4 Min In Clinical
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Problem representation
An elderly man with multi-morbidities displaying possible signs of confusion. He currently takes: Spiolto Respimat, 2 puffs od; salbutamol, 2 puffs prn; sitagliptin, 100mg od; paracetamol, 1g qds prn for hand pain; lactulose, 15ml bd prn for constipation; GTN spray, 1-2 puffs prn; amlodipine, 10mg od; and nicorandil, 20mg bd.
Confusion is common, especially in the over-65s, and increases with age. Acute confusion in an elderly patient is usually a symptom of delirium, sometimes referred to as ‘acute confusional state’.
Delirium is characterised by fluctuating disturbances in attention and awareness, disorganised thinking and altered levels of consciousness, typically developing over days or weeks. It is generally categorised into hyperactive delirium (e.g. inappropriate behaviour, hallucinations or agitation) or hypoactive delirium (e.g. lethargy, reduced concentration and appetite).
Delirium can be precipitated by a number of factors, the most likely causes being infection and medication.
Likely diagnosis
- Infection
- Medication
Possible diagnosis
- COPD exacerbations (not applicable in this case)
- Dementia
- Depression
- Metabolic disturbances
- Psychoses
- Stroke (not applicable in this case)
- Thyroid dysfunction
- Urinary retention
- Vitamin deficiencies
Critical diagnosis
- Head injury.
Continued information gathering
The carer’s description hints at signs of confusion and this must be explored fully. Gaining information from a third party can be difficult, but asking the carer to describe what they mean by the patient “being confused” will give you a good indication whether or not the patient has delirium.
The carer says Mr T seems generally okay but sometimes can be inattentive, muddled and not hearing what is said to him. She has also struggled to get him up and about in the morning.
This description of relatively sudden lethargy, increased confusion and inattention does point to Mr T having symptoms of mixed delirium (both hypo- and hyperactive delirium). In addition,
he is more at risk of delirium due to his age, sex
and co-morbidities.
Problem refinement
Working on the premise that the patient is suffering from delirium, it is important to try to establish the cause. We know that medication can be the sole precipitant of delirium in many cases, but you understand from his recent medication review that no changes were made, which means that his symptoms are probably not due to any alterations.
Reviewing his medicines also shows that none are usually implicated with delirium. A medication-induced cause therefore seems unlikely. This leaves infection as the other obvious candidate to consider.
His carer has been to see him today and says he did not appear visibly unwell, which you might expect if he had an infection. However, atypical presentations are common in the elderly and can cause confusion. In the community, these are often urinary tract infections (UTIs) or pneumonia.
You ask the carer if he has wanted to go to the toilet more or has had a cough. She says she hasn’t noticed a cough and is unsure about the toilet, as he uses it a lot anyway so it is difficult to know if he has been going more than normal.
This information seems to rule out a chest infection but is not helpful regarding a possible UTI. While you suspect that infection could be the cause, given the carer’s description of Mr T’s visits to the toilet, urinary retention cannot be discounted.
At this point, you also need to consider other more unlikely causes. While dementia and delirium can show similar symptoms, dementia is associated with long-term decline in functioning and this has not been reported by the carer.
A first-time presentation of psychoses would be unusual in an elderly patient and for now can be ruled out. Other causes, however, are less straightforward to discount. In metabolic changes and thyroid dysfunction, other signs and symptoms should be apparent, and while not reported they cannot be ruled out without tests.
Likewise, other symptoms should be present with vitamin B12 deficiency but this cannot be ruled out, especially as incidence is highest in people of Mr T’s age. Depression is also common in the elderly and hypoactive delirium does show many of the signs of depression.
The differential diagnosis is not clear, with many causes still possibly accounting for the patient’s symptoms. On probability, you are erring on the side of infection as the most likely cause.
Red flags
You need to exclude any trauma to the head through recent falls.
Management
It is important that the patient is seen by a GP and thoroughly assessed as soon as possible. You tell the carer that you will speak with his GP and ask them to go to the practice as you suspect delirium but are unsure of the cause.
Self-care
Dehydration is often associated with delirium, so ensure he drinks regular fluids. Poor diet can also be a problem. Finding out about what he is eating may give some idea as to his nutritional state, which might require a dietician to help with meal planning.
You also know that the patient uses lactulose occasionally for constipation. His constipation may be due to not eating or drinking as much as he should, and again can contribute to delirium.
Prescribing options
If the GP suspects a UTI, this needs to be treated as per local antibiotic prescribing policies. This will generally be a week’s course of trimethoprim 200mg bd or nitrofurantoin MR 100mg bd – both would be suitable for the patient.
Safety netting
Since you will try to instigate a GP visit, there is nothing immediate that the carer needs to do.
Author: Professor Paul Rutter, University of Portsmouth
Causes: conditions to consider
Likely diagnoses
Infection
A range of infections, such as UTIs, pneumonia and even sepsis, can present atypically in the elderly, with confusion being a prominent symptom. Infection always needs to be considered in an acutely confused patient.
Medication
A range of medication classes have been implicated, most commonly tricyclic antidepressants, first generation antihistamines, antimuscarinics, opioids and benzodiazepines.
Possible diagnoses
Dementia
Dementia is characterised by a decline in intellectual functioning to the extent that the patient is unable to perform the usual activities of daily living.
Memory deficit is a predominant component of dementia but it can manifest with symptoms that mimic delirium – for instance, fluctuating levels of awareness, functioning and attention. However, these symptoms tend to occur over months to years.
Depression
Hypoactive delirium and depression have a number of symptoms in common. For example, mood change, anorexia, sleep disturbance, poor concentration/indecisiveness and agitation.
To help diagnose depression, the questions ‘During the last month, have you been bothered by feeling down, depressed or hopeless?’ and ‘During the last month, have you often been bothered by having little interest or pleasure in doing things?’ need to be asked.
If either is answered ‘yes’ and symptoms have been present most days, most of the time, this suggests depression. Depression questionnaires are available to help make a diagnosis.
Metabolic disturbances
Metabolic disturbances such as hypoglycaemia, hyperglycaemia and electrolyte abnormalities can all give rise to symptoms of delirium. In altered glucose states, hypoglycaemia is more common; it leads to confusion, poor concentration and impaired judgement.
A complication in type 2 diabetes is hyperglycaemic hyperosmolar state, which alters the mental state of the patient, leading to confusion, disorientation and lethargy.
At the beginning of this syndrome, the patient will experience increased thirst and urination. If there are electrolyte imbalances, this also can cause confusion. For example, hyponatraemia can produce confusion, disorientation and irritability. However, other symptoms, such as dizziness, headache, muscle cramps and nausea, may also be present. Likewise, hypernatraemia, hypocalcaemia and hypomagnesaemia can cause confusion.
Psychoses
Positive symptoms of psychoses can present like hyperactive delirium, while negative symptoms can present as hypoactive delirium. A prodromal period is often present. This may have been present from a few days to many months previously, with symptoms of uncharacteristic behaviour, anxiety, poor concentration, illogical speech and a decline in social functioning.
Thyroid dysfunction
Hyperthyroidism and hypothyroidism can have similar features to hyperactive delirium (e.g. inappropriate behaviour, hallucinations or agitation) or and hypoactive delirium (e.g. lethargy, reduced concentration and appetite).
In hyperthyroidism, other symptoms such as breathlessness, exercise and heat intolerance, increased appetite with unintentional weight loss and thirst should be present. In hypothyroidism, dry skin, hair loss, cold intolerance, weight gain and constipation are also often seen.
Urinary retention (chronic)
Symptoms can be similar to an infection – namely urgency, dysuria and frequency. However, symptoms should have been present for a period of time and other symptoms, such as a weak or interrupted urine stream, should be present. If untreated, this may lead to agitation.
Vitamin deficiencies
Confusion is associated with vitamin B12 and occasionally vitamin D deficiency. First signs or symptoms in vitamin B12 deficiency manifest as tiredness, lethargy, skin discolouration and breathlessness (signs of anaemia), headache, tinnitus and loss of appetite.
As the deficiency progresses, neurological and psychological symptoms like confusion, balance problems and mood disturbances are seen. Vitamin D deficiency is often asymptomatic, but where symptoms are experienced, they are often vague and involve tiredness, muscle weakness and bone pain. In the elderly, it may cause confusion.
Critical diagnosis
Head injury
Delirium is commonly seen after a traumatic brain injury, either sustained from high impact forces or a direct blunt force. Symptoms associated with blunt force injuries include headache, nausea, dizziness, drowsiness, blurred vision and mood changes.
Now check your knowledge of confusion in elderly patients by answering these questions:
1. Which of the following best describes the clinical features of delirium?
a. Acute onset, fluctuating attention and awareness
b. Gradual onset with stable cognitive impairment
c. Memory loss without attention disturbance
d. Steady decline in cognition over time
e. Persistent hallucinations
2. Which ONE of the following is not a known risk factor for developing delirium?
a. Advanced age
b. Constipation
c. Male gender
d. Polypharmacy
e. Recent surgery
3. Which ONE of the following symptoms is most characteristic of hyperactive delirium?
a. Agitation
b. Excessive drowsiness
c. Immobility
d. Slow response to questions without confusion
e. Being withdrawn
4. Which ONE of the following medicines is least likely to precipitate delirium?
a. Amitriptyline
b. Codeine
c. Diazepam
d. Hyoscine
e. Omeprazole
5. Which ONE of the following helps to differentiate dementia from delirium?
a. Always occurs in the elderly
b. Has an acute onset
c. Has a gradual onset
d. Is reversible
e. None of the above
Answers
1.a 2.b 3.a 4.e 5.c
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