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

Abstract

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.

Keywords: ED(95); Infant; Intranasal dexmedetomidine; Pulmonary function testing; Sedation.