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.
Resumen Objetivo: Determinar la utilidad de conocidos biomarcadores como predictores de apendicitis aguda complicada (AAC) y perforada (AP). Método: Estudio observacional, analítico, transversal, de recuperación prospectiva, realizado en el Hospital Teodoro Maldonado Carbo (agosto de 2016 a diciembre de 2017). Biomarcadores evaluados: glóbulos blancos, porcentaje de neutrófilos (%N), índice neutrófilo/linfocito, glucosa, bilirrubina total, proteína C reactiva y procalcitonina (PCT). El análisis estadístico se realizó mediante estimación del área bajo la curva ROC (Receiver Operating Characteristics). Se individualizó el valor de corte mediante el índice de Youden. Se estimaron la sensibilidad, la especificidad, el valor predictivo positivo (VPP) y el valor predictivo negativo (VPN). Resultados: Se incluyeron 128 casos (mediana de edad 30 años, 44% mujeres), de los que 70 (54%) correspondieron a AAC (AP 38/70). El %N y la PCT obtuvieron un área ROC del 78% y el 80% para AAC (AP 76% y 81%), respectivamente. Un %N > 78.1% predijo AAC con una sensibilidad, una especificidad, un VPP y un VPN del 82%, 62%, 72% y 72% (> 74.9%, AP: 94%, 53%, 46% y 96%). Una PCT > 0.14 ng/dl predijo AAC con una sensibilidad, una especificidad, un VPP y un VPN del 69%, 79%, 80% y 68% (AP: 84%, 69%, 53% y 91%). Conclusión: El %N y la PCT constituyen biomarcadores útiles en el descarte de AP cuando se sospecha una apendicitis aguda.