关键词: 清醒镇静, 插管法, 气管内, 剂量效应关系, 药物, 右美托咪啶

Abstract:

【Abstract】 Objective To investigate the effective dose of dexmedetomidine at which awake fiberoptic bronchoscopic intubation was tolerable in 50% of patients (ED50). Methods Twenty patients with difficult airways,.ASA physical grading Ⅰor Ⅱ,.aged 38-65 years,.body weight 45-70 kg, undergoing elective surgery under general anaethesia were enrolled in this study..After intravenous administration of dexmedetomidine over 10 minutes, the local mucous anesthesia of tongue-root, throat and supraglottic region was performed with 1% dicaine by laryngeal spray,.and the intratracheal topical anesthesia was performed with 2 ml of 2% lidocaine through thyrocricocentesis..Median effective dose (ED50) was determined by modified Dixon's up-and-down sequential experiment. The ratio of two successive dose of dexmedetomidine was 1.2..The ED50 and 95% confidence interval.(CI).of dexmedetomidine were calculated by the modified Dixon's up-and-down method and the ED50 and 95% CI were analyzed using the probit test in a logistic regression model..Results ED50 of dexmedetomidine for awake fiberoptic  bronchoscopic intubation obtained by modified Dixon's up-and-down method was 0.74 μg/kg (95%CI 0.68-0.82 μg/kg). Conclusion Intravenous administration of dexmedetomidine 0.74 μg/kg over 10 min in conjunction with local anesthesia would provide good intubating condition for awake fiberoptic bronchoscopic intubation in 50% of patients,and there are no intubation responses.

Key words: Dexmedetomidine, Conscious sedation, Intubation, Intratracheal, Dose-response relationship, Drug