Hongfei Xiong, Yingxue Xu, Jiayi Liu, Guangbo Liu, Yunyun Zhang, Ziwen Wei, Wenwen Liang, Xuemei Zhao, Siyuan Li, Gang Xiao, Rongliang Xue
BACKGROUND: Preoperative anxiety is a prevalent concern among preschool pediatric patients. Esketamine, an S-enantiomer of ketamine, has emerged as a potential option for pediatric premedication. This study aimed to determine the 95% effective dose (ED95) of oral or intranasal esketamine for alleviating preoperative anxiety in this age group. METHODS: Children patients aged between 1 to 6 years old who were undergoing elective surgery under general anesthesia were recruited in the study. The initial patient received a single dose of esketamine orally (2.5 mg/kg) or intranasally (1 mg/kg), which was adjusted for subsequent patients using the Dixon up-and-down method, where the dose of esketamine administered orally or intranasally to each patient depended on the sedation success of the previous patient. Doses were increased or decreased by increments of 0.5 mg/kg (oral) or 0.05 mg/kg (intranasal). An effective response was defined as having a modified Ramsay sedation score ≥3a, separation anxiety score ≤2, and mask acceptance score ≤2 during inhalational anesthesia induction. RESULTS: A total of 62 children in the oral group and 66 children in the intranasal group were included in the final analysis. The ED95 for a single dose of oral or intranasal esketamine to alleviate preoperative separation anxiety in children was 8.2125 mg/kg (95% confidence interval [CI]: 7.4250-8.4597) and 2.1770 mg/kg (95% CI: 2.0952-2.1958), respectively. After surgery, the median of consciousness recovery time in esketamine oral and intranasal group was 30.00 (13.00-41.25) and 31.00 (20.00-45.00) min, respectively. Nausea, vomiting, increased secretions, and emergence delirium were the major adverse events that occurred following esketamine administration. CONCLUSION: This study demonstrates the efficacy of single-dose esketamine regimens, administered orally (ED95: 8.2125 mg/kg; 95% CI: 7.4250-8.4597 mg/kg) and intranasally (ED95: 2.1770 mg/kg; 95% CI: 2.0952-2.1958 mg/kg), in mitigating preoperative anxiety within a pediatric population. These findings highlight the safety and efficacy of esketamine for this patient group.