To compare time to awakening and upper airway morbidity between desflurane and sevoflurane using a Laryngeal Mask Airway (LMA) and a balanced anesthetic regimen inclusive of opioids.

Randomized, double-blinded, placebo-controlled clinical trial.

Ambulatory surgery unit of a university hospital.

80 subjects receiving general anesthesia for outpatient gynecological surgery using a LMA.

Desflurane/fentanyl or sevoflurane/fentanyl were used for anesthetic maintenance.

Patients were randomly assigned to receive desflurane or sevoflurane. The primary outcome was time to awakening as determined by an observer who was blinded to study group allocation. Secondary outcomes included the frequency of sore throat, cough, and pain perioperatively and at 2 and 24 hours postoperatively. Quality of recovery (QoR; via QoR-40 questionnaire) at 24 hours also was determined.

The median (IQR) time to eye opening following desflurane was 6.8 (5.0 - 9.8) minutes versus 11.8 (8.8 - 14.6) minutes following sevoflurane (P < 0.001), or a difference of 5.0 (99% CI 2.3 - 6.8) minutes. The median difference in response to verbal commands was 5.3 (99% CI 2.4 - 7.1) minutes. The frequency of cough, laryngospasm, sore throat, and hoarseness did not differ between groups. Quality of recovery at 24 hours was better in the desflurane group: difference in medians 6 (99% CI 0 – 12; P = 0.003).

Desflurane retains faster awakening properties than does sevoflurane when used in combination with fentanyl as part of anesthetic maintenance in outpatient surgery with a LMA. The balanced anesthetic maintenance regimen seems to reduce the potential airway reactivity properties of desflurane.