Predicting pulmonary embolus in orthopedic trauma patients using the Wells score

The decision to perform computed tomography pulmonary angiography (CTPA) to rule out pulmonary embolism (PE) in orthopedic trauma patients is challenging. The Wells score is a commonly used clinical probability tool developed to determine the likelihood of PE and assist in determining the need for CTPA examination. This study evaluated the usefulness of the Wells score for predicting PE in patients admitted to the orthopedic trauma service. All patients who were admitted to the orthopedic trauma service at the authors' institution between 2001 and 2011 who underwent CTPA were identified. The Wells score was calculated retrospectively for each patient, and risk categories using the traditional and alternative interpretations of the Wells score were assigned. Pulmonary embolism was diagnosed in 27 (16%) of 169 patients who underwent CTPA. In total, 27 (0.39%) of 6854 patients admitted to the orthopedic trauma service were diagnosed with PE during initial hospitalization. Mean Wells score was 3.31 (95% confidence interval, ±.28) for the entire population, 3.32 for those without PE (95% confidence interval, ±.31), and 3.28 for those with PE (95% confidence interval, ±.72) (P=.91). Average times from admission to CTPA examination for those with and without PE were 6.18 and 5.7 days, respectively (P=.94). No significant correlation existed between the Wells score and CTPA results, indicating that the Wells score is limited in predicting PE risk in orthopedic trauma patients.