EEG-Guided Analgesic Titration During General Anesthesia to Improve Early Neurocognitive Recovery in Older Patients

EEG-Guided Analgesic Titration During General Anesthesia to Improve Early Neurocognitive Recovery in Older Patients

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.

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.

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