Effect of Intranasal Dexmedetomidine or Midazolam for Premedication on the Occurrence of Respiratory Adverse Events in Children Undergoing Tonsillectomy and Adenoidectomy

Importance: Perioperative respiratory adverse events (PRAEs) are the most common complication during pediatric anesthesia, and they may be affected by the administration of preoperative sedatives. Objective: To investigate the effect of intranasal dexmedetomidine or midazolam used for premedication on the occurrence of PRAEs. Design, Setting, and Participants: This single-center, double-blind, randomized clinical trial was conducted among children aged 0 to 12 years undergoing elective tonsillectomy and adenoidectomy from October 2020 to June 2021 at Children's Hospital of Xuzhou Medical University, Xuzhou, China. Data analysis was performed from June to October 2021. Interventions: Children were randomly assigned to 3 groups: the midazolam group received intranasal midazolam (0.1 mg/kg), and the dexmedetomidine group received intranasal dexmedetomidine (2.0 μg/kg) for premedication. The normal saline group received intranasal 0.9% saline for control. Main Outcomes and Measures: The primary outcome was the difference in the incidence of PRAEs among the 3 groups. The secondary outcomes were the frequency of the individual PRAEs, including the incidence of such events during the induction and recovery periods, postoperative emergence delirium, postoperative pain score, sedation success rate, and heart rate values. Results: A total of 384 children (median [IQR] age, 7 [5-10] years; 227 boys [59.1%]) were enrolled and randomized; 373 data sets were available for intention-to-treat analysis (124 children in the midazolam group, 124 children in the dexmedetomidine group, and 125 children in the normal saline group). After the data were adjusted for age, sex, American Society of Anesthesiologists physical status, body mass index, obstructive sleep apnea, upper respiratory tract infection, and passive smoking, children in the midazolam group were more likely to experience PRAEs than those in the normal saline group (70 of 124 children [56.5%] vs 51 of 125 children [40.8%]; adjusted odds ratio [aOR], 1.99; 95% CI, 1.18-3.35), whereas the dexmedetomidine group had a significantly lower PRAEs incidence than the normal saline group (30 of 124 children [24.2%] vs 51 of 125 children [40.8%]; aOR, 0.45; 95% CI, 0.26-0.78). Compared with the dexmedetomidine group, the midazolam group had a higher risk of PRAEs (aOR, 4.44; 95% CI, 2.54-7.76), but no other serious clinical adverse events were observed. Conclusions and Relevance: In this randomized clinical trial, intranasal midazolam used for premedication was associated with increased incidence of PRAEs, whereas premedication with intranasal dexmedetomidine was associated with reduced incidence of PRAEs. Where clinically appropriate, anesthesiologists should consider using intranasal dexmedetomidine for sedation in children undergoing tonsillectomy and adenoidectomy. Trial Registration: Chinese Clinical Trial Register Identifier: ChiCTR2000038359.