Head Injury and Pulmonary Embolism: A Retrospective Report Based on the Pennsylvania Trauma Outcomes Study

OBJECTIVE: We retrospectively examined the database of the Pennsylvania Trauma Systems Foundation to determine the risk of pulmonary embolism in adult patients sustaining isolated head trauma or multiple injuries, including head trauma, to answer two questions: What is the incidence of symptomatic pulmonary embolism during hospitalization in a trauma center in patients who have sustained a head injury? Are patients with head injuries more at risk for pulmonary embolism than trauma patients without head injuries? METHODS: We determined the total number of adult submissions per year to the Pennsylvania Trauma Outcomes Study from 1992 to 1996. Age, sex, Glasgow Coma Scale score, Abbreviated Injury Score for head injury, Injury Severity Score, intensive care unit days, hospital days, and the presence or absence of head injury, spinal injury, pelvic fractures, and/or femur fractures were recorded. Statistical techniques to evaluate their correlation with the incidence of pulmonary embolism included χ² testing, linear regression analysis, Kendall analysis, and logistic regression analysis. RESULTS: The average incidence of symptomatic pulmonary embolism in head-injured patients occurring during their acute hospital stay was 0.38%. This rate was not significantly greater than the 0.27% incidence of pulmonary embolism in patients without head injury. Factors that significantly increased this incidence were age greater than 45 years, Injury Severity Score greater than 15, male sex, and the presence of pelvic or femur fractures or of spinal cord injury. CONCLUSION: We found no evidence that head injury is a significant independent risk factor for development of symptomatic pulmonary embolism during the acute hospitalization of the trauma patient.