Risk factors for delirium in palliative care
Delirium is triggered by one or more precipitating factors in a patient who may or may not have predisposing risk factors. Although delirium commonly occurs in adults with one or more predisposing risk factors (eg cognitive impairment, advanced age, multimorbidity), it can also be triggered by a significant event in adults without predisposing risk factors (eg a young adult who is critically unwell). The more predisposing factors present, the fewer precipitating factors needed to trigger delirium. The exact pathophysiology of delirium is not well understood; however, assessing and (if possible) addressing predisposing and precipitating factors is a key part of managing delirium.
Patients with a life-limiting illness are at significant risk of developing delirium, and the risk increases with disease progression and general deterioration.
Precipitating risk factors for delirium to consider in adults include:
- acute organ failure—especially kidney, liver and respiratory failure
- cardiac events—for example, arrhythmias, heart failure, myocardial infarction
- constipation, urinary catheterisation and retention
- critical illness
- dehydration
- drugs and polypharmacy—particularly corticosteroids, drugs with central nervous system activity (eg opioids, benzodiazepines, dopamine agonists, drugs with anticholinergic activity); see also Drugs and drug groups that commonly cause or contribute to delirium in the Psychotropic guidelines
- infections (eg urinary tract infections)
- intracranial events—for example, brain tumoursBush, 2018, leptomeningeal disease, stroke, seizures, postictal states
- metabolic disturbances—including hypercalcaemia1, hyperglycaemia, hypoglycaemia, hyperkalaemiaInouye, 2014, hypernatraemia and hyponatraemia
- pain and discomfort
- radiotherapy to the brain
- trauma (eg hip fracture) and major surgery
- withdrawal states—especially from alcohol, opioids or benzodiazepines.