Delirium and confusion

Delirium and confusional states are among the most common disorders affecting adults admitted to a hospital. Delirious patients may present dramatically, exhibiting agitated, combative behavior. Or, signs of delirium might be more subtle, remaining undetected by an unsuspecting clinician. The spectrum of delirium poses significant challenges for hospital staff and family alike. Moreover, delirium is also strongly associated with negative outcomes and adds significantly to the cost of healthcare. The recognition of confusion and delirium may, on the surface, seem simple, but the available evidence suggests otherwise [1, 2]. These are not disease diagnoses in their own right, but rather symptoms of an underlying disorder. Delirium and confusional states are clinical syndromes with many potential causes. The greater diagnostic challenge often lies in identifying the underlying disease or disturbances. Obtaining a useful history and examination can be difficult, if not impossible. Since delirium and confusional states can be seen in such a wide range of diseases, no one diagnostic test is reliably informative in their evaluation. Therefore, the clinician must take a systematic approach to the delirious patient. Despite being a daily occurrence in nearly every hospital, our understanding of delirium and confusional states remains limited. The heterogeneous nature of the condition makes studying delirium difficult, which is a barrier to both clinical management and research. Practice guidelines based on expert opinion must still rely heavily on the results of small and/or observational rather than prospective studies [3]. This chapter reviews the current definition of delirium and confusional states, highlighting its key features. A systematic approach is key to identifying the underlying cause or causes of delirium so that the appropriate treatment can then be applied.