Effect of Esketamine on the median effective dose of Propofol for inhibiting body movement responses during pediatric caudal block

DU Bing; WU Xiaole; WANG Ruiyu; WANG Dandan; SHAN Chengjing

doi:10.3969/j.issn.1002-3429.2025.23.019

Abstract：Objective To investigate the effect of Esketamine on the median effective dose(ED50)of Propofol for inhibiting body movement response during pediatric caudal block.Methods We selected forty-eight children scheduled for elective surgery and requiring caudal block from April to October 2023.Using the random number table method,patients were divided into the Esketamine combined with Propofol(E+P)group and the 0.9%Sodium Chloride injection combined with Propofol(NS+P)group,with 24 patients in each group.After intravenous administration of 2.5 mg/kg Propofol to the first patient in the two groups,the E+P group received intravenous injection of 0.5 mg/kg Esketamine,while the NS+P group received intravenous injection of an equal amount of 0.9%Sodium Chloride injection.Propofol induction dose was determined using the Dixon modified sequential method.Caudal block was performed under ultrasound guidance when Obeserver's assessment of alertness/sedation(OAA/S)score of patients was≤1.The Propofol induction doses and time required for caudal block of the two groups were recorded.Mean arterial pressure(MAP),heart rate(HR),and pulse oxygen saturation(SpO2)of the children were monitored upon entering the operating room in a calm state(T0),at 1 min after drug administration(T1),and immediately after the initiation of caudal block puncture(T2),and incidents of adverse events such as injection pain and tachycardia were also recorded.Results Compared with the NS+P group,the ED50 and ED95 of Propofol induction in the E+P group were significantly reduced(P<0.05).Compared with the NS+P group,the E+P group showed significantly increased MAP and HR at T1 and T2(P<0.05),and compared with those at T0,the E+P group had significantly increased MAP and HR at T1 and T2(P<0.05).Compared with those at T0,the NS+P group had significantly decreased MAP and HR at T1 and T2(P<0.05),the E+P group had significantly decreased SpO2 at T1 and T2(P<0.05),and the NS+P group also had significantly decreased SpO2 at T1 and T2(P<0.05).The incidence of Propofol injection pain in the E+P group was 33.3%(8/24),which was significantly lower than that in the NS+P group(75.0%,18/24),with a significant difference(P<0.05).No obvious adverse reactions were observed in either group.Conclusion Intravenous injection of 0.5 mg/kg Esketamine can significantly reduce the ED50 of Propofol required for caudal block in children during caudal puncture,and also reduce the incidence of Propofol injection pain without significantly affecting the children's hemodynamics.