Delirium is an important and life threatening consequence of trauma, particularly among older adults, so having a high index of suspicion is essential.

Definition

Delirium, also known as the acute organic reaction can be defined as the state of confusion in the individual, characterised by an acute onset of fluctuating cognitive impairment, a disturbance of consciousness, impairment in attention and concentration and abnormalities of perception, emotional response and behaviour. Delirium develops over a short period of time, usually hours to days and tends to fluctuate during the course of the day.

ICD-10 diagnostic criteria

Symptoms in all of the following areas should be present:

• impairment of consciousness and attention
• global disturbance of cognition
• psychomotor disturbances (hypo- or hyper-active delirium)
• disturbance of the sleep
• emotional disturbances

Clinical presentation

Impairment of consciousness ('clouding') is a primary feature of delirium and two main types of delirium are recognised:

Hyperactive delirium	Hypoactive delirium
Agitation or restlessness	Confusion
Disorientation to time and place	Psychomotor retardation (slowness of movement and thought)
Psychotic symptoms, eg. hallucinations and delusions	Sedation
Sensory misperceptions	Patient quiet, withdrawn, stuporose or comatose
Pressured or incoherent speech

The patient may rapidly fluctuate between the two presentations. In general, patients have difficulty in focussing and sustaining their attention and have abnormal sleeping pattern. Although usually delirium resolves within four weeks, it may last for six months or more.

Predisposing factors:
Extremes of age	Unfamiliar environment
Sensory impairment (vision, hearing)	Cognitive impairment
Medical co-morbidities	More than 3 concurrent medications
Alcohol abuse	Smoking
Damaged brain: (Previous head injury, stroke, alcoholic brain damage, etc.)	History of delirium/dementia
COPD	Hypertension
Immobilisation	Sleep deprivation
Abnormal U&Es/LFTs	Use of opioid analgesics

Common precipitating factors (non-exhaustive)
Trauma	Head injury, hypovolemic shock, falls, fracture, dislocation, pain
Central nervous system	Space occupying lesions, migraine, epilepsy, intracranial haemorrhage, stroke, TIA, tumour, hydrocephalus, meningitis
Systemic illness	Infections, burns, cancer, hyperpyrexia vitamin deficiency (thiamine, B12, nicotinic acid)
Alcohol/drugs	Intoxication, withdrawal, poisoning
Medication	Opioid analgesics, steroids, antibiotics, anticholinergics, anticancer drugs, neuroleptic malignant syndrome, serotonin syndrome, anticonvulsants, cardiac medication: digoxin, antihypertensives
Metabolic disturbance	Renal failure, liver failure, electrolyte imbalance, hypoxia, dehydration
Endocrine disorder	Thyroid or parathyroid abnormality, adrenal abnormality
Miscellaneous	Acute coronary syndrome, COPD, blood dyscrasias, any surgical procedure

Course, prognosis and complications

• Half of all patients with delirium are diagnosed by the third day of presentation
• Typically, symptoms of delirium usually last three to five days but there is wide variation.
• Slow resolution of symptoms can lead to persistence of delirium six to eight weeks in the severely ill with as many as 15% remain symptomatic six months after the onset of delirium, especially in the elderly.
• The increased risk of mortality associated with deliriummay last up to three years with a risk ratio of at least two. Also, the risk of cognitive and functional impairment remains high two years after the onset.
• A serious complication of poorly resolved delirium is death and the most common complication is dementia (13-fold increase).

Management

The management of delirium involves the following four principles:

1. identifying the precipitating and contributing causes of the delirium and effectively treating them (whether directly or indirectly related to the trauma or unrelated to trauma)
2. ensuring patients’ safety and educating patients, families and staff about the presentation
3. management of the environment of the patent and providing general supportive measures
4. pharmacological management and symptomatic treatment of behaviour

Identifying and treating the cause

• Take detailed history from patient and informants
• Check drug list, prescribed and other
• Physical examination
• Investigations should include FBC, U&E, LFT, TFT, blood glucose infections screen, toxicology screen, urinalysis and CXR if indicated

Ensuring safety and family and staff education

• Give advice regarding the diagnosis and what to expect in the short and medium term
• Enrol relatives and carers in helping with orientation
• Staff to provide repeated orientation to patient
• Staff to monitor patient condition and levels of hydration
• Staff to ensure patient is kept safe at all times – this may require a 1:1 special if the patient is ambulant and disorientated

The environment

• Nurse in an adequately lit room with an appropriate level of stimulation
• Provide orientation cues like clocks, calendars, etc
• Provide a high level of continuity of care by preferably having the same set of nursing staff to rotate through the day
• Correcting sensory impairments, eg. make sure the patient is wearing their hearing aid/spectacles
• Promote mobilisation
• Maintaining the sleep-wake rhythm

Pharmacological management

This involves rationalising current medication, avoiding adverse drug interactions and poly-pharmacy. Only use sedation if all non-pharmacological measures have failed and:

• essential investigations/procedures are required
• the patient is a danger to themselves or others through their behaviour
• the patient is in significant distress where all non-pharmacological interventions have failed.
• gain consent where possible or treat in best interests (involving the family) under the Mental Capacity Act if capacity is lacking
• refer to the local guidelines and protocol for pharmacological management of symptoms of delirium.
• use a single sedative drug at the lowest effective dose and monitor for unwanted side effects such as respiratory depression, arrhythmias or extrapyramidal symptoms. Usually typical antipsychotics are preferred over atypical, which in turn are preferred over benzodiazepines.

Key messages

• Delirium is often missed and may be associated with a poor outcome
• Lucid intervals in delirium may often lead to false impressions
• The hypo-active type may be easily missed in busy medical/surgical wards.
• Delirium is associated with cognitive and functional decline, medical complications, increased risk of mortality, delayed discharge, increasing nursing care and increased use of nursing home placements
• Reverse the reversible and provide consistent support in a structured environment
• Avoid sedatives unless essential for the health and safety of the patient or others

Look out for delirium – it is easily missed!