Adequate Depth of Anesthesia: the Anesthesiologist's Assessment and the EEG Processed Monitoring

Study Overview
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Brief Summary
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Comparison of conventional assessment of anesthetic depth by anesthesiologists (moderate, deep or light anesthesia) with EEG monitoring (Narcotrend® state/index). In case of mismatch statistical analysis for underlying factors are done.

Detailed Description
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In this observational study estimation of anesthetic depth by anesthesiologists is compared with the EEG based monitoring Narcotrend®. 10-20 voluntary anesthesiologists of the Kepler University Hospital, unfamiliar with EEG-monitoring during anesthesia, assess depth of anesthesia (moderate, deep or light level) during a steady-state period by clinical signs and measured or calculated concentrations of anesthetics. Concurrently Narcotrend® provides data of anesthetic depth (index, stadium) blinded for the anesthesiologist. Each anesthesiologist is included 30 times during study period. The aim of this study is to define conformity between subjective and objective assessment of narcotic depth. In the cases of divergence data of the patient (age, body mass index, comorbidity…), data of the anesthesiologist (age, years of practice…), data of anesthesia (balanced anesthesia, target controlled infusion, endtidal concentration of volatile anesthetic…) and data of the operation (eye surgery, cardiac surgery…) will be analyzed by statistics with regard to underlying or concomitant factors. These findings could help to develop recommendations in the use of EEG-processed monitoring to improve subjective assessment and facilitate an adequate depth of anesthesia to be provided for every patient.

Official Title
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Adequate Depth of Anesthesia: the Anesthesiologist's Assessment and the EEG Processed Monitoring

Conditions
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Anesthesia

Intervention / Treatment
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* Device: EEG monitoring


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: operation under general anesthesia duration of surgery ≥ 10 minutes informed consent ASA physical status 1-4 age 1-110y performance check of Narcotrend Exclusion Criteria: proximity of EEG electrodes to the operating field frontal skin lesion frontal cerebral pathology hypoxic brain damage hypothermia (≤33°C) language barrier

Ages Eligible for Study
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Minimum Age: 1 Year
Maximum Age: 110 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

| Intervention/Treatment |
| --- |
|Device: EEG monitoring|EEG will be performed. Data obtained will be analyzed using software. Anesthesiologists will enter their assumption in a blinded fashion and data obtained will be compared with EEG data|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Comparison of subjective (anesthesiologist) vs. objective (Narcotrend) assessment of anesthesia depth. | Depth of anesthesia will be assessed by the anesthesiologist in an subjective way. During a defined period of stable anesthesia state, the indicated subjective depth levels will be assessed by the anesthesiologist and will be compared to those obtained by narcotrend (Narcotrend-Index). Anesthesiologists will assess by deep, moderate and superficial depth of anesthesia. Narcotrend indices will also be assigned to three groups (superficial, moderate, deep levels). After the procedure, both systems will be compared. In the case of non-correlation, other factors like i.e. patient's age, comorbidities, years of practice of the anesthesiologist etc. will be analysed for any other type of correlation. | up to 1 year |