16 Psychiatry
Delirium (see also p. 153)
How would you diagnose delirium?
An acute onset and fluctuating course is valuable diagnostically. Delirium represents an acute generalised impairment of cognitive function (see Information box). The primary feature is disorientation in time and place (more rarely person). A well patient should know the day of the week, month and year (people who are well can occasionally get the date and time wrong). They should know that they are in hospital, its name and location, and the name of the ward. Other psychoses do not affect orientation.
• ‘Clouding of consciousness’: refers to the variable level of attention seen in delirium, so that the patient cannot learn information and therefore cannot recall it.
• Visual hallucinations or illusions: are commonly present, so the patient may mistake a curtain movement in a dimly lit ward as a threatening person, resulting in extreme fear and agitation, especially at night.
• Persecutory delusions: are the most common and may make patients refuse food, drink and medicines because they believe that they are being poisoned. Alternatively, these delusions can cause aggression as patients defend themselves against a perceived threat.
What were the predisposing factors in this patient?
• Extremes of age (the young and old)
• Newly prescribed or multiple medications
• Prolonged operative procedure and anaesthesia
• Immobilisation and social isolation
• Dislocation to an unfamiliar environment (such as admission to hospital)
• Sensory deficits (e.g. visual or hearing) and extremes (overload or deprivation).
Specific causes of delirium include:
• Epilepsy (ictal, interictal, postictal)
• Neoplasm (intracranial or extracranial
• Other brain-space-occupying lesions (e.g. abscess)
• Metabolic encephalopathies (e.g. hypoglycaemia, hypoxia, hyponatraemia)
• Infections (intracranial and systemic)
• Drugs and poisons (see p. 519)
• Withdrawal from drugs (e.g. alcohol and sedatives; see p. 521)
• Vascular (cerebral or myocardial)
How would you investigate this patient?
Nursing care
A carefully controlled consistent and balanced environment is essential:
• Windows that do not allow exits
• Minimal stimulation by noise
• Persistent orientation by nurses and notices (a very disturbed patient may require one-to-one nursing temporarily)
• Minimal visitors: only those the patient knows well
• Reverse dehydration and do not neglect nutrition
Management
• Delirium requires urgent management because complications (e.g. falls, pressure ulcers and infections) can exacerbate the condition and contribute to significant mortality, particularly in the elderly.
• Find the cause and reverse it.
• A psychiatric opinion can be useful regarding differential diagnosis (see below) and management.
• Reduce all drug treatments to a minimum (see p. 521). Avoid anti-psychotic drugs unless the patient is a danger to him- or herself (or others), is distressed or if the patient’s general health is suffering.
• Symptomatic treatments include anti-psychotic drugs, initially in small doses, avoiding strong anti-muscarinics.
Drug therapy
• Haloperidol by mouth: 1.5 mg then 1.5–5 mg up to three times a day depending on level of disturbance, sensitivity to drug and response. Note: liquid or tablet form; lowest effective dose; beware extrapyramidal side effects.
• Phenothiazines are best avoided because of their anti-muscarinic and alpha-blocking actions.
If intramuscular medication is required
These drugs should not be given intravenously. If the patient is sensitive to medication and extrapyramidal side effects (EPSEs) are likely or present, use an ‘atypical’ anti-psychotic drug, such as risperidone (starting at 0.5 to 1 mg orally). Check doses carefully. Reversal of acute EPSEs can be achieved with a low dose of an anti-muscarinic drug (e.g. procyclidine 5 mg oral/IM).
Drugs and poisons as causes of delirium
Drugs causing delirium
Therapeutic drugs affecting the brain
Drugs with anti-muscarinic properties (common cause of delerium)
• Atropine and scopolamine: remember eye drops and pre-meds in anaesthesia
• Other topical cycloplegics and mydriatics
• Anti-parkinsonian agents: in patients with both Parkinson’s disease and pseudoparkinson’s, caused by dopamine antagonists
• Anti-depressants: especially tricyclics; amitriptyline most frequently
• Anti-psychotics: commonly the phenothiazines, especially chlorpromazine
How would you treat anti-muscarinic-induced delirium?
• General supportive nursing measures (see p. 517)
• Management usually conservative with observation of vital signs
• IV line and ECG Monitor if symptoms marked
• Oral or IM benzodiazepine (e.g. diazepam 10 mg adult dose) for agitation or seizures
• Cholinergic therapy with an anticholinesterase (physostigmine) is potentially hazardous (heart block, bronchospasm, respiratory failure) and used, if at all, for life threatening cases (uncontrolled seizures, coma, respiratory depression). Discuss with senior and/or poisons unit.
Drug withdrawal
Clinical presentation of sedative withdrawal (beyond delirium)
• Mental: anxiety, irritability, agitation, insomnia, nightmares.
• Arousal: tremor, sweating, tachycardia, sensitivity to light, noise and touch, muscle tension, uncommonly convulsions (with the exception of barbiturate withdrawal).
• Physical: nausea, anorexia, ‘flu-like’ symptoms, metallic taste.
Treatment of sedative withdrawal
• Replace the original class of drug in adequate doses to control the withdrawal symptoms, reducing to the minimum amount to prevent their re-emergence.
• Try to use a long-acting drug (e.g. diazepam), although sometimes the original drug itself is required.
• Therapeutic drug cessation can be achieved gradually later but the patient should be monitored closely and supported. Even patients with long-term dependence can manage some reduction and stabilisation on a reduced dose in the short term.
Dementia
Dementia is a global, acquired, progressive deterioration of intellect, memory and personality. Altered (‘clouded’) consciousness is not usually involved, in contrast to delirium, although dementia is often an underlying predisposition for delirium (see p. 515).
How does dementia present?
• Loss of memory, especially short term
• Episodes of increasing ‘confusion’
• Falls, with or without head injury
• Wandering and getting lost (getting into the wrong bed), especially at night
• Slow recovery and mobilisation after injury (e.g. hip fracture) or illness (e.g. myocardial infarct, pneumonia)
• Difficulty dressing: parietal lesion of dressing dyspraxia
• Behavioural disinhibition: frontal lobe sign
• Severe extra-pyramidal reaction to dopamine antagonists: Lewy body dementia.
What are the causes?
Differential diagnosis
• Amnestic syndrome: relatively specific memory loss, e.g. Wernicke–Korsakoff syndrome (see p. 527).
Investigations
• A corroborative history: duration, presentation, mood, alcohol, past history
• A Mini Mental State Examination (MMSE): a brief, structured bed-side screening test of memory
• Intelligence quotient (IQ) (performed by a psychologist) to confirm cognitive decline
• HIV testing after counselling in at-risk group
• CT/MRI brain scan: tumour, subdural haematoma, normal pressure hydrocephalus and infarcts might confirm generalised cerebral atrophy
• EEG: diffuse slow waves are rare before 75 in normal health. A normal EEG would suggest an alternative diagnosis
Examination
• Cardiovascular, neurological and endocrine system: to exclude secondary causes.
• Simple cognitive screening bedside tests: dementia may be suggested by the quality of the responses, e.g. ‘perseveration’ (repeating a response beyond the relevant question), ‘confabulation’ (inventing recollections to compensate for memory loss).
Information
Simple cognitive screening
• Orientation in time, place and person: ask day, month, year; ward, hospital, town/city, country; identity of relatives or key ward staff
• Attention and concentration: ask patient to recite the days of the week, or the months of the year, backwards (should be 100% accurate)
• Verbal short-term memory: teach patient to immediately recite a name and address accurately (a test of registration: they should be able to do this in two attempts). Then ask the patient to recall the name and address 5 min later (test of memory recall; should recall 95% of the individual items)
• Long-term memory: tests of general information, e.g. recent news, world events or on a subject of their interest
• Premorbid intelligence (necessary to judge whether there has been a deterioration in intellect): establish level of education achieved and occupation
