Predictors of outcome for children with perforated appendicitis initially treated with non-operative management.

BACKGROUND: Initial non-operative therapy for children with perforated appendicitis has become increasingly popular with the advent of powerful broad-spectrum antibiotics. However, there is no consensus regarding which patients may be managed effectively with this strategy. We reviewed all children with perforated appendicitis who were treated initially with non-operative therapy to determine those characteristics that may predict a successful outcome.
METHODS: We reviewed the medical records of children admitted to our hospital between January 1, 2000 and May 1, 2003 with the diagnosis of perforated appendicitis. Only those who were treated initially with a single broad-spectrum antibiotic (piperacillin-tazobactam), with the intention of performing an interval appendectomy, were included in this study. Patients were divided into two groups based on whether they were managed successfully with non-operative therapy: Responders and non-responders. Non-responders were defined as patients who either did not improve with antibiotic therapy or who required appendectomy prior to their electively scheduled time (six weeks). Demographic data, duration and type of presenting symptoms, initial white blood cell count (WBC), percent bands, percent neutrophils (PMNs), computed tomography (CT) interpretation, and interventions/operations were abstracted. Categorical data were compared using Chi-square analysis or the Fisher exact test; continuous variables were compared using the Student t-test and the Mann-Whitney U-test.
RESULTS: Overall, 26% (19/73) of patients treated initially non-operatively required appendectomy prior to the electively scheduled date. There was no difference between responders (n = 54) and non-responders (n = 19) with respect to age, gender, initial WBC, percent bands, percent PMNs, or duration and type of presenting symptoms. However, responders were more likely to have a phlegmon on CT scan compared to non-responders (11/54 vs. 0/19, p = 0.03). Non-responders were twice as likely to undergo drainage of an abscess by interventional radiology (10/19 vs. 13/54, p = 0.02) compared to responders. Among all patients who required percutaneous drainage, the failure rate of non-operative management was 43% (10/23).
CONCLUSIONS: Children with perforated appendicitis can be managed effectively with nonoperative therapy, even in the presence of intra-abdominal abscesses. However, the need for abscess drainage increases the failure rate, perhaps due to inadequate source control. Those patients with a phlegmon on CT scan as opposed to an abscess, are most likely to respond to non-operative management. Initial non-operative therapy of perforated appendicitis in children is appropriate under certain clinical circumstances, especially when the body itself or interventional radiology can achieve adequate source control.