The Value of Complete Blood Count Parameters in Predicting Complicated Acute Appendicitis; a Prognostic Accuracy Study

INTRODUCTION: Low accuracy of clinical variables can result in delayed diagnosis and increase the incidence of complicated appendicitis in some cases. This study aimed to determine the value of simple complete blood count (CBC) biomarkers in predicting complicated appendicitis. METHODS: This is a single-center retrospective cross-sectional study, which was conducted on cases referred to emergency department following acute appendicitis who underwent appendectomy, to evaluate the accuracy of some cell blood count variables (white blood cell count (WBC), neutrophil percent, neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR), mean platelet volume (MPV)) in predicting complicated cases (gangrenous and ruptured appendicitis). RESULTS: There were 252 (68.3%) patients in the uncomplicated appendicitis group and 117 (31.7%) patients in the complicated appendicitis group. The mean age of patients was 34.1 ± 1.09 (Range: 18 -79) years (55.3% male). There were no differences between groups regarding the mean age (p = 0.053), gender distribution (p=0.07), Alvarado score (p = 0.055), platelet count (p =0.204), PLR (p = 0.115), and MPV (p = 0.205). The complicated appendicitis cases had longer onset of symptoms (p <0.001), higher WBC count (p = 0.011), higher neutrophil count (p < 0.001), and higher NLR (p < 0.001). Neutrophil count (area under the curve (AUC) = 0.61, 95% confidence interval (CI) = 0.56-0.66; p = 0.001) and NLR (AUC = 0.65, 95% CI = 0.60-0.69; p = 0.001) had higher level of accuracy in this regard. In contrast, the area under the curve of WBC count (AUC = 0.57, 95% CI = 0.52-0.63; p = 0.22), platelet count (AUC = 0.44, 95% CI = 0.38-0.49; p = 0.049), PLR (AUC = 0.57, 95% CI = 0.52-0.62; p = 0.026), and MPV (AUC = 0.54, 95% CI = 0.49-0.60; p = 0.193) showed low accuracy in predicting complicated acute appendicitis. CONCLUSION: Based on the findings of present study it seems that WBC, neutrophil percent, NLR, PLR, and MPV have failed to poor accuracy in predicting cases with complicated appendicitis in emergency department.