Delirium is a state of mental confusion that has a variety of causes including illness, surgery or the use of some medications.
Also called “acute confusional state,” delirium usually starts suddenly and can be frightening for the person experiencing it, as well as for those around them. However, the condition usually resolves once the underlying cause is diagnosed and treated.
Fever and infection
Delirium can be caused as a result of fever due to infection. In these cases, antibiotics and a medication for reducing fever are administered. As the fever subsides, the features of delirium also subside.
Inflammation of the brain
Inflammatory conditions of the brain such as encephalitis or meningitis can also cause delirium and can be treated with antibiotics.
Medication and drugs of abuse
Delirium can be caused by the use of certain medications such as steroids or by sudden withdrawal from alcohol or drugs. In these cases, appropriate measures are taken to detoxify the patient and correct the withdrawal symptoms.
Dehydration and associated hypoglycemia and electrolyte imbalance can cause delirium. In these cases, treatment may involve correction of arterial blood gases and levels of blood sugar and electrolytes to restore the body’s fluid balance and ease symptoms.
Major surgery can also cause dehydration and delirium due to the amount of blood and body fluid lost, pre-operative fasting and anxiety.
Some examples of other causes of delirium include liver and kidney disorders, epilepsy, neurological disorders and head injury. Poisoning with certain substances such as carbon mono-oxide can also cause delirium. Severe pain, especially in terminal illnesses, is another cause and can be eased with the use of strong pain relievers.
Treatment also needs to maintain optimal conditions for the brain such as adequate oxygenation along with the provision of sufficient hydration and nutrients using intravenous fluids. Healthcare workers also need to be alert to symptoms such as stress, anxiety and depression, which are commonly associated with delirium and may require treatment.
Antipsychotics such as haloperidol or risperidone are the most commonly used drugs for treating delirium. Sedatives such as benzodiazepines (eg, diazepam) can cause or worsen the condition and are not usually used, although they can help when the delirium is caused by alcohol withdrawal.
Reviewed by Sally Robertson, BSc