Cerebral Flow-metabolism Coupling During Adult Surgery

• Status: Recruiting
• Trial end date: 2025-12-31
• Target enrollment: 0
• Participant gender: All

Summary

The brain is a highly active organ that requires a large blood flow to function properly. Normally, blood flow is tightly linked to the brain's energy demands. However, during surgery, anesthesia can affect this relationship in different ways. Some types of anesthesia can decrease blood flow to the brain, while others can increase it. Anesthesiologists need to be careful to maintain adequate blood flow to the brain during surgery, especially when blood pressure drops. Drugs may be used to increase blood pressure, but some of these drugs can also affect blood flow to the brain. It is still unclear how to best maintain blood flow to the brain during surgery and how different types of anesthesia and drugs affect this process.

The study aims to assess the clinical utility of a new technique that uses light-based neuromonitoring to measure changes in cerebral blood flow and metabolism. The investigators will recruit 80 adult patients undergoing surgery under general anesthesia and randomize them into one of four groups to evaluate the effects of different anesthetic agents and vasopressors on brain hemodynamics and metabolism. The study will include patients over 18 years of age with no history of neurological conditions, substance abuse, or contraindications to cerebral oximetry devices or specific anesthetic agents. The patients will receive standard anesthesia care and be monitored with our light-based neuromonitoring system. This study aims to demonstrate the device's ability to detect changes in cerebral hemodynamic parameters related to anesthesia induction and systemic hypotension. This study will also evaluate the effects of anesthetic maintenance agents and vasopressors on cerebral hemodynamics and neurovascular coupling.

• Phase: Phase 4
• Accepts Healthy Volunteers?: No

Details

• Lead Sponsor: Jason Chui
• Treatments: Anesthetics; Ephedrine; Oxymetazoline; Phenylephrine; Propofol; Pseudoephedrine; Sevoflurane; Vasoconstrictor Agents

Criteria

Inclusion Criteria:

1. Adult patients over the age of 18 years old.

2. ASA I-IV

3. Undergoing surgery under general anesthesia at London Health Sciences Centre or St. Joseph's Healthcare that is scheduled to last longer than 1 hour.

Exclusion Criteria:

1. Had any neurological conditions such as history of stroke, TIA, neurodegenerative disease, or carotid stenosis

2. Had a history of substance abuse such as heavy cannabis users

3. Have a contraindication of applying the cerebral oximetry device (e.g., skin lesions in the forehead)

4. Have contraindications to receive specific anesthetic agents or vasopressors such as malignant hyperthermia or an allergy.

5. Unable to communicate with the research staff