Identify Patient-Specific Risk Factors

Predisposing vs. Precipitating Risk Factors

Patient-specific risk factors can be classified as:

  • “Predisposing” risk factors: factors about the patient or environment that might predispose someone to develop dementia
  • “Precipitating” risk factors: factors/acute diagnoses that might lead to delirium, acronym, ‘DELIRIUM’

Predisposing Factors

It is important to identify patients at high risk for delirium in the ED and initiate preventive strategies when indicated.

For patients with predisposing risk factors, several nonpharmacologic interventions can be implemented early to help prevent delirium. For example, providing glasses or hearing aids to patients with sensory impairment, allowing extended hours for family at bedside, trying to expedite admission or discharge.

  • Advanced age (>80)
  • Male
  • Dementia
  • ADL impairment
  • Sensory impairment1
    • Vision impairment
    • Hearing impairment
  • High medical comorbidity
  • Severity of physical illness
    • Urinary catheterization
    • Polypharmacy1
    • Low albumin
  • Prolonged ED/hospital stay1

Precipitating Factors


Drugs, dehydration, deprivation (sleep)
Electrolyte abnormalities (Na, Ca)
Lack of drugs (withdrawal)
Infection, ingestion
Reduced sensory input
Intracranial problems, increased pain
Urinary retention
Metabolic problems, malnutrition

Drug levels: digoxin, lithium, acetaminophen, salicylate

Medications are the most common remediable cause of delirium.

Most common meds that lead to delirium are those with psychoactive effects: sedatives-hypnotics, narcotics, meds with anticholinergic effects.

Delirium Provoking Drugs

  • Anticholinergic medications
    • Tricyclic antidepressants (TCAs)
    • Antispasmodics
    • Typical antipsychotics
    • Skeletal muscle relaxants
    • Promethazine
    • Olanzapine
    • Paroxetine
    • Antihistamines
  • Sedative-hypnotic medications
    • Benzodiazepines
    • Zolpidem
  • Meperidine
  • H2-receptor antagonists
  • Steroids


Differential for delirium is broad. Need to consider metabolic derangements, infection, acute neurologic or cardiac event, urinary retention, severe constipation, etc.

1potentially modifiable predisposing risk factors


Ahmed S, et al. Age Ageing. 2014;43(3):326–333.

Aslaner MA, Boz M, Celik A, et al. Etiologies and delirium rates of elderly ED patients with acutely altered mental status: a multicenter prospective study. Am J Emerg Med. 2017;35(1):71–76

Elie M, et al. J Gen Intern Med. 1998;13(3):204–212.

Inouye SK. Clin Geriatr Med. 1998;14(4):745–764.

Naeije G, Pepersack T. Delirium in elderly people. Lancet. 2014;383(9934):2044–2045


ADL, activities of daily living

ED, emergency department