Low-Dose Rocuronium Maintenance During Spine Surgery With Intraoperative Neurophysiological Monitoring (ROC-IONM)

A Randomized Controlled Trial Comparing Low-Dose Rocuronium Maintenance Versus Discontinuation After Induction on Motor Evoked Potential Quality During Spine Surgery With Intraoperative Neurophysiological Monitoring

This randomized controlled trial will compare two strategies for rocuronium use during general anesthesia for spine surgery with intraoperative neurophysiological monitoring. Participants undergoing spine surgery under general anesthesia with motor evoked potential and/or somatosensory evoked potential monitoring will be randomized to either low-dose rocuronium maintenance targeting a train-of-four ratio of 0.60 to less than 0.90, or no rocuronium maintenance after induction.

The main objective is to compare the effects of these two strategies on the quality of intraoperative neurophysiological monitoring, especially motor evoked potential signals. Secondary objectives include comparing surgical field conditions, unwanted patient movement, emergence and extubation times, early respiratory events, and new postoperative neurological deficits.

The study will be conducted at the Center for Anesthesia and Surgical Intensive Care, Bach Mai Hospital, Hanoi, Vietnam. The planned sample size is 62 participants, with 31 participants in each group.

Study Overview

• Status: Not yet recruiting
• Conditions: Spine Surgery; Neuromuscular Blockade; Intraoperative Neurophysiological Monitoring
• Intervention / Treatment: Drug: Low-Dose Rocuronium Maintenance; Drug: Rocuronium

Detailed Description

Intraoperative neurophysiological monitoring is commonly used during complex spine surgery to help detect early neurological injury. Motor evoked potentials are particularly sensitive to neuromuscular blockade. Avoiding maintenance neuromuscular blockade may improve motor evoked potential signal quality, but may increase the risk of unwanted patient movement and suboptimal surgical field conditions. Conversely, low-dose rocuronium maintenance may improve surgical conditions, but may reduce motor evoked potential amplitude if neuromuscular blockade is excessive.

This trial will evaluate whether low-dose rocuronium maintenance, titrated by quantitative neuromuscular monitoring, can preserve intraoperative neurophysiological monitoring quality while improving surgical field conditions compared with discontinuation of rocuronium after induction.

All participants will receive standardized total intravenous anesthesia with propofol-based maintenance, bispectral index monitoring, quantitative train-of-four monitoring, and intraoperative neurophysiological monitoring. Rocuronium will be administered for tracheal intubation in both groups. In the low-dose maintenance group, rocuronium will be titrated to maintain a train-of-four ratio from 0.60 to less than 0.90. In the no-maintenance group, no additional rocuronium will be given after induction unless predefined safety rescue is required.

The primary outcome will be intraoperative motor evoked potential signal quality, including mean motor evoked potential amplitude. Secondary outcomes will include successful motor evoked potential recording, motor evoked potential warning events, somatosensory evoked potential stability, surgical field condition, unwanted patient movement, time to emergence, time to extubation, early postoperative respiratory events, and new postoperative neurological deficits.

• Study Type: Interventional
• Enrollment (Estimated): 62
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Duc Minh Tran, MD; Phone Number: 84589916666 84869319291; Email: tdminh1312@gmail.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

- 1. Patients aged 18 years or older. 2. Patients scheduled for spine surgery under general anesthesia. 3. Patients undergoing spine surgery with intraoperative neurophysiological monitoring, including motor evoked potentials and/or somatosensory evoked potentials.

4. Patients who agree to participate in the study and provide written informed consent.

Exclusion Criteria:

• 1. Pre-existing central or peripheral neurological disease that may affect intraoperative neurophysiological monitoring, such as quadriplegia, persistent sensory disorder, sequelae of stroke, or polyneuropathy.

  2. History of epilepsy or electroencephalographic disorder. 3. Use of neuropsychiatric drugs, strong sedatives, or drugs affecting neuromuscular or neurological conduction within 48 hours before surgery.

  4. Decompensated cardiovascular disease or severe respiratory disease that may affect emergence or anesthetic drug metabolism.

  5. Contraindication to intraoperative neurophysiological monitoring. 6. Contraindication to rocuronium. 7. Refusal to participate or withdrawal of consent at any time..

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Low-Dose Rocuronium Maintenance; Participants in this group will receive rocuronium for tracheal intubation followed by low-dose rocuronium maintenance during surgery. Rocuronium will be titrated using quantitative train-of-four monitoring to maintain a train-of-four ratio from 0.60 to less than 0.90. All participants will receive standardized total intravenous anesthesia and intraoperative neurophysiological monitoring.	Drug: Low-Dose Rocuronium Maintenance; Rocuronium will be administered for tracheal intubation and then maintained at a low dose during surgery. The infusion will be titrated according to quantitative train-of-four monitoring to maintain a train-of-four ratio from 0.60 to less than 0.90.
Active Comparator: No Rocuronium Maintenance After Induction; Participants in this group will receive rocuronium for tracheal intubation only. No maintenance rocuronium will be administered after induction. Additional rocuronium may be given only as predefined safety rescue if clinically necessary. All participants will receive standardized total intravenous anesthesia and intraoperative neurophysiological monitoring.	Drug: Rocuronium; Rocuronium will be administered only for tracheal intubation during induction of anesthesia. No maintenance rocuronium will be administered after induction, except for predefined safety rescue if clinically necessary.; Other Names: Rocuronium for Intubation Only

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Mean Intraoperative Motor Evoked Potential Amplitude	Mean intraoperative motor evoked potential amplitude, measured in microvolts, recorded from predefined target muscles during spine surgery. The mean of three consecutive technically acceptable responses will be used at standardized intraoperative time points after stabilization of anesthesia and physiologic parameters.	From baseline intraoperative neurophysiological monitoring after patient positioning to the final intraoperative neurophysiological monitoring recording before wound closure

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Successful Motor Evoked Potential Recording	Proportion of participants with successful intraoperative motor evoked potential recording from at least one predefined target muscle.	During surgery
Motor Evoked Potential Warning Events	Number of intraoperative motor evoked potential warning events, defined as a decrease of 50 percent or more in amplitude from baseline lasting more than 5 minutes and not attributable to surgical manipulation after correction of physiologic and technical factors.	During surgery
Surgical Field Condition	Surgical field condition assessed using the Leiden-Surgical Rating Scale, ranging from 1 to 5, with higher scores indicating better surgical conditions.	During surgery
Unwanted Patient Movement	Occurrence and number of unwanted patient movement events that affect surgical manipulation or require anesthetic or neuromuscular blockade adjustment.	During surgery
Time to Extubation	Time from discontinuation of maintenance anesthetic infusion to safe tracheal extubation, measured in minutes.	From discontinuation of maintenance anesthesia to tracheal extubation
New Postoperative Neurological Deficit	Occurrence of new postoperative motor or sensory neurological deficit assessed in the post-anesthesia care unit and within 24 to 48 hours after surgery.	Post-anesthesia care unit and 24 to 48 hours after surgery
Somatosensory Evoked Potential Stability	Proportion of intraoperative monitoring time without significant somatosensory evoked potential changes, defined as latency increase of 10 percent or more or amplitude decrease of 50 percent or more from baseline lasting more than 5 minutes and not attributable to surgical manipulation.	During surgery
Time to Emergence	Time from discontinuation of maintenance anesthetic infusion to eye opening on verbal command, measured in minutes.	From discontinuation of maintenance anesthesia to eye opening on verbal command
Early Postoperative Respiratory Events	Occurrence of early respiratory events, including oxygen desaturation below 92 percent, laryngospasm, bronchospasm, sputum obstruction, or delayed extubation due to respiratory muscle weakness.	During emergence and within 60 minutes after arrival in the post-anesthesia care unit

Collaborators and Investigators

• Sponsor: Bach Mai Hospital
• Collaborators: Hanoi Medical University
• Investigators: Principal Investigator: Toan Thang Nguyen, MD, PhD, Associate Professor, Hanoi Medical University

Study record dates

Study Major Dates

• Study Start (Estimated): June 1, 2026
• Primary Completion (Estimated): December 1, 2028
• Study Completion (Estimated): December 1, 2028

Study Registration Dates

• First Submitted: May 30, 2026
• First Submitted That Met QC Criteria: May 30, 2026
• First Posted (Actual): June 4, 2026

Study Record Updates

• Last Update Posted (Actual): June 4, 2026
• Last Update Submitted That Met QC Criteria: May 30, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Spine Surgery; Rocuronium; Intraoperative Neurophysiological Monitoring; Somatosensory Evoked Potentials; Total Intravenous Anesthesia; Motor Evoked Potentials; Train-of-Four Ratio
• Additional Relevant MeSH Terms: Polycyclic Compounds; Steroids; Fused-Ring Compounds; Androstanes; Androstanols; Rocuronium
• Other Study ID Numbers: HMU-BMH-ROC-IONM-2025-01; 225/BM-HDDD (Other Identifier: Ethics Committee of Bach Mai Hospital); 6513/QD-DHYHN (Other Identifier: Hanoi Medical University)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Individual participant data will not be publicly shared because the study involves sensitive clinical and perioperative data. Data are protected by privacy and ethical restrictions. De-identified aggregate data may be available from the corresponding author upon reasonable request and with approval from the relevant ethics committee.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No