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

摘要

Study Objective: To determine the effects of dexmedetomidine premedication on the minimum alveolar concentration of sevoflurane for tracheal intubation (MACTI) in children. Design: Prospective, randomized, clinical comparison study. Setting: Operating room of an academic hospital. Patients: 90 pediatric, ASA physical status 1 patients, aged 3 to 7 years, scheduled for minor elective surgery. Interventions: Patients 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 Results: The 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. Conclusion: Intranasal dexmedetomidine premedication produces a dose-dependent decrease in the concentration of sevoflurane needed for tracheal intubation in children.