Multidisciplinary team interventions for delirium in patients with chronic cognitive impairment

Delirium is common in hospitalized elderly people. In the frail elderly, delirium may occur in 60% of those hospitalized. In the cognitively impaired, 45% have been shown to develop delirium and these patients have longer lengths of hospital stay and a higher rate of complications which, with other factors, together contribute to an increase in cost of care. The combination of being elderly and chronically cognitively impaired leads to a high risk of delirium with the associated increased risk of prolonged hospital stay, complications, and poor outcomes. The management of delirium has commonly been multifaceted - the primary emphasis has always been on the diagnosis and therapy of the precipitating factors, but as these may not be immediately resolved, symptomatic and supportive care may become of major importance.

The objective of this review is to assess the available evidence for the effectiveness, if any, of multidisciplinary team interventions in the coordinated care of patients with delirium superimposed on an underlying chronic cognitive impairment compared with the usual care of older cognitively impaired patients.

A search of all available databases and sources of references was carried out in July 2000; this comprised the CDCIG specialised register in addition to the Reviewer's files and bibliographic sources.

Selection for possible inclusion in this review is made on the basis of the research methodology - controlled trials whose participants are reported as having chronic cognitive impairment, and who then developed incident delirium and were randomly assigned to either coordinated multidisciplinary care or usual care.

Nine (9) controlled trials were identified for possible inclusion in the review, none of which meets the inclusion criteria, for reasons which are recorded in the table of excluded studies, and no data, therefore, were extracted for cross study analysis or synthesis.

No studies focused on patients with prior cognitive impairment, so management of delirium in this group could not be assessed. There is very little information on the management of delirium in the literature but there is an increasing body of information about the incidence, risks and prognosis of the disorder in the elderly population.

The management of delirium needs to be studied in a more clearly defined way before evidence-based guidelines can be developed. Insufficient data are available for the development of evidence based guidelines on diagnosis or management. There is scope for research in all areas - from basic pathophysiology and epidemiology to prevention and management. Though much recent research has focused on the problem of delirium, the evidence is still difficult to utilize in management programmes. Research needs to be undertaken targeting specific groups known to be at high risk of developing delirium, for example the cognitively impaired and the frail elderly. As has been highlighted by Inouye 1999, delirium has very important economic and health policy implications and is a clinical problem which affects all aspects of care of the elderly. Delirium, though a frequent problem in the hospitalised elderly patient, is still managed empirically and there is no evidence in the literature to support change to current practice at this time.