Salbutamol prevents the increase of respiratory resistance caused by tracheal intubation during sevoflurane anesthesia in asthmatic children

Asthmatic children having their tracheas intubated with sevoflurane often h ave an increase in respiratory system resistance (Rrs). In this randomized, placebo-controlled, double-blinded study, we investigated the protective e ffect of an inhaled beta (2)-adrenergic agonist. Either salbutamol or place bo was administered 30 to 60 min before anesthesia to 30 mildly to moderate ly asthmatic children scheduled for elective surgery. Induction was perform ed with sevoflurane in a mixture of 50% nitrous oxide in oxygen and maintai ned at 3%, with children breathing spontaneously via a face mask and Jackso n-Rees modification of the T-piece. Airway opening pressure and flow were m easured before and after insertion of an oral endotracheal tube. Rrs and re spiratory system compliance were calculated with multilinear regression ana lysis. The groups were comparable with respect to age, weight, asthma histo ry, and breathing pattern. Intubation induced a different Rrs response in t he two groups: children treated with salbutamol showed a 6.0% (-25.2% to +1 3.2%) decrease (mean, 95% confidence interval), whereas in the Placebo grou p there was a 17.7% (+4.4% to +30.9%) increase (P = 0.04). Neither asthma h istory nor the serum inflammation marker eosinophilic cationic protein was predictive for this response. We conclude that when using sevoflurane in mi ldly to moderately asthmatic children, a preanesthetic treatment with inhal ed salbutamol is protective of an increase in Rrs.