Delirium Bedside Diagnosis and Precipitant Search in Medical Wards
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Direct answer
Delirium is an acute, fluctuating disturbance of attention and cognition caused by an underlying medical, surgical or drug-related trigger, and it is recognised at the bedside with the Confusion Assessment Method rather than a single test. Its core features are acute onset with a fluctuating course, inattention, and disorganised thinking or altered consciousness. The hypoactive form is often missed, and management begins by removing the precipitant rather than with sedation.
What you must remember
- CAM diagnosis: acute onset with fluctuation and inattention are both required, plus either disorganised thinking or altered consciousness.
- Common precipitants: infection such as urinary tract infection or pneumonia, drugs including anticholinergics, benzodiazepines and opioids, electrolyte disturbance, hypoxia, urinary retention, constipation and sleep deprivation.
- Hypoactive delirium: quiet, drowsy and withdrawn, easily mistaken for depression, and associated with worse outcomes than the agitated form.
- Delirium versus dementia: delirium begins over hours to days and fluctuates through the day, whereas dementia progresses over months to years with attention relatively preserved early.
- Delirium versus depression: depression gives poor effort and "don't know" answers, while delirium gives true inattention that fluctuates.
- Alcohol withdrawal: delirium tremens typically appears two to three days after the last drink with autonomic hyperactivity, and benzodiazepines are first-line.
- Non-drug care: reorientation, glasses and hearing aids, sleep protection, early mobilisation and family presence; antipsychotics are reserved for distress or danger.
A worked case: night-time confusion after a chest infection
A 72-year-old man admitted with pneumonia starts pulling at his drip at night, does not recognise his nurse, and drifts in and out of alertness.
- Confirm with the CAM: The CAM is positive on acute onset, fluctuation, inattention and disorganised thinking, so delirium is the working diagnosis rather than a new psychiatric illness.
- Search for precipitants: Check oxygen saturation, glucose, sodium, urea, calcium, urine and bladder volume, and review the chart for an opioid or sedative added on the day of admission.
- Start non-drug measures: Lights and sleep protection, reorientation, glasses, a family member at the bedside and early mobilisation start at once.
- Avoid restraints: Restraints worsen agitation and injury, so they are avoided.
- Use antipsychotics only for danger: If agitation endangers the patient or staff despite these measures, a low dose of an antipsychotic may be used briefly and reviewed.
- Recognise superimposed delirium: A 78-year-old with stable Alzheimer disease whose confusion suddenly worsens over two days has delirium superimposed on dementia until proven otherwise, and the dementia workup can wait.
Where the examiner sets the trap
Most errors here come from mislabelling the state rather than from the drug list.
- Trap: treating delirium as dementia and ordering a dementia workup. Correct: impaired, fluctuating attention points to delirium first.
- Trap: giving a sedative or benzodiazepine for agitation in an older patient. Correct: it deepens the delirium unless the cause is alcohol or sedative withdrawal.
- Trap: using antipsychotics as the treatment. Correct: they only manage distressing symptoms while the precipitant persists.
- Trap: labelling the quiet, drowsy patient as depression or fatigue. Correct: hypoactive delirium is easily mistaken for depression, so recognise the patient who is not sleeping but not engaging.
In Indian wards, family members often stay at the bedside, and a trained attendant can deliver reorientation and sleep measures that cost nothing and work.
Frequently asked questions
Which features does the Confusion Assessment Method require for a diagnosis of delirium?
The Confusion Assessment Method requires acute onset with a fluctuating course and inattention, plus either disorganised thinking or an altered level of consciousness. When these features are present, the bedside diagnosis of delirium is made and the precipitant search begins.
How does delirium differ from dementia at the bedside?
Delirium begins over hours to days and fluctuates during the day, with marked inattention, whereas dementia progresses over months to years with attention relatively preserved early. An acute change in a patient with known dementia should prompt a search for delirium before any dementia reassessment.
Should antipsychotics be used to treat delirium in older adults?
Low-dose antipsychotics such as haloperidol are used only for severe distress or risk to self or others, because they treat symptoms and do not correct the cause. Non-drug measures and precipitant correction come first, and sedatives should be minimised unless alcohol or sedative withdrawal is the cause.
Which laboratory tests are useful in a new case of delirium?
Blood glucose, sodium, urea, creatinine, calcium, a full blood count, oxygen saturation, urinalysis and a chest X-ray guide the early search for precipitants. Further tests are chosen from the history and examination, and a careful drug review is central in older patients.