[Postoperative delirium].

This article reviews the incidence, pathophysiological hypotheses, and etiology of postoperative delirium, especially in the elderly. Preoperative, intraoperative, and postoperative risk factors for delirium following surgery are discussed. Results of various studies on postoperative delirium appear hardly comparable due to methodological and population differences. Therefore, it is difficult to draw any conclusions on postoperative delirium in general. Special attention is paid to delirium after cardiac surgery since this syndrome has been studied most.