Neurological Dysfunction after Cardiac Surgery and Cardiac Intensive Care Admission: A Narrative Review Part 2: Cognitive Dysfunction after Critical Illness; Potential Contributors in Surgery and Intensive Care; Pathogenesis; and Therapies to Prevent/treat Perioperative Neurological Dysfunction

Severe cognitive decline and cognitive dysfunction has been attributed to patient's stay in the cardiovascular intensive care unit. Prolonged mechanical ventilation, long duration of stay, sedation protocols, and sleep deprivation contribute to patients developing neurocognitive disorder after intensive care admission and it is associated with poor clinical outcomes. Trauma of surgery, stress of critical care, and administration of anaesthesia evoke a systemic inflammatory response and trigger neuroinflammation and oxidative stress. Anaesthetic agents modulate the function of the GABA receptors. The persistence of these effects in the postoperative period promotes development of cognitive dysfunction. A number of drugs are under investigation to restrict or prevent this cognitive decline.