Risk Stratification for Venous Thromboembolism After Electrical Injury

Background: In extremities, electricity travels within nerves, along bones, and in close proximity to major veins. Thus, electrically injured patients may be at increased risk for deep venous thrombosis (DVT) and subsequent pulmonary embolus (PE). Using the National Burn Repository (NBR), we sought to describe the incidence and risk factors for DVT and PE in electrically injured patients. Methods: We identified adult patients in the NBR admitted with an electrical injury between 1996 and 2005 (n=1464). Patients who died within 24 hours or were admitted for less than 1 day and hospitals reporting no complications were excluded. Independent variables included total body surface area (TBSA) burned and need for fasciotomy. Fasciotomy was used as a proxy for severity of electrical injury. Venous thromboembolism (VTE), including DVT or PE, was the dependent variable. Bivariate statistics identified risk factors for VTE. Multivariate logistic regression identified risk factors which predicted risk of developing VTE. Results: Patients with electrical injury who were admitted for more than 24 hours had an overall VTE incidence of 0.9%; this was higher than patients with thermal injuries alone (0.6%). Of all patients admitted with electrical injury, 10.3% required fasciotomy. Electrically injured patients who required fasciotomy had significantly increased VTE incidence when compared to non-fasciotomy patients (9.5% vs. 0.58%, p<.001). In a logistic regression model, both need for fasciotomy (OR 14.8, p<0.001) and increased TBSA by percent (OR 1.04, p=0.012) were significantly associated with VTE. The combination of need for fasciotomy and increased TBSA was strongly predictive of patients who developed VTE (c-statistic=0.89). Hosmer-Lemeshow goodness of fit test demonstrated that this model discriminates between patients at the lowest and highest risk of developing VTE. Conclusion: The combination of need for fasciotomy and increased TBSA is strongly associated with VTE in electrically injured patients. Clinicians should consider these factors when evaluating patients for VTE prophylaxis at admission.