Characterizing the spectrum of body mass index associated with severe postoperative pulmonary complications in children.

PURPOSE: While high body mass index (BMI) is a recognized risk factor for pulmonary complications in adults, its importance as a risk factor for complications following pediatric surgery is poorly described. We evaluated the association between BMI and severe pediatric perioperative pulmonary complications (PPCs).

METHODS: In this retrospective cohort study, we evaluated pediatric patients (aged 2-17 years) undergoing elective procedures in the 2015 Pediatric National Surgical Quality Improvement Program (NSQIP-P). Severe PPCs were defined as either pneumonia/reintubation within 3 days of surgery, or pneumonia/reintubation as an index complication within 7 days. Univariate and multivariable logistic regression analyses adjusting for patient factors and surgical case-mix tested associations between BMI class-using the Centers for Disease Control age- and sex-dependent BMI percentiles-and severe PPCs.

RESULTS: Among 40,949 patients, BMI class was distributed as follows: 2740 (6.7%) were underweight, 23,630 (57.7%) normal weight, 6161 (15.0%) overweight, and 8418 (20.6%) obese. Overweight BMI class was not associated with PPCs in univariate analyses, but became statistically significant after adjustment [OR 1.84 (95% CI 1.07-3.15), p = 0.03], and persisted across multiple adjustment approaches. Neither underweight [OR 1.01 (95% CI 0.53-1.94), p = 0.97] nor obesity [OR 1.10 (95% CI 0.63-1.94), p = 0.73] were associated with PPCs after adjustment.

CONCLUSION: Overweight pediatric patients have an elevated, previously underappreciated risk of severe PPCs. Contrary to prior studies, the present study found no greater risk in obese children, perhaps due to bias, confounding, or practice migration from "availability bias". Findings from the present study, taken with prior work describing pulmonary risks of obesity, suggest that both obese and overweight children may be evaluated for tailored perioperative care to improve outcomes.