The Predictive Value of Plasma Sodium and Other Laboratory Parameters in Determining Complicating Appendicitis in Children.

Objective: Finding a reliable preoperative predictor of complicated acute appendicitis (AA) has been a challenging diagnostic problem. The present study aimed to identify potential factors that may predict complicated AA in the pediatric emergency department (ED) based on routine, widely available laboratory tests on admission to the ED, including plasma sodium concentration. Methods: We retrospectively reviewed clinical and laboratory data of pediatric patients with AA who underwent emergency surgery at our department between January 2020 and December 2022. The patients were divided into two groups: histopathologically proven complicated AA (n = 80) and noncomplicated AA (n = 155). Results: Complicated AA was associated with reduced plasma sodium and chloride concentrations (p < 0.001, both), decreased values of lymphocytes (p = 0.002), elevated C-reactive protein (CRP) (p < 0.001), and elevated values of white blood cells (WBC) and neutrophils (p = 0.012 and 0.001, respectively). In binomial logistic regression, increased levels of CRP and WBC and decreased levels of sodium were predictors of complicated AA. The area under the receiver operating characteristic curve was 0.825 (95% confidence interval: 0.764, 0.886). Conclusion: We identified mild hyponatremia and elevated CRP and WBC values as potential markers for distinguishing complicated from uncomplicated pediatric AA with implications for surgical approaches for treating complicated AA and conservative approaches for treating uncomplicated AA. Highlights of the Study: Finding reliable preoperative predictors of complicated acute appendicitis (AA) has been a challenging diagnostic problem in emergency departments worldwide. We identified mild hyponatremia and elevated levels of C-reactive protein and white blood cells as potential markers for distinguishing between complicated and uncomplicated pediatric AA. Our study may have implications for surgical approaches in complicated disease and conservative approaches in uncomplicated disease. Routine blood tests can help emergency physicians discriminate between complicated and uncomplicated AA. [ABSTRACT FROM AUTHOR]