Postoperative cognitive decline

Abstract

Memory loss and lack of concentration are symptoms that frequently occur in patients who have undergone a surgical procedure. Although cognitive function can be assessed using neuropsychological tests, reliable diagnosis of postoperative cognitive decline (POCD) appears to be difficult. Therefore, the true incidence of POCD is unknown. Severe POCD, which is apparent even without neuropsychological testing, is reported most frequently after cardiac and hip-replacement surgery. In these cases, POCD probably reflects microembolic brain injury. Apart from the nature of the surgical procedure, advanced age is the most important risk factor for POCD. The anesthetic technique is not a determinant of POCD: the risk of POCD appears to be similar after both general and regional anesthesia.

Inhibition of learning and memory by general anesthetics

“…Such insights may allow the development of strategies to prevent and treat memory disorders associated with anesthetic states, such as intraoperative awareness [149][150][151] and memory deficits in the postoperative period. [152][153][154] …”

Postoperative Cognitive Dysfunction: Knowns and Unknowns

“…However, some authors even stated that POCD rarely occurs, but is only based on wrongful interpretations of the results of neuropsychological tests (11). An alarming prevalence of POCD, of more than 30% at 1 year after coronary bypass surgery, decreases to 10% when applying a more conservative definition (12). Therefore, it is possible that the arbi-…”

Management of cognition as reported in Japanese historical documents and modern anesthesiology research papers

“…However, several months after surgery, the incidence decreases to less than half of the patients, and at one year after surgery, decreases to approximately one-quarter of patients. Although it may be true that most of the early cognitive loss is transient, multiple longitudinal studies demonstrated that, in some cases, it persists for several years after surgery [10,11].…”

“…Many previous studies demonstrated that this complication is associated with the duration of cardiopulmonary bypass, valve surgery and impaired cardiac function. Embolization of particulate and gaseous material into the cerebral microvasculature, resulting in focal areas of cerebral ischemia, has been best studied as the mechanism underlying cognitive dysfunction following cardiac and orthopedic surgeries [11,12]. However, it is still controversial whether cerebral embolization is the cause of such cardiac surgery-related cognitive impairment, since, in some studies, the rates of cognitive dysfunction were similar even after coronary artery bypass surgery without cardiopulmonary bypass [13].…”

“…Advanced age is also an important risk factor for POCD [10,11]. Although cognitive dysfunction may occur regardless of the age of the patient, the dysfunctions seen at younger ages, when nervous systems are actively growing, should be considered separately from geriatric cases [16].…”