Postoperative Delirium


Published: 16 July 2017

What is Delirium?

Delirium is a common disorder that mostly affects older adults however it doesn’t discriminate, and can also affect young people – especially following surgery.

It is defined as ‘an acute confusional state characterised by inattention, abnormal level of consciousness, thought disorganisation, and a fluctuating course’ (Marcantonio & Discussant 2012).

The Difference Between Delirium and Dementia

Other causes of cognition changes, such as a pre-existing dementia, need to be ruled out before a diagnosis of delirium is given to a patient. And because the symptoms of delirium and dementia are similar, delirium can sometimes be misdiagnosed as dementia.

It is also important to note that postoperative delirium can remain unrecognised in older adults and not addressed by healthcare staff in up to 80% of delirium cases (Marcantonio & Discussant 2012).

One of the main differences between delirium and dementia is that delirium is a reversible condition, whereas dementia is not. This is why diagnosis of delirium is essential in order to effectively reverse the condition. If this does not occur, then treatment is delayed and, in turn, recovery which can have many negative consequences on the individual and their family.

Delirium also develops over a short period of time in comparison with dementia. Dementia can be quite insidious with its progression. It takes a longer time to develop and is a degenerative disease process.

Delirium can often be caused as a direct physical consequence of a general medical condition, such as a fluid electrolyte imbalance following surgery. It is not a degenerative process, but rather one linked with a specific medical condition which has caused changes to the individual’s normal homeostasis and bodily function (Koutoukidis et al. 2017).

This is why gaining a comprehensive history of the individual is essential as well as attending to frequent mental and physical assessments of the individual to gain information regarding their current status and to ensure the diagnosis of delirium is timely and accurate.

Postoperative Delirium - Signs and Symptoms of Delirium | Ausmed

Signs and Symptoms of Delirium

The signs and symptoms of delirium can fluctuate in the individual during the course of a 24 hour period. Each individual will vary in their presentation of delirium and some of the symptoms they may display include:

  • Reduced awareness of their environment
  • Decreased ability to focus attention
  • Easily distracted
  • Changes in cognition such as memory impairment, language disturbance or disorientation
  • Adversely affected recent memory disturbances
  • Disorientation to time, place and person
  • Language disturbances such as inability to name objects, write or present with rambling speech
  • Perceptual disturbance such as hallucinations, illusions or misinterpretations

(Koutoukidis et al. 2017)

Postoperative Delirium

Postoperative delirium is, as the name mentions, a delirium that presents in individuals following surgery. It can be triggered by a variety of factors including:

  • Fluid and electrolyte imbalances
  • Dehydration
  • Hypoxia
  • Hypercarbia
  • Acid-base disturbances
  • Infections such as respiratory, wound or urinary tract infections
  • Medications including anticholinergics, benzodiazepines, opioids and central nervous system depressants
  • Unrelieved pain
  • Blood loss
  • Decreased cardiac output
  • Vertebral hypoxia
  • Heart failure
  • Acute myocardial infarction
  • Hypothermia or hyperthermia
  • Unfamiliar surroundings and sensory deprivation
  • Emergency surgery
  • Alcohol withdrawal
  • Urinary retention
  • Fecal impaction

(Farrell & Dempsey 2013)

There are also certain risk factors individuals can have that increase their risk of developing postoperative delirium. These include people who are:

  • Older adults
  • Have a history of alcohol abuse
  • Have decreased preoperative cognitive function
  • Have a decreased physical function
  • Have had certain types of surgeries including emergency surgery

(Farrell & Dempsey 2013; Robinson & Eiseman 2008)

An important factor to remember in regards to the individual who is suffering from postoperative delirium is that often this state of confusion can be an early indicator of infection, fluid and electrolyte imbalance or physical deterioration. This is why frequent mental and physical monitoring of someone suffering from postoperative delirium is an essential part of surgical nursing care (Farrell & Dempsey 2013).

It is important that the cause of the delirium is identified and then promptly treated in order to reverse the delirium. This is done in conjunction with the implementation of management strategies for the person suffering from delirium (Vijayakumar et al. 2014).

Management Strategies

Nurses can help implement many strategies to assist in managing postoperative delirium in patients. In addition to the close monitoring of the patient, the patient’s immediate environment is also assessed. The patient should be kept close to the nurses station for monitoring, have a well lit room to assist with orientation and, at the same time, care is also taken to minimise any distracting or unfamiliar noises. A clock and calendar can also be placed in their room to help improve their cognitive function and it is also important to ensure the patient has uninterrupted night-time sleep (Farrell & Dempsey 2013; Robinson & Eiseman 2008).

Staff should introduce themselves every time they come into contact with the patient as well as re-orientate them as often as necessary, even if this means every time they enter the room. Engaging the patient in conversation and involving them in any care activities which are occurring can also help manage postoperative delirium (Farrell & Dempsey 2013).

Safety issues for those suffering from postoperative delirium should also be considered in all patients. These include the risk of the patient becoming agitated and inadvertently pulling out drains, tubes or lines, as well as remembering that just by having delirium, their risk of falling also increases.

The patient should not be restrained if possible, as this can worsen the confusion. Other options in this incidence can be utilised, such as having a staff member or family member sit with the patient to ensure their safety. It is also important not to neglect physical activity in the individual during this stage as this can not only worsen the delirium but additionally place the individual at risk of other postoperative complications such as the development of pressure areas and deep vein thrombi (Farrell & Dempsey 2013; Robinson & Wiseman 2008).

Medication management of postoperative delirium including the use of medication such as lorazepam or haloperidol should be avoided if possible as these can have additional side effects for individuals. If the postoperative delirium has been attributed to pain or the use of certain analgesic medication, the nurse must ensure the patient’s pain is managed in a way that isn’t increasing their confusion (Farrell & Dempsey 2013; Marcantonio & Discussant 2012).


Postoperative delirium is a significant complication following surgery and can result in both a functional decline of the individual as well as a longer hospitalisation. Postoperative delirium also increases the individual’s risk of developing other complications whilst in hospital, including falls and aspiration pneumonia (Robinson & Eiseman 2008).

The duration of the delirium varies from person to person; roughly half of the people with delirium will have their symptoms resolving within 2 days of the onset and another one third will have symptoms continuing until their hospital discharge. But, up to 50% of people will still continue to show some signs of delirium one month following surgery (Marcantonio & Discussant 2012). This is why it is such a significant complication of surgery and as nurses, we need to be aware of this and how we can implement strategies to assist the patient and their family with postoperative delirium.

  • Farrell, M & Dempsey, J (eds) 2013, ‘ Smeltzer & Bare’s Textbook of Medical-Surgical Nursing, 3rd edn, Lippincott Williams & Wilkins, Broadway
  • Koutoukidis, G, Stainton, K & Hughson, J (eds) 2017, ‘Tabbner’s Nursing Care: Theory and Practice, 7th edn, Elsevier, Chatswood
  • Marcantonio, ER & Discussant, SM 2012, Postoperative Delirium, Journal of the American Medical Association, vol. 308, no. 1, pp. 73-81, available from:
  • Robinson, TN & Eiseman, B 2008, Postoperative delirium in the elderly: Diagnosis and management, Clinical Interventions in Aging, vol. 3, no. 2, pp. 351-355, available from:
  • Vijayakumar, B, Elango, P & Ganessan, R 2014, Post-operative delirium in elderly patients, Indian Journal of Anaesthesia, vol. 58, no. 3, pp. 251-256, available from:


Portrait of Sally Moyle
Sally Moyle

Sally Moyle is a rehabilitation nurse educator who has completed her masters of nursing (clinical nursing and teaching). She is passionate about education in nursing so that we can become the best nurses possible. Sally has experience in many nursing sectors including rehabilitation, medical, orthopaedic, neurosurgical, day surgery, emergency, aged care, and general surgery. See Educator Profile

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