Delirium is an acute, transient, and reversible state of confusion, typically caused by other organic processes such as infection, drugs, or dehydration. About one in five elderly patients on medical and surgical wards have delirium at any given time.
There are two main states of delirium: hyperactive and hypoactive delirium. It is common for patients to switch between the two states.
Hyperactive delirium is the more well-known presentation of delirium. Clinical features include agitation, delusions, hallucinations, wandering, and aggression.
Hypoactive delirium is often mistaken for depression. Clinical features of hypoactive delirium include lethargy, slowness with everyday tasks, excessive sleeping, and inattention.
Environmental changes and sensory impairment can increase the risk of developing delirium. Other causes or factors include CHIMPS PHONED: Constipation, Hypoxia, Infection, Metabolic disturbance, Pain, Sleepiness, Prescriptions, Hypothermia/Pyrexia, Organ dysfunction, Nutrition, Environmental changes, Drugs.
A comprehensive assessment of patients with suspected delirium is essential due to the various causes and clinical features. A history from the patient is ideal, and should include conversation to assess their mental state, reassurance, and gentle re-orientation. Collateral history from family, friends, and nursing staff, as well as medical notes are also useful sources of information.
The Abbreviated Mental Test Score (AMTS) can be used to objectively monitor a patient's cognition for improvement or deterioration over time. Other cognitive screening tools that provide more detailed assessment include the MMSE and ACE-III.
A thorough clinical examination should be conducted, including assessment of vital signs. This should look for signs that may help identify the underlying cause of confusion, such as fever in infection and low SpO2 in pneumonia. Asterixis may indicate uraemia or encephalopathy.
When investigating confusion, a standard set of further investigations is often referred to as a 'confusion screen'. This panel of investigations is useful for identifying or ruling out common causes of confusion.
Blood Tests may include: FBC (e.g. infection, anaemia, malignancy), U&Es (e.g. hyponatraemia, hypernatraemia), LFTs (e.g. liver failure with secondary encephalopathy), coagulation/INR (e.g. intracranial bleeding), TFTs (e.g. hypothyroidism), calcium (e.g. hypercalcaemia), B12 + folate/haematinics (e.g. B12/folate deficiency), glucose (e.g. hypoglycaemia/hyperglycaemia), and blood cultures (e.g. sepsis).
Urinalysis should look for UTI, as this is a common cause of delirium in the elderly. A positive urine dipstick without clinical signs is NOT satisfactory to diagnose urinary tract infection as a cause of delirium. Look for other evidence to support the diagnosis (e.g. WCC↑/supra-pubic tenderness/dysuria/offensive urine/positive urine culture).
Imaging may include CT head if intracranial pathology (bleeding, ischaemic stroke, abscess) is suspected. Chest x-ray may be performed if lung pathology (e.g. pneumonia, pulmonary oedema) is suspected.
Definitive management of delirium involves identifying and treating the underlying cause.
General supportive management strategies include keeping a consistent nursing and medical team, gentle re-orientation, calm and consistent care, regular introductions of yourself and your role, clear and concise communication. Ensure the patient has access to aids such as glasses, hearing aids and walking sticks where appropriate. Enable the patient to do what they can for themselves, offering independent washing, dressing, eating, toileting and other activities with varying levels of encouragement.
Environmental adaptation management strategies may include providing access to a clock and other orientation reminders for the day, date and time, familiar objects (e.g. photographs), involving the family, friends and/or carers in the care of the patient, controlling the level of noise, and ensuring adequate lighting and ambient temperature.
Key points include avoiding unnecessary medications wherever possible.
Persistent wandering and delirium are not absolute indications for sedation. Aim to keep the patient safe by the least restrictive method, as the use of medications, especially for sedation, can worsen delirium. Haloperidol (oral, IV, or IM) is usually the first-line medical option, with a low dose in the elderly (0.5mg). If benzodiazepines are to be used, lorazepam is first-line (0.5mg starting dose) due to its rapid onset and short half-life.
Key points include:
Take appropriate steps to prevent episodes of delirium:
