Grant: Project Grant

Many older patients undergo surgery that prolongs/saves life or improves its quality. Anesthesia allows one to tolerate the stress, trauma, and invasiveness of surgery. A common complication after heart surgery is postoperative cognitive decline, an impairment in memory and thinking. It occurs in up to 25% and can last for months to years. These patients can have decreased quality of life, early retirement, less independence, potentially earlier death and may be at higher risk of dementia. These changes are often not recognized by doctors and there are no ways to prevent it yet. Our study is investigating the medication dexmedetomidine (DEX), which is sometimes, but not routinely used to sedate patients in ICU. DEX reduces cognitive dysfunction after surgery in mice and decreases the chance of delirium and early cognitive dysfunction after surgery in humans. Based on this, we believe DEX may also prevent long-term cognitive dysfunction after heart surgery. Patients participating in this study will be randomly (ie. flip of a coin) receive sedation in the ICU after cardiac surgery with DEX or with usual sedation. We will also try to determine if people who already have mildly decreased cognition before surgery, experience delirium after surgery, and have other conditions such as heart disease and diabetes, are more likely to develop cognitive changes after surgery. To assess these changes, we will use a state-of-the-art, computerized testing tool, which can be administered by computer from anywhere and allows us to see small changes compared to traditional pen-and-paper tests. CODEX is the first trial to investigate and identify a preventative treatment for postoperative cognitive dysfunction. We believe, that our study will provide a chance to preserve brain function and the 18,000 patients undergoing heart surgery every year in Canada. This therapy could lead to better patient outcomes and decreased healthcare costs across Canada and worldwide.