Ketamine dosing for sedation during repeated radiotherapy sessions in children

Abstract

Background/aim: We report the analysis of ketamine doses needed and the recovery times in pediatric oncology patients undergoingrepeated radiotherapy sessions.Materials and methods: In a single-blind prospective study design, thirty-three pediatric patients undergoing radiotherapy due tooncologic disorders received 2 mg/kg ketamine and 10 µg/kg atropine intravenously and the rescue drug to be administered wasketamine at 0.5 mg/kg when the sedation level was inadequate. Total ketamine consumption, additional doses, and recovery time wererecorded.Results: Data of 635 consecutive radiotherapy sessions were evaluated. There was no significant alteration in total ketamine consumptionrequired to complete the radiotherapy periods during consecutive procedures (P > 0.05). However, the recovery times started to decreaseby the fourth session (P = 0.02) and continued to decrease onwards during the whole study period (P = 0.001). The mean of the firstrecovery time was 13.68 ± 3.99 min, whereas the mean of the last recovery time was 7.66 ± 6.35 min.Conclusion: A requirement for an incremental increase in ketamine dose after subsequent administrations was not detected, despitea significant decrease in recovery times being anticipated when ketamine is used repeatedly for sedative purposes in consecutiveradiotherapy sessions.