Intranasal esketamine versus esketamine-dexmedetomidine combination for premedication in pediatric patients undergoing strabismus surgery: a randomized controlled trial.

Background: Preoperative fear and anxiety are prevalent in children undergoing surgery. The combination of esketamine and dexmedetomidine has been proposed as a promising premedication for enhancing preoperative sedation and analgesia. This study compared the premedication efficacy of intranasal esketamine alone and esketamine-dexmedetomidine combination in pediatric patients undergoing strabismus surgery. Methods: One hundred and eighty preschool children aged 2-6 years scheduled for strabismus surgery were enrolled and randomly assigned to one of the three groups: intranasal premedication with esketamine 2 mg/kg (Group K), esketamine 1 mg/kg and dexmedetomidine 1 µg/kg (Group KD1), or esketamine 0.5 mg/kg and dexmedetomidine 2 µg/kg (Group KD2). The primary outcome was the level of sedation following the intervention, as measured by the modified Yale preoperative anxiety scale (mYPAS) and sedation scale (SS). Secondary outcomes included onset time of sedation, the successful rate of peripheral intravenous cannulation, parental separation anxiety scale (PSAS), mask acceptance scale (MAS), wake-up time, duration of stay in the post-anesthesia care unit (PACU), and premedication-related adverse effects. Results: After premedication, the mYPAS score gradually decreased in the three groups, with lower values in Group K than in Group KD1 and Group KD2 patients in 1, 5, and 10 min. SS in Group KD1 and Group KD2 steadily increased until 40 min after premedication, while SS in Group K increased in the first 5 min after premedication and maintained consistent levels during the remaining time. Sedation onset was substantially faster in Group K patients (11.4±7.8 min) than Group KD1 (18.1±7.5 min, P=0.006) and Group KD2 (18.4±6.8 min, P<0.001). PSAS, separation status, the successful rate of peripheral intravenous cannulation, and MAS were comparable among groups. There was no significant difference in terms of emergence time or duration of stay in the PACU among groups. More gastrointestinal events were observed in Group K (P<0.001). Conclusions: Intranasal premedication with 2 mg/kg esketamine produced a more rapid onset of sedation accompanied by more gastrointestinal reactions compared with a combination of esketamine and dexmedetomidine. Trial Registration: ClinicalTrials.gov identifier: NCT04757675.