[End-tidal sevoflurane concentrations for laryngeal mask airway insertion and tracheal intubation in children].

BACKGROUND: Sevoflurane, a new inhalation anesthetic agent characterized by a low blood-gas partition coefficient and nonpungent odor, appears suitable as an induction agent for children. This study was conducted to determine the sevoflurane concentration required for tracheal intubation and insertion laryngeal mask in children. METHODS: Thirty patients, aged 3-7 years, scheduled for surgery during general anesthesia were randomly assigned into two groups: Group I (n=15)--tracheal intubation (IT), Group II (n=15)--laryngeal mask insertion (LMI). After the predetermined end-tidal concentration of the sevoflurane, tracheal intubation or laryngeal mask insertion was attempted without neuromuscular relaxants. RESULTS: Sevoflurane MAC-LMI was 1.53 +/- 0.23%, sevoflurane MAC-TI was 2.35 +/- 0.31%, significantly greater than MAC-LMI. CONCLUSIONS: Laryngeal mask insertion can be performed at a lesser sevoflurane concentration than that required for tracheal intubation.