Association between BMI z-score and postinduction hypotension in Chinese children undergoing oral surgery: A cross-sectional study

Background: Hypotension normally occurs in children after induction under general anesthesia. Limited studies related to the development of postinduction hypotension in children undergoing oral surgery. The aim of this study is to test the hypothesis that BMI z-score is associated with postinduction hypotension. Methods: In this retrospective study, we included 334 Chinese children undergoing oral surgery under general anesthesia. The primary measurement and observation indicators were BMI z-score and postinduction hypotension events. Smooth curve fitting and multivariate logistic regression analysis were used to test the relationship between BMI z-score and postinduction hypotension. Results: Our study presented postinduction hypotension in 29 children (9%). The average age was 5.8± 2 years old, and approximately 67% were male. Every 0.01 increase in BMI z-score was associated with a 28% decreased risk of postinduction hypotension (OR 0.72, 95% CI(0.54~0.95)). Compared to normal children (-2< BMI z-score<1), the adjusted odds ratios (ORs) of postinduction hypotension for participants in thinness (BMI z-score< -2) and overweight (BMI z-score>1) were 5.66 (95% CI: 1.74–18.41) and 0.75 (95% CI: 0.25–2.18), respectively. The P-trend values are significant across all models. The fitted smooth curve showed a linear association between the BMI z-score and the incidence of postinduction hypotension. Conclusions: The BMI z-score was negatively correlated with the incidence of postoperative hypotension in Chinese children undergoing oral surgery. Thin children, presumably, have a higher incidence of postinduction hypotension.