Background: Delirium and long-term cognitive dysfunction (CD) are important complications of major surgery and intensive care treatment. Delirium is associated with increased mortality and CD has an important impact on mortality, independency, social interactions, and quality of life. Delirium is an important risk factor for the development of long-term CD. Particularly, patients aged 65 or older undergoing cardiac surgery are at a high risk of developing these problems. There are data suggesting that inflammation plays a key role in the development of delirium and possibly CD. It has been shown that n-3 fatty acids modulate the immune response of patients and have beneficial effects in abdominal surgery.