Each year, over 312 million patients undergo surgery. Anesthesia is a drug-induced reversible, comatose state that facilitates surgery. It is widely assumed cognition returns to baseline afterwards.

Surgery and anesthesia induce stress responses in the body, potentially damaging brain cells. Many patients develop postoperative neurocognitive disorders (PND), including delirium (fluctuating confusion, memory problems shortly after surgery) and more importantly, cognitive changes. PND affects memory and thought processes and can last for months, possibly years, after surgery. Up to 60% of patients have cognitive decline 6 months after heart surgery.

Patients who develop PND stay in hospital longer, have reduced functional independence, and can develop dementia earlier. The mechanisms linking PND to long-term cognitive decline are complex and under investigation. While no proven treatments to prevent or treat PND exist yet, regular cognitive assessments can detect early decline, which is important for diagnosing PND and specific types of dementia, like Alzheimer’s disease.

Every patient receives sedation after open heart surgery in the ICU. Our study is investigating whether the sedative dexmedetomidine can prevent PND after heart surgery, enhancing postoperative cognitive recovery. Since we know dexmedetomidine prevents delirium, we believe it can also help prevent long-term cognitive issues and potentially mitigate the development of processes associated with dementia.

In this study, each participant is screened for cognitive decline up to 1 year after surgery. Testing can be done either in hospital or remotely. Participating individuals will be randomly assigned (flip of a coin) to receive sedation after surgery with dexmedetomidine or placebo (inactive medication) in the ICU in addition to normal sedation. Our study offers an approach that can intervene before cognitive decline occurs and improve the quality of life of many surgical patients.