Confusion (delirium in the elderly)

Delirium is avoidable and treatable – not an accepted factor in ageing!!



  • Substantial morbidity and mortality
  • Distress to patients and families
  • Expensive (most common complication of hospital admission for older people - 30% of elderly admissions)
  • If develops, Increase of 8 days in length of hospitalisation (worse physical & cognitive recovery at 12 mths.)
  • Symptoms of delirium persist in about 1/3 of patients with a worse prognosis

Possible pathophysiology:

  • Neurotransmitter disturbance – ACh >> dopamine
  • Illness related stress overactivity of hypothalamic pituitary-adrenal axis
  • Increase cytokine production (effect on cerebral fxn.)
  • Reduced activity of plasma esterases (drug metabolising)

Criteria for delirium

  • Disturbance of consciousness - reduced ability to focus
  • Changed cognition or development of perceptual disturbance – inc. hallucinations
  • Disturbance of sleep-wake cycle
  • Fluctuations over the course of the day

Three clinical subtypes:


  • Heightened arousal
  • Sensitivity to surroundings
  • Verbally & physically threatening
  • Aggressive
  • Restless / wandering
  • Carphologia – pulling at clothing


  • Listless / Sleepy
  • Anorexia / neglect
  • Speech incoherent
  • More common


  • Commonest

Clinical diagnosis

More on EM Dx / Mx on Delirium Page.

Three fold assessment:

  1. Cognitive assessment
  2. Collateral history/history of cognitive change
  3. Delirium precipitants and risk factors

Short cognitive tests in acute setting of delirium

Screen in ED with 4AT (on delirium page). Other tests include:

  • Dysnomnia – get patient to identify pen, watch
  • Dysgraphia – write down a sentence
  • Assess orientation in time and space
  • Inattention via serial 7’s or spelling world backward
  • Memory for recent events since delirium began distorted
  • Daily monitoring of MMT

Delirium Risk Factors

  • Age >65
  • Physical frailty
  • Severe illness / Multiple disease
  • Dementia
  • Infection/dehydration
  • Visual / hearing impairment
  • Polypharmacy
  • Alcohol
  • Renal dysfxn
  • Malnutrition

Delirium Precipitants

  • LRTI/ UTI / Catheter
  • Constipation
  • Dehydration, Hypokalaemia
  • Hypercalcaemia, hyper/hypo Na+
  • Stroke, Epilepsy, SDH
  • Hypoxia
  • Sleep deprivation
  • Environmental
    • absence of clock/watch
    • absence of reading glasses
    • family member

Specific precipitant drugs

Please check the anti-cholinergic burden calculator (ACBCalc) on the delirium page.

  • Those with anticholinergic activity
  • Antihistamine - diphenhydramine
  • Antispasmodic - Alverine, hyoscyamine
  • Tricyclic antidepressant - Amitriptyline
  • Benzodiazepine - Lorazepam
  • Analgesic - Codeine
  • Antiarrhythmic - Digoxin
  • Diuretic - Furosemide
  • Bladder stabiliser - Oxybutynin
  • Brochodilator - Theophylline


  • Orienting communication
  • Early mobilisation and walking
  • Monitoring medications
  • Non-pharm approaches to sleep and anxiety
  • Maintain nutrition and hydration
  • Address vision and hearing impairment

Urgent treatment

Immediate while identifying and correcting underlying causes:

  • Drug use (above) or drug withdrawal
  • Electrolyte and physiologic abnormalities (above)
  • Infection (esp. UTI or respiratory infection)
  • ↓ sensory input (eg, blind, deaf, new surrounds)
  • Intracranial problems (stroke, SDH etc)
  • Urinary retention / faecal impaction, Myocardial problems

Emergency intervention

Please see delirium page for more.

Low dose haloperidol - 0.25mg and 0.5mg every 4 hrs in elderly. Higher doses re- prolongation of QT interval. IV haloperidol is twice as potent as in oral form

Delirium v. Dementia
Delirium Dementia
Sudden onset Insidious onset
Precise time onset Uncertain time of onset
Usually reversible Slowly progressive
Short duration (days/weeks) Long duration (years)
Fluctuations (minutes / hours) Good days and bad days
Abnormal level consciousness Normal level consciousness
Worse at night (sun downing) Often worse at night
Inattention Attention not sustained
Variable disorientation Disorientation time and place
Slow, incoherent, inappropriate speech Difficulty finding right word
Impaired but variable recall Memory loss (particularly recent events)

Content by Dr Íomhar O' Sullivan 22/10/2009. Last reviewed Dr ÍOS 21/02/23.