Accuracy of ED sonography in the diagnosis of acute appendicitis.

The objective was to compare the accuracy of abdominal sonography performed by emergency physicians in the diagnosis of acute appendicitis with that of the surgeons' clinical impression. Three hundred-seventeen patients with right lower abdominal pain admitted to the Department of Emergency Medicine at National Taiwan University Hospital in Taipei, Taiwan were prospectively included in this study. Patients were divided into two groups according to the time of day they visited the emergency department. Those patients visiting the emergency department during the day were included in group I and those during the night were in group II. Group I was diagnosed by sonography. Group II was diagnosed by surgeons' clinical impression without sonographic examination. The definitive diagnosis of acute appendicitis was confirmed by the pathological reports. In the diagnosis of acute appendicitis, group I had a sensitivity of 96.4%, a specificity of 67.6%, a positive predictive value of 89.8%, a negative predictive value of 86.2%, and an accuracy of 89.1%, and group II had a sensitivity of 86.2%, a specificity of 37.0%, a positive predictive value of 74.6%, a negative predictive value of 55.6%, and an accuracy of 70.6%. The overall accuracy of sonography performed by emergency physicians in the diagnosis of acute appendicitis was superior to that of the surgeons' clinical impression.