The 95% effective dose of intranasal dexmedetomidine sedation for pulmonary function testing in children aged 1-3 years: A biased coin design up-and-down sequential method.

STUDY OBJECTIVE:Intranasal dexmedetomidine (DEX) can provide adequate sedation during short examinations in children. However, we found no data regarding the 95% effective dose (ED95) of intranasal DEX for children's pulmonary function testing (PFT). DESIGN:Prospective study and a biased coin design up-and-down sequential method. SETTING:Sedation center of Children's Hospital of Chongqing Medical University. PATIENTS:Children aged 1-3 years undergoing pulmonary function testing. INTERVENTION:The dose of DEX for each subsequent patient was determined by the response of the previous patient with the biased coin design up-and-down sequential method with an interval of 0.25 μg∙kg-1. MEASUREMENTS:Children aged 1-3 years who received pulmonary function testing were involved in this dose-finding trial. Intranasal DEX started at a dose of 2 μg∙kg-1 on the first patient. The dose of DEX for each subsequent patient was determined by the response of the previous patient with the biased coin design up-and-down sequential method with an interval of 0.25 μg∙kg-1. The sedation was assessed by the Modified Observer Assessment of Alertness and Sedation (MOAA/S) scale, and recovery was assessed by the modified Aldrete recovery score. The ED95 was calculated using isotonic regression. Other variables, including the sedation onset time, examination time, wake-up time, blood pressure (BP), heart rate (HR), respiratory rate (RR), and oxyhaemoglobin desaturation (SpO2), were recorded. Adverse events such as hypotension, bradycardia, respiration depression, oxyhaemoglobin desaturation, regurgitation and vomiting were recorded. MAIN RESULTS:A total of 68 children were enrolled for the study; 62 children had successful sedation, and 6 had failed sedation. The ED95 of intranasal DEX was estimated to be 2.64 μg∙kg-1 [95% confidence interval (CI), 2.49-2.87 μg∙kg-1]. The sedation onset time for all patients was 15.0 (12.3-19.0) min. The sedation onset time of successful sedation patients was 15.0 (12.0-19.0) min, the sedation onset time of failed sedation patients was 16.0 (15.0-27.8) min, the examination time was 8 (7-10) min, and the wake-up time was 40 (35-43) min. There were no adverse events during the whole procedure. CONCLUSION:The ED95 of intranasal DEX sedation in children aged 1-3 years undergoing PFT was 2.64 μg∙kg-1.