Perioperative Brain Health Centre
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Research

A custom surgical simulator is shown that was used to determine appropriate freehand techniques of cortical screw insertion in the thoracic and lumbar spine.

Pre-clinical research

Members

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

Members

Investigators

Dr. Stephen Choi
Clinical Research Officer


Research Partners

Dr. Sinziana Avramescu
Humber River Hospital

Dr. George N. Djaiani
TGHRI

Dr. Nathan Herrmann
Dept of psychiatry

Dr. Philip Jones
LHSC University Hospital

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

Cogstate
We thank Cogstate for generous in-kind donation of online cognitive assessment tool

Senior Friendly

Dr. Krista Lanctôt
Depts of psychiatry and pharmacology & toxicology

Dr. David Mazer
Dept of anesthesia (SMH)

Dr. Tarit Saha
KGH Research Institute

Kevin Thorpe
Dalla Lana School of Public Health

Dr. Summer Syed
Hamilton General Hospital, McMaster University

Dr. Angela Jerath
Sunnybrook Health Sciences Centre, University of Toronto


Research team

Dr. Lilia Kaustov
Director of operations
Research manager

Dr. Andrew Fleet
Clinical research coordinator

Boris Yakubov
Research coordinator

Cheng (Queenie) Zhang
Graduate student

Elizabeth Lappin
Research coordinator

Connor Brenna
Research fellow

Clinical trials

Investigator initiated

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

Postoperative cognitive dysfunction (POCD) is thought to affect a significant proportion of patients after major surgery (up to 10 per cent at 3 months). This is a condition that can occur after surgery and anaesthesia affecting memory and thought processes. Cognitive testing is not routinely done before and after major joint replacement surgery. The aim of this study is to measure the likelihood of POCD through a standardized cognitive test completed once before surgery and three times in the days and months following surgery. Based on our pilot study, we are currently recruiting a total of 600 patients to assess for cognitive changes after major joint replacements.

Dexmedetomidine to reduce the incidence of persistent cognitive dysfunction after open cardiac surgery - Multicentre Trial (NCT04289142)

Anesthesia is a drug induced reversible, comatose state that facilitates surgery. While it is widely assumed that cognition returns to baseline after anesthetics have been eliminated, many patients have persistent memory impairment for weeks to months after surgery. These cognitive deficits, termed postoperative cognitive dysfunction (POCD), are associated with significant negative health and social implications. There are no existing preventative or treatment strategies.

POCD has been reported in patients undergoing anesthetia associated with all types of surgeries, while cardiac surgeries appear to carry the highest risk. Notably, up to 80% of patients have POCD 3 weeks after cardiac surgery and up to 60% have persistent POCD at 6 months.

In this clinical trial we investigate the role of the Precedex (Dexmedetomidine) in preventing POCD up to three months after cardiac surgery and enhancing early postoperative recovery. Precedex is a drug that is used in clinical practice as a sedative and analgesic. The results of this trial will provide an insight on the efficacy of Precedex in reducing the incidence of POCD after anesthesia, and may lead to identification the first POCD preventative therapeutics.

Redesigning the surgical pathway: optimizing PReOperative assessMent in anesthesia clinic for adulT surgical patiEnts (PROMoTE, NCT05114876)

Postoperative delirium (POD), a short-term state of confusion, is a common postoperative complication affecting older adults. In addition to being stressful for patients and their families, POD is linked to longer hospital stays, health-care costs, higher mortality rates and potential risk of dementia.

While pharmacological interventions have proven ineffective, non-pharmacological strategies (ie. CHASM protocol) effectively reduce POD but are frequently under-utilized due to limited awareness and perceived barriers to implementation. Perioperative assessment of cognitive function is critical and a target for early intervention.

In this two-phase, prospective, observational clinical study in patients ≥60 scheduled to undergo major elective, non-cardiac surgery, in Phase I we will implement a telemedicine-based routine preoperative cognitive screening to identify at-risk patients, or patients with pre-existing cognitive impairment (pre-CI), which is a strong, but under-recognized POD risk factor. In Phase II, we will implement and evaluate a multicomponent delirium-reduction protocol, which includes directly informing the care team of high-risk (pre-CI) patients, implementing non-pharmacological delirium reduction strategies and a patient/caregiver education program which informs patients of cognitive risks and evidence-based delirium prevention strategies.


Collaborations

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.

Benzodiazepine-free cardiac anesthesia for reduction of postoperative delirium in the intensive care unit (b-free): a multicentre, randomized, cluster crossover trial (NCT03928236)

Delirium is a sudden change in mental abilities characterized by confused thinking and attention problems. It affects about 20 per cent of patients after heart surgery and can lead to worse long-term outcomes.

There is evidence that use of a type of drugs, called benzodiazepines, after surgery can increase the chances of getting delirium. Therefore, benzodiazepines are usually avoided after heart surgery. However, benzodiazepine use during heart surgery is still common, yet unfortunately we do not know whether this approach increases delirium.

To address this lack of knowledge, the B-Free trial is studying whether a hospital policy limiting benzodiazepines during heart surgery decreases delirium, when compared with a hospital policy which does not limit benzodiazepines. B-Free is being done at 16 hospitals across Canada over a 48 week period. Each policy will be used for a total of 24 weeks, with a possible change in policy every 4 weeks.

This study will help us decide which policy should be used in Canadian hospitals. This knowledge could help improve the outcomes of tens of thousands of patients undergoing heart surgery each year.

The functional improvement trajectories after surgery study (FIT After Surgery)

Around 190 million adults undergo major surgery in developed countries every year. The populations in these countries, including Canada, are aging; people ≥65 years are the fastest growing age group. Older surgical patients are more likely to be less healthy and frailer than younger surgical patients. Thus, older sicker people are now more commonly undergoing surgery.

There is currently limited data on long-term recovery in older adults after major surgery. Unfortunately, most studies have only tracked older patients for 30 days after surgery, which does not necessarily predict long-term outcomes. To address this issue, our study (FIT After Surgery) is following 2,000 older adults at 10 Canadian centres for up to a one year after major elective non-cardiac surgery. FIT will assess long-term recovery and development of significant new disability in these patients. Further, we will also identify risk factors for poor long-term outcomes.

It is important to understand the risks of surgery in order to help patients and health-care professionals make informed decisions. This study could help transform decision-making and patient care before and after major surgery.

Select Publications from our Centre

Patients are critical to the success of our research. Read more »