Identifying preoperative laboratory parameters to predict complicated acute appendicitis in children

Background: Acute appendicitis (AA) is a common surgical condition among children. Assessing the prognosis stage of the disease evolution is particularly crucial, and is still challenging. Aim: To analyse the preoperative parameters of children with confirmed AA, and to determine the predictive factors of complicated appendicitis (CA). Methods: The data of 402 children younger than 16 years with a confirmed diagnosis of AA were retrospectively evaluated. Enrolled children were divided into two groups: group A (children with non-complicated AA (NCA), n=221) and group B (children with CA, n=181). Preoperative biological parameters were comparatively analysed between the two groups to determine predictive factors for CA. Results: White blood cell count (WBC), absolute neutrophil count (ANC), neutrophil percentage (NE%), neutrophil-to-lymphocyte ratio (NLR), platelet count (PLT), platelet-to-lymphocyte ratio (PLR), red blood cell distribution width (RDW), systemic immune inflammatory index (SII), and C-reactive protein (CRP) were higher within group B than group A children (p=0.0001, p=0.0001, p=0.0001, p=0.0001, p=0.0001, p=0.0001, p=0.002, p=0.01, p=0.04, respectively). The best area under the curve (AUC) to predict CA was for CRP (0.83, p<0.0001), followed by SII (0.64, p<0.0001), PLR (0.63, p<0.0001), NLR (0.62, p<0.0001), WBC (0.61, p=0.0002), and ANC (0.60, p=0.0002). The best cut-off for CRP in predicting CA was 73 mg/L (sensitivity: 73.89%; specificity: 82.11%), 3610.3 for SII (sensitivity: 41.67%; specificity: 82.11%), 174.53 for PLR (sensitivity: 67.22%; specificity: 57.14%), 9.54 for NLR (sensitivity: 54.44%, specificity: 66.97%), 18.33×103 cells/μL for WBC (sensitivity: 46.11%, specificity: 76.36%), and 15.65×103 cells/μL for ANC (sensitivity: 42.22%, specificity: 78.54%). Conclusion: CRP level followed by SII, PLR, NLR, WBC and then ANC can be used in differentiating simple from CA in children. Keywords: Acute Appendicitis, Complicated Appendicitis, Risk Prediction, Biomarkers, Children.