Evaluation of systemic immune-inflammation index efficacy in predicting complicated appendicitis in pediatric emergency department.

Background: Acute appendicitis (AA) is one of the most important causes of acute abdominal pain in children who are admitted to the pediatric emergency department. This study aims to determine the usefulness of the systemic immune-inflammation index (SII) in predicting complicated appendicitis (CA) in pediatric patients.

Methods: The patients who underwent surgery with the diagnosis of AA were evaluated retrospectively. AA and control groups were formed. AA was divided into noncomplicated and CA groups. C-reactive protein (CRP), white blood cell (WBC) count, absolute neutrophil count (ANC), absolute lymphocyte count, neutrophil/lymphocyte ratio (NLR), platelet (PLT)/lymphocyte ratio (PLR), and SII values were recorded. The SII was calculated with the formula of PLT count × neutrophil/lymphocyte. The efficacy of biomarkers in predicting CA was compared.

Results: Our study included 1072 AA and 541 control patients. There were 74.3% of patients in the non-CA (NCA) group and 25.7% in the CA group. CRP, WBC count, ANC, NLR, PLR when AA and control group, complicated and NCA groups are compared in terms of laboratory parameters and SII level AA and it was higher in the CA group. While the SII value was 2164.91±1831.24 in the patients with NCA and 3132.59±2658.73 in those with CA (P<0.001). When the cut-off values were determined according to the area under the curve, CRP and SII were found to be the best biomarkers in predicting CA.

Conclusion: Inflammation markers together with clinical evaluation may be useful in distinguishing noncomplicated and complicated AA. However, these parameters alone are not sufficient to predict CA. CRP and SII are the best predictors of CA in pediatric patients.