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%