High BMI in children as a risk factor for intraoperative hypotension

INTRODUCTION: childhood obesity is a risk factor for many perioperative complications. Hypotension is a well described complication of general anaesthesia in both adults and children. This observational study compared the incidence of preincision hypotension (PIH) between children with high BMI and lean controls. METHODS: children aged 2-17 years undergoing noncardiac procedures were classified into high or normal BMI groups. The incidence of PIH was then compared between the two groups using SBP data abstracted from our electronic anaesthesia monitoring system. Binary logistic regression was used to examine factors associated with the likelihood of PIH. RESULTS: the study population was 19 400 children (54% boys) with a mean (SD) age of 8.3 ± 4.7 years and BMI of 19.3 ± 5.7 kg m(-2). Most (94.7%) of the patients were elective American Society of Anesthesiology I-II (79.7%) procedures. Single episode of PIH occurred in 36.8% of patients, whereas 8.3% had at least three episodes of PIH. PIH was more frequent in children with high BMI than their lean peers (40.9 vs. 31.4%, P < 0.001). Independent predictors of PIH were high BMI, high American Society of Anesthesiology status, propofol coinduction, baseline hypotension, age and preincision duration. CONCLUSION: these results imply that children with high BMI have a higher incidence of hypotension than their lean peers following induction of anaesthesia for noncardiac procedures.