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Monitoring Awareness and Pain Under Anesthesia Using a New EEG Based System

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ClinicalTrials.gov Identifier: NCT02938325
Recruitment Status : Active, not recruiting
First Posted : October 19, 2016
Last Update Posted : April 9, 2019
Sponsor:
Information provided by (Responsible Party):
Rambam Health Care Campus

Brief Summary:

General anesthesia (GA) is the process of induction of unconsciousness in order to undergo surgery. Unlike sleep, a process of "anesthesia" is not related at all, 'Sleep' and does not include dreams - but is done by using drugs that cause a kind of "unconsciousness" control.

The induction of GA includes combination of drugs - for sleep (inhalation anesthesia or hypnotic drugs intravenously), analgesia (opiates) and muscle relaxants. Since most of our patients paralyzed during surgery, the anesthesiologists have no way of knowing whether our paralyzed patient is asleep or awake. If the patient is awake and paralyzed, a situation named "awareness under anesthesia" it can cause him a traumatic experience that would leave him a cripple for his whole life.

There are many stories about patients who lay paralyzed, awake, while been operated, who remembered every word of what happened during the operation and of course could not mark the anesthetist that they are awake. The anesthesiologist might suspect that his patient is awake and paralyzed through "signals" from the sympathetic nervous system - for example the increase in heart rate and blood pressure. But many of our patients receive different medications (eg, beta-receptor blockers that does not allow the rise of a pulse) obscuring the clinical signs, so that the patient is awake and paralyzed without being noticed by the anesthesiologist.

Some patients are at a higher risk to suffer from awareness under anesthesia, because the anesthesiologist cannot provide "enough" anesthesia, due to their medical condition, for example: women in caesarean section under GA, patients in cardiac surgery or injured trauma patients.

Twenty years ago, an EEG based tool, naming "BIS" was developed. Nowadays, BIS monitor's credibility is questionable 1. The effect of different hypnotic drugs is not uniform. 2. Recently it was shown that a paralyzed patient BIS index could fall mimicking a situation of a sleep - enabling a paralyzed patient being awake. Thus, it is not clear whether the calculation of the BIS monitor is based on physiological models that define what is consciousness, loss of consciousness and how consciousness arises. It seems that the BIS is only suitable for certain drugs - not as a general monitor for the level of anesthesia.

The purpose of the present study is to develop a universal system for determining awareness under GA using an innovative algorithm for analyzing EEG waves, based on the physiological processes of attention and perception underlying the basis for sedation and GA.


Condition or disease
Awareness Under Anesthesia

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Study Type : Observational
Estimated Enrollment : 90 participants
Observational Model: Case-Control
Time Perspective: Prospective
Official Title: Monitoring Awareness and Pain Under Anesthesia Using a New EEG Based System
Actual Study Start Date : January 1, 2017
Estimated Primary Completion Date : December 2019
Estimated Study Completion Date : December 2019

Group/Cohort
No intervention: General Anesthesia

Thirty patients undergoing elective surgery under general anesthesia who will be monitored with standard ASA, BIS and EEG for comparisons. In recovery unit, at the end of the surgery, patients will be questioned for awareness under anesthesia by Modified Brice Questionnaire.

There will be no intervention. Patients will be anesthetized with general anesthesia as they were supposed to be for their elective surgery. The EEG during the anesthesia will be assessed afterwards, and patients will be asked about their memory from the surgery.

No intervention: Sedation

Fourty patients undergoing elective cardiac catheterization under conscious sedation who will be monitored with standard ASA, BIS and EEG for comparisons. In recovery unit, at the end of the procedure, patients will be questioned for awareness under sedation by Modified Brice Questionnaire.

There will be no intervention. Patients will be anesthetized with sedation as they were supposed to be for their elective cardiac catheterization. The EEG during the anesthesia will be assessed afterwards, and patients will be asked about their memory from the surgery.

No Intervention - Awake Volunteers
EEG and BIS will be recorded in twenty volunteers, for 10 minutes, in supine position, while their eyes are closed. This recording will be utilized as for positive control for recall.



Primary Outcome Measures :
  1. Could a new EEG based Posteriorization/Anteriorization (P/A) index identify recall under sedation [ Time Frame: Immediately after surgery ]
    Posteriorization/ Anteriorizatio index is analyzed at the end of the surgery, with no influence on the intraoperative treatment of the patient.


Secondary Outcome Measures :
  1. The association between the P/A index to muscle activity [ Time Frame: Sub- analysis, within 6 months from the date the last patient was recruited for the study ]
    The correlation between the electromyelograph (EMG) activity, to the calculated index

  2. The association between BIS to muscle activity [ Time Frame: Sub- analysis, within 6 months from the date the last patient was recruited for the study ]
    The correlation between the electromyelograph (EMG) activity, to BIS

  3. Could Bis identify recall under sedation [ Time Frame: Immediately after surgery ]
    BIS index is recorded during the procedure, but the anesthesiologists is blinded to its results. The association between BIS and recall is analyzed at the end of the surgery.



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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Sampling Method:   Non-Probability Sample
Study Population
Patients undergoing elective procedures under sedation, or patients undergoing surgery under general anesthesia. Another twenty volunteers will undergo elective EEG and BIS recording for 10 minutes, for comparison.
Criteria

Inclusion Criteria:

  • ASA 1-3
  • Patients for elective surgery under general anesthesia or elective procedures under sedation (such as cardiac electrical studies, liver chemo-embiolization, biliary tract drainage)
  • The willing of the patient to fulfil the Modified Brice Questionnaire at the end of the procedure in recovery unit
  • Healthy volunteers that will accept to be monitored with EEG and BIS for 10 minutes in supine position, as control.

Exclusion Criteria:

  • Lack of consent
  • Emergent surgery Emergent procedure (catheterization)

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT02938325


Locations
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Israel
Rambam Health Care Campus
Haifa, Israel
Sponsors and Collaborators
Rambam Health Care Campus
Investigators
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Principal Investigator: Dana Baron Shahaf, MD PhD Rambam Health Care Campus

Publications:

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Responsible Party: Rambam Health Care Campus
ClinicalTrials.gov Identifier: NCT02938325     History of Changes
Other Study ID Numbers: 152-16 rambam-CTIL
First Posted: October 19, 2016    Key Record Dates
Last Update Posted: April 9, 2019
Last Verified: April 2019
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

Keywords provided by Rambam Health Care Campus:
Electroencephalogram
awareness

Additional relevant MeSH terms:
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Anesthetics
Central Nervous System Depressants
Physiological Effects of Drugs