Postoperative Cognitive Dysfunction in Elderly Patients: A Frequent Complication

also weeks or months after surgery and not always recognized in the early postoperative period because its recognition need the employment of neurological and psychological tests [2]. POCD must be distinguished by delirium that is present early in postoperative period and is characterized by an acute change of attention and thought. It can be diagnosed utilizing confusion assessment method (CAM) [3]. The reported incidence of POCD varies from 7 to 71% at seven-eight postoperative days and 6 to 56% at an interval of 42-84 days [4]. The exact incidence is not known because POCD is not always recognized in the postoperative period since diagnosis requires many sensitive neuropsychological tests and these tests can be difficult to administer in clinical trials in which the sample of the patients may be elevated. Tests are different for the cognitive domain that they study. The working group ISPOCD (International Study of Postoperative Cognitive Dysfunction) has conducted several studies in this field and has also created some recommendations. It was found that in the diagnosis of POCD it should be used a battery of tests to investigate the different domains involved in cognitive functions such as memory, attention, speed motion sensory and flexibility cognitive; moreover, these tests should be sensitive to allow the diagnosis of mild deficits such as those characteristic of POCD. The assessment of cognitive function in the postoperative period is based on the results of pre-and postoperative tests. Often, to correct the “practice effect” that is often present when performing neuropsychological tests repeated over time it is used a control group [5].