Emergency Medicine: Open Access
Open Access

Abstract

Accuracy of the Fast Exam: A Retrospective Analysis of Blunt Abdominal Trauma Patients

Adeyinka A. Adedipe, Brandon H. Backlund, Eric Basler and Sachita Shah

Background: Point-of-care ultrasound (POCUS) is a vital tool for diagnosis and management of emergency room patients. Focused assessment with sonography for trauma (FAST) is a bedside ultrasound performed by clinicians in the evaluation of trauma patients. In 2012, Haroborview Medical Center, the only level-one trauma center in five northwestern states, officially incorporated emergency physician (EP) performed FAST exams for critically injured blunt abdominal trauma (BAT) patients.
Objective: We sought to determine the accuracy of EP performed FAST exams for severely injured patients with blunt abdominal trauma (BAT). Secondary objectives included trends in use of diagnostic peritoneal lavage (DPL) to identify hemoperitoneum after the implementation of the new protocol.
Design: We conducted a retrospective chart review using the emergency department tracking system to identify all Emergency Severity Index (ESI) 1 trauma patients with BAT over a 26-month study period (July 1, 2011 to August 31, 2013). Hemodynamically unstable BAT patients who had a FAST exam performed were included for further analysis. Results of EP FAST exams and radiology department FAST exams were compared against peritoneal fluid analysis, computed tomography results, and operative findings, where available.
Results: 185 patients met inclusion criteria. In total there were 33 true positive, 109 true negative, 2 false positive, 12 false negative, and 29 indeterminate examinations, for an overall sensitivity, specificity, and accuracy of 73%, 98%, and 91% respectively. EP performed FAST exams had a sensitivity, specificity and accuracy of 88% (95% CI 67 to 96 %), 98% (95% CI 87 to 99 %), and 94% for moderate to large amounts of intra-peritoneal hemorrhage. The overall use of DPL in the evaluation of critically ill blunt trauma patient decreased slightly with the protocol change, however this decrease was not significant (p=0.17).
Conclusion: Our study demonstrated that emergency physicians are accurate in identifying hemoperitoneum in critically injured BAT patients. Secondary findings suggest that utilization of DPL in hemodynamically unstable BAT patients decreased modestly