Confusion, acute in adults

Question 1

Probability diagnosis

Answer 1

Hypoxia

Hypoglycaemia

Alcohol excess

Drug withdrawal incl. alcohol, hypnotics

Head injury

Question 2

Serious disorders not to be missed

Answer 2

Vascular:

• Cerebral insufficiency incl. TIAs
• Acute coronary syndrome
• Cardiac arrhythmias
• Subdural or extradural haematoma

Infection:

• Any systemic infection esp. sepsis
• Cerebral e.g. meningitis, abscess
• HIV/AIDS

Tumor/cancer:

• Cerebral tumour

Other:

• Kidney failure
• Hepatic failure
• Respiratory failure e.g. COPD
• Electrolyte disturbance
• Dehydration
• Post-ictal state
• Psychosis

Question 3

Pitfalls (often missed)

Answer 3

Iatrogenic-drugs incl. serotonin syn.

Hyperparathyroidism

Hypo/hyper-calcaemia

Sleep apnoea

Rarities:

• Fat embolism
• Wernicke’s encephalopathy
• Prion disorders esp. CJS
• Vitamin deficiency e.g. B1 and B12

Question 4

Masquerades checklist

Answer 4

Depression

Diabetes: ketoacidosis, hypoglycaemia

Drugs (see list)

Thyroid/other endocrine—hyper/hypothyroid?

Urinary tract infection—nocturia

Question 5

Is the patient trying to tell me something?

Answer 5

A consideration if nil findings.

Question 6

Key history

Answer 6

A careful hx incl. an interview with family members and witnesses.

Investigate the onset and circumstances of the behaviour, any possible bizarre behaviour.

PMHx diabetes, hypertension, cerebrovascular disease.

Drug history esp. alcohol or illicit drugs, prescription and OTC drugs.

Check thyroid status, esp. hyperthyroidism.

Question 7

Key examination

Answer 7

General features;

• central cyanosis
• hydration status
• vital signs
• BMI

Head and neck

General respiratory and cardiovascular examination

Possible source of infection

Neurological examination

Mental state examination

Question 8

Key investigations

Answer 8

First line:

• urinalysis
• blood sugar
• pulse oximetry
• FBE
• ESR
• U&E
• calcium
• Others according to history and findings

Consider:

• CXR
• ECG
• cardiac enzymes
• TFTs
• LFTs (γGT)
• CT scan
• CSF analysis

Question 9

Diagnostic tips

Answer 9

Pay close attention to drug use, esp.

• alcohol
• psychotrophic
• narcotics
• illicit agents
• anticholinergics
• digoxin
• corticosteroids
• benzodiazepines esp. if desperate request for drugs.