Acute Confusional States in Hospital

Acute confusional state (delirium) is an acute disturbance of brain function. The incidence of such states varies according to the group of patients con- cerned: it ranges from 30% to 80% among patients in intensive care and from 5.1% to 52.2% among surgical patients, depending on the type of procedure. The earlier German term "Durchgangssyndrom" (usually rendered as "transitory psychotic syn- drome") tended to imply a self-limited and thus relatively harmless condition. In fact, however, delirium is associated with longer hospital stays, poorer treatment out- comes, and higher mortality. Approximately 25% of patients who have experienced an acute confusional state have residual cognitive deficits thereafter.

This review is based on publications retrieved by a selective search in MEDLINE, PubMed, the Cochrane Library, and in the International Standard Randomised Controlled Trial Number (ISRCTN) registry.

Validated instruments are available for the reliable diagnosis of an acute confusional state, e.g., the Confusion Assessment Method for the ICU (CAM-ICU) for patients in intensive care and the 3D-CAM or CAM-S for patients on regular hospital wards. The prevention and treatment of this condition are achieved primarily by a nonpharmacological, multidimensional approach including early mobilization, reorientation, improvement of sleep, adequate pain relief, and the avoidance of polypharmacy. A meta-analysis has shown that these measures lower the incidence of delirium by 44%. The authors find no basis in the current literature for recommending prophylactic medication, although current data promisingly suggest that the incidence of delirium in surgical patients can be lowered by the perioperative administration of dexmedetomidine (odds ratio 0.35). The pharmaco- therapy of acute confusional states involves a careful choice of drug based on the clinical manifestations in the individual case.

The key elements of success in the treatment of acute confusional states in the hospital are adequate prevention, rapid diagnosis, the identification of precipitating factors, and the rapid initiation of both causally oriented and symptom- directed treatment.