The diagnosis of appendicitis in children: Outcomes of a strategy based on pediatric surgical evaluation

Objective. To determine the accuracy of a protocol for diagnosis of appendicitis in children based on clinical evaluation by a pediatric surgeon with selective use of diagnostic imaging studies. We performed this study because 1) current reports in the medical, pediatric, emergency medical, and surgical literature advocate imaging, particularly computed tomography (CT), as the gold standard for diagnosis of appendicitis, and 2) the value of pediatric surgical evaluation early in the management of the child with possible appendicitis has rarely been emphasized. Methods, Design, Setting, and Participants. Retrospective review of 356 children (mean age: 9.6 years; range: 1-18 years) referred to a regional pediatric surgical center for possible appendicitis from 1999 through 2001. Interventions. Initial pediatric surgical evaluation consisted of history, physical examination, white blood cell count, differential count, and urinalysis. Children diagnosed with appendicitis underwent appendectomy without additional studies; those with equivocal findings received intravenous fluids, rest, and reevaluation after 4 to 6 hours. Imaging was used selectively by the pediatric surgeon. Outcome Measures. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the protocol based on final diagnoses; rate of appendiceal perforation; and rate of negative appendectomy. Results. Of 356 children evaluated for appendicitis, 220 (62%) had an appendectomy. Two-hundred nine (95%) had histologically proven appendicitis, and 11 (5%) had a normal appendix. Of the 209 children with appendicitis, 139 (66%) had acute appendicitis, 34 (16%) had advanced appendicitis without perforation, and 36 (17%) had advanced appendicitis with perforation. Appendectomy was performed after initial evaluation in 195 (89%) of the 220 children and after a period of supportive care and observation in 25 (11%) of 220. One hundred thirty-six children (38%) did not have an appendectomy and were discharged with other diagnoses. The sensitivity of this protocol was 99%, specificity was 92%, positive predictive value was 95%, and negative predictive value was 99%. The accuracy was 97% compared with an accuracy of 82% for ultrasound alone and 90% for CT scan alone. Conclusions. These data show that a protocol based on clinical evaluation by a pediatric surgeon with selective use of imaging was highly accurate for the diagnosis of appendicitis in children. Low rates of negative appendectomy (5%) and perforation (17%) were achieved without the potential costs and radiation exposure of excess imaging.