Effect of Binaural Beats for Maintenance of General Anesthesia

Study Overview
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Brief Summary
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The goal of this clinical trial is to learn about the effects of binaural beats on maintenance of general anesthesia in patients undergoing thyroidectomy without intraoperative neuromonitoring. The main question it aims to answer is: 1) Does applying binaural beats during surgery reduce the gas anesthetics (especially sevoflurane) requirement to maintaining adequate anesthetic depth during general anesthesia? 2) Does applying binaural beats during surgery affect intraoperative hemodynamic stability or post operative nausea and vomiting? Participants will wear headsets with a sound generator which contains music files (binaural beat file in the intervention group (BB) ; silent file in control group (C)) according to the randomization. Researchers will compare the BB and C group to see if intraoperative binaural beats reduce the requirements of sevoflurane for maintaining adequate anesthetic depth.

Detailed Description
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This study will look at thyroidectomy patients without neuromonitoring. Before entering the operating room, patients will be randomized according to the randomization table, with the test group receiving a sound generating device with a binaural sound file and the control group receiving a sound generating device with a silent file. After entering the operating room, electrocardiogram, pulse oxymetry, non-invasive blood pressure monitor, and sensor for depth of anesthesia will be attached. At the beginning of anesthesia induction, the headset will be placed on the patient and a sound generator will be connected to the headset to play the file. The induction of anesthesia will be done with administration of fentanyl and propofol in both groups, and after confirming that the patient is unresponsive to voice, rocuronium and sevoflurane will be administrated to the patient. During the operation, the inhaled anesthetic concentration will be adjusted to maintain a patient state index (PSI) between 25 and 50. Fentanyl can be titrated up to 100 mcg to account for the hemodynamic response to intraoperative pain, and neuromuscular blocking agents are titrated to maintain a train of four (TOF) count of 1-3. The headset is continuously applied to the patient during surgery, and blood pressure, pulse oximetry, PSI, end tidal sevoflurane and end tidal minimal alveolar concentration will be monitored during the operation. At the time of the final suture of the skin, the sound generator will be removed from the headset. Save the raw EEG data from the Sedline® sensor for further analytical evaluation.

Official Title
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) The Effect of Intraoperative Binaural Beats on the Quantity of Inhaled Anesthetic Gas Required for the Maintenance of General Anesthesia: a Randomized, Placebo Controlled Trial

Conditions
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Anesthesia, General

Intervention / Treatment
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* Procedure: Silent
* Procedure: Binaural beats


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients who are scheduled for thyroidectomy without neuromonitoring Patients aged 20-60 who require general anesthesia over 2 hours Patients who are able to provide written consent to participate in the clinical trial, to understand the procedure of this clinical trial, and to fill out the questionnaire appropriately Patients with ASA physical status classification 1-2 Exclusion Criteria: Patients with hearing loss or using hearing aids Patients who received narcotic analgesics or sedative drugs within 1 week Patients with alcohol or drug dependence Patients with drug hypersensitivity to sevoflurane Patients with family history or past history of malignant hyperthermia Patients with neuromuscular disease of myasthenia gravis Patients with arrhythmia, cardiovascular disease, and decreased heart function Patients with kidney failure Patients who are judged to be inappropriate for this clinical trial according to the opinions of investigators

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 60 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

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
Interventional Model Description: A prospective randomized, placebo-controlled trial
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: Control<br>In the control group, a silent state (a wave file made without sound) is applied via the sound generator and a headset, at the starting of general anesthesia induction. The sound generator volume is set to 60 dB. The sound generator and the headset is assigned after the randomization, and is blinded to the patient and the investigator. This sound is applied during the operation, and at the time of the final skin suture, the sound generator and the headset will be removed from the patient. | Procedure: Silent<br>* Apply wave file created in silence.<br>|
| Experimental: Binaural Beat<br>In the experimental group, the binaural beat which is produced by the beat of 1Hz difference is applied via the sound generator and a headset, at the starting of general anesthesia induction. The sound generator volume is set to 60 dB. The sound generator and the headset is assigned after the randomization, and is blinded to the patient and the investigator. This sound is applied during the operation, and at the time of the final skin suture, the sound generator and the headset will be removed from the patient. | Procedure: Binaural beats<br>* Apply wave file which is intended to generate binaural beats by applying waves of different frequency (1Hz difference) in each ear.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Average end tidal sevoflurane concentration | Average end tidal sevoflurane concentrations required for maintenance of general anesthesia from surgical incision to skin closure | From the starting of surgery to the final suture of skin | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| End tidal minimal alveolar concentration - Maximum | Maximal value of end tidal minimal alveolar concentration during maintenance of general anesthesia | From the starting of surgery to the final suture of skin | 
| End tidal minimal alveolar concentration - Minimum | Minimal value of end tidal minimal alveolar concentration during maintenance of general anesthesia | From the starting of surgery to the final suture of skin | 
| Anxiety | Anxiety is evaluated using visual analogue score(0-100mm ruler without a scale), after entering the operating room | Right after arriving the operating room | 
| Anxiety | Anxiety is evaluated using visual analogue score(0-100mm ruler without a scale), just before leaving the post anesthesia care unit | Just before leaving the post anesthesia care unit | 
| Vital sign | Noninvasive blood pressure (systolic & diastolic & mean, mmHg) | From the starting to the end of general anesthesia | 
| Vital sign | Heart rate (bpm) | From the starting to the end of general anesthesia | 
| Vital sign | Saturation by pulse oximeter (%) | From the starting to the end of general anesthesia | 
| Brain wave | Patient state index (PSI) by Sedline device | From the starting of surgery to the final suture of skin | 
| Brain wave | brainwaves (raw data) which are collected in the Sedline device - alpha, beta, theta, delta, gamma brain wave | From the starting of surgery to the final suture of skin | 
| Post operative nausea vomiting | The incidence of post operative nausea vomiting, in the post anesthesia care unit | During the patients stay in post anesthesia care unit | 
| Post operative nausea vomiting | The incidence of post operative nausea vomiting, in the ward within 24 hours | Since the patient leaves the post anesthesia care unit, until post operative 24 hours | 
| Post operative pain | Pain is evaluate in Numerical rating scales score (0-10, 0 for no pain and 10 for for worst pain imaginable), in the post anesthesia care unit | While the patient stay in post anesthesia care unit | 
| Post operative pain | Pain is evaluate in Numerical rating scales score (0-10, 0 for no pain and 10 for for worst pain imaginable), 24 hours after operation | 24 hours after operation | 
| Delirium | The incidence of delirium in the ward within 24 hours after operation | Since the patient leaves the post anesthesia care unit, until post operative 24 hours | 
| Delirium | The incidence of delirium in the ward within 48 hours after operation | Since the patient leaves the post anesthesia care unit, until post operative 48 hours | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Sevoflurane, Brain waves, Binaural Beats