Relationship Between Pre-induction Electroencephalogram Pattern of Adult Patients and Their Sensitivity to Propofol

Study Overview
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Brief Summary
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The induction dose of propofol is generally determined based on patients' characteristics, underlying disease, general condition, and also by clinician's experiences. However, It is difficult to anticipate and objectively calculate an adequate dose of propofol for every patient considering the variability of an individual's response to propofol. If there is a specific pattern in EEG prior to induction of anesthesia that can provide information about the patient's susceptibility to propofol, every induction may be performed far more smoothly with a precisely optimized dose of propofol for each patient. The study is to find a relationship between the pre-induction EEG pattern of adult patients and their sensitivity to propofol.

Official Title
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Relationship Between Pre-induction Electroencephalogram Pattern of Adult Patients and Their Sensitivity to Propofol

Conditions
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Propofol Overdose of Undetermined Intent

Intervention / Treatment
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* Drug: Propofol
* Device: EEG monitoring


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adult patients undergoing general anesthesia Exclusion Criteria: Patients undergoing cardiac or brain surgery Patients with neurological deficit or impaired communication (Glasgow Coma Scale < 15) Unstable vital sign (cardiogenic, hemorrhagic, septic shock) Patients with eclampsia Patients who administered preoperative anxiolytics Patients who do not require intubation Patients who are considered unsuitable for the study

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 89 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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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Pre EEG group<br>This cohort includes all participants in this study. EEG sensor will be attached to the patient's forehead before induction of anesthesia. Patterns of EEG and data will be obtained | Drug: Propofol<br>* The dose of propofol required for loss of consciousness and the total induction dose of propofol will be recorded for every patients.<br>Device: EEG monitoring<br>* The processed EEG spectrogram and indices, such as patient status index, 95% spectral edge frequency, and suppression ratio, will be obtained from Sedline monitoring device. The raw pre-induction EEG will be extracted from Sedline at the end of induction and it will be analyzed by an external software to calculate the mean frequency, frequency band power and its distribution.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Absolute and Relative power in distinct frequency (% δ: 1-4 Hz, % θ: 5-8 Hz, % α: 9-12 Hz, % β: 13-25 Hz) | Relative power in distinct frequency (% δ: 1-4 Hz, % θ: 5-8 Hz, % α: 9-12 Hz, % β: 13-25 Hz) | During the induction of anesthesia (up to 15 min) | 
| Processed EEG index (PSI; patient state index) | Processed EEG index (PSI; patient state index) | During the induction of anesthesia (up to 15 min) | 
| Mean frequency and 95% spectral edge frequency (Hz) | Mean frequency and 95% spectral edge frequency (Hz) | During the induction of anesthesia (up to 15 min) | 
| Burst suppression ratio (%) | Burst suppression ratio (%) | During the induction of anesthesia (up to 15 min) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The effect-site concentrations of propofol at loss of consciousness (μg/ml) | The effect-site concentrations of propofol at loss of consciousness (μg/ml) | During the induction of anesthesia (up to 15 min) | 
| The dose of propofol required for loss of consciousness (mg) | The dose of propofol required for loss of consciousness (mg) | During the induction of anesthesia (up to 15 min) | 
| Total amount of propofol used (mg) | Total amount of propofol used (mg) | During the induction of anesthesia (up to 15 min) | 
| Time to loss of consciousness (second) | Time to loss of consciousness (second) after the start of induction | During the induction of anesthesia (up to 15 min) | 
| Vital sign - blood pressure | Check blood pressure (mmHg) | During the induction of anesthesia (up to 15 min) | 
| Vital sign - heart rate | Check heart rate (beats per minute) | During the induction of anesthesia (up to 15 min) | 
| Administration of vasopressors (ephedrine, phenylephrine, epinephrine, etc) | Administration of vasopressors (ephedrine (mg), phenylephrine (mcg), epinephrine (mcg), etc) | During the induction of anesthesia (up to 15 min) |