Objective: To analyze the application and safety of preoperative administration of different doses of dexmedetomidine (Dex) in children undergoing endoscopic-assisted transoral adenoidectomy. Methods: A total of 120 children who underwent adenoidectomy in the Tangshan maternal and child Health Care Hospital between January 2019 and June 2020 were selected as the research subjects

and they were divided into three groups with 40 cases in each group according to the random number table method. The children were given different concentrations of dex through the nasal cavity at 60min before entering the room

and group A

group B and group C were given nasal drops of 1 μg/kg

2 μg/kg and 3 μg/kg respectively. The hemodynamic indicators [heart rate (HR)

mean arterial pressure (MAP)

blood oxygen saturation (SpO2)] before nasal drop (T0) and at 10 min (T1)

30 min (T2) and 60 min (T3) of nasal drip

preoperative sedative effect (sedation onset time

sedation score

separation resistance score

behavioral response score of venous access establishment)

postoperative anesthesia recovery time (respiratory recovery time

extubation time

awakening time

orientation recovery time) and postoperative adverse reactions were compared among the three groups. Results: There were no statistically significant differences in the between-group effect

time-point effect and interaction effect of between-group×time-point of HR

MAP and SpO2 (P>0.05). There were statistically significant differences in the sedation onset time

sedation score

separation resistance score and behavioral response score of venous access establishment among the three groups (F=30.18

10.37

9.18 and 23.05

all P<0.05). There were significant differences in postoperative respiratory recovery time and extubation time among the three groups (P>0.05)

and there were statistical differences in awakening time and orientation recovery time (F=3.85

29.41

both P<0.05). The total incidence rate of adverse reactions was 5.00% in group A

7.50% in group B and 12.50% in group C. Conclusion: Nasal drop of 2 μg/kg Dex before endoscopic-assisted transoral adenoidectomy in children is relatively safe and effective

and can produce good sedative effect

and has fewer adverse reactions after surgery. It can be used as the recommended dose of preoperative anesthesia in children with this type of surgery.