Modulation Of Frontal EEG Alpha Oscillations During Maintenance and Emergence Phases of General Anesthesia

Study Overview
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Brief Summary
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The investigators intend to recruit 600 participants to see if alpha power during anesthesia is influenced by analgesic medication and associated with a reduction of delirium following surgery.

Detailed Description
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Postoperative delirium may manifest in the immediate post-anesthesia care period. Such episodes appear to be predictive of further episodes of inpatient delirium and associated adverse outcomes. Intraoperative monitoring of frontal electroencephalogram (EEG) has been associated with postoperative delirium and poor outcomes. However, the efficacy of titrating anesthesia medication to proprietary index targets for preventing delirium remains contentious. The investigators aim to assess the efficacy of two pharmacologic strategies which could prevent post-anesthesia care unit (PACU) delirium (1) maximization of intraoperative alpha power during maintenance and (2) switching anesthesia regimes during the emergence phases of anesthesia.

Official Title
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Modulation Of Frontal EEG Alpha Oscillations During Maintenance and Emergence Phases of General Anesthesia to Improve Early Neurocognitive Recovery in Older Patients

Conditions
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Postoperative Delirium

Intervention / Treatment
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* Procedure: Alpha Optimization
* Behavioral: Emergence from anesthesia with propofol


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adults aged 60 years or over Has capacity to provide informed consent Undergoing elective non-cardiac surgery, which does not involve the head or neck, with planned volatile-based general anesthesia of expected duration of at least 2 hours Exclusion Criteria: Chronic pain with opioid requirement or concurrent use of enzyme inducers, e.g. carbamazepine, phenytoin, Illicit substance use or excessive alcohol intake Refusal by patient or case anesthesiologist responsible for patient's care

Ages Eligible for Study
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Minimum Age: 60 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Supportive Care
Allocation: Randomized
Intervention Model: Factorial Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Maintenance-Alpha Optimization / Wake from Propofol<br>During the first randomization, participants randomized to intraoperative oscillatory EEG alpha optimization will receive individualized titration of anesthetic gas and opioid. During the second randomization, participants randomized to conversion to a propofol infusion for emergence from anesthesia will received an infusion of propofol 400mg/h and simultaneous reduction of desflurane concentration during the final 10-20 minutes of surgery. | Procedure: Alpha Optimization<br>* Intraoperative oscillatory EEG alpha optimization involves real-time acquisition of oscillatory alpha power from the frontal EEG with individualized titration of desflurane and opioid.<br>Behavioral: Emergence from anesthesia with propofol<br>* Infusion of 400 mg/h of propofol during the final 10-20 minutes of surgery. Total doses of propofol administered are likely to be in the range of 1-3 mg/kg.<br>|
| Active Comparator: Maintenance-Alpha Optimization / Wake from Volatile<br>During the first randomization, participants randomized to intraoperative oscillatory EEG alpha optimization will receive real-time monitoring of alpha recordings and individualized titration of desflurane and opioid. During the second randomization, participants randomized to standard emergence from volatile anesthesia will be woken up per standard practice. | Procedure: Alpha Optimization<br>* Intraoperative oscillatory EEG alpha optimization involves real-time acquisition of oscillatory alpha power from the frontal EEG with individualized titration of desflurane and opioid.<br>|
| Active Comparator: Maintenance-Routine Care / Wake from Propofol<br>During the first randomization, participants randomized to standard of care will receive anesthesia per usual care with quantitative processed EEG index values and EEG wave forms. During the second randomization, participants randomized to conversion to a propofol infusion for emergence from anesthesia will received an infusion of propofol 400mg/h and simultaneous reduction of desflurane concentration during the final 10-20 minutes of surgery. | Behavioral: Emergence from anesthesia with propofol<br>* Infusion of 400 mg/h of propofol during the final 10-20 minutes of surgery. Total doses of propofol administered are likely to be in the range of 1-3 mg/kg.<br>|
| No Intervention: Maintenance-Routine Care / Wake from Volatile<br>During the first randomization, participants randomized to standard of care will receive anesthesia per usual care with quantitative processed EEG index values and EEG wave forms. During the second randomization, participants randomized to standard emergence from volatile anesthesia will be woken up per standard practice. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Incidence of PACU Delirium | 3-Minute Diagnostic Interview for Confusion Assessment Method(3D-CAM), Confusion Assessment Method for the ICU (CAM-ICU), Speech / Language Assessment will be administered to check for signs of delirium. | Up to 24 hours post-surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Frontal Alpha Power | The EEG data collected during the study duration will be processed using a customized script. Frontal alpha power (i.e., the cumulative power in the EEG alpha range) will be extracted from the EEGs and analyzed to compare the groups for the differences in the frontal alpha power. | Up to 24 hours post-surgery | 
| Change in pain in PACU: numerical rating score (NRS) | The numerical rating score (NRS) requires the patient to rate their pain from 0-10 where 0 is no pain and 10 is the worst pain imaginable (high score indicates worse outcome). | Up to 24 hours post-surgery | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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EEG, General Anesthesia