Intranasal dexmedetomidine premedication reduces the minimum alveolar concentration of sevoflurane for tracheal intubation in children: a randomized trial

Study ObjectiveTo determine the effects of dexmedetomidine premedication on the minimum alveolar concentration of sevoflurane for tracheal intubation (MACTI) in children.DesignProspective, randomized, clinical comparison study.SettingOperating room of an academic hospital.Patients90 pediatric, ASA physical status 1 patients, aged 3 to 7 years, scheduled for minor elective surgery.InterventionsPatients were randomized to three groups to receive placebo, dexmedetomidine 1 μg/kg, or dexmedetomidine 2 μg/kg approximately 60 minutes before anesthesia. Anesthesia was induced with sevoflurane. Each concentration of sevoflurane for which a tracheal intubation was attempted was predetermined according to modification of the Dixon’s up-and-down method, with 0.25% as a step size and held constant for at least 15 minutes before tracheal intubation. All responses (“movement” or “no movement”) to tracheal intubation were assessed.Measurements and Main ResultsThe MACTI of sevoflurane was 2.82% ± 0.17% in the control group, 2.26% ± 0.18% in the 1 μg/kg dexmedetomidine group, and 1.83% ± 0.16% in the 2 μg/kg dexmedetomidine group. Dexmedetomidine premedication (1 and 2 μg/kg) decreased the MACTI of sevoflurane by 20% and 35%, respectively. There were no clinically significant episodes of hypotension or bradycardia in any patients.ConclusionIntranasal dexmedetomidine premedication produces a dose-dependent decrease in the concentration of sevoflurane needed for tracheal intubation in children.