Question 24

a)    Define delirium.    (20% marks)

b)    Outline your approach to the prevention of delirium in patients in your ICU.    (80% marks)

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College answer

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This question is the repeat of a repeat of a repeat, and is an absolute gift. The weary exam candidate should be able to relax, letting their pen produce a muscle-memory automatic answer while their mind wanders away to a less depressing place.

a) Definition of delirium (the DSM V definition)

  • Disturbance in attention (ie, reduced ability to direct, focus, sustain, and shift attention) and awareness.
  • Change in cognition (eg, memory deficit, disorientation, language disturbance, perceptual disturbance) that is not better accounted for by a preexisting, established, or evolving dementia.
  • The disturbance develops over a short period (usually hours to days) and tends to fluctuate during the course of the day.
  • 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.

b) Prevention of delirium:

  • Identification of at-risk patients
    • Pre-existing dementia
    • Hypertension
    • Alcoholism
    • High severity of illness at admission
  • Control preventable risk factors:
    • Minimise the use/duration of urinary catheters
    • Minimise the use of restraints
    • Decrease the use of opiates (especially morphine)
    • Minimise the use of benzodiazepines (restrict to those who are withdrawing from drugs/alcohol)
    • Rationalise polypharmacy
    • Where possible, cease or reduce the dose of anticholinergic drugs
  • Decrease deliriogenic stimuli of critical care environment:​​​​​​​
    • Is deliriogenic even a word?
    • Encourage mobility: early mobilisation is the most evidence-supported intervention to prevent delirium (
    • Minimise intrusive care during sleep, reducing sleep deprivation
    • Encourage normal sleep-wake diurnal cycle, sun exposure, make use of rooms with outward-facing windows for delirium-prone patients
    • Involve the relatives to calm the patient
    • Keep noise to a minimum (eg. silence internal room alarms, turn off loud devices such as the suction catheter)
    • Manage pain aggressively
    • Prevent constipation proactively
    • Watch electrolytes carefully (hypo/hypernatremia, hypo/hypercalcemia, uraemia, etc)
    • Give them back their hearing aids and spectacles as soon as practical
    • I they are intubated, minimise their sedation doses
  • Treat underlying condition:
    • ​​​​​​​Hypoxia, hypercapnia, hypotension - obviously the reason for the ICU admission


Cavallazzi, Rodrigo, Mohamed Saad, and Paul E. Marik. "Delirium in the ICU: an overview." Ann Intensive Care 2.1 (2012): 49.

Van Rompaey, Bart, et al. "Risk factors for intensive care delirium: a systematic review." Intensive and Critical Care Nursing 24.2 (2008): 98-107.

Schweickert, William D., et al. "Early physical and occupational therapy in mechanically ventilated, critically ill patients: a randomised controlled trial."Lancet (London, England) 373.9678 (2009): 1874-1882.

Stevens, Robert D., Karin J. Neufeld, and Tarek Sharshar. "Delirium in the ICU: time to probe the hard questions." Crit Care 15.1 (2011): 118.