Delirium superimposed on dementia (DSD) - where an individual with pre-existing dementia develops delirium - poses significant diagnostic challenges due to the symptom overlap between delirium and dementia. It is essential, however, that nurses and other healthcare professionals can accurately identify DSD, as delirium is a medical emergency and misattributing symptoms of delirium to dementia can result in extended hospital stay and increased morbidity and mortality. It is often a family member's or carer's report of an acute alteration in the person's cognition, function or behaviour that alerts healthcare professionals to potential delirium in a person with dementia. This article provides an overview of dementia, delirium and DSD, discusses the important role of family carers in identifying early signs of delirium in a person with dementia, and explores the use of evidence-based delirium screening tools. The article outlines implications for nursing practice and includes a composite case study illustrating some of the issues discussed.
