Clinical trial NCT02938325: Monitoring Awareness and Pain Under Anesthesia Using a New EEG Based System
Official title: Monitoring Awareness and Pain Under Anesthesia Using a New EEG Based System
Study type: OBSERVATIONAL
Overall status: RECRUITING
Conditions: Awareness Under Anesthesia
Keywords: Electroencephalogram
awareness
Lead sponsor: Rambam Health Care Campus
Sponsor class: OTHER
First posted: 2016-10-19
Enrollment: 90
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Observational model: CASE_CONTROL
Time perspective: PROSPECTIVE
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.

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.


Eligibility 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)

Primary outcomes:
measure: Could a new EEG based Posteriorization/Anteriorization (P/A) index identify recall under sedation
timeFrame: Immediately after surgery
Secondary outcomes:
measure: The association between the P/A index to muscle activity
timeFrame: Sub- analysis, within 6 months from the date the last patient was recruited for the study
measure: The association between BIS to muscle activity
timeFrame: Sub- analysis, within 6 months from the date the last patient was recruited for the study
measure: Could Bis identify recall under sedation
timeFrame: Immediately after surgery
Other outcomes:
Locations:
city: Haifa
country: Israel
facility: Rambam Health Care Campus
Study officials:
affiliation: Rambam Health Care Campus
name: Dana Baron Shahaf, MD PhD
role: PRINCIPAL_INVESTIGATOR
References:
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citation: Shahaf G, Pratt H. Thorough specification of the neurophysiologic processes underlying behavior and of their manifestation in EEG - demonstration with the go/no-go task. Front Hum Neurosci. 2013 Jun 24;7:305. doi: 10.3389/fnhum.2013.00305. eCollection 2013.
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