subsegmental branches, rather than in the main or lobar pulmonary arteries (39%). Only seven of the 46 patients (15%) diagnosed with PE also had a pelvic or lower-extremity DVT on simultaneous imaging with CT venography.
Bottom line: Trauma patients with PE often do not have a DVT at the time of diagnosis, though it remains unknown whether this is due to in-situ pulmonary thrombosis or complete embolization from the lower extremities.
Citation: Velmahos GC, Spaniolas K, Tabbara M, et al. Pulmonary embolism and deep venous thrombosis in trauma: are they related? Arch Surg. 2009;144:928-932.