Observational Study on the Predictive Value of the BAMCOG and Cortisol Levels for the Incidence of Postoperative Delirium/Postoperative Acute Encephalopathy Measured by the MoCA and the DeltaScan in Patients Who Undergo Aortic Valve Replacement Surgery

Background of the study:

The mean age of surgical patients is rising worldwide and this is associated with more multi-morbidity. Especially geriatric patients who undergo surgery have a higher risk to develop Postoperative Cognitive Dysfunction or a Postoperative Delirium, which leads to higher morbidity and mortality after surgery and this leads to higher healthcare costs.

A delirium is an acutely disturbed state of mind characterized by restlessness, illusions, and incoherence, occurring in intoxication, fever, and other disorders and can fluctuate over time. The hypoactive delirium, the most common type of delirium, is hard to recognize compared to the active delirium that is expressed by restlessness and agitation.

Postoperative cognitive dysfunction is defined as a new cognitive impairment arising after a surgical procedure. Its diagnosis requires both pre- and postoperative psychometric testing. Its manifestations are subtle and manifold, depending on the particular cognitive domains that are affected, and therefore hard to recognize too.

To assess preoperative cognitive function in large groups of patients, it's needed to have a simple and quick tool to screen. In this study, the investigators use the BAMCOG, which is a tool with 3 short games played on a tablet that can provide information about cognitive functioning. When writing this new study protocol, a validation study in which the BAMCOG is validated against the MoCA is running.