Delirium Flashcards
Define delirium
Reversible, acute onset condition that typically develops over a short period of time, results in transient global cognitive dysfunction, not solely attributable to another neurocognitive disorder
What are 4 core features of delirium?
Disturbance of cognition
Fluctuations
Reduced awareness
Changes in psychomotor behavior
What are the cognitive disturbances in delirium?
Reduced ability to direct, focus, sustain, or shift attention, which hinders other cognitive domains
What type of psychomotor behavior occurs in alcohol withdrawal?
Hyperkinetic psychomotor behavior
What is asterixis?
Wrist tremor, noticeable when hands and arms are extended and often referred to as a hand flapping tremor.
It can be observed in liver failure (with hepatic encephalopathy) and other types of delirium (e.g., Wilson disease, metabolic encephalopathy)
What types of neuropathology can cause delirium?
the mnemonic I WATCH DEATH includes the common causes of delirium:
- Infection
- Withdrawal
- Acute metabolic
- Trauma
- CNS pathology
- Hypoxia
- Deficiencies (nutritional)
- Endocrinopathies
- Acute vascular
- Toxins or drugs
- Heavy metals
What is hypernatremia?
An acute metabolic disturbance in which serum sodium concentration is abnormally high (above 145 mmol/L). Caused by dehydration or conditions resulting in excessive water loss, causing cerebral dehydration and delirium
What is hyponatremia?
- Electrolyte disturbance in which serum sodium concentration is below 135 mmol/L
- Occurs when water accumulates in the body faster than it’s excreted
- Can lead to cerebral edema; often occurs postoperatively (25%)
What is hepatic encephalopathy?
Acute metabolic cause of delirium caused by liver failure. Toxic substances such as ammonia accumulate in bloodstream, which is treated with lactulose or other drugs that suppress production of toxic substances in the intestine. When left untreated can lead to coma and death.
Effects of B12 deficiency
Nutritional deficiency with physical, psych, and cognitive impairments. Sx include anemia, weakness, fatigue, mood changes, memory loss, disorientation. May eventually lead to damage to dorsal sections and lateral pyramidal tracts in the sc causing impaired recognition of pressure and vibration, gait dysfunction, and paresthesias.
Chronic irreversible damage marked by depression, irritability, impaired attention, hallucinations, and sx of dementia.
What medications can cause delirium?
anticholinergics, TCAs, dopaminergics, serotonergics, narcotic analgesics, benzos, corticosteriods, H2-reception antagonists
What are common features of serotonin syndrome?
Early stages marked by tremor and diarrhea, followed by diaphoresis, confusion, increased anxiety. Full recovery expected after meds are discontinued
What is Neuroleptic malignant syndrome (NMS)?
- Complication of neuroleptic use
- Muscle rigidity, pallor, dyskinesia, hyperthermia, incontinence, unstable blood pressure, tachycardia, and pulmonary congestion
- Requires discontinuation of neuroleptics, intravenous hydration, close monitoring of vital signs and mental status
What are the primary neurotransmitters involved in delirium?
Dopamine and acetylcholine, but serotoninergic systems play a role in some types of delirium
What is the cholinergic deficiency hypothesis of delirium?
Decrease in acetylcholine contributes to attention and memory impairment; based on observation that delirium occurs with drugs and toxins that impair cholinergic function
What are predisposing factors for delirium?
Older age, preexisting brain disease, medical comorbidities, cognitive impairments, physical problems, depression, sensory loss or dysfunction, respiratory failure or myocardial infarction, infections
What are precipitating factors for delirium?
Major surgery (complications like hyponatremia, infection), anticholinergic drugs, drug withdrawal, infections, iatrogenic complications, metabolic derangements, pain, and acute injuries with metabolic complications can lead to acute confusion
What’s the most common cause of delirium in young patients?
Toxic. Children can experience delirium with iatrogenic med side effects, and illicit/licit drug abuse is most common cause in young adults.
Prevalence of delirium among patients on ICU or requiring critical care?
60-80%
Prevalence of delirium among hospitalized patients over age 70
25-50%
What features of delirium increase severity or risk for permanent injury?
- Multisystem organ failure
- Sustained autonomic hyperarousal or storms despite tx
- Status epilepticus or treatment resistant seizures
- Wernicke’s encephalopathy or delirium tremens (global confusion, hallucinations, autonomic hyperactivity)
- Chronic uncorrected metabolic disturbance/physiological condition
How does delirium effect mortality?
- Mortality rates are similar to patients with acute myocardial infarction or sepsis
- Those hospitalized with delirium: 20-25% die as a result of underlying medical condition or complications
- 80% of patients experience delirium in the stages prior to death
- Those who survive delirium have increased risk of death within 1 year
What are two potential courses of delirium?
- Abrupt/immediate onset
- Slow onset/fluctuating course developing over hours or days
What does neuroimaging show in delirium?
- Often negative in cases caused by metabolic factors, sepsis, or systemic medical issues
- EEG typically abnormal in delirium with nonfocal generalized slowing or fast activity, especially in metabolic delirium
What laboratory studies are important for physicians to run in cases of delirium?
Renal and liver function, oxygen saturation, CBC, electrolytes, creatinine, glucose, thyroid function tests, urinalysis, toxicology screens
What differentiates psychotic sx in delirium versus chronic psychiatric disorders?
Delirium: unsystematic and variable hallucinations and delusions, may come and go throughout the day.
Psychosis: consciousness and cognition aren’t as severely impaired as in delirium, hallucinations and delusions are consistent and systematic.
What are formication hallucinations?
- Perception or feelings of crawling over skin
- During drug withdrawal delirium
- Unilateral suggests focal parietal or thalamic lesions
What are visceral hallucinations?
- Sensations believed to stem from internal organs
- Unpleasant and difficult to localize
- Can occur in neurological and psychiatric conditions
What are hypnagogic hallucinations?
Occur in the process of falling asleep
What are hypnopompic hallucinations?
Occur in the process of awakening and often coincide with sleep paralysis
What is metamorphopsia?
Perception that one’s body is changing in size or shape
What is Capras syndrome?
- Delusional belief that a person has been replaced by an imposter or duplicate
- Associated with frontal system dysfunction
- Rare in delirium
What is reduplicative paramnesia?
- delusional belief that a place has been replaced or duplicated
- Associated with severe neurocognitive dysfunction
What are peduncular hallucinations?
- Vivid, motion-filled hallucinations that include the perception of small objects, animals, people, familiar landscapes
- Experienced as pleasant or entertaining
- Associated with lesions in posterior circulation regions
What are release hallucinations?
-Occur as consequence of sensory loss and subsequent disengagement of higher cerebral systems
What is palinopsia?
- Visual image continues to appear of be re-experienced hours or days after it’s no longer present
- Type of release hallucination
What emergency treatment is given to patients with delirium of unknown etiology?
- Thiamine followed by glucose is given to cover a range of potential problems
- Hydration, nutrition, and airway management are primary focus
- Vitals and medical status are closely monitored
- Nonessential medications placed on hold
Effects of delirium on sleep?
Sleep wake cycle is disturbed- diurnal rhythm often reversed so there’s pronounced lethargy during the day and agitated arousal at night
What are psychological and behavioral interventions for delirium?
- Frequent orientation, cueing, reassurance
- Use large clocks and calendars
- Place familiar objects in the room
- Quiet, well-lit surroundings, night lights
- One-on-one observers rather than restraints
- Encourage family and familiar faces to be present
- Support exercise and range of motion
How are hallucinations treated in delirium?
Neuroleptics
What medication helps alcohol withdrawal syndrome?
Benzodiazepines
What medication helps agitation in patients with TBI?
Divalproex (Depakote)
What’s the Beers Criteria?
Resource listing potentially harmful medication for older adults
What are autonomic storms, causes, and symptoms?
- Autonomic hyperreflexia: a reaction of autonomic nervous system to severe injury, metabolic disturbance, or overstimulation
- Caused by spinal cord injury above T5, illicit substance use, med side effects, severe brain trauma
- Sx: high blood pressure, tachycardia, diaphoresis, other signs of sympathetic hyperarousal
What conditions can mimic delirium?
Conditions such as alcohol withdrawal syndrome, PTA, sundowning, postictal confusion, can appear similar but not meet all criteria of delirium
How does cognitive reserve affect delirium?
Patients with reduced cog reserve are typically more susceptible
How does delirium affect intelligence?
- Significant decline during delirium
- Variable return to baseline after resolution, some return and others have lasting decline in fluid aspects of intelligence
How are attention deficits in delirium distinct from dementia?
- Delirium causes mod-severely impaired concentration and distractibility that significantly impairs other cognitive functions
- Dementia can show intact basic attention
How does delirium affect memory?
- Typically impaired, compounded by severe attention impairments
- Confabulations and confusion are common
- Disoriented to time and place but retain orientation to self
Executive functioning in delirium
- Always impaired
- Poor mental flexibility, reasoning, and judgment
- Circumstantiality, flight of ideas, perseveration, poor initiation, and unawareness of deficits
Emotion/personality effects of delirium
- Emotional lability
- Dramatic changes in personality or emotional expression
- Hyperactive, hypoactive, or both
