Impact of low-dose sevoflurane with propofol-based anesthesia on motor-evoked potentials in infants: a single-arm...

The influence of anesthetic interactions on motor-evoked potentials in infants has rarely been reported. In infants, adding a small dose of sevoflurane to propofol-based total intravenous anesthesia is reasonable for reducing propofol administration. We collected preliminary data regarding the effect of low-dose sevoflurane in propofol-based total intravenous anesthesia on motor-evoked potentials in infants.

This pilot interventional study included 10 consecutive infants requiring motor-evoked potentials between January 2023 and March 2024. The motor-evoked potential amplitudes in the upper and lower extremities were recorded twice when general anesthesia was maintained using (1) propofol-based total intravenous anesthesia and (2) 0.1-0.15 age-adjusted minimum alveolar concentration sevoflurane + propofol-based total intravenous anesthesia.

The motor-evoked potential amplitude in the right upper extremity was not significantly different after the addition of a small dose of sevoflurane [192 (75.3-398) μV, 121 (57.7-304) μV, P = 0.19]. All the motor-evoked potential amplitudes in the right lower extremity (quadriceps femoris, anterior tibialis, and gastrocnemius muscles) were significantly attenuated by adding a small dose of sevoflurane (median [interquartile range]: 47.9 [35.4-200] μV, 25.2 [12.4-55.3] μV, P = 0.014; 74.2 [51.9-232] μV, 31.2 [2.7-64] μV, P = 0.0039; 29.8 [20-194] μV, 9.9 [3.8-92.4] μV, P = 0.0039, respectively). Similar results were observed in the left lower extremities.

Adding even 0.1-0.15 age-adjusted minimum alveolar concentration sevoflurane to propofol-based total intravenous anesthesia attenuated the motor-evoked potential amplitudes in the lower extremities. A further prospective interventional study with an appropriate sample size is required to investigate the study hypothesis.