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Cognitive and Neurophysiological Outcomes Associated With EEG-Guided Administration of General Anesthesia

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ClinicalTrials.gov Identifier: NCT03442179
Recruitment Status : Not yet recruiting
First Posted : February 22, 2018
Last Update Posted : August 15, 2018
Sponsor:
Information provided by (Responsible Party):
Patrick L. Purdon, Massachusetts General Hospital

Brief Summary:
Brain activity can be inferred from brain waves that can be observed using a technology known as the Electroencephalogram (EEG). Anesthetic drugs change these EEG patterns. A patient's state of consciousness during general anesthesia is closely related to their EEG brain wave patterns, and these patterns are visible using existing EEG monitors that are readily available in the operating room. However, currently, most anesthesiologists do not use EEG brain monitors in their routine practice. During aging, the brain undergoes structural and functional changes that can increase a patient's sensitivity to anesthetic drugs, leading to an increased potential for delayed cognitive recovery following anesthesia and surgery. Safe delivery of anesthesia in elderly patients is of great importance. By using the EEG, the investigators can track brain activity during anesthesia and use it to provide a more personalized form of anesthesia care. In this study, the investigators are trying to understand if monitoring brain waves can help anesthesiologists administer anesthetic drug more precisely, specifically in elderly patients.

Condition or disease Intervention/treatment Phase
Elderly General Anesthesia Device: EEG Not Applicable

Detailed Description:

Everyday in the United States, nearly 100,000 patients undergo general anesthesia and sedation for surgical and diagnostic procedures. Approximately 35% of all surgical procedures are performed on adults older than 65 years. Advanced age has been identified as a predominant risk factor for postoperative cognitive dysfunction (POCD) as well as postoperative delirium (POD), a more acute complication of major surgery. POD and POCD are commonly reported as being part of the same continuum. Although many factors, such as surgical stress, inflammation, and other comorbidities may contribute to POCD, there is evidence that anesthetic exposure plays a major role. Pre-clinical studies have demonstrated that exposure to anesthetic drugs is neurotoxic, and that older animals are particularly vulnerable. It is also generally understood that the elderly are more sensitive to anesthetics meaning that lower doses of anesthetic drugs are required to induce and maintain unconsciousness.

Propofol and sevoflurane, two of the most commonly-used anesthetic drugs, induce a stereotyped sequence of brain oscillations with increasing drug concentration. These brain oscillations are directly related to the states of sedation and unconsciousness induced by anesthetic drugs, and readily observed using the EEG. At high concentrations, propofol and sevoflurane produce a pattern referred to as burst suppression, a deep state of brain inactivation in which brain activity is punctuated by long periods of neuronal and EEG silence. Elderly patients are far more likely to be in burst suppression, even when age-adjusted anesthetic dosing is used. Recent studies have shown compelling evidence that EEG burst suppression during anesthesia is an independent risk factor for POD and predicts deficits in cognitive function after surgery. Since burst suppression occurs at higher anesthetic doses, and is not required to maintain unconsciousness, an obvious implication is that cognitive outcomes might be improved if anesthesiologists used the EEG to maintain unconsciousness but avoid burst suppression.

Although anesthesiologists and researchers have advocated the use of the unprocessed EEG and EEG spectrogram as tools to manage a patient's state of consciousness during general anesthesia for many decades, few anesthesiologists use the EEG in their routine practice. A major limiting factor has been the absence of training programs to teach anesthesiologists how to interpret the EEG in the context of their clinical practice. Alongside this problem, to date no studies have been conducted to measure the benefits, if any, of using the unprocessed EEG and EEG spectrogram for anesthetic management. In this study the investigators hypothesize that: 1) Anesthesiologists can be trained to read the unprocessed EEG and EEG spectrogram to manage general anesthesia; and 2) EEG-based anesthetic management to maintain unconsciousness but avoid burst suppression can improve patient outcomes.


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Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 175 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary Purpose: Prevention
Official Title: Cognitive and Neurophysiological Outcomes Associated With EEG-Guided Administration of General Anesthesia
Estimated Study Start Date : March 2019
Estimated Primary Completion Date : April 2020
Estimated Study Completion Date : December 2020

Arm Intervention/treatment
Active Comparator: Treatment Group
Anesthesiologists in the treatment group use the unprocessed EEG waveforms and EEG spectrogram to maintain appropriate levels of unconsciousness for general anesthesia while avoiding burst suppression.
Device: EEG
the anesthesiologists (attending faculty, residents, and CRNAs) in the treatment group use the unprocessed EEG waveforms and EEG spectrogram to maintain appropriate levels of unconsciousness for general anesthesia while avoiding burst suppression. The presence of slow (0.1-1 Hz) and frontal alpha (8-12 Hz) oscillations on EEG time trace and spectrogram will be used as indicators of anesthesia-induced unconsciousness in these patients who are receiving propofol and sevoflurane for induction and maintenance of general anesthesia, respectively.

No Intervention: Control Group
Anesthesiologists managing patients assigned to the control group will manage each anesthetic based on their clinical judgment, using standard monitoring required by American Society of Anesthesiologists (ASA), which include cardiac and respiratory monitoring, but not EEG monitoring.



Primary Outcome Measures :
  1. Postoperative Delirium Incidence [ Time Frame: on postoperative day 1 ]
    postoperative delirium will be assessed using 3-Minute Diagnostic Interview for Confusion Assessment Method (CAM)

  2. Postoperative Cognitive Decline [ Time Frame: one week before the surgery and postoperative day 7 ]
    postoperative cognitive dysfunction will be assessed using the Montreal Cognitive Assessment (MoCA)

  3. Intraoperative Burst Suppression Time [ Time Frame: during the surgical procedure under general anesthesia ]
    we will use the EEG data recorded during the surgical procedure to calculate time spent in burst suppression



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Ages Eligible for Study:   65 Years and older   (Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • 65 years old or above (male and female) American Society of Anesthesiologists (ASA) physical status classification of I, II or III.
  • Candidates scheduled for open or laparoscopic general surgical procedures under general anesthesia
  • Montreal Cognitive Assessment (MoCA) (Nasreddine et al., 2005) score ≥ 26

Exclusion Criteria:

  • Preoperative delirium (based on 3D-CAM)
  • Dementia (MoCA < 26)
  • Prior history of psychiatric or neurological diseases including:

    • Schizophrenia
    • Parkinson's Disease
    • Epilepsy
    • Brain injury
    • Brain tumors/metastases
    • Encephalitis
    • Stroke
  • Drug or alcohol abuse
  • Hearing or visual impairment
  • Comorbidities:

    • Renal failure
    • Hepatic failure
    • Heart failure
    • Respiratory diseases (COPD)
    • Poorly controlled hypertension
    • Severe obesity (BMI ≥40 kg/m2)

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): NCT03442179


Contacts
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Contact: Patrick L. Purdon, PhD 617- 970-6739 patrickp@nmr.mgh.harvard.edu
Contact: Pegah Kahaliardabili, MD 617-470-4712 Pegah.Kahaliardabili@MGH.HARVARD.EDU

Locations
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United States, Massachusetts
Massachusetts General Hospital Not yet recruiting
Boston, Massachusetts, United States, 02114
Contact: Patrick L. Purdon, PhD    617-970-6739    patrickp@nmr.mgh.harvard.edu   
Contact: Pegah Kahaliardabili, MD    617-470-4712    Pegah.Kahaliardabili@MGH.HARVARD.EDU   
Sponsors and Collaborators
Massachusetts General Hospital
Investigators
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Principal Investigator: Patrick L. Purdon, PhD Massachusetts General Hospital

Publications:

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Responsible Party: Patrick L. Purdon, Associate Professor of Anaesthesia, Massachusetts General Hospital
ClinicalTrials.gov Identifier: NCT03442179     History of Changes
Other Study ID Numbers: 2017P000413
First Posted: February 22, 2018    Key Record Dates
Last Update Posted: August 15, 2018
Last Verified: August 2018
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: Undecided

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: Yes
Device Product Not Approved or Cleared by U.S. FDA: No
Pediatric Postmarket Surveillance of a Device Product: No

Keywords provided by Patrick L. Purdon, Massachusetts General Hospital:
Aging
Anesthesia
EEG monitoring
Burst suppression

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