Impact of helical computed tomography on the outcomes of emergency department patients with suspected appendicitis

Objectives: To assess the impact of an emergency department (ED) guideline employing selective use of helical computed tomography (CT) on clinical outcomes of female patients with suspected appendicitis. Methods: All patients presenting with suspected appendicitis were prospectively enrolled and managed in accordance with a guideline incorporating selective use of helical CT. Although not the objective of this investigation, male patients were included for purposes of comparison. Patients with clinically evident appendicitis were referred to the surgical service, and patients with equivocal presentations were studied with helical CT. Patients were followed to final surgical or clinical outcomes. Outcome measures included time from ED presentation to laparotomy and rate of appendiceal perforation. These measures were compared with those of a historical cohort of patients preceding the use of helical CT. Results: A total of 310 consecutive patients with suspected appendicitis were enrolled; 92 had appendicitis. Sixty patients were referred to the surgical service without helical CT, and 41 had appendicitis (68%). Helical CT was performed on 250 patients; 51 had appendicitis (20%). For males, the mean interval from ED presentation to laparotomy was 559 minutes (95% CI=444 to 674 minutes) during guideline use and 480 minutes (95% CI=405 to 555 minutes) before. This interval for females was 433 minutes (95% CI=326 to 540 minutes) during guideline use and 710 minutes (95% CI=558 to 862 minutes) before. Appendiceal perforation rate for males was 0.25 (95% CI=0.14 to 0.36) during guideline use and 0.38 (95% CI=0.29 to 0.47) before; perforation rate for females was 0.06 (95% CI=-0.05 to 0.17) during guideline use and 0.23 (95% CI=0.14 to 0.32) before. Helical CT had 92% sensitivity 97% specificity, and 96% accuracy in diagnosing appendicitis. Conclusions: Helical CT is highly accurate in detecting appendicitis in patients with equivocal ED presentations. The use of a guideline employing selective helical CT was associated with a decline in the time from ED presentation to operative intervention in females.