Delirium: Causes

Pathogenesis (development of disease)

Delirium may be due to many different causes. The deficit in attention is thought to be localized in the brainstem, medial dorsal thalamus (forms most of the diencephalon), prefrontal cortex (part of the frontal lobe of the cerebral cortex, located at the front of the brain), and right temporal lobe. Delirium usually results from cortical (originating in the cerebral cortex) and subcortical disorders (subcortical refers to brain regions and brain functions located “below” the cerebral cortex (cortex cerebri) in terms of the hierarchy of central nervous system instances). In addition, acetylcholine deficiency (acetylcholine is a neurotransmitter) and/or dopamine/serotonin excess is thought to play an important role in the development of delirium. Increase the risk of delirium:

Biographical causes

  • Age of life – older age (>65 years).
  • Visual and hearing impairment

Behavioral causes

  • Nutrition
    • Malnutrition
  • Consumption of stimulants
    • Alcohol (here: alcohol abuse)
  • Drug use
    • Amphetamines and metamphetamines (“crystal meth”).
    • Ecstasy (also XTC, Molly, etc.) – methylenedioxymethylamphetamine (MDMA); dosage on average 80 mg (1-700 mg); structurally belongs to the group of amphetamines.
    • GHB (4-hydroxybutanoic acid, obsolete also gamma-hydroxybutanoic acid or gamma-hydroxybutyric acid; “liquid ecstasy“).
    • Cocaine
    • LSD (lysergic acid diethylamide/lysergide)
    • Opiates – powerful painkillers such as morphine.
    • PCP (phenylcyclohexylpiperidine, abbreviation of: phencyclidine; “angel dust”).

Disease-related causes

Respiratory system (J00-J99)

  • Pulmonary insufficiency with hypoxemia (decreased blood oxygen content) and hypercapnia (increased blood carbon dioxide content).
  • Pneumonia (inflammation of the lungs)

Blood, blood-forming organs – immune system (D50-D90).

Endocrine, nutritional and metabolic diseases (E00-E90).

  • Dehydration (lack of fluid).
  • Diabetic ketoacidosis – severe metabolic derailment (ketoacidosis) due to insulin deficiency.
  • Folic acid deficiency
  • Hyperglycemia (high blood sugar)
  • Hypercalcemia (excess calcium)
  • Hypernatremia (excess sodium)
  • Hyperparathyroidism (parathyroid hyperfunction).
  • Hyperthyroidism (hyperthyroidism)
  • Hypoglycemia (low blood sugar)
  • Hypocalcemia (calcium deficiency)
  • Hypomagnesemia (magnesium deficiency)
  • Hypoparathyroidism (parathyroid insufficiency).
  • Hyponatremia (sodium deficiency)
  • Hypothyroidism (hypothyroidism)
  • Malnutrition
  • Cushing’s disease – renal cortical hyperfunction with elevated cortisol levels.
  • Adrenal insufficiency
  • Niacin deficiency (nicotinic acid deficiency)
  • Vitamin B1 deficiency (thiamine)
  • Vitamin B12 deficiency (cobalamin)
  • Wernicke’s encephalopathy (synonyms: Wernicke-Korsakow syndrome; Wernicke’s encephalopathy) – degenerative encephaloneuropathic disease of the brain in adulthood; clinical picture: brain-organic psychosyndrome (HOPS) with memory loss, psychosis, confusion, apathy, as well as gait and stance unsteadiness (cerebellar ataxia) and eye movement disorders / eye muscle paralysis (horizontal nystagmus, anisocoria, diplopia)); vitamin B1 deficiency (thiamine deficiency).

Skin and subcutaneous (L00-L99).

  • Infections of skin/soft tissues, unspecified.

Cardiovascular system (I00-I99)

  • Apoplexy (stroke)
  • Heart failure (cardiac insufficiency)
  • Hypertensive encephalopathy – hypertensive emergency characterized by an increase in intracranial (inside the skull) pressure with consequent intracranial pressure signs.
  • Intracranial hemorrhage (bleeding within the skull; parenchymal, subarachnoid, sub- and epidural, and supra- and infratentorial hemorrhage)/intracerebral hemorrhage (ICB; cerebral hemorrhage), unspecified

Infectious and parasitic diseases (A00-B99).

  • Sepsis (blood poisoning)
  • Systemic infections, unspecified

Liver, gallbladder, and biliary tract-pancreas (pancreas) (K70-K77; K80-K87).

Neoplasms – tumor diseases (C00-D48).

  • Gliomatosis cerebri – diffuse growths originating from specific cells of the nervous system.
  • Brain metastases – daughter tumors in the brain.
  • Brain tumor
  • Meningeosis carcinomatosa – occurrence of malignant infiltrates on the meninges.

Psyche – nervous system (F00-F99; G00-G99).

Symptoms and abnormal clinical and laboratory findings not elsewhere classified (R00-R99).

  • Hypothermia (hypothermia)
  • Uremia (occurrence of urinary substances in the blood above normal values).

Genitourinary system (kidneys, urinary tract – reproductive organs) (N00-N99).

  • Urinary tract infections, unspecified
  • Renal insufficiency (kidney weakness)

Laboratory diagnoses – laboratory parameters that are considered independent risk factors.

  • Folic acid deficiency
  • Hypercalcemia (excess calcium)
  • Hypomagnesemia (magnesium deficiency)
  • Hyponatremia (sodium deficiency)
  • Niacin deficiency (nicotinic acid deficiency)
  • Vitamin B1 deficiency (thiamine)
  • Vitamin B12 deficiency (cobalamin)

Further

  • Analgesia – drug elimination of pain (analgesia) with simultaneous sedation (sedation).
  • Ventilation
  • Surgical intervention (= postoperative delirium)
  • Permanent catheter
  • Freedom-restricting measures (e.g., fixation).
  • Foreign environment
  • Hospitalization with, for example, frequent change of ward.
  • Hyperthermia (overheating)
  • Hypoxia (tissue oxygen deficiency; respiratory/breath-related and cardiac/blood-related).
  • Intensive care unit stay
  • Immobility or immobilization
  • Polypharmacy (> 6 prescribed drugs).
  • Prefinal delirium – state of confusion in the context of near death.
  • Reduced sensory perceptions such as impaired vision, hearing, etc.
  • Sleep deprivation
  • Poor general health
  • Lack of daylight

Medication (modified according to)

  • ACE inhibitors
  • Alpha blocker
  • Analgesics:
    • Acetylsalicylic acid (delirogenic only in high doses).
    • Nonsteroidal anti-inflammatory drugs (NSAIDs) can cause delirium
    • Opiates (high-risk substances when starting and also when discontinuing).
  • Antiarrhythmics
  • Antibiotics
  • Anticholinergics
  • Antidepressants:
  • Antidiabetic agents, oral – which induce hypoglycemia.
  • Antiepileptic drugs, including phenytoin.
  • Antihypertensives (antihypertensive medications) – Alpha-receptor blockers (CNS depressant effects may be increased by alcohol, antipsychotics, antihistamines, benzodiazepines, and opiates)
  • Anticonvulsants (antiepileptics) – adverse drug reaction usually due to overdose; Cave! Hyponatremia under carbamazepine and oxcarbazepine.
  • Antipsychotics (neuroleptics) – preparations with anticholinergic potency (e.g., clozapine and olanzapine) are more delirogenic
  • Antivertiginosa
  • Beta blockers
  • Benzodiazepines (3-fold risk of delirium) – withdrawal may cause delirium
  • Calcium antagonists
  • Narcotics (BtM)
  • Digitalesglycosides, e.g., digitoxin, digoxin.
  • Diuretics (especially thiazides).
  • Hormones
    • Corticosteroids, systemic
    • Steroids, systemic (delirogenic risk is dose-dependent).
  • Ketamine (narcotic)
  • Lithium
  • MAO inhibitors
  • Neuroleptics (D2 antagonists and serotonin-dopamine antagonists) (4.5-fold risk of delirium)
  • Nonsteroidal anti-inflammatory drugs (NSAIDs).
  • Nitrates and other vasodilators.
  • Lidocaine
  • Opiates
  • Opioids (2.5 times the risk of delirium)
  • Parasympatholytics
  • Parkinson’s drugs:
    • Amantadine and dopamine agonists (e.g., bromocryptine) (higher risk).
    • Cathechol-O-methyltransferase (COMT) inhibitors (low risk).
    • Levodopa (lowest delirogenic potency).
  • Herbal agents, unspecified.
  • Psychoactive drugs (including antipsychotics, antidepressants, tranquilizers).
  • Sedating H1 antihistamines (also known as antiemetics).
  • Theophylline

Operations

  • State n. operation

Environmental pollution – Intoxications (poisoning).

  • Alcohol withdrawal
  • Alcohol intoxication (alcohol poisoning)
  • Benzodiazepine withdrawal
  • Toxins such as carbon monoxide, ethylene glycol (antifreeze), pesticides (pesticides).

Increase the risk of delirium in the hospital:

  • Acute metabolic derailment
  • Dehydration
  • Urinary bladder catheterization
  • Infections
  • Insomnia (sleep disturbance), unspecified
  • Cognitive deficits
  • Physical disability (immobility), unspecified
  • Artificial respiration
  • Malnutrition (malnutrition)
  • Mental and physical stress (eg, surgery).
  • Senile dementia of the Alzheimer type
  • Sensory disturbances (visual impairments; hearing impairments).
  • Hours of waiting for surgery
  • Therapy with at least three new drugs
  • Inadequate/exaggerated pain therapy.