Assessing delirium in adults
A history taken from a reliable source (eg significant other or carer) and physical examination may reveal delirium (see Evaluating mental state) and its likely precipitant.
Comprehensively review the patient’s drug history and consider stopping drugs that could be causing or contributing to delirium. Many patients recover without specific treatment once causative drugs are stopped.
The following investigations can assist in determining the cause(s) of delirium:
- blood tests, including:
- blood glucose concentration
- blood urea, creatinine, electrolyte and calcium concentrations
- full blood count
- liver biochemistry
- blood pressure
- brain imaging (eg computerised tomography [CT])—particularly in older patients or those taking anticoagulants
- electrocardiogram (ECG)
- heart rate
- oxygen saturation (with or without blood gas measurement) and respiration rate
- pain assessment
- temperature.
If a specific cause is suspected, consider other investigations as indicated; for example:
- bladder ultrasound
- cardiac enzymes
- blood cultures
- chest X-ray
- lumbar puncture
- urine toxicology.
If a urinary tract infection is suspected to be the cause of delirium in an aged-care facility resident, see Assessment and treatment of residents of an aged-care facility with suspected urinary tract infection for assessment and management.
Delirium can be a response to several concurrent insults to brain functioning, without a single main cause. In some cases, no clear cause can be identified.