Body Mass Index Is Associated With Pediatric Complicated Appendicitis and Postoperative Complications

Objective:To investigate the association between body mass index (BMI) spectrum and complicated appendicitis and postoperative complications in pediatric patients. Background:Despite the impact of being overweight and obese on complicated appendicitis and postoperative complications, the implications of being underweight are unknown. Methods:A retrospective review of pediatric patients was conducted using NSQIP (2016-2020) data. Patient's BMI percentiles were categorized into underweight, normal weight, overweight, and obese. The 30-day postoperative complications were grouped into minor, major, and any. Univariate and multivariable logistic regression models were performed. Results:Among 23,153 patients, the odds of complicated appendicitis were 66% higher in underweight patients [odds ratio (OR)=1.66; 95% CI: 1.06-2.59] and 28% lower in overweight patients (OR=0.72; 95% CI: 0.54-0.95) than normal-weight patients. A statistically significant interaction between overweight and preoperative white blood cells (WBCs) increased the odds of complicated appendicitis (OR=1.02; 95% CI: 1.00-1.03). Compared to normal-weight patients, obese patients had 52% higher odds of minor (OR=1.52; 95% CI: 1.18-1.96) and underweight patients had 3 times the odds of major (OR=2.77; 95% CI: 1.22-6.27) and any (OR=2.82; 95% CI: 1.31-6.10) complications. A statistically significant interaction between underweight and preoperative WBC lowered the odds of major (OR=0.94; 95% CI: 0.89-0.99) and any complications (OR=0.94; 95% CI: 0.89-0.98). Conclusions:Underweight, overweight, and interaction between overweight and preoperative WBC were associated with complicated appendicitis. Obesity, underweight, and interaction between underweight and preoperative WBC were associated with minor, major, and any complications. Thus, personalized clinical pathways and parental education targeting at-risk patients can minimize postoperative complications.