[Delirium: a common complication of severe pathological conditions]

Delirium is a complex syndrome caused most often by secondary neuronal dysfuncions due to systemic disorders. Because of the central nervous system manifestations of the general disease processes that are getting through the blood-brain barrier, the vigilance of attention flucutates and, therefore, the integration of incoming stimuli fails - resulting in inadequate behavioral answers. Delirium is one of the most common and serious complications of diseases, particularly in the elderly and patients in critical state. It cannot be traced back to a single etiologic process; one should consider all those pathophysiologic mechanisms that are interacting with one another simultaneously impairing the integrated functioning of the brain. Despite the high prevalence rate of delirium and the marked adverse effects on the outcome of the underlying disorders, management and therapy are basically lacking professional guidelines. The syndrome is a threatening state, requiring increased clinical attention and often intensive care. Beside evidence based therapeutic methods, conscious, targeted screening of the known risk factors and measures against them when they present themselves may exert remarkable influence on the prevention of delirium, which is also an exceptionally important aspect of the care of patients in critical state.