Effect of Head Position on MACEI of Sevoflurane in Children With Obstructive Airway

Children scheduled for tonsillectomy surgery were recruited into the study. General anesthesia was induced with 8% sevoflurane inhaled with 8 l.min-1 of oxygen via mask, followed by adjustment of inspired sevoflurane to the target concentration based on the result in previous patient at which laryngoscopy and tracheal intubation were attempted and maintained for 12 min. All responses to tracheal intubation were assessed. At the end of the procedure, sevoflurane was titrated to the target concentration, which was kept constant for 12 min before a standard stimulus was applied to determine whether the children was awake. The Dixon's 'up and down'method was used to determine progression of subsequent concentrations.The aim of this study was to determine whether the minimum alveolar concentration of endotracheal intubation（MACEI）of sevoflurane in children with obstructive airway are different from that observed in normal children.