Summary

Delirium is an acute, fluctuating disturbance of consciousness, attention, and cognition. It is a medical emergency that signifies "Acute Brain Failure" in response to a physiological stressor. It affects 20% of general hospital admissions and up to 50% of hip fracture patients. It is a marker of frailty and carries a high mortality risk (doubled in hospitalized patients). [1,2]

Clinical Phenotypes

1. Hyperactive: Agitated, aggressive, wandering, hallucinations. (Easy to spot, often sedated improperly).
2. Hypoactive: Drowsy, withdrawn, sleepy, slow. (Hard to spot, often misdiagnosed as "tired" or "depressed". Associated with higher mortality due to missed diagnosis/aspiration).
3. Mixed: Fluctuates between both states.

Clinical Pearls

Delirium vs Dementia:

• Onset: Acute (Days) vs Chronic (Months).
• Course: Fluctuating (Lucid intervals) vs Progressive.
• Attention: Impaired (Can't focus) vs Intact (until late stages).
• Consciousness: Altered vs Clear.

The Vulnerable Brain: Think of delirium as a threshold. A robust 20-year-old needs a massive insult (e.g., Meningitis/ICU) to become delirious. A frail 90-year-old with background dementia needs only a tiny insult (e.g., Constipation/Codeine) to tip over the edge.

The "Asymptomatic Bacteriuria" Trap: 50% of elderly women have bacteria in their urine without infection. A positive dipstick in a confused patient does not prove UTI is the cause. Look for fever, dysuria, or raised inflammatory markers before blaming the bladder.

• Screening Tool: 4AT (Rapid less than 2 mins).
  1. Alertness: Normal/Sleepy/Agitated.
  2. AMT4: Age, DOB, Place, Year.
  3. Attention: Months of year backwards.
  4. Acute Change: Yes/No.
  • Score >4 = Probable Delirium.
• Physical: Look for PINCH ME.

• Resolution: Can take days to weeks/months. It does not disappear the moment the antibiotics start.
• Recurrence: High risk.

Key Guidelines

Landmark Evidence

1. Inouye et al (HELP Study)

• Hospital Elder Life Program.
• Proved that multicomponent intervention (volunteers reorientating, fluid check, mobilizing) reduced delirium incidence by 40%.

Why is he confused?

It is like "Acute Brain Failure". Just as a lung infection can make you short of breath, the infection has stressed the brain, making it confused. It is very common.

Is it Dementia?

Not necessarily. Dementia is a slow, permanent memory loss. Delirium is a sudden, temporary reaction to illness. However, people with dementia are much more likely to get delirium.

Will he recover?

Usually, the confusion lifts as the illness improves, but it is often the last thing to get better. It can take weeks.

Why not give a sleeping pill?

Sedatives usually make confusion worse. We try to use natural methods (calm environment, family presence) unless strictly necessary for safety.

Common Exam Questions

1. Diagnosis: "Inattention + Acute Onset?"
   • Answer: Delirium.
2. Assessment: "Best scoring tool?"
   • Answer: 4AT (or CAM).
3. Management: "Agitated patient with Parkinson's?"
   • Answer: Lorazepam (Avoid Haloperidol).
4. Cause: "Hypoactive delirium, pin-point pupils, RR 8?"
   • Answer: Opiate toxicity.

Viva Points

• Wernicke's Encephalopathy: The classic triad (Confusion, Ataxia, Ophthalmoplegia). Caused by Thiamine (B1) deficiency. Treat with IV Pabrinex.
• Anticholinergic Burden: Drugs like Amitriptyline, Oxybutynin, Codeine, and Chlorphenamine have cumulative anticholinergic effects that tip elderly patients into delirium.

Medical Disclaimer: MedVellum content is for educational purposes and clinical reference. Clinical decisions should account for individual patient circumstances. Always consult appropriate specialists.