[Anesthetic induction with nitrous-oxide-free sevoflurane in pediatric patients]

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.

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 (SpO2), limb response to venous puncture, alveolar concentration of sevoflurane, and incidence of adverse events.

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, SpO2, 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).

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.