Ciprofol and Remimazolam for Intraoperative Neurophysiological Monitoring During Spine Surgery

NCT07718152 | Not Yet Recruiting Phase 4

• 1 other identifier: 2026-KT253
• Study Type: interventional
• Target: 60
• Locations: 0 countries
• Sites: N/A

Brief Summary

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.

Conditions

Intraoperative Neurophysiological Monitoring; Spine Surgery; Anesthesia

Keywords

Ciprofol; Remimazolam; Motor evoked potential; Somatosensory evoked potential; Intraoperative neurophysiological monitoring; Spine surgery; Total intravenous anesthesia; Crossover trial

Outcome Measures

Primary Outcomes (1)

• Within-participant difference in lower-extremity MEP peak-to-peak amplitude between ciprofol and remimazolam periods

  Lower-extremity target-muscle motor evoked potential peak-to-peak amplitudes will be recorded during stable intraoperative monitoring windows under ciprofol and remimazolam. The primary analysis will compare log-transformed MEP amplitude or amplitude ratio between the two drug periods within the same participant.

  During surgery, at predefined stable monitoring windows under each study drug; up to 6 hours

Secondary Outcomes (1)

• Within-participant difference in lower-extremity SEP amplitude

  During surgery, at predefined stable monitoring windows under each study drug; up to 6 hours

Study Arms (2)

Ciprofol-Remimazolam Sequence

EXPERIMENTAL

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.

Drug: Ciprofol; Drug: Remimazolam

Remimazolam-Ciprofol Sequence

EXPERIMENTAL

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.

Drug: Ciprofol; Drug: Remimazolam

Interventions

Ciprofol DRUG

Ciprofol will be administered intravenously for induction and/or maintenance according to the institutional anesthesia protocol and product labeling. A suggested maintenance range is approximately 0.8 to 1.5 mg/kg/h, adjusted according to anesthetic depth, hemodynamics, surgical conditions, and patient safety.

Ciprofol-Remimazolam Sequence; Remimazolam-Ciprofol Sequence

Remimazolam DRUG

Remimazolam will be administered intravenously for induction and/or maintenance according to the institutional anesthesia protocol and product labeling. A suggested maintenance range is approximately 0.5 to 2 mg/kg/h or 1 to 2 mg/kg/h, adjusted according to anesthetic depth, hemodynamics, surgical conditions, body movement, and patient safety.

Ciprofol-Remimazolam Sequence; Remimazolam-Ciprofol Sequence

Eligibility Criteria

• Age: 18 Years - 75 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Age 18 to 75 years.
• Scheduled to undergo elective spine surgery.
• Planned intraoperative monitoring with MEP and SEP/SSEP.
• Expected surgical duration sufficient to complete two study drug periods and intraoperative monitoring windows, preferably at least 3.5 to 4 hours.
• American Society of Anesthesiologists physical status I to III.
• Able to provide written informed consent, or consent provided by a legally authorized representative where applicable.

You may not qualify if:

• Known allergy or contraindication to ciprofol, remimazolam, benzodiazepines, propofol-related formulations, opioids, or relevant excipients.
• Severe preoperative motor or sensory deficit preventing interpretable target MEP or SEP baseline recordings.
• Implanted cardiac pacemaker, skull defect, or other condition considered unsuitable for transcranial electrical stimulation.
• Severe neuromuscular disease, poorly controlled epilepsy, severe cognitive impairment, or inability to complete postoperative neurological assessment.
• Severe hepatic or renal dysfunction, severe hemodynamic instability, shock, or requirement for high-dose vasoactive medications before enrollment.
• Long-term benzodiazepine, sedative-hypnotic, antiepileptic drug use, or drug/alcohol dependence that may substantially alter anesthetic response.
• Expected need for continuous deep neuromuscular blockade during surgery, preventing valid MEP monitoring.
• Any other condition judged by the investigators to make participation unsuitable or unsafe.

Sponsors & Collaborators

• Affiliated 2 Hospital of Nantong University: lead

MeSH Terms

Interventions

(2-(1R)-1-cyclopropyl)ethyl-6-isopropyl-phenol; remimazolam

Study Design

• Study Type: interventional
• Phase: phase 4
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Masking Details: 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.
• Purpose: SUPPORTIVE CARE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Dr

Model Details: Participants will be randomized in a 1:1 ratio to one of two two-period sequences. In the CR sequence, ciprofol will be used during the first stable intraoperative monitoring period and then switched to remimazolam for the second period. In the RC sequence, remimazolam will be used first and then switched to ciprofol. A stabilization and washout period of approximately 45 to 60 minutes will be used after drug transition before the second monitoring window whenever surgical conditions allow.

Study Record Dates

• First Submitted: July 17, 2026
• First Posted: July 21, 2026
• Study Start: August 1, 2026
• Primary Completion (Estimated): December 1, 2026
• Study Completion (Estimated): January 1, 2027
• Last Updated: July 21, 2026

Record last verified: 2026-07