Pulmonary embolism after injury: more common than we think?

BACKGROUND: We have previously demonstrated that pulmonary embolism (PE) can occur early and explain hypoxia immediately after injury. We hypothesized that an increased awareness of early PE would result in an increased incidence, an earlier diagnosis, and a decreased mortality of PE after injury.
METHODS: The trauma registry identified patients diagnosed with a PE between time period (TP) 1 (June 1999 and December 2004) and TP 2 (January 2005 and December 2006). Demographics, injury specific data, time from injury to diagnosis, diagnostic modality, and mortality were compared with a t test for the two TPs.
RESULTS: There were 35,424 and 15,022 patients, respectively, treated in our trauma center during the two study periods. During TP1, 94 (0.27%) patients were diagnosed with PE. Mean age was 45 years (+/-18.5) and mean Injury Severity Score (ISS) was 23 (+/-11.4); 81.9% were men and 91.6% sustained blunt trauma. Eighty-three (0.55%) patients in TP2 were identified with a PE. Mean age was 43 years (+/-17.4) and mean ISS was 23 (+/-13.0); 78.3% were men and 86.7% sustained blunt trauma. In TP1, the diagnosis was confirmed by a computed tomography (CT) in 76 of 94 (80.9%) patients. In TP2, the CT scan diagnosed 80 of 83 (96.4%) patients. Time to diagnosis was postinjury day 11.8 (+/-14) in TP1 and 9.2 (+/-11.5) in TP2. Mortality in patients diagnosed with PE was 10.6% in TP1 and 9.6% in TP2.
CONCLUSION: Our incidence of PE has doubled from 0.27% to 0.55% in a 6-year TP when mean ISS and thromboembolic prophylaxis protocols have remained the same. We attribute this increase in incidence to heightened awareness through recent publications, as well as 24 hour availability of multiple multidetector-row spiral CT scanners and not necessarily an increase in prevalence of PE.