Retrospective analysis of emergency department ultrasound for acute appendicitis.

OBJECTIVES: To determine whether emergency physicians (EPs) who have skills in the other applications of ultrasound can apply these in appendicitis diagnosis.

METHODS: EPs did not have focused training in bedside ultrasound for appendicitis. We identified patients receiving an ED bedside ultrasound evaluation for appendicitis from our ultrasound log. Criterion reference was radiology ultrasound (RUS), CT scan, or pathology report.

RESULTS: We performed 155 ED ultrasounds for appendicitis. There were 27/155 cases where the ED ultrasound was true positive and agreed with pathology (sensitivity = 39%, 95% CI 28 - 52%). In 42/155 (27%) the ED ultrasound was non-diagnostic (false negative) with pathology positive. In 77 cases the ED ultrasound was true negative with non-visualization of the appendix in concert with non-visualization by RUS or CT scan (specificity = 90%, 95% CI 81-95%). In nine cases (6%), ED ultrasound was falsely positive, compared to CT scan with surgical consult.

CONCLUSION: ED ultrasound by EPs prior to focused appendicitis ultrasound training is insufficiently accurate.