Early Predictors of Abscess Development after Perforated Pediatric Appendicitis

Approximately one-third of children with appendicitis present with advanced disease or perforation. Whereas this increases the risk for post-operative complications and re-admission, it is not yet possible to predict early on who will develop an abdominal abscess. We sought to identify specific risk factors for this complication, in an attempt to streamline post-operative care.

We reviewed the records of all cases of perforated appendicitis over a 12-month period at a tertiary children's hospital. All patients who developed an abscess despite treatment minimum of seven days of antibiotic therapy were identified. Patients who presented or were re-admitted with an abscess were excluded from analysis. Records were reviewed for demographics, laboratory results, progression of oral intake, and vital signs.

Of 273 patients with appendicitis, we identified 59 cases of perforated appendicitis. Fifteen patients were excluded. Eight of the remaining 44 patients (18.2%) developed an abscess during their initial admission. Their mean length of stay was longer than that of patients without an abscess (13.4 ± 7.1 vs. 6.9 ± 1.9 d, p < 0.0001). Gender, leukocytosis, or diarrhea at presentation, maximum temperature on post-operative day 3, and maximum heart rate on post-operative day 3 were not statistically different. Diet progression was different between the two groups: none of the 21 patients who were tolerating a regular diet by post-operative day 3 developed an abscess, compared with 8 of the 23 patients who were not yet eating a regular diet on post-operative day 3 (p < 0.01). Late leukocytosis also correlated with the presence of an abscess: 7 of the 8 patients with an abscess had persistent leukocytosis at days 5 through 7, compared with 3 of 31 patients without abscess (p < 0.05). An ultrasound was obtained for these 3 patients and proved normal.

Tolerating a regular diet three days after appendectomy for perforated appendicitis decreased the likelihood of a post-operative abscess. No other parameter was predictive of this complication early in the post-operative period. If confirmed in a larger prospective study, this finding may help decrease the length of stay for low-risk patients, and identify abscesses in high-risk patients in a timely fashion.