Diagnostic value of laboratory parameters for complicated appendicitis: A two-center study

There are two types of treatment for acute appendicitis (AA): surgery and antibiotic therapy. Some patients with complex appendicitis are treated with surgery; however, for uncomplex appendicitis, most could be treated effectively with antibiotics instead. How to distinguish complex appendicitis from uncomplex appendicitis before surgery is currently unknown. The present study aimed to assess the efficacy of the laboratory parameters to diagnose complicated appendicitis. Data from 1,514 cases with acute appendicitis who were admitted to Beijing Tsinghua Changgung Hospital and Beijing Aerospace General Hospital (both Beijing, China) from January 2016 to September 2021 were retrospectively analyzed. All cases were divided into uncomplicated and complicated appendicitis. Independent variables were analyzed by uni- and multivariate logistic regression analyses. Receiver operating characteristic (ROC) curve analysis was used to identify significant parameters in the multivariate logistic regression analysis. Cut-off values, sensitivity, specificity and accuracy with area under the curve (AUC)>0.600 were considered significant parameters. Significant differences were found in age (P<0.001), body temperature (P<0.001), white blood cell (WBC) count (P<0.001), C-reactive protein (CRP; P<0.001), neutrophil count (P<0.001), neutrophil-to-lymphocyte ratio (NLR, P=0.019), platelet-to-lymphocyte ratio (PLR, P<0.001), platelet count (P<0.001), coefficient of variation (CV) and standard deviation (SD) of red blood cell distribution width (RDW); both P<0.001), mean platelet volume (MPV, P<0.001) and total (P<0.001) and direct bilirubin (P<0.001) between the two groups. CRP, neutrophil count, NLR, PLR, platelet count, RDW-CV, RDW-SD, MPV and direct bilirubin levels were found as the independent variables to diagnose complicated appendicitis. In patients with acute appendicitis, CRP >22.95 mg/l, NLR >5.7, serum direct bilirubin >6.1 mmol/l and RDW-SD>17.7 fl were significantly associated with complicated appendicitis.