The 90%effective dose of midazolam for oral mucosal administration for sedation during head magnetic resonance imaging examination in infants weighing less than 5 kg

LAN Jiangli; ZHENG Jianqiu; DENG Lingyan; CHEN Ying; HONG Wei; PAN Lixia; FENG Jifeng

doi:10.3969/j.issn.1674-3806.2025.10.16

Abstract：Objective To analyze the90%effective dose(ED90)of midazolam for oral mucosal administration for sedation during head magnetic resonance imaging(MRI)examination in infants weighing less than 5 kg.Methods The infants who underwent head MRI examination under sedation in Maternity and Child Health Care of Guangxi Zhuang Autonomous Region from March 2024 to October 2024 were recruited.Sedative intervention was conducted on the included infants in sequence using a biased-coin design method.The first infant received midazolam oral solution at a dose of 0.15 mg/kg through oral mucosal route of administration.The dose for each subsequent infant was determined based on the sedation outcome of the previous infant:(1)If the previous infant experienced sedation failure,the current infant received midazolam oral solution at a dose increased by1 unit(0.05 mg/kg)through oral mucosal route of administration compared to the previous dose given to the the previous infant.(2)If the previous infant achieved success of sedation,the dose for the current infant was either maintained(with 89%probability)or reduced by 1 unit(with 11%probability)using a biased-coin design method.The trial was terminated when the number of successful sedation cases reached 45.The ED90 was calculated,and isotonic regression with bootstrap resampling was employed to estimate the 95%effective dose(ED95)and the99%effectivedose(ED99).Results A total of 53 infants were included in this study,among whom 45 infants were successfully sedated and 8 infants failed to be sedated.The ED90 of midazolam administered via the oral mucosal route for sedation during MRI examination in the infants weighing less than 5 kg was 0.295 mg/kg(95%CI=0.236-0.335 mg/kg).After calculation using isotonic regression and bootstrap resampling,the ED95 was estimated to be 0.325 mg/kg(95%CI=0.289-0.345 mg/kg)and the ED99 was estimated to be 0.347 mg/kg(95%CI=0.340-0.364 mg/kg).Conclusion The ED90 of midazolam administered via oral mucosal route for sedation during head MRI examination in infants weighing less than 5 kg is 0.295 mg/kg(95%CI=0.236-0.335 mg/kg).