Predictive biomarkers for complicated acute appendicitis: A prospective Ecuadorian study

Abstract

Aim: The aim of the study was to determine the usefulness of known biomarkers as pre-operative predictors of complicated acute appendicitis (CAA) and perforated appendicitis (PA). Materials and methods: This was an observational, analytic, cross-sectional, and prospective study at Hospital Teodoro Maldonado Carbo (August 2016-December 2017). Evaluated biomarkers: white blood cells count, neutrophil percentage (N%), neutrophil-to-lymphocyte ratio, glucose, total bilirubin, C-reactive protein, and procalcitonin (PCT). The statistical analysis was performed by means of the area under the receiver operating characteristics (AUROC) curve estimation. Biomarkers' cutoff point was identified using Youden's index. Sensitivity, specificity, positive, and negative predictive value (NPV) (positive predictive value [PPV] and NPV) were estimated. Results: One hundred and twenty-eight cases were included (median age 30 years, 44% female), 70 cases (54%) corresponded to CAA (PA 38/70). N% and PCT obtained an AUROC of 78% and 80% for CAA (PA 76% and 81%), respectively. A N% > 78.1% predicted CAA with a sensitivity, specificity, PPV, and NPV of 82%, 62%, 72%, and 72% (> 74.9%, PA: 94%, 53%, 46%, and 96%), respectively. PCT > 0.14 ng/dL predicted CAA with sensitivity, specificity, PPV, and NPV of 69%, 79%, 80%, and 68% (PA: 84%, 69%, 53%, and 91%). Conclusion: The N% and PCT represent useful pre-operative biomarkers for discarding PA when an acute appendicitis is suspected.