Medicine — The Unconscious Patient, NMC MBBS licence examination syllabus (Nepal Medical Council).
The unconscious patient
A presentation with a hundred causes and a fixed opening sequence.
An unconscious patient offers no history, cannot cooperate with examination, and arrives with a differential that spans almost every system. That combination makes it feel unmanageable — which is precisely why the approach is protocolised. You do the same things first every time, in the same order, and the reversible causes are excluded before the elaborate ones are considered.
Two of those first steps deserve stating on their own. An unconscious patient cannot protect their airway, so airway management precedes diagnosis. And the glucose is checked in every case, without exception — hypoglycaemia is instantly reversible, rapidly fatal, and takes seconds to exclude.
🩺 Where this lives: Hypoglycaemia is the most important diagnosis in this chapter because it is the one that is entirely reversible and entirely unforgiving. A patient found unconscious may be assumed to have had a stroke, taken an overdose, or been drinking — and each of those assumptions costs minutes during which glucose-deprived neurones are dying. The test costs seconds and needs no laboratory. It is checked before the CT, before the toxicology, and before anyone speculates about the cause.
💡 A note on scope. This chapter is the general approach. The specific conditions have their own chapters: head injury and the Glasgow Coma Scale in Trauma, delirium in Psychiatry, seizures and status in Seizures and Headache, poisoning and antidotes in Poisoning, DKA in its own chapter, stroke in Stroke, and cerebral malaria in Malaria and Dengue. No doses are given here, and the GCS is not re-tabulated — see the trauma chapter.
The immediate sequence
The order is not negotiable. Airway first — reduced consciousness is itself an airway risk, and a patient who is not protecting their airway will aspirate while you take a history from relatives. Then the glucose, in every patient, every time. Then the other rapidly reversible causes: opioid toxicity, hypoxia, hypercapnia, ongoing seizure and hypothermia — each of which has a specific and available treatment.
THE REVERSIBLE CAUSES, AND WHAT GIVES THEM AWAY
HYPOGLYCAEMIA
Check it in EVERY patient. No exceptions, no assumptions,
no waiting for the laboratory. Treat immediately if low.
OPIOID TOXICITY
PINPOINT PUPILS with a slow respiratory rate and reduced
consciousness. Reversible — see the poisoning chapter for
management.
HYPOXIA AND HYPERCAPNIA
Both cause confusion progressing to coma. Check
saturations and consider blood gases; a retaining patient
may look peaceful while deteriorating.
ONGOING SEIZURE ACTIVITY
A patient may still be seizing subtly — twitching of a
limb or the face, or nystagmoid eye movements — or may be
deeply postictal. See the seizures chapter.
HYPOTHERMIA
Measure it properly with a low-reading thermometer, and
handle the patient gently.
AND THE THIAMINE RULE
In anyone dependent on alcohol or malnourished, give
THIAMINE before or alongside glucose — glucose metabolism
consumes thiamine and can precipitate Wernicke's
encephalopathy. But DO NOT WITHHOLD GLUCOSE from a
hypoglycaemic patient while waiting for thiamine. Give
both.
Only once these are addressed does the search for a
structural or systemic cause become the priority.
Grouping the causes
💡 Exam angle: the most useful organising question is symmetrical or asymmetrical? A metabolic or toxic cause depresses the whole brain, so the examination is usually symmetrical with pupils preserved. A structural lesion produces focal signs and asymmetry — one pupil different, one side moving less, asymmetrical tone or reflexes. That single observation determines whether the next step is urgent imaging or a metabolic screen, and it can be made in under a minute.
Examining a patient who cannot cooperate
A SYSTEMATIC EXAMINATION WITHOUT COOPERATION
PUPILS — size, equality and reaction
PINPOINT and reactive → opioid
ONE FIXED AND DILATED → third nerve compression; treat as
raised intracranial pressure until proven otherwise
EQUAL AND REACTIVE in a comatose patient → favours a
metabolic or toxic cause, since pupil pathways are
relatively resistant
MOTOR RESPONSE AND TONE
Apply a standard stimulus and watch BOTH sides. Does one
side move less? Is tone or reflex activity asymmetrical?
What do the plantars do? Asymmetry is the finding that
matters.
RESPIRATORY PATTERN
Rate and regularity. Slow breathing suggests opioid or
hypercapnia; irregular patterns may accompany brainstem
involvement.
THE REST OF THE PATIENT — undress them
TEMPERATURE, high or low
RASH — particularly non-blanching
NECK STIFFNESS, remembering it is often absent when it
matters most
Breath smell — ketones, alcohol
Needle marks, injuries, incontinence, tongue biting
MEDIC-ALERT jewellery or a steroid card in a pocket
FUNDOSCOPY for papilloedema and for retinal haemorrhage.
AND SEEK COLLATERAL INFORMATION relentlessly: relatives,
ambulance crew, the scene, empty medicine packets, previous
records. In this presentation the history comes from
everywhere except the patient.
Raised intracranial pressure
Three findings together should prompt immediate action: a falling conscious level, a new fixed dilated pupil, and rising blood pressure with bradycardia. That last combination is often misread — the hypertension is a compensatory response maintaining cerebral perfusion against a rising intracranial pressure, so treating it by lowering the blood pressure makes cerebral perfusion worse. And where raised pressure is suspected, lumbar puncture is not performed.
Suspected meningitis
💡 Exam angle: this is the recurring examinable tension — imaging and lumbar puncture are important, but antibiotics come first. Delay to the first antibiotic dose is what worsens outcome in bacterial meningitis, and blood cultures taken beforehand plus later CSF findings usually still allow a diagnosis. Note also that neck stiffness is frequently absent in infants, the elderly and the deeply unconscious — its absence excludes nothing.
Clinical reasoning: four presentations
🔍 Case 1 — assumed to be drunk
PresentationA man is brought in unconscious, smelling of alcohol. He is placed in the recovery position to "sleep it off" and reviewed two hours later, still unresponsive. No glucose has been checked.
ErrorAn assumption substituted for a test.
ReasoningAlcohol on the breath explains nothing — hypoglycaemia, head injury, hypothermia and infection are all commoner in dependent drinkers, and each is missed by this assumption.
AnswerAirway, oxygen, and check the glucose immediately. Give thiamine with glucose if he is dependent or malnourished, examine fully for injury and infection, and reassess conscious level formally.
🔍 Case 2 — one pupil larger
PresentationAn unconscious patient has a conscious level that has fallen over an hour. The right pupil is now dilated and unreactive. Blood pressure is rising and the pulse is slow. The team plans a lumbar puncture to exclude meningitis.
DangerRaised intracranial pressure, and a lumbar puncture that could precipitate herniation.
ReasoningA falling conscious level, a new fixed dilated pupil, and hypertension with bradycardia together indicate rising intracranial pressure with impending herniation.
AnswerDo not perform lumbar puncture. Airway and oxygenation, head up, avoid hypotension and hypoglycaemia, urgent imaging and neurosurgical referral. Do not treat the hypertension — it is compensating.
🔍 Case 3 — fever and no neck stiffness
PresentationAn elderly woman is febrile and unresponsive. There is no neck stiffness, so meningitis is considered unlikely and antibiotics are deferred pending a CT scan and lumbar puncture.
Two errorsRelying on neck stiffness, and delaying antibiotics.
ReasoningNeck stiffness is frequently absent in the elderly and the deeply unconscious. Delay to the first antibiotic dose is the factor most strongly associated with poor outcome in bacterial meningitis.
AnswerTake blood cultures and give antibiotics immediately, then proceed to imaging and lumbar puncture as indicated. Check the glucose, and in an endemic area test for malaria.
🔍 Case 4 — symmetrical and slow-breathing
PresentationA young man is unresponsive with a respiratory rate of 6 and pinpoint pupils. There are no focal neurological signs and tone is symmetrical. An urgent CT head is arranged first.
PatternSymmetrical examination with pinpoint pupils and hypoventilation.
ReasoningThis is opioid toxicity until proven otherwise — a reversible cause with an available antidote. The absence of asymmetry argues against a structural lesion, and imaging delays a treatment that takes moments.
AnswerSupport ventilation, check the glucose, and treat for opioid toxicity per protocol — see the poisoning chapter. Image afterwards if the picture does not fit or does not respond.
Commonly confused
Confusion
The distinction
Why it matters
Smell of alcohol vs a diagnosis
It explains nothing on its own
Hypoglycaemia and head injury are commoner in drinkers.
Symmetrical vs asymmetrical signs
Metabolic versus structural
Determines imaging versus metabolic screen.
Pinpoint vs fixed dilated pupil
Opioid versus compression
One has an antidote; one needs a surgeon.
Hypertension with bradycardia vs treating the BP
It is compensating for raised pressure
Lowering it worsens cerebral perfusion.
Absent neck stiffness vs no meningitis
Often absent when it matters most
Infants, elderly, deeply unconscious.
Imaging vs antibiotics first
Antibiotics come first
Delay worsens outcome in meningitis.
Lumbar puncture vs raised pressure
Do not perform it if suspected
It can precipitate herniation.
Glucose vs thiamine order
Give both; do not withhold glucose
Hypoglycaemia kills while you wait.
Rapid revision
MUST-KNOW FACTS
1. An unconscious patient CANNOT PROTECT THE AIRWAY.
2. Airway, breathing and circulation come before diagnosis.
3. CHECK THE GLUCOSE IN EVERY PATIENT, EVERY TIME.
4. Hypoglycaemia is instantly reversible and rapidly fatal.
5. Other reversible causes: OPIOID, hypoxia, hypercapnia, seizure, hypothermia.
6. PINPOINT PUPILS with slow breathing → opioid toxicity.
7. Give THIAMINE before or alongside glucose in dependence or malnutrition.
8. But NEVER withhold glucose from a hypoglycaemic patient.
9. Three groups: STRUCTURAL, METABOLIC/TOXIC, DIFFUSE.
10. METABOLIC causes are the commonest group.
11. ASYMMETRY points to STRUCTURE; SYMMETRY points to METABOLISM.
12. Examine PUPILS, motor response, TONE, reflexes and plantars.
13. One FIXED DILATED pupil suggests compression — urgent.
14. Equal reactive pupils in coma favour a metabolic cause.
15. Check temperature, rash, neck stiffness, breath smell, needle marks.
16. UNDRESS the patient and look for injuries and medic-alert jewellery.
17. Examine the FUNDI.
18. Seek COLLATERAL information from every available source.
19. RAISED ICP: falling conscious level, new fixed dilated pupil.
20. Plus rising blood pressure with BRADYCARDIA — a late sign.
21. Do NOT lower that blood pressure — it is compensating.
22. Head up, oxygenate, avoid hypotension and hypoglycaemia, treat seizures.
23. DO NOT PERFORM LUMBAR PUNCTURE if raised pressure is suspected.
24. Suspected meningitis: ANTIBIOTICS BEFORE imaging and lumbar puncture.
25. Delay to the first dose is what worsens outcome.
26. NECK STIFFNESS IS OFTEN ABSENT in infants, the elderly and deep coma.
27. Fever with a NON-BLANCHING rash — antibiotics immediately.
28. In an endemic area, TEST FOR MALARIA in any unexplained coma.
29. Alcohol on the breath explains NOTHING by itself.
30. The GCS is defined in the trauma chapter — record components separately.
💡 Exam angle: the sequence is the answer to most questions here — airway, glucose, reversible causes, then symmetry. A stem that offers imaging or lumbar puncture before antibiotics in suspected meningitis, or before glucose in any unconscious patient, is testing whether you will follow it.
Syllabus points
Why airway precedes diagnosis
Checking the glucose in every patient
The immediately reversible causes
Opioid toxicity and pinpoint pupils
Thiamine and glucose together
Structural, metabolic and diffuse causes
Asymmetry versus symmetry
Examining the pupils
Motor response, tone and reflexes
The whole-body examination
Seeking collateral information
Signs of raised intracranial pressure
Why the hypertension is not treated
Antibiotics before imaging in meningitis
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