Postoperative delirium represents a serious complication after major surgery. Patients suffer from anxiety, hallucinations and delusions and have higher postoperative morbidity and mortality. A long-term cognitive impairment is its common consequence. Delirium thus represents a nursing, therapeutic as well as economic problem. In this review article the basic characteristics and incidence of postoperative delirium are summarized, and hypotheses of its development published so far are presented.

        Key words: postoperative delirium – hallucination – cognitive impairment