Early Versus Late Pulmonary Embolism in Trauma Patients: Not All Pulmonary Embolisms are Created Similarly

Abstract Background Pulmonary embolism (PE) is an uncommon complication occurring in up to 5% of trauma patients. In small previous studies, patients with long-bone fractures were associated with a higher risk of early PE while those with severe head injuries were at higher risk for late PE. Materials and methods This was a retrospective analysis at a single level I trauma center from 2010 to 2017. Patients with early PE (≤4 d) were compared to those with late PE (>4 d) using bivariate analysis and multivariable logistic regression analysis. We sought to confirm risk factors for early and late PE, hypothesizing that early PE is associated with long-bone fractures and late PE is associated with above-the-knee deep venous thrombosis (DVT). Results From 12,833 trauma admissions, 76 patients (0.6%) had a PE. Of these, 33 (43.4%) had an early PE and 43 (54.6%) were diagnosed with late PE. After adjusting for covariates, independent risk factors for late PE included above-the-knee DVT (odds ratio [OR] = 12.01, confidence interval [CI] = 1.34-107.52, P  = 0.03), blood transfusion (OR = 8.99, CI = 1.75-46.22, P  = 0.009), and craniotomy (OR = 8.82, CI = 1.03-75.97, P  = 0.04), while the only independent risk factor for early PE was smoking (OR = 4.56, CI 1.06-19.66, P  = 0.04). Severe head injury and long-bone fractures were not risk factors for early or late PE ( P  > 0.05) Conclusions The strongest risk factor for late PE is above-the-knee DVT. Contrary to previous reports, long-bone extremity fractures and severe head injuries are not associated with early or late PE. The only risk factor for early PE was a history of smoking.