Intraoperative Neurophysiological Monitoring, Neuromuscular Blockade, Spine Surgery
Conditions
Keywords
Rocuronium, Motor Evoked Potentials, Somatosensory Evoked Potentials, Train-of-Four Ratio, Spine Surgery, Intraoperative Neurophysiological Monitoring, Total Intravenous Anesthesia
Brief summary
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.
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.
Interventions
DRUGLow-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.
DRUGRocuronium
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.
Sponsors
Bach Mai Hospital
Hanoi Medical University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Outcomes Assessor)
Masking description
The anesthesia team will not be masked because they administer and titrate rocuronium according to group assignment. The intraoperative neurophysiological monitoring assessor and the data analyst will be masked to group allocation when feasible.
Intervention model description
Participants will be randomized in a 1:1 ratio to one of two parallel groups: low-dose rocuronium maintenance targeting a train-of-four ratio of 0.60 to less than 0.90, or no rocuronium maintenance after induction.
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
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..
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Mean Intraoperative Motor Evoked Potential Amplitude | From baseline intraoperative neurophysiological monitoring after patient positioning to the final intraoperative neurophysiological monitoring recording before wound closure | 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. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Successful Motor Evoked Potential Recording | During surgery | Proportion of participants with successful intraoperative motor evoked potential recording from at least one predefined target muscle. |
| Motor Evoked Potential Warning Events | During surgery | 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. |
| Surgical Field Condition | During surgery | Surgical field condition assessed using the Leiden-Surgical Rating Scale, ranging from 1 to 5, with higher scores indicating better surgical conditions. |
| Unwanted Patient Movement | During surgery | Occurrence and number of unwanted patient movement events that affect surgical manipulation or require anesthetic or neuromuscular blockade adjustment. |
| Time to Extubation | From discontinuation of maintenance anesthesia to tracheal extubation | Time from discontinuation of maintenance anesthetic infusion to safe tracheal extubation, measured in minutes. |
| New Postoperative Neurological Deficit | Post-anesthesia care unit and 24 to 48 hours after surgery | Occurrence of new postoperative motor or sensory neurological deficit assessed in the post-anesthesia care unit and within 24 to 48 hours after surgery. |
| Somatosensory Evoked Potential Stability | During surgery | 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. |
| Time to Emergence | From discontinuation of maintenance anesthesia to eye opening on verbal command | Time from discontinuation of maintenance anesthetic infusion to eye opening on verbal command, measured in minutes. |
| Early Postoperative Respiratory Events | During emergence and within 60 minutes after arrival in the post-anesthesia care unit | Occurrence of early respiratory events, including oxygen desaturation below 92 percent, laryngospasm, bronchospasm, sputum obstruction, or delayed extubation due to respiratory muscle weakness. |
Contacts
CONTACTDuc Minh Tran, MD
PRINCIPAL_INVESTIGATORToan Thang Nguyen, MD, PhD, Associate Professor
Hanoi Medical University
Outcome results
None listed