Low-Dose Rocuronium Maintenance 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.

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..