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 : October 14, 2019
|Condition or disease||Intervention/treatment||Phase|
|Elderly General Anesthesia||Device: EEG||Not Applicable|
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.
|Study Type :||Interventional (Clinical Trial)|
|Estimated Enrollment :||175 participants|
|Intervention Model:||Parallel Assignment|
|Masking:||Single (Outcomes Assessor)|
|Official Title:||Cognitive and Neurophysiological Outcomes Associated With EEG-Guided Administration of General Anesthesia|
|Estimated Study Start Date :||January 2020|
|Estimated Primary Completion Date :||June 2021|
|Estimated Study Completion Date :||June 2021|
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.
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.
- Postoperative Delirium Incidence [ Time Frame: on postoperative day 1 ]postoperative delirium will be assessed using 3-Minute Diagnostic Interview for Confusion Assessment Method (CAM)
- 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)
- 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
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03442179
|Contact: Patrick L. Purdon, PhD||617- firstname.lastname@example.org|
|Contact: Pegah Kahaliardabili, MD||617-470-4712||Pegah.Kahaliardabili@MGH.HARVARD.EDU|
|Principal Investigator:||Patrick L. Purdon, PhD||Massachusetts General Hospital|