Povidone-iodine Irrigation for Pediatric Perforated Appendicitis May Be Protective: A Bayesian Pilot Randomized...

A randomized controlled trial was conducted to test the hypothesis that povidone-iodine (PVI) irrigation versus no irrigation (NI) reduces postoperative intra-abdominal abscess (IAA) in children with perforated appendicitis.

A 100 patient pilot randomized controlled trial was conducted. Consecutive patients with acute perforated appendicitis were randomized (1:1) to PVI or NI from April 2016 to March 2017 and followed for 1 year. Patients and postoperative providers were blinded to allocation. The primary endpoint was 30-day image-confirmed IAA. Secondary outcomes included initial and total 30-day length of stay (LOS), emergency department (ED) visits, and readmissions. Intention-to-treat analyses were performed to estimate the probability of clinical benefit using Bayesian regression models (an optimistic prior for the primary outcome and neutral priors for secondary outcomes). Frequentist statistics were also used.

Baseline characteristics were similar between treatment arms. The PVI arm had 12% postoperative IAA versus 16% in the NI arm (relative risk 0.72, 95% credible interval 0.38-1.23). Bayesian analysis estimates 89% probability that PVI reduces IAA. High probability of benefit was seen in all secondary outcomes for the PVI arm: fewer ED visits and readmissions, and shorter initial and total 30-day LOS. The probability of benefit in reduction of total 30-day LOS in PVI patients was 96% and was significant (P = 0.05) on frequentist analysis.

PVI irrigation for perforated appendicitis in children demonstrated a strong probability of reduction in postoperative IAA with a high probability of decreased LOS. With the favorable probability of benefit in all outcomes, this pilot study serves as evidence to continue a definitive trial.