Labs Do Not Predict Postoperative Intra-abdominal Abscess in Pediatric Perforated Appendicitis

Abstract

Introduction: We aim to evaluate the utility of postoperative labs in predicting the development of an intra-abdominal abscess (IAA) in pediatric patients with perforated appendicitis. We hypothesize that postoperative labs are not predictive of IAA development.

Methods: This was a single-institution retrospective cohort study that included pediatric patients (n = 61) who underwent surgery for perforated appendicitis from January 1, 2019 to December 1, 2020. Patients were stratified into those who developed a postoperative IAA (n = 22) and those who did not (n = 39). Postoperative labs (white blood cell [WBC] count, absolute neutrophil count, platelet count, C-reactive protein) were examined. Mann-Whitney U tests and chi-square tests were used to assess for differences between groups.

Results: There was extensive heterogeneity and overlap in postoperative lab values between patients who developed an IAA and those who did not. Almost all patients who developed an IAA had clinical signs that were indicative of abscess formation regardless of their postoperative WBC count or change in WBC count. While patients who developed an IAA had a higher postoperative median WBC count (10.8 versus 8.4, P = 0.003) and a smaller WBC count decrease (-4.9 versus -7.4, P = 0.01), no cutoff value for any of the examined lab values specifically predicted abscess formation. Postoperative median absolute neutrophil count (7.4 versus 4.0, P = 0.15), platelet count (360 versus 353, P = 0.98), and C-reactive protein (8.20 versus 5.32, P = 0.06) did not differ significantly.

Conclusions: We conclude that postoperative labs have limited clinical utility in evaluating IAA development in children with perforated appendicitis.

Keywords: Intra-abdominal abscess; Pediatrics; Perforated appendicitis; Postoperative labs.