A Low Prognostic Nutritional Index Level, an Independent Predictor for Postoperative Intra-abdominal Abscess After Laparoscopic Appendectomy.

Background: Intra-abdominal abscess (IAA) is a very common postoperative complication after laparoscopic appendectomy and is associated with poor prognosis.

Materials and methods: This study retrospectively analyzed elderly patients who underwent laparoscopic appendectomy from 2015 to 2024, examining demographic, clinical, and laboratory data to identify IAA risk factors. Independent risk factors for IAA were screened and finally identified by multivariate logistic regression analysis.

Results: A total of 37 patients developed IAA within postoperative 30 days, with an incidence of 9.6% (37/385). Receiver operating characteristic (ROC) curve analysis indicated white blood cell (cut-off value: 13.35, sensitivity: 54.60%, specificity: 70.27%, P=0.003) and Prognostic Nutritional Index (PNI) (cut-off value: 41.95, sensitivity: 72.41%, specificity: 59.46%, P<0.0001) were 2 predictors for IAA with an area under the curve of 0.649 and 0.727, respectively. Based on the multivariate analysis, perforated appendicitis (odds ratio: 2.48, 95% CI: 1.15-5.32, P=0.021) and a lower PNI score (odds ratio: 3.44, 95% CI: 1.49-7.58, P=0.002) were 2 independent risk factors for IAA in elderly patients after laparoscopic appendectomy.

Conclusions: Elderly patients with perforated appendicitis and a PNI score <41.95 have higher risks for IAA after laparoscopic appendectomy.