Comatose Patient (OSCE focused)

Candidate Instructions:You are the medical student in the Emergency Department. A 56-year-old patient has been found unresponsive and brought in by ambulance. Demonstrate a structured assessment of this unconscious patient. You do not need to perform invasive procedures, but explain what you would do. You have 8 minutes.

Key OSCE Focus 🔑

• 💡 Immediate ABCDE approach (don’t jump to neuro exam too soon).
• ⚡ Think of reversible causes (hypoglycaemia, hypoxia, intoxication, seizures).
• 🧠 Then localise possible structural causes (stroke, trauma, raised ICP).

Initial Approach 🛑

• 🧯 Call for help, ensure safety, attach monitoring (SpO₂, ECG, BP).
• 🔑 Airway: check for obstruction, place airway adjunct if needed.
• 🫁 Breathing: look, listen, feel; give high-flow O₂.
• ❤️ Circulation: pulse, BP, IV access, bloods, fluids if hypotensive.
• 🧪 Disability: GCS, pupils, capillary glucose (must be done early!).
• 🌡️ Exposure: temperature, full top-to-toe exam for trauma, rashes, track marks.

Focused Neurological Assessment 🧠

• 📝 GCS (eye, verbal, motor response).
• 👀 Pupils: size, reactivity, symmetry.
• 🖐️ Motor: spontaneous movements, response to pain (localising vs decerebrate/decorticate).
• 💪 Tone & reflexes: deep tendon reflexes, plantar responses.
• 🌊 Signs of raised ICP: Cushing’s triad, papilloedema (if fundoscopy possible).

Investigations 🔬

• 🩸 Bedside: capillary glucose, blood gases, ECG.
• 🧪 Bloods: FBC, U&E, LFTs, CRP, coagulation, toxicology screen.
• 🧠 Imaging: urgent CT brain (exclude bleed, large stroke, mass).
• 💉 Lumbar puncture: if meningitis/encephalitis suspected AND no raised ICP on CT.

Common Causes of Coma (mnemonic: “AEIOU TIPS”) 🧾

• Alcohol, drugs, toxins.
• Epilepsy, post-ictal.
• Insulin (hypo/hyperglycaemia).
• Oxygen lack (hypoxia, CO₂ retention).
• Uraemia, metabolic.
• Trauma, tumour.
• Infection (meningitis, encephalitis, sepsis).
• Psychiatric (rare, diagnosis of exclusion).
• Stroke, SAH, structural lesions.

Immediate Management 🚑

• 🧪 Give IV dextrose if hypoglycaemia cannot be excluded.
• 💉 Consider IV thiamine before glucose if alcoholism suspected.
• 💊 Naloxone trial if opioid overdose suspected.
• 🛏️ Protect airway: may need intubation if GCS ≤ 8.
• 👩‍⚕️ Treat underlying cause: antibiotics for meningitis, anticonvulsants for seizures, neurosurgical referral if bleed/mass.

Examiner’s Marking Guide 📋

• Introduces self, checks for safety, calls for help.
• Uses structured ABCDE approach.
• Checks blood glucose promptly.
• Performs GCS + pupil assessment clearly.
• Lists relevant differentials logically.
• Mentions urgent CT brain.
• Knows immediate treatments (O₂, IV glucose, thiamine, naloxone, intubation).

🧑‍⚕️ Case Examples - Coma

• Case 1 (Hypoglycaemia): 🍬 A 54-year-old man with type 1 diabetes is found unconscious at home. Paramedics note blood glucose of 1.8 mmol/L. He recovers rapidly after IV dextrose. Diagnosis: Hypoglycaemic coma. Teaching point: Always check capillary glucose in any unconscious patient.
• Case 2 (Intracerebral haemorrhage): 🧠 A 72-year-old woman with poorly controlled hypertension suddenly collapses with a severe headache, vomiting, and right-sided weakness before becoming comatose. CT head shows a large left basal ganglia haemorrhage. Diagnosis: Hypertensive intracerebral bleed. Teaching point: Structural brain lesions cause rapid coma from raised ICP and brainstem compression.
• Case 3 (Drug overdose): 💊 A 25-year-old man is found unconscious with pinpoint pupils and shallow breathing. Empty packets of morphine are nearby. Naloxone is given with prompt improvement. Diagnosis: Opioid overdose with respiratory depression. Teaching point: Pupil size and respiration pattern give key diagnostic clues in toxic coma.
• Case 4 (Sepsis with meningitis): 🌡️ A 19-year-old university student presents with fever, photophobia, and a purpuric rash. He rapidly deteriorates to GCS 6. CSF shows gram-negative diplococci. Diagnosis: Meningococcal meningitis with septic encephalopathy. Teaching point: Infective causes of coma require urgent antibiotics and supportive care.
• Case 5 (Post-cardiac arrest hypoxic brain injury): ❤️ A 66-year-old man collapses with ventricular fibrillation cardiac arrest. ROSC is achieved after 20 minutes of CPR, but he remains comatose with absent brainstem reflexes. Diagnosis: Hypoxic–ischaemic encephalopathy. Teaching point: Global cerebral hypoxia is a major cause of poor neurological outcome post-arrest.
• Case 6 (Status epilepticus): ⚡ A 30-year-old woman with epilepsy is admitted after a prolonged tonic–clonic seizure. Despite IV benzodiazepines, she does not regain consciousness. Diagnosis: Post-ictal coma due to refractory status epilepticus. Teaching point: Always consider non-convulsive status as a cause of coma; EEG may be required.