Table 1 Predisposing and precipitating factors for delirium1,3,7,10,11,12,13.
| Predisposing | Precipitating |
|---|---|
| Older age | Severe acute illness |
| Presence and severity of dementia | Infection |
| Previous delirium | Operation with general anaesthesia |
| Functional dependence | Electrolyte imbalance (eg, hyponatraemia, hypoglycaemia, hypercalcaemia) |
| Immobility | Liver failure with hepatic encephalopathy |
| Dehydration | Renal failure |
| Polypharmacy | Respiratory failure with hypoxia (eg, secondary to pulmonary embolus, lymphangitis carcinomatosis) |
| Hypoalbuminaemia | Drugs (eg, alcohol withdrawal, opiates, benzodiazepines, steroids, TCAs, chemotherapy, anticholinergics) |
| Renal impairment | Pain |
| Defects in vision or hearing | Haematological (eg, anaemia, disseminated intravascular coagulopathy) |
| Alcoholism | Cerebral causes (primary and secondary tumours, post‐ictal seizures, cerebrovascular disease, raised ICP) |
| Severity of physical illness | Urinary retention (and also bladder catheter use) |
| ? Genetics | Faecal impaction |
| Unfamiliar environment |
ICP, intracranial pressure; TCAs, tricyclic antidepressants.