Effects of Desflurane-propofol Balanced Anesthesia on Visual Evoked Potentials Monitoring

Study Overview
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Brief Summary
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Intraoperative flash visual evoked potentials (FVEPs) can be used to monitor the integrity of the visual pathway in real-time during surgeries, and is to prevent the damage and deterioration of visual function caused by visual pathway damage, which is the key method of intraoperative monitoring of visual function. Spinal surgery in the prone position may compress the eyeball and reduce the blood supply of the ophthalmic artery, which is still one of the main causes of postoperative visual impairment. Intraoperative FVEPs monitoring is easily affected by inhale anesthetics, and there is little studies on the effect of intravenous-inhalation balanced anesthesia on FVEPs monitoring. Desflurane wakes up quickly, which is conducive to the recovery of early respiratory function and orientation, and early neurological evaluation. This study aims to compare the effects of desflurane-propofol balanced anesthesia and desflurane pure inhalation anesthesia on the amplitude and latency of FVEPs during spinal surgery under the same sedation depth monitored by bispectral index (BIS) monitoring.

Official Title
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Effects of Desflurane-propofol Balanced Anesthesia on Visual Evoked Potentials Monitoring: a Randomized Controlled Study

Conditions
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Visual Evoked Potentials

Intervention / Treatment
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* Drug: Desflurane
* Drug: Desflurane, Propofol


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients undergoing spinal cord surgery under elective general anesthesia; At the same time, other electrophysiological monitoring is required; 18-65 years old; ASA I-III; Sign the informed consent form. Exclusion Criteria: Patients with visual impairment; Patients with severe liver and kidney function diseases; History of asthma; Uncontrolled hypertension, diabetes, severe arrhythmia or unstable angina pectoris; Have mental illness or unable to communicate; BMI≥30kg/m2； Abuse of analgesics and drug abuse history; Silicone allergy; Visual evoked potential monitoring was rejected.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Desflurane Inhalational group (DR group)<br> | Drug: Desflurane<br>* After induction, anesthesia will be maintained with 0.7-1.0 MAC desflurane and remifentanil 0.05-0.2 μg/kg/min<br>|
| Active Comparator: Desflurane propofol balanced anesthesia group (DPR group)<br> | Drug: Desflurane, Propofol<br>* After induction, anesthesia will be maintained with 0.5 MAC desflurane, propofol 1.5-2.5 μg/ml and remifentanil 0.05-0.2 μg/kg/min<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| N75-p100 amplitude value | Wave amplitude difference between N75-P100 peak and trough | 60 minutes after anesthesia induction | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| N75-P100 amplitude decline rates | The decrease rate of wave amplitude of P100-N145 under corresponding anesthesia maintenance methods compared to the baseline measurements under total intravenous anesthesia | 30minutes and 60 minutes after anesthesia induction | 
| P100-N145 amplitude decline rates | The decrease rate of wave amplitude of P100-N145 under corresponding anesthesia maintenance methods compared to the baseline measurements under total intravenous anesthesia | 30minutes and 60 minutes after anesthesia induction | 
| P100 latency prolongation rate | The rate of prolongation of P100 latency compared to the baseline measurements under total intravenous anesthesia | 30minutes and 60 minutes after anesthesia induction | 
| Success rate of FVEP monitoring | The number of individuals obtaining satisfactory FVEP monitoring waveforms as a ratio to the total number of individuals monitored in each group | 30minutes and 60 minutes after anesthesia induction | 
| FVEPs stacking satisfaction | Assessed by the electrophysiological monitoring physician, if good waveforms can be obtained with no more than three superimpositions, it is considered satisfactory | Intraoperative | 
| Respiratory recovery time | The time from the cessation of anesthesia to the patient's spontaneous breathing recovery | Within 60 minutes after surgery | 
| Eye-opening time | The time from anesthesia cessation to when the patient can be called to open their eyes | Within 60 minutes after surgery | 
| Extubation time | The time from the cessation of anesthesia to the removal of the patient's tracheal catheter | Within 60 minutes after surgery | 
| Postextubation agitation score | 1 point, calm sleep; 2 points, awake and calm; 3 points, irritable, easily agitated, crying; 4 points, difficult to console, uncontrollable crying; 5 points, unable to settle, confused, delirious. | Immediately after extubation, 15 minutes after extubation, 30 minutes after extubation, 1 hour after extubation. | 
| Ramsay Sedation Score | 1 point - awake, anxious, and restless; 2 points - cooperative, oriented, and calm; 3 points - drowsy, responds to commands; 4 points - drowsy, responds promptly to light tapping on the forehead or loud auditory stimulation; 5 points - drowsy, responds sluggishly to light tapping on the forehead or loud auditory stimulation; 6 points - drowsy, unresponsive. Sedation is considered satisfactory with a score of 2-4, and excessive sedation with a score of 5-6. | Immediately after extubation, 15 minutes after extubation, 30 minutes after extubation, 1 hour after extubation. | 
| Intraoperative anesthetic drugs dosage | Including the total amount of intraoperative application of sufentanil, remifentanil, propofol, and rocuronium | The time period between the patient entering the operating room and leaving the operating room | 
| Intraoperative vasoactive drugs dosage | The total amount of norepinephrine, ephedrine, perdipine, and atropine used during surgery | The time period between the patient entering the operating room and leaving the operating room |