Question 6

Define delirium and describe your management approach to this problem in the ICU.

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College Answer


The acute onset of a disturbance of consciousness with inattention, changes in cognition and/orperception, that fluctuates over time, occurs as a consequence of a general medical condition and isnot better accounted for by a pre-existing, established or evolving dementia.


  1. Early recognition of delirium.
  1. Stabilise and ensure safety of the patient:
    • Attend to airway, breathing and circulation issues as required.
  1. Consider and rule out any potentially life-threatening causes of delirium (comprehensive history and physical examination will provide clues):
    • Hypoxia
    • Hypoglycaemia
    • Intra-cerebral haemorrhage
    • Meningitis/Encephalitis
    • Poisoning
    • Wernicke’s Encephalopathy
    • Infection: local (wound, anastomotic leaks etc.), UTI, lung etc.
    • Withdrawal from drugs
    • Hypertensive encephalopathy
    • Metabolic derangements – sodium, renal, liver.
  1. Consider non-pharmacological strategies to control symptoms:
    • Application of hearing aids, spectacles and dentures if worn.
    • Continuous re-orientation of patient - verbal, visual with photographs etc.
    • Enlist help of family members and/or interpreters.
    • Ensure as close to normal as possible sleep/wake cycles in a quiet and calm environment.
    • Treat pain, constipation, urinary retention if present.
    • Check drug chart and beware/attend to poly-pharmacy and cessation of drugs associated with delirium.
    • Mobilise early.
    • Avoid physical restraints if safe to do so.
  1. Obtain pharmacological control of symptoms if necessary:
    • Anti-psychotics are first line agents e.g. haloperidol, olanzepine, quetiapine.
    • Haloperidol 1-5mg iv q30 PRN. Dose can be doubled and repeated. Beware long QTc.
    • Benzodiazepines as first line agents for alcohol withdrawal only. Often used in combination with anti-psychotics in difficult to control symptoms in non-alcohol withdrawal delirium.
  1. Treat cause if found:
  2. O2, antibiotics, thiamine, glucose, electrolyte replacement, intra-venous fluids if dehydrated.



Directed by history, physical examination and differential diagnosis but include/consider;


FBC, EUC, Glucose, LFT, ABG, CXR, ECG, Urinalysis + Dipstick, Septic screen, Urinary Drug Screen.


CT Brain, LP, TTE.


Delirium is a favourite of the examiners. It is discussed in greater depth elsewhere ("Delirium in the ICU")

In order to simplify revision, I reproduce the salient points here:

The DSM -V diagnostic criteria for delirium:

  • Disturbance in attention and awareness.
  • Change in cognition
  • The disturbance develops over a short period and tends to fluctuate
  • There is evidence from the history, physical examination, or laboratory findings that the disturbance is caused by a direct physiologic consequence of a general medical condition, an intoxicating substance, medication use, or more than one cause.

A systematic approach to this question would resemble the following:

Urgently exclude and manage any lifethreatening aetiologies of delirium:

A) - Look for airway compromise due to decreased level of consciousness

B) - Assess for hypoxia and hypercapnea

C) - Assess for hypotension (thus cortial hypoperfusion) or hypertension (thus, hypertensive encephalopathy)

D) - Exclude hypoglycaemia and intoxication or poisoning; investigate for focal intracranial causes of delirium, such as intracranial haemorrhage or space-occupying lesion. Think about non-convulsive status epilepticus as the cause of delirium. Also consider withdrawal from alcohol and other drugs.

E) - Evaluate electrolytess, looking for hyponatremia

F) - Assess renal function, looking for uremia and dehydration

G) - Assess hepatic function, suspecting hepatic encephalopathy. Don't forget Wernicke's.

H) - Assess bone marrow function - cytopenia may be a clue to a space-occupying metastatic lesion, whereas blood film findings such as macrocytosis may suggest a chronic nutritional deficiency associated with alcoholism or IV drug abuse.

I) - Assess temperature, inflammatory markers and features of sepsis, ranging from UTI to septic shock (thinking about septic encephalopathy). Consider neurosyphilis and think about meningitis or encephalitis.

Investigation of delirium:

Stemming from the abovementioned differentials,

  • ABG
  • Urinalysis
  • EUC
  • CMP
  • FBC
  • Blood film
  • Inflammatory markers
  • CT brain
  • EEG
  • Lumbar puncture

Management of delirium


    • Good analgesia
    • Clear and firm communication with the patient
    • Frequent re-orientation
    • Family presence
    • Low-noise environment
    • Restoration of hearing aids and spectacles
    • Avoidance of sleep disturbance, promotion of normal sleep–wake cycle.
    • Avoidance of physical restraints
    • Early removal of IV lines and IDCs


    • Dexmedetomidine
    • Atypical antipsychotics
    • Classical antipsychotics
    • Benzodiazepines (if withdrawing from alcohol or benzodiazepines)


Oh's Intensive Care manualChapter 49   (pp. 549) Disorders  of  consciousness  by Balasubramanian  Venkatesh

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