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CDHB

Delirium

Refer also to the CDHB Guidelines for Care of Patients with Delirium, Ref. 0020 (search for "delirium guidelines" on the CDHB intranet).

Clinical Features of Delirium

• Acute confusion - an abrupt change in mental state and ADL functioning.
• Fluctuation during the course of the day (often worse at night).
• Difficulty focusing, sustaining, or shifting attention is the most striking cognitive deficit; also forgetfulness and disorientation.
• Change in level of alertness - either reduced level of consciousness or increased (hypervigilant), sleep/wake cycle often disturbed.
• Disorganized thinking (rambling, illogical, or incoherent), suspiciousness.
• Psychomotor changes - either agitation or retardation.
• Misperceptions - vivid "dreams", recognition errors, illusions, hallucinations.
• Emotional changes, anxiety, tearfulness, anger, blunting.

  The presence of any of these features should trigger a diagnostic evaluation for delirium using the Confusion Assessment Method (CAM) and a cognitive screening test, Mental Status Quotient (MSQ), Mini Mental State Examination (MMSE), or Montreal Cognitive Assessment Test (MOCA).

  Delirium can be missed when superimposed upon pre-existing dementia. It is therefore vital to obtain collateral history regarding pre-morbid cognitive function from relatives, friends, rest home, or GP.

The Confusion Assessment Method (CAM)

Risk Factors for Developing Delirium

• The very young or elderly.
• Pre-existing cognitive impairment.
• Structural brain disease (e.g., previous CVA, Parkinson's disease, brain damage).
• Impaired functional status (especially poor mobility).
• Chronic comorbidities, with multiple medications.
• Severe acute illness or major surgery.
• Nutritional deficiencies.
• History of alcohol abuse.
• Visual and/or hearing impairment.
• Use of physical restraints.
• Use of a bladder catheter.

Common Causes of Delirium

Systemic Disease

• Toxic:
  • Drugs:
    • Medication toxicity/withdrawal (see table below)
    • Alcohol - intoxication/withdrawal
    • Street drugs of abuse
  • Heavy metals
• Infections
• Metabolic: electrolyte imbalance, acid base disorders, renal failure, liver failure.
• Hypoxia: cardiovascular disease, respiratory disease, anaemia.
• Endocrine: thyroid disorders, parathyroid disorders, hypoglycaemia, hyperglycaemia.
• Vitamin deficiency: thiamine (Wernicke's), B12 and folic acid.
• Hypothermia.
• Recent surgery/anaesthesia.
• Pain.
• Faecal impaction/urinary retention.

CNS Disease

• Head injury.
• Space-occupying lesion.
• Encephalitis, meningitis.
• Acute stroke.
• Subdural haematoma.
• Epilepsy: post-ictal, absence seizures.

Some Drugs that may Cause or Worsen Confusion

Management of Delirium

• Prevention: vigilance in high risk patient, accurate medication/drug/alcohol history, optimize hydration, nutrition, oxygenation, mobility, avoid unnecessary medications.
• Seek, identify and treat underlying cause(s).
• Educate and support patient and their family (explanatory leaflet available from Delirium Service).
• Ensure a safe and secure environment for patient and staff (refer to Restraint Policy). A nurse-aide sitter may be required. Occasionally, Mental Health Act certification may need to be sought if the patient is persistently unwilling to consent to vital treatment or is endangering others.
• Consent: It is important to gain appropriate consent for medical interventions. However, treatments which are restrictive or invasive are sometimes used without a patient’s consent when they have an illness that causes impairment to their insight and judgement to a degree that there is a significant threat to their interests, their safety, or the safety of others. In this case the treatments are given within a legal and ethical framework that recognises the importance of maximising a patient’s potential for autonomous decision making and promotes their best interests. This framework and advice regarding ‘best practice’ can be found in the guideline of the Older Persons Health Specialist Service: OPHSS Guidelines for Applying Coercive Treatments.
• General supportive management:
  • Re-orientation and reassurance (utilize support of friends/family) - includes provision of clock, calendar, familiar objects, view to outside.
  • Quiet, single room whenever possible; minimize room changes.
  • Make sure glasses and hearing aids are worn.
  • Minimize physical restraints and tubes, avoid unnecessary bed rest.
  • Encourage oral fluids and good nutrition; vitamin supplements for malnourished/alcoholic patients.
  • Close, sympathetic surveillance - ideally by consistent nursing personnel.
  • At night keep the room quiet with low-level lighting, relaxation strategies to help sleep and reduce anxiety.
• Psychotropic medication (in parallel with general measures, not as a substitute):
  • Indicated if the patient is distressed from psychotic symptoms/anxiety or is posing a risk to themselves or others.
  • Haloperidol is generally the tranquillizer of choice. Exceptions include patients with:
    • Parkinsonism and dementia with Lewy bodies (see below).
    • Alcohol or benzodiazepine withdrawal delirium (see below).
  • For elderly patients haloperidol 0.25 - 0.5 mg PO or subcut, once or twice daily. In urgent situations, higher doses (0.5 - 2.5 mg) of haloperidol may be necessary (best given subcut or IM with additional doses every 30-60 minutes as required).
  • Younger patients may need higher doses (1 mg subcut or IM initially, for milder symptoms; up to 5 mg for severe), repeated every 30-60 minutes as required.
  • If IV haloperidol is contemplated discuss with the Consultant first as there is a risk of prolongation of QT interval and torsades de pointes tachycardia with higher doses. IV treatment seldom causes extrapyramidal side effects.
  • Cerebral Lewy body disease (Parkinson's disease, dementia with Lewy bodies): neuroleptics with dopamine-blocking action can cause serious neurotoxic reactions. If tranquillizer is required, use lorazepam 0.25 - 0.5 mg PO once or twice daily. In emergencies, use lorazepam 0.5 - 1 mg IM or clonazepam 0.25 - 0.5 mg IM. For distressing psychotic symptoms oral atypical neuroleptics in low dosage (e.g., quetiapine 12.5 - 25 mg PO) may be used (Consultant endorsement recommended).
  • Alcohol withdrawal or benzodiazepine withdrawal delirium: Diazepam is the treatment of choice (generally by oral administration).
  • Apart from the above situation, benzodiazepines should be avoided if possible, especially in the elderly. However, do not stop habitual benzodiazepines abruptly (especially short-acting). Short-term use of lorazepam or clonazepam as an adjunct to haloperidol may be appropriate for severe agitation, anxiety, or sleep disruption.
  • Psychotropic drugs should be tapered gradually as target symptoms resolve - usually over 1-2 weeks. At discharge, every remaining psychotropic drug must have a withdrawal plan in the discharge summary, or a rationale for its continuation, especially any started during the admission.
  • Resolution of delirium may be prolonged - sometimes many weeks.

Topic Code: 1613