Delirium

Definition

  • acute

  • transient

  • global

  • organic disorder of higher nervous functions

  • involving impaired consciousness and attention

Epidemiology

  • General adults in community 0.4%

  • over 55 in community 1.1%

  • hospital patients 10%

  • elderly medical inpatients 30%

  • following hip fractures 50%

Risk Factors

  • age -v. young, old

  • dementia

Prognosis

  • increases mortality

  • 25% elderly die

Aetiology

  • Metabolic

    • hypoxia - cardiac failure, COPD

    • hypoglycaemia

    • hypercalcaemia

    • hyponatraemia

  • Toxic

    • alcohol

    • drugs

      • cimetidine

      • digoxin

      • steroids

      • anticholinergics

    • carbon monoxide

  • Infections

  • Renal Failure

  • Liver Failure

  • Constipation

  • Trauma

  • Endocrine

  • CNS

    • space occupying lesions

    • haemorrhage

    • TIA

Clinical Features

  • Impaired consciousness
  • Reduced ability to maintain attention to external stimuli
  • disorganised thinking
  • Memory impairment - working and short term memory
  • perceptual distortions
  • disturbed sleep-wake cycle
  • disorientation in time/place
  • changes in mood
    • anxiety, depression, lability, irritability, aggression
  • sudden onset
  • tendency to fluctuations, nocturnal exacerbations
  • physical signs of underlying cause

Differential diagnosis

  • Dementia
    • Lewy body dementia (fluctuations, prominent visual hallucinations, parkinsonism)
  • Mania
  • Dissociative disorders
  • Schizophrenia

Delirium vs. Dementia

  delirium dementia
onset acute/subacute chronic
course fluctuating stable / progressive
attention markedly reduced normal/reduced
arousal increased/decreased usually normal
delusions fleeting systematised
hallucinations common less common
psychomotor activity usually abnormal usually normal
autonomic features abnormalities normal

Variants

Investigation

  • Identify physical agent responsible for delirium
  • Pulse Oximeter
  • Bloods
    • FBC, U&E, LFT, TFT, ESR/CRP, glucose
  • Urine dipstick
  • ECG
  • CXR, hip X-ray
  • CT (?)

Management

  • Identification of clinical syndrome
  • Identification of causative agent
  • General supportive measures
  • Treatment of underlying condition
    • correction of electrolyte, fluid imbalance
  • Liaison of medical and surgical teams with psychiatrist
  • symptomatic treatment of acutely disturbed behaviour
    • haloperidol
    • benzodiazepines (lorazepam if IM needed)
      • alcohol/ benzodiazepine withdrawal
      • hepatic failure
  • Thiamine, nutrition
 

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