Anesthetic induction with nitrous oxide-free sevoflurane in pediatric patients

OBJECTIVE: To evaluate the pediatric use of inhaled nitrous oxide (N2O)-free induction with sevoflurane for the purpose of protecting staff from exposure to workplace air pollution. PATIENTS AND METHODS: Prospective, randomized trial in ASA class 1-2 children in whom a tidal breathing technique was used for anesthetic induction in a variety of surgical procedures. Patients were allocated to 2 groups. The sevo-N2O group inhaled 8% sevoflurane in a 60/40% mixture of oxygen and N2O. The sevo-air group received 8% sevoflurane in a mixture of oxygen and air (inspired oxygen fraction, 40%). We recorded mean arterial pressure (MAP), heart rate, oxygen saturation by pulse oximetry (SpO(2)), limb response to venous puncture, alveolar concentration of sevoflurane, and incidence of adverse events. RESULTS: Twenty-two patients were assigned to each group. The vein was catheterized in all patients without a pain reflex in the limb, and there were no statistically significant differences in MAP, heart rate, SpO(2) , or incidence of adverse events. Mean (SD) alveolar concentration of sevoflurane, however, differed between the 2 groups: 53% (0.51%) in the sevo-N2O group and 4.91% (0.41%) in the sevo-air group (P=.028). CONCLUSIONS: N2O-free anesthetic induction by tidal breathing of 8% sevoflurane provides similar anesthetic conditions (efficacy, safety, and rapid onset) without a higher incidence of adverse events. The use of N2O can therefore be avoided.