Editors

JoukoLaurila

Delirium in the Elderly

Essentials

Delirium or acute confusional state is an extensive, rapid-onset disturbance of brain function due to an organic cause.
Delirium is difficult to recognize (more than half of the cases remain unrecognized) and the prognosis is poor.
Delirium increases the incidence of complications and mortality during hospitalization.

Prevalence and prognosis

Delirium occurs in 10-40% of the elderly during hospital care. Physicians recognize only one third of the cases.
The patient may recover even from a delirium that has endured for several weeks.
Mortality is up to 25%, and among the oldest of the elderly, up to 40% end up in institutional care.

Symptoms

Delirium is manifested by impairment of attention and apperception (attention deficit) and disorganized logical thinking. Consciousness becomes clouded and cognitive functions are suddenly deteriorated. The state is often associated with hallucinations and aberrant thoughts, disorders of the sleep-wake schedule, alteration of psychomotor activity, disorientation, impairment of memory and fluctuations of mood.
Clinical features develop over a short period of time and tend to fluctuate over the course of the day.

Predisposing factors

Advanced age
Degenerative brain diseases (especially memory diseases)
Severe somatic illnesses (e.g. cancer)
Polypharmacy (especially anticholinergic drugs and opioids)
Impairment of vision and hearing, sleeplessness, unfamiliar environment, physical restraints
Surgery

Triggering factors

A variety of underlying conditions can cause delirium.
Medications
- Drugs with anticholinergic properties (tricyclic antidepressants, phenothiazines, hydroxyzine, biperidine)
- Opioids, sedatives, levodopa, lithium, bromocriptine, steroids, many antimicrobials (such as quinolones and clindamycin)
- Abrupt discontinuation of a regularly used anxiolytic or of alcohol use (delirium tremens, see also Treatment of Alcohol Withdrawal)
Infections
- Pyelonephritis, pneumonia, sepsis, erysipelas, meningitis, febrile viral infections
Cardiovascular diseases
- Myocardial infarction, arrhythmias, pulmonary embolism, hypotension, etc.
Cerebrovascular diseases
- Cerebral infarction, TIA, cerebral haemorrhage, subarachnoid haemorrhage
Metabolic and endocrinological disorders
- Disorders in acid-base balance, disorders in fluid and electrolyte balance, hypoalbuminaemia, hypophosphataemia, insufficiency of the liver, kidneys or lungs, hypo- or hyperglycaemia, hypo- or hyperthyroidism, disorders of calcium balance, deficiencies of different B-vitamins, anaemia, other endocrinological disorders, etc.
Others
- Traumas (head injury, subdural haematoma, burns, hip fracture, surgery, etc.)
- Epilepsy, postictal state
- Tumours (intracerebral, pulmonary), myeloma
- Poisoning (e.g. digitalis intoxication)
- Extensive life stress (especially in patients with memory disease)

Diagnosis

History: When was the patient last well? Course of symptoms? Cognition before the illness? Usage of medications? Usage of alcohol?
Careful physical examination
CRP, basic blood count with platelet count, plasma sodium, potassium, creatinine, blood glucose, ECG
As needed: chemical urinalysis, TnT, ESR, glytamyl transferase, alkaline phosphatase, TSH, free T₄, ionized calcium, vitamin B₁₂, erythrocyte folate and arterial blood gas analysis, etc.
Chest x-ray
Analysis of cerebrospinal fluid, head CT scan, full body CT scan, EEG when needed
Further tests when needed, aiming at identifying aforementioned aetiological factors. Underlying causal factors are found in almost all cases when investigated carefully. Delirium in an elderly patient is often multicausal.

Differential diagnosis

Memory disease
- Insidious onset and slow course, usually with no daily variation in the intensity of symptoms
- Level of consciousness is normal, and attention intact until late stages
Psychotic disorders
- Level of consciousness is normal, cognitive functions are not globally disturbed. Speech is not totally disorganized. Also the psychiatric patient history is differrent.
- Auditory hallucinations are common in psychosis, whereas visual hallucinations are more common in delirium.
Dementia and delirium are often seen in same patient.
The Confusion Assessment Method (CAM) is a good differential diagnostic tool (see e.g. http://help.agscocare.org/productAbstract/H00101)http://www.dynamed.com/condition/delirium-in-hospitalized-patients#TOOLS_FOR_DIAGNOSING_DELIRIUM_IN_HOSPITALIZED_PATIENTS. It is easy to use and has been validated in a number of different patient groups.

Management Droperidol for Psychosis-Induced Aggression or Agitation

Management of the underlying factors that triggered the delirium
Critical review of the patient's medication and reduction of dosage or discontinuation of any suspicious drugs (especially opioids, anticholinergic drugs)http://www.dynamed.com/condition/delirium-in-hospitalized-patients#NONPHARMACOLOGIC_TREATMENT_STRATEGIES
Management of the general condition: fluid and oxygen balance, prevention of urinary obstruction, management of bowel movements, prevention of bedsores and injuries, rehabilitation, adequate lighting, familiar objects.http://www.dynamed.com/condition/delirium-in-hospitalized-patients#NONPHARMACOLOGIC_TREATMENT_STRATEGIES
Control of restlessness Valproate for Agitation in Dementia
- Thiamine 250 mg once daily intravenously for 3-5 days. If Wernicke is suspected, thiamine is administered 250 mg 3 times daily intravenously, even for weeks.
- Peaceful environment, unhurried conversation, orientation, closeness of patient's own nurse, early mobilization.
- Only in extreme cases (severe restlessness, distressing hallucinations) as short as possible symptomatic drug therapyhttp://www.dynamed.com/condition/delirium-in-hospitalized-patients#PHARMACOLOGIC_TREATMENT_STRATEGIES, starting from dosage
  - orally: risperidone 0.25-0.5 mg once or twice daily, olanzapine 2.5-5 mg once daily or quetiapine 12.5-25 mg once daily
  - intramuscularly: haloperidol 0.5 mg once daily or ziprasidone 10 mg once daily.
- In alcoholic delirium, the first line treatment is an anxiolytic. In elderly persons lorazepam or oxazepam is used instead of diazepam that has a long half-life, until the patient is sleeping Treatment of Alcohol Withdrawalhttp://www.dynamed.com/condition/alcohol-withdrawal-syndrome#BENZODIAZEPINES.
- After recovery from delirium the patient often feels anxious because of the bewildering experience. Going through of the episode is beneficial for the recovery.

Prevention

Effective fluid therapy, management of pain, oxygenation, nutrition, optimization of drug therapy, mobilization, as well as (non-pharmacological) maintenance of orientation and sleep rhythm decreases the incidence of delirium by about 50% http://www.dynamed.com/condition/delirium-in-hospitalized-patients#NONPHARMACOLOGIC_PREVENTION_STRATEGIES.

References

Oh ES, Fong TG, Hshieh TT ym. Delirium in older persons: advances in diagnosis and treatment. JAMA 2017;318(12):1161-1174. [PubMed]
Nikooie R, Neufeld KJ, Oh ES ym. Antipsychotics for treating delirium in hospitalized adults: a systematic review. Ann Intern Med 2019;171(7):485-495. [PubMed]
Shenvi C, Kennedy M, Austin CA ym. Managing delirium and agitation in the older emergency department patient: the ADEPT Tool. Ann Emerg Med 2020;75(2):136-145. [PubMed]
Hshieh TT, Yue J, Oh E ym. Effectiveness of multicomponent nonpharmacological delirium interventions: a meta-analysis. JAMA Intern Med 2015;175(4):512-20. [PubMed]