Acute confusion (2) Flashcards
What should you assess in a patient with delirium?
Patients are vulnerable.
It is a common scenario for errors - e.g., missing the diagnosis and poor management; it has the potential to become serious rapidly.
Do not assume confusion is due to long-term dementia or mental handicap even in the elderly and those with learning difficulties:
- It is important to check the previous level of function from relative/carer/home circumstances.
- If this is not possible, treat as acute confusion until proven otherwise.
Always perform a full physical examination, including airway/breathing/circulation and vital signs; however, bear in mind that the patient may not be able to co-operate fully.
Always check blood glucose and pulse oximetry.
What are the subtypes of delirium?
Hypoactive subtype - apathy and quiet confusion are present and easily missed. This type can be confused with depression.
Hyperactive subtype - agitation, delusions and disorientation are prominent and it can be confused with schizophrenia.
Mixed subtype - patients vary from hypoactive to hyperactive.
How does delirium present?
The diagnosis of delirium is clinical. The following features may be present:
- Usually acute or subacute presentation.
- Fluctuating course.
- Consciousness is clouded/impaired cognition/disorientation.
- Poor concentration.
- Memory deficits - predominantly poor short-term memory.
- Abnormalities of sleep-wake cycle, including sleeping in the day.
- Abnormalities of perception - eg, hallucinations or illusions.
- Agitation.
- Emotional lability.
- Psychotic ideas are common but of short duration and of simple content.
- Neurological signs - eg, unsteady gait and tremor.
Only some of these symptoms may be present. The symptoms may coincide with underlying dementia - which is common.
How do you assess a patient with delirium?
Check:
-Airway/breathing/circulation.
-Conscious level.
-Vital signs - eg, pulse oximetry, pulse, blood pressure, temperature.
-Capillary blood glucose.
Full cardiovascular and respiratory examination.
Full abdominal and genitourinary examination, if appropriate.
Full neurological examination.
Further examination depending on the suspected problem - eg, ENT or rectal examination.
There are several assessment methods available for the diagnosis of delirium. The easiest to use in the primary care setting is the Confusion Assessment Method (CAM) screening instrument
What is CAM?
Based on ICD 10 criteria for delirum
To have a positive result the patient must have:
-Acute onset and fluctuating course; and
-Inattention (eg, 20-1 test with reduced capacity to shift attention or keep attention focused); and either
-Disorganised thinking (disorganised or incoherent speech) or
-Changed level of consciousness (usually the patient is lethargic or is in a state of stupor).
What is 4AT?
The 4AT is a validated tool that is quick to complete and easy to use in most clinical settings. It incorporates a short version of the Abbreviated Mental Test Score or AMTS.
What does the 4AT test consist of?
There are four sections/categories that the patient is assessed on (all starting with ‘A’ – a good way to remember the features), scoring points for the presence or absence of each feature. Alertness
- Normal/Fully alert/Mild sleepiness on waking = 0
- Clearly abnormal (drowsy/hypoactive or agitated/hyperalert) = 4
AMT4: Ask the patient the following – their age, their date of birth, the current year and the current location/place
- No mistakes = 0
- 1 mistake = 1
- 2 or more mistakes/untestable = 2
Attention: Ask the patient to name the months backwards starting at December
- 7 or more correctly = 0
- Less than 7 or does not attempt = 1
- Untestable (drowsy/inattentive) = 2
Acute and Fluctuating course
- No = 0
- Yes = 4
How is the diagnosis of delirium made from the 4AT test?
Diagnosis is then based on score
- 4 or above = possible delirium +/- cognitive impairment
- 1 – 3 = possible cognitive impairment
- 0 = delirium or cognitive impairment unlikely
What are the differentials for delirium?
Dementia
Depression
Bipolar disorder
Functional psychoses such as schizophrenia
What are the investigations performed to assess delirium?
Bloods - include FBC, U&Es and creatinine, glucose, calcium, magnesium, LFTs, TFTs, cardiac enzymes, vitamin B12 levels, syphilis serology, autoantibody screen and PSA. Creatinine is vital to obtain an estimated glomerular filtration rate (eGFR), as this may indicate impaired renal function and affect the handling of medications, and may predispose to drug-induced delirium.
Urine dipstick testing and microscopy.
Blood cultures and serology, if indicated.
ECG.
Pulse oximetry and arterial blood gas, if indicated.
CXR and possibly abdominal X-ray, if indicated.
Further imaging - eg, CT scan of the brain.
Lumbar puncture may be necessary.
Electroencephalography (EEG) - this is usually only performed if there is doubt regarding the diagnosis and shows a generalised diffuse slowing in 80% of delirious patients
What is the limitation of urine dipstick in over 65s?
Urine dipsticks are a very poor predictor of urine infection in older people as they have a very high false-positive rate. Guidelines suggest that urine dipsticks should not be used in people over 65 to diagnose urinary tract infections.
What is the management of delirium?
This begins with increased awareness of delirium and regular measures of cognitive function. The underlying cause needs to be treated.
In delirium, the features are fluctuating and some patients are lucid between episodes and can thus provide informed consent during these periods. However, if the patient is not able to provide informed consent then they can be treated in their best interests under common law.
If the patient becomes violent or is a danger to themself, it may be possible to manage them initially using verbal and non-verbal de-escalation techniques.
But more specific to delirium, the management can be divided into:
- Supportive management.
- Environmental measures.
- Medical management.
- Management post-discharge.
What is the supportive management of delirium?
Clear communication.
Reminders of the day, time, location and identification of surrounding persons.
Have a clock available.
Have familiar objects from home around patients, especially glasses, walking aids and hearing aids.
Staff consistency - both doctors and nurses.
Relaxation - eg, watch television.
Involve the family and carers.
What are the environmental measures to treat delirium?
Avoid sensory extremes (over-or under-stimulation).
Adequate space and sleep.
Single rooms if possible.
Avoid speciality jargon.
Control excess noise.
Control room lighting and have a low-wattage bulb at night.
Control room temperature (aim for 21-23°C).
Use health advocates (interpreters) where needed and if possible.
Maintain competence - eg, maintain walking in ambulant patients.
Adequate nutrition and attention to continence.
What is the medical management of delirium?
Using drugs to treat delirium can lead to adverse effects and worsening of delirium; therefore, careful consideration is required.
Antipsychotics have beneficial effects in selected patients, particularly those who are aggressive and do not respond to verbal and non-verbal de-escalation techniques.
Haloperidol or olanzapine are preferred, using the lowest possible dose for the shortest possible time (normally a week or less). The dose should be titrated gradually until symptoms are controlled. Note that both drugs have the potential to cause extrapyramidal side-effects and should be used in caution or avoided altogether in some patients (eg, people with Lewy-body Parkinson’s disease.
In delirium resulting from alcohol withdrawal (delirium tremens), a benzodiazepine such as diazepam or chlordiazepoxide is preferred. The benzodiazepine is usually used as a reducing course. Large doses may lead to sedation and therefore close observation is required.
