###### Created: 2023-03-20 12:13 ###### Areas & Topics: #medicine #psychiatry ###### Note Type: #permanent ###### Connected to: [[Dementia]] - Delirium (A.K.A acute confusional state) is defined as an "acute, fluctuating syndrome of encephalopathy causing disturbed consciousness, attention, cognition, and perception" - Delirium is often misdiagnosed as dementia, depression, acute psychosis or as a part of old age. - It is a medical emergency and requires urgent treatment of the underlying cause. - The term delirium is used interchangeably with terms such as acute confusion, acute confusional state and encephalopathy. ### Aetiology - The exact cause of any patient's delirium is unknown and appears to be multifactorial. - There are known factors which can increase the chance a patient will develop delirium. - These factors are grouped as predisposing (i.e features or traits the patient has which may increase their risk of delirium such as genetics or age) and precipitating (i.e. specific conditions or events which can lead to development of delirium such as using a new medication or having constipation). The most common known predisposing factors are: - Older age (above 70) - Dementia - Functional Disability - Male Gender - Poor Hearing and Vision - Mild Cognitive Impairment The most common knon precipitating factors are: - Medication Side-Effects (seen in up to 39% of delirium cases and more commonly caused by psychoactive drugs and anticholinergics) - The other causes can vary widely between patients Delirium is typically transient, meaning it normally only lasts a short period before resolving. However it can persist for extended periods in more severe cases or when affecting more vulnerable patients. ### Pathophysiology - The pathophysiology, similar to the aetiology, is largely unknown due to the transient and multifactorial nature of delirium. - Some main pathophysiological processes might include neuroinflammation, neurotransmitter imbalance and circadian rhythm disruption. ### Clinical Features - Mainly, delirium can be identified when a patient has an acute change of behaviour that fluctuates over the course of each day. - In most cases there should also be a clear underlying cause (e.g. medication, UTI etc.) - This means it is vitally important to find out what a patient is normally like and how they normally behave to determine their symptomology and the extent of their delirium. #### Acute Onset - Onset is typically over hours to days. #### Fluctuating Symptoms - The patient symptoms fluctuate throughout the day, becoming better and worse. #### Disturbance in Awareness and Attention - This means the patient is likely to be disorientated to time, place and person. - Their attention is also likely to be impaired and they might be easily distractable and unable to focus. - They may be hyperactive in some cases or exhibit somnolescence or inactivity in hypoactive cases. #### Disturbance in Cognition and Perception These can include: - Memory loss - Disorientation - Poor langauge and speech - Disturbed and disorganised thinking - Visual or auditory hallucinations - Paranoid delusions - Misperception (e.g. incorrectly identifying objects or people) #### Not Stemming from Other Conditions - The patient's symptoms shouldn't be better explained by a different pre-exisiting, current or newly developed neurocognitive or seperate condition(s) - The patient should also not have a severely reduced Glasgow Coma Score (GCS) #### Evidence of an Organic Cause - Examples include infection, medication, electrolyte imbalance, constipation etc. ### Types of Delirium - Delirium can be seperated into hyperactive, hypoactive or mixed delirum, which each possess more specific features #### Hyperactive - Essentially, hyperactive delirium is where patients have more active clinical features. - Patients with hyperactive delirium are characterised with symptoms of increased agitation and sympathetic activity. - Other symptoms can include positive psychiatric symptoms (e.g. hallucinations), inappropriate behaviour, wandering and restlessness but this list is not exhaustive. #### Hypoactive - Hypoactive delirium is characterised by reduced activity. - Patients may appear quiet, lethargic, withdrawn and display increased somnolescence (drowsiness) and decreased general arousal. - This form of delirium is more dangerous as it can be easily mistaken for depression, dementia or other disorders and thereby can take longer to effectively diagnose and treat. - The best way to identify patients in these cases is by using the time-frame of their symptoms and their normal reported behaviour to try and see if delirium fits. #### Mixed - Mixed delirium is characterised by the presence of both hyperactive and hypoactive features. ### Differentiating Delirium and Dementia - Delirium and Dementia can easily be confused, so it is important to be aware of the features which seperate them from eachother **Delirium** - Acute Onset (days to weeks) - Fluctuating Symptoms (over the course of each day) - Attention and Consciousness affected - Thoughts are more likely to be disorganised or incoherent - Psychomotor changes are more likely (depending on delirium type) - Typically reversible **Dementia** - Insidious Onset (months to years) - Symptoms are more likely to progress rather than fluctuate - Attention and Consciousness preserved (excluding severe cases) - Thoughts are more likely to be impoverished or vage - Psychomotor function is often normal - Typically irreversible ### Investigations and Diagnosis - Investigating delirium is mainly comprised of assessing cognition using an appropriate tool depending on the setting - Part of the GPCOG includes assessment points for delirium - The 4AT test is a very quick and useful tool for assessing delirium in hospital or community as well (https://www.the4at.com/) - A patient scoring 4 or more on the 4AT would be suggestive of delirium, but diagnosis can only be made clinically - Once a diagnosis of delirium is made, finding the underlying organic cause is imperative for management and is typically done using normal investigations. ### Management - The main management is attempting to find and treat the underlying cause of the delirium. - Assessment of capacity should also be performed so clinicians are able to act in patients best interests. #### Non-Pharmacological - Keep the patient in a stable, well-lit and quiet environment where possible - Moving them away from others and keep distance - Try to involve carers or relatives who are close to the patient - Refer for specialist advice #### Rapid Tranquilisation - Patients who are particularly distressed or aggressive may pose a risk to themselves or others, and therefore may require short-term pharmacology (this is known as rapid tranquillisation or RT). - There are usually site specific guidelines for this. - RT is given orally but if this is not possible then IM injection is used. NICE recommends: - Haloperidol (low-dose used for 1 week or less) N.B. other anti-psychotics (e.g. olanzapine, risperidone) or benzodiazepines (e.g. lorazepam) can be used but aren't NICE recommended ### Epidemiology - Delirium is thought to affect up to 50% of older people (those over 65) who are in hospital. - It is much more common post-operatively and in ICU. - Delirium following treatment can lead to prolonged hospital stays, increased treatment cost and worse outcomes. ### Prognosis - Since delirium is transient, most patients will recover in days to weeks. - Delirium is associated with increased mortality and length of hopsital stay. - Prognoses may be worse for patients with previous cognitive conditions such as dementia or mild cognitive impairment. - Older patients are at higher risk of having a prologned derlirium. ### Resources Delirium - NICE CKS https://cks.nice.org.uk/topics/delirium/ Delirium - Statpearls https://www.ncbi.nlm.nih.gov/books/NBK470399/ Delirium - Pulsenotes https://app.pulsenotes.com/medicine/neurology/notes/delirium 4AT Delirium Test - https://www.the4at.com/4atguide Lancaster Medical School Cognitive Disorders Lecture by Dr. Marisa Wray(2022)