Identify and treat the precipitating cause
- Deliriogenic drugs should be reduced or withdrawn whenever possible.
- Use daily sedation targets and spontaneous awakening trials if tolerated.
- Biochemical, hypoxic and haemodynamic derangements should be corrected
- Screen for infection, identify or treat most likely source.
Delirium once diagnosed should be treated pharmacologically if it is persistent, delays the patients progress e,g, extubation, mobilisation or is hyperactive and distressing.
Haloperidol, on the current limited evidence available, is the drug of choice in all available guidelines. It is the only antipsychotic given intravenously; starting dose of 2 to 5 mgs depending on patient age and weight. This dose can be doubled and repeated.
Remember a) give it at least 30 minutes to work and b) don’t give it in a patient who has a QTc over 500 msecs and with extreme care if the QTc is over 450msecs.
Olanzapine has been shown to work as well in critically ill patients - it can be given intramuscularly as well as enterally.
Other antipsychotics available, but similarly with limited evidence for their use and safety, include risperidone and quetiapine.
Benzodiazepines are deliriogenic. Ideally they should be reserved for the treatment of alcohol withdrawal - for which they are indeed the drugs of choice - or when patient or staff safety may be at risk.