Intraoperative neurophysiological monitoring, including motor evoked potentials and somatosensory evoked potentials, is commonly used during spine surgery to help detect impending neurological injury. The quality of these signals can be affected by anesthetic agents. Ciprofol and remimazolam are newer intravenous hypnotic agents that may be suitable for total intravenous anesthesia during procedures requiring neurophysiological monitoring, but direct within-patient comparisons between the two agents are lacking. This single-center, prospective, randomized, two-sequence crossover trial will compare the effects of ciprofol and remimazolam, administered with remifentanil, on intraoperative MEP and SEP signal quality during spine surgery. Eligible participants will be randomized to receive either ciprofol followed by remimazolam or remimazolam followed by ciprofol during predefined stable intraoperative monitoring windows. The primary outcome is the within-participant difference in lower-extremity MEP peak-to-peak amplitude between the ciprofol and remimazolam periods. Secondary outcomes include SEP amplitude and latency, MEP latency, warning-threshold events, hemodynamic variables, rescue medication requirements, recovery characteristics, and postoperative neurological status.
Inclusion Criteria:
Exclusion Criteria:
The attending anesthesiologist cannot be fully masked because the study drugs require different preparation and infusion strategies. Intraoperative neurophysiological monitoring interpreters, data abstractors, and statistical analysts will be blinded to the coded drug sequence whenever feasible.
Participants assigned to this sequence will receive ciprofol-based total intravenous anesthesia during the first stable intraoperative monitoring period. After the predefined first-period MEP and SEP recordings are completed, the hypnotic agent will be switched to remimazolam. After an approximately 45- to 60-minute stabilization and washout period, second-period MEP and SEP recordings will be obtained under remimazolam-based anesthesia. Remifentanil analgesia and standard physiologic targets will be maintained as consistently as clinically feasible across both periods.
Participants assigned to this sequence will receive remimazolam-based total intravenous anesthesia during the first stable intraoperative monitoring period. After the predefined first-period MEP and SEP recordings are completed, the hypnotic agent will be switched to ciprofol. After an approximately 45- to 60-minute stabilization and washout period, second-period MEP and SEP recordings will be obtained under ciprofol-based anesthesia. Remifentanil analgesia and standard physiologic targets will be maintained as consistently as clinically feasible across both periods.
Effect of Remimazolam on Motor Evoked Potential
Comparison of IONM Between Remimazolam and Propofol
Efficacy and Safety of Remimazolam (CNS7056) Compared to Propofol for Intravenous Anesthesia During Elective Surgery
Remimazolam and Endovascular Procedures of Cerebrovascular Diseases
Comparison of Efficacy and Safety Between Ciprofol and Remimazolam During Fiberoptic Bronchoscopy
Comparison of Remimazolam and Propofol Combination vs. Propofol in IOM
The Effect of General Anesthesia with Remimazolam and Propofol on Rhythmic State and Cognitive Function
Safety and Efficacy of Remimazolam in OPCAB Surgery