Multiple-deep-breath inhalation induction with 5% sevoflurane and 67% nitrous oxide: comparison with intravenous...

To evaluate the clinical characteristics of multiple-deep-breath inhalation induction with sevoflurane and nitrous oxide followed by the same inhalational anesthetics for maintenance, we compared the technique with intravenous propofol anesthesia.

Forty patients scheduled for ophthalmic surgery under general anesthesia with a laryngeal mask airway (LMA) were assigned to two groups. Anesthesia was induced with multiple-deep-breath inhalation of 5% sevoflurane and 67% nitrous oxide in oxygen (group S: n = 20) or intravenous injection of 1% propofol at the rate of 1200 ml.h(-1) with spontaneous inhalation of 67% nitrous oxide in oxygen until the patient lost consciousness or received propofol up to 2 mg.kg(-1) (group P: n = 20). We attempted to insert an LMA when the patient's jaw relaxation was adequate. We compared induction times, recovery times, occurrence of adverse events, and patient satisfaction between the two groups.

The mean time to insertion of the LMA was significantly shorter in group P (209 +/- 118 s) than in group S (302 +/- 102 s; P < 0.05). The recovery times did not differ significantly between the groups. There were no serious side effects during the induction and recovery period in either group. Significantly more patients in group P than in group S wanted to have the same anesthetic method (90% vs 50%; P < 0.05).

Multiple-deep-breath inhalation induction with 5% sevoflurane and 67% nitrous oxide followed by the same inhalational anesthetics for maintenance was safely performed without serious adverse events. However, the induction time was shorter and patient satisfaction was higher in propofol group than in the inhalational group.