Delirium in the ICU

What is Delirium?

  • “Disturbance in attention (i.e., reduced ability to direct, focus, sustain, and shift attention) and awareness (reduced orientation to the environment).
  • The disturbance develops over a short period of time (usually hours to a few days), represents an acute change from baseline attention and awareness, and tends to fluctuate in severity during the course of a day.
  • An additional disturbance in cognition (e.g.memory deficit, disorientation, language, visuospatial ability, or perception).
  • Are not better explained by a pre-existing, established or evolving neurocognitive disorder and do not occur in the context of a severely reduced level of arousal such as coma.
  • There is evidence from the history, physical examination or laboratory findings that the disturbance is a direct physiological consequence of another medical condition, substance intoxication or withdrawal (i.e. due to a drug of abuse or to a medication), or exposure to a toxin, or is due to multiple etiologies”  (DSM-5 American Psychiatric Association. 2013).

Delirium Diagnostic Tools

 Sedation and delirium in the intensive care unit by Reade & Finfer, 2014.

Standardised Approach 

The Australian Commission on Safety and Quality in Health Care (2016) Delirium Clinical Care Standard provides guidance across healthcare for consumers and professionals.

Delirium Factors

A few to consider, the full list of potentials from ICU is extensive:

  • Hyper and Hypo Delirium 
  • Sedation in ICU (SPICE study)
  • Pain
  • Sepsis
  • Anxiety
  • Environmental

Interventions That Are Not Medications.

  • Sleep (all those alarms and interruptions)
  • Day/night or light/dark cycles
  • Cognitive stimulation
  • Early mobilisation
  • Ensure sensory aids are utilised
  • Family
  • Get the hell out of ICU asap?

Post Intensive Care Syndrome

As ever early detection and intervention is essential for improving patient outcomes.


Australian Commission on Safety and Quality in Health Care. (2016) Delirium Clinical Care Standard. Sydney:

DSM-5 American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders. Arlington: American Psychiatric Publishing.

European Delirium Association. (2014). The DSM-5 criteria, level of arousal and delirium diagnosis: inclusiveness is saferBMC medicine12(1), 141.

Inouye, S. K., van Dyck, C. H., Alessi, C. A., Balkin, S., Siegal, A. P., & Horwitz, R. I. (1990). Clarifying confusion: The confusion assessment methoda new method for detection of deliriumAnnals of internal medicine113(12), 941-948.

Reade, M. C., & Finfer, S. (2014). Sedation and delirium in the intensive care unitNew England Journal of Medicine370(5), 444-454.

Shehabi, Y., Bellomo, R., Reade, M. C., Bailey, M., Bass, F., Howe, B., … & Sedation Practice in Intensive Care Evaluation (SPICE) Study Investigators and the ANZICS Clinical Trials Group. (2012). Early intensive care sedation predicts long-term mortality in ventilated critically ill patientsAmerican journal of respiratory and critical care medicine186(8), 724-731.

Tullmann, D. F. (2001). Assessment of delirium: Another step forward. Critical care medicine29(7), 1481-1482.