SP2.08 Can bilirubin level predict complicated acute appendicitis?

Aims Acute appendicitis is a common surgical emergency. Elevated bilirubin levels have been suggested as a predictor of complicated appendicitis. This study aimed to explore the correlation between bilirubin levels and appendicitis severity. Methods This multicentre retrospective observational study involved adult patients who underwent emergency appendicectomy across four hospitals between August 2018 and November 2020. Data was collected from electronic patient records, including peak perioperative LFTs and appendicitis severity from pathology reports. Patients with normal pathology were excluded. Results 1,094 patients were identified. 790 (72.2%) patients had uncomplicated appendicitis, and 304 (27.8%) patients had complicated appendicitis. The median age was 37 years old (range 16-88, IQR 26-51) and 631 (57.7%) were male. The majority of patients underwent laparoscopic appendicectomy across both groups (87.7% vs 65.8%) The mean bilirubin levels were higher for patients with gangrenous or perforated appendicitis than those with uncomplicated appendicitis (19umol/l vs 17umol/l, p=0.011) but within the normal laboratory reference range (0-20umol/l). There was no significant difference in the mean levels of any of the LFTs (AST, ALT, ALP) between patients with uncomplicated vs complicated appendicitis. Patients with complicated appendicitis were significantly more likely to develop wound infection (5.3% vs 1.1%, p<0.001) and intrabdominal infection (11.18% vs 2.5%, p<0.001) Conclusions Higher bilirubin levels were associated with gangrenous and perforated appendicitis, but remained within normal reference ranges, limiting their clinical utility. Therefore, bilirubin cannot be recommended as a predictor for complicated appendicitis based on this study.