Impact of low-dose sevoflurane with propofol-based anaesthesia on motor-evoked potentials in infants: protocol for a single-centre randomised controlled study

Abstract

Introduction Motor-evoked potentials (MEP) are widely used to mitigate the risk of nerve injury resulting from surgical manipulation. Infants are more susceptible to anaesthetics that suppress MEP because of the immaturity of their nervous structures. Current evidence of the impact of the interaction between a small dose of sevoflurane and propofol-based total intravenous anaesthesia (TIVA) on MEP in infants is controversial. This current study aims to evaluate the impact of the coadministration of low-dose sevoflurane with propofol-based TIVA on MEP in infants.Methods and analysis A randomised controlled study will be conducted at a single tertiary care children’s hospital in Japan between July 2024 and June 2029. Children between 35 and 87 weeks of postconceptual age undergoing spinal surgery requiring MEP under general anaesthesia will be enrolled in this study. The participants will be randomly allocated into two groups: propofol+remifentanil with (intervention group) or without (control group) low-dose sevoflurane (0.10–0.15 age-adjusted minimum alveolar concentration). MEP top-to-bottom amplitudes will be measured at two chronological points: T1 (first transcranial MEP (TcMEP) recording), T2 (second TcMEP recording) in the same patient. The primary and secondary endpoints will be a reduction in MEP amplitudes (T1–T2) in the right upper and lower extremities between the control and intervention groups, respectively. The sample size was calculated to be a total of 40 based on the preliminary data of 10 infants, which showed a 35% reduction in mean values of MEP amplitudes in the right adductor muscle (SD=31) with a 10% assumed dropout rate.Ethics and dissemination The study protocol was approved by the Institutional Review Board of the Aichi Children’s Health and Medical Center (2022058). The results will be reported in a peer-reviewed journal at the relevant academic conference.Trial registration number jRCT1041230094.