ABSTRACT
Delirium is an acute confusional state. Its key features are listed below:
acute onset
fluctuating course
cognitive impairments: short-term memory, orientation, attention and consciousness.
It is characterised by an onset that is usually a matter of hours to days. There is also a fluctuation in severity that is typically worse in the evening or night-time ('sun downing'). Cognitive function most often shows a reduction in attention (97%), but impairments in short-term memory (88%), visuospatial skills (87%) and orientation (76%) are frequently detected. 1 Consciousness is impaired - in this context consciousness refers to awareness of one's surroundings rather than a Glasgow Coma Scale (GCS) score. Misinterpretation of events or objects is common. This may be associated with full-blown hallucinations - usually visual and involving animals such as spiders. There may also be delusions, often of persecution. Patients may continually pick at bed sheets, clothing or the air as though trying to grasp an object (termed carphology' or 'floccillation'). Disturbances in mood may also be associated.