SLR - March 2017 - Lisa Zhang

Toward a More Robust Prediction of Pulmonary Embolism in Trauma Patients: A Risk Assessment Model Based on 38,000 Patients

Reference: Black SR, Howard JT, Chin PC, Starr AJ. Toward a More Robust Prediction of Pulmonary Embolism in Trauma Patients: A Risk Assessment Model Based on 38,000 Patients. J Orthop Trauma. 2016 Apr;30(4):200–7.

Scientific Literature Review

Reviewed By: Lisa Zhang, DPM
Residency Program: University Hospital, Newark, NJ

Podiatric Relevance: Since a pulmonary embolus (PE) has mortality rates ranging from 17 percent to 26 percent, it is important to investigate the causes of PE in trauma patients. Previous studies have explored the topic of DVT prophylaxis; however, a significant number of DVTs in the lower extremity remain asymptomatic. The authors’ purpose was to develop a risk assessment model for the patients at highest risk for developing a PE using a large number of trauma patients, using a prospective approach.

Methods: 38,597 trauma patients were included in the final analysis. Of those, 239 (0.619 percent) developed a PE. A binary regression model was developed to predict the odds of develop a PE during hospitalization, and diagnosis was confirmed by chest CT.

Results: 239 patients developed a PE out of the 38,597. Seven statistically significant variables were identified, including age, obesity, injury from motorcycle accident, arrival to hospital by ambulance or helicopter, pulse rate in the emergency department, location of injury (including lower extremity, thorax and abdomen) and admission to ICU. The authors found that each age increased the changes of developing PE by one percent. Obese patients (BMI > 30) were found to have a 154 percent increased chance of developing a PE than nonobese patients. Patients who arrive by motorcycle are 100 percent more likely to develop PEs than patients injured in any other way. High pulse rates in the ED were also positively correlated with PEs. Patients with lower extremity injuries were 185 percent more likely to experience PEs.

Conclusions: Admission to the ICU, obesity, tachycardia in the ED, arrival by motorcycle and advanced age are all proxies for increased injury severity. An increased number of the above heightens the suspicion for PE and thereby prolonged prophylaxis by the podiatric surgeon. Interestingly, the study found that 23.8 percent to 50 percent of PE events are "early," occurring the first four days of hospitalization. This refutes traditional thinking that PEs occur seven to 10 days after trauma. In patients meeting the appropriate criteria, early and stringent efforts in prophylaxis are warranted.

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