Delirium is a common and often serious neuropsychiatric complication in the management of medically ill patients. It is associated with increased morbidity and mortality, causing distress in patients, family members, and staff (Breitbart and Alici 2008). It is characterized by an abrupt onset of disturbances of consciousness, attention, cognition, and perception that fluctuate over the course of the day. It is a sign of significant physiological disturbance, usually involving multiple medical etiologies, including infection, organ failure, and adverse effects of medication (APA 1999, 2000).
- Disturbance of consciousness with reduced ability to focus, sustain, or shift attention.