Perioperative Brain Health Centre

Pre-clinical research


Pre-clinical research is performed in the laboratory for mechanisms of anesthesia located in the department of physiology, University of Toronto. The team is led by Dr. Beverley Orser, scientist & professor in the department of anesthesia and physiology, and chair of the department of anesthesia, University of Toronto.

Pre-clinical studies

The discovery of general anesthesia is one of the greatest advances in the history of medicine. However, the molecular mechanisms of how anesthetics work have eluded scientists for centuries. This lack of understanding has stalled drug development and contributes to an inability to treat anesthesia-related disorders. The main goal of the laboratory is to understand the molecular mechanisms of general anesthetics and discover new therapeutic drugs to improve patient care.

Clinical research 



Dr. Stephen Choi
Clinical Research Officer

Dr. Sinziana Avramescu
Clinical Investigator


Dr. Nathan Herrmann
Dept of Psychiatry

Dr. Alex Kiss
Dept of health policy, management and evaluation

Dr. Krista Lanctôt
Depts of Psychiatry and Pharmacology & Toxicology

Dr. David Mazer
Dept of Anesthesia (SMH)

Kevin Thorpe
Dalla Lana School of Public Health

Research team

Shelly Au
Research Manager

Kathrina Flores
Research Coordinator

Brendan Flynn
Research Assistant

Jessica Pacquing
Research Assistant

Raina Ladha
Co-op Student

Gajathree Ananthathurai
Co-op Student

Ibrahim Alqalami
Research Volunteer

Clinical trials

Investigator initiated

Cognitive Changes After Major Joint Replacement – Pilot Trial (NCT02964221)

Patients assume that cognitive performance rapidly returns to baseline after anesthesia and surgery. Several studies have shown that one week after major non-cardiac surgery about 27% of patients have postoperative cognitive dysfunction (POCD) and 10% of patients at 3 months. Very few studies have assessed the incidence of POCD beyond 3 months. POCD significantly reduces quality of life. Identifying risk factors for POCD is important because it is associated with prolonged hospital stay, loss of independence, and premature retirement. There is an urgent need to measure and document the level of cognitive change associated with surgery with an easy to use tool, both prior to admission and after discharge. This information can be used to plan appropriate care paths and to identify or test the efficacy of potential new treatments to alter the negative trajectory.

Cognitive Changes After Major Joint Replacement - Full Trial (NCT03147937)

Based on our pilot study, we are currently recruiting a total of 600 patients to assess for cognitive changes after major joint replacement.


PODESA (NCT02954224)

Delirium is a common complication in elderly patients following surgery. Patients who develop delirium after surgery are at increased risk for serious complications, and even death. This multi-centre randomized controlled trial will enroll elderly patients scheduled for elective hip/knee replacement surgery. The objective of this trial is to identify obstructive sleep apnea using ApneaLink Air and to determine whether auto-titrating CPAP treatment of obstructive sleep apnea will decrease the incidence of post-operative delirium in elderly patients undergoing elective hip and knee replacement surgery.

REGAIN (NCT02507505)

Spinal and general anesthesia represent the two standard care approaches to anesthesia for hip fracture surgery. Basic and clinical research has identified multiple plausible mechanisms by which spinal anesthesia may improve outcomes after hip fracture, such as delirium; nonetheless, major guidelines and systematic reviews have identified key evidence gaps and anesthesia care for hip fracture varies markedly in practice. REGAIN is the first pragmatic multicenter prospective randomized trial of spinal versus general anesthesia for hip fracture surgery designed to evaluate the association of anesthesia technique with functional recovery after hip fracture.