Association Between Extreme Weight-for-Age and Airway-Related Adverse Events During Anesthesia Induction: An Analysis...

Children are particularly vulnerable to hypoxia during airway management, which can lead to life-threatening complications. However, pediatric evidence quantifying the association between body weight range and airway management-related adverse events (ARAEs) during anesthesia induction remains limited. This study aimed to evaluate the association between body weight and incidence of adverse events during general anesthesia induction.

This multicenter retrospective cohort study used data from the Japanese Pediatric Difficult Airway Registry from June 2022 to February 2025 across 12 tertiary care hospitals. All airway management encounters (from the initiation of preoxygenation to successful tracheal intubation) during the initial induction of general anesthesia in children aged <18 years who underwent tracheal intubation during the study period were included. Patients were grouped into obese, overweight, normal, or underweight, based on the standard deviations calculated using the World Health Organization pediatric body mass index-for-age and weight-for-age datasets. The primary outcome was the occurrence of ARAEs, and the secondary outcomes were first-attempt tracheal intubation success and desaturation of at least 10% (pulse oximetry oxygen saturation drop ≥10% during the encounter). Multilevel mixed-effects logistic regression models were used to adjust for potential confounders and clustering effects within each institution.

Data from 18,835 encounters were analyzed. Of these, 14,546 (77.2%) were categorized as normal-weight, 667 (3.5%) as obese, 1403 (7.4%) as overweight, and 2219 (11.8%) as underweight. The incidence of ARAEs was as follows: normal-weight, 285/14,546 (2.0%); obese, 13/667 (1.9%); overweight, 23/1403 (1.6%); and underweight, 61/2219 (2.8%). The incidence of first-attempt tracheal intubation success in children with normal weight, obese, overweight, and underweight was 12,978/14,546 (89.2%), 611/667 (91.6%), 1283/1403 (91.4%), and 1786/2219 (80.5%), respectively. No evidence supporting an association between ARAEs and any weight category was found. In contrast, both obese and underweight status were associated with desaturation ≥10% (obese: adjusted odds ratio [aOR], 2.12; 95% confidence interval [CI], 1.17-3.84; P = .013; underweight: aOR, 1.31; 95% CI, 1.05-1.64; P = .017). Underweight status was also associated with lower odds of first-attempt tracheal intubation success (aOR, 0.69; 95% CI, 0.60-0.79; P < .001).

Obese and underweight status were associated with desaturation, whereas underweight status was additionally associated with lower odds of successful first-attempt tracheal intubation during the induction of general anesthesia. Although these findings reflect associations rather than causal relationships, extreme body weight status may serve as a clinically useful risk marker for identifying high-risk pediatric patients.