Guillain–Barré syndrome
Weak legs that are getting weaker — measure the FVC, not the SpO₂. Recognise rapidly progressive symmetrical weakness with reduced reflexes, monitor breathing with serial vital capacity, watch for autonomic instability, exclude the mimics (especially cord compression), and start immunotherapy. Built for revision, not live patient decisions.
Settle them, and check the basics
breathing firstRed flags — what each should make you think
Oxygen saturations stay normal until very late in neuromuscular respiratory failure. Measure the forced vital capacity (with a facemask if facial weakness) regularly, and refer to ITU early if it's falling: don't wait for the gas.
First actions
- FVCForced vital capacity
- 🗣Bulbar function
- ECGCardiac monitoring
- MRIExclude cord compression
- 🧪Bloods + LP
- ☎Neurology + ITU
Understand the patient
recognise itTypical features
- Often 1–4 weeks after an infection (Campylobacter, CMV, EBV, respiratory)
- Progressive, fairly symmetrical weakness, usually starting in the legs, over days to 4 weeks
- Reduced or absent reflexes
- Distal paraesthesia, back or limb pain
- Facial and bulbar weakness, respiratory muscle weakness
- Autonomic dysfunction: BP swings, arrhythmias, urinary retention
Miller Fisher variant: ophthalmoplegia, ataxia, areflexia.
Respiratory warning signs ("20/30/40")
- FVC below 20 mL/kg
- Maximal inspiratory pressure weaker than −30 cmH₂O
- Maximal expiratory pressure below 40 cmH₂O
- Any of these, or a rapidly falling FVC, bulbar weakness or a weak cough → ITU for possible ventilation
Work A–E — assess and act as you go
The diagnoses you must not miss
tap to open eachWhat points toward it, what would rule it in, and how to manage it.
Breathlessness, weak cough, using accessory muscles, FVC below 20 mL/kg.
Serial FVC; ABG is late.
ITU, elective intubation before crisis.
Labile BP, tachy/bradyarrhythmias, ileus, retention.
Continuous monitoring.
ITU/HDU; cautious treatment of BP swings.
Sensory level, early sphincter involvement, back pain, upper motor neurone signs (may be absent early).
Urgent MRI spine.
See the spinal cord compression page.
Hypokalaemia, myasthenic crisis (fatigable, ptosis, normal reflexes), botulism (descending, pupils), transverse myelitis, critical illness neuropathy.
U&E, CK, antibodies, nerve conduction.
Treat the specific cause.
Investigate — what to order, when, and what it tells you
test with a question in mindBedside
Bloods
LP
Neurophysiology / MRI
How the plan comes together
disposition · handoverneurology ward
Stable FVC, no bulbar or autonomic problems: IVIG (2 g/kg over 5 days) or plasma exchange if unable to walk independently or progressing; VTE prophylaxis, pain control, physio. Steroids are not effective.
ITU
Falling FVC, bulbar weakness, autonomic instability.
Hand over: FVC trend, bulbar function, rate of progression, treatment started.
Ascending weakness with lost reflexes: think GBS, measure the FVC regularly, exclude cord compression, and get neurology and ITU involved early. Nicely done getting here.
Clerking template
copy or downloadGuillain–Barré syndrome — documentation structure
A structure and prompt list to help you document and think systematically. It is not a completeness check and cannot guarantee nothing is missed — use your trust's own proforma, your seniors, and your clinical judgement.
Test yourself
active recallCover the answer, say it out loud, then reveal. Retrieval beats re-reading.
0 / 10 knownFrequently asked questions
quick answersWhat are the red flags for Guillain–Barré syndrome?
- FVC below 20 mL/kg, or falling — think respiratory failure — ITU
- Weak cough, bulbar weakness — think airway risk
- Fluctuating BP, arrhythmias — think autonomic dysfunction
- Sensory level, bladder involvement — think cord compression — MRI
- Fatigable weakness, ptosis — think myasthenia gravis
- Low potassium — think hypokalaemic paralysis
What is the initial management of Guillain–Barré syndrome?
- Forced vital capacity — baseline and every 4–6 h (more often if falling)
- Bulbar function — cough, swallow, speech; NBM if unsafe
- Cardiac monitoring — arrhythmias, BP lability
- Exclude cord compression — if sensory level, bladder signs, or asymmetry
- Bloods + LP — U&E (K⁺), CK; LP for protein/cells
- Neurology + ITU — early
Always alongside senior support and your local guideline.
What diagnoses must you not miss in Guillain–Barré syndrome?
- Neuromuscular respiratory failure — FVC falling
- Autonomic instability — BP · arrhythmia
- Spinal cord compression (mimic) — sensory level
- Other mimics — K⁺ · myasthenia · botulism
Open each one in the must-not-miss section for what points toward it, how to rule it in, and how to manage it.
What investigations should a junior doctor order for Guillain–Barré syndrome?
- Bedside — Every 4–6 h.
- Bloods — U&E (K⁺), Mg, phosphate, CK, glucose, FBC, LFT.
- LP — Raised protein with a normal cell count (may be normal in the first week).
- Neurophysiology / MRI — Supports diagnosis and subtype.
Admit or discharge: how is the plan decided for Guillain–Barré syndrome?
- Neurology ward — Stable FVC, no bulbar or autonomic problems: IVIG (2 g/kg over 5 days) or plasma exchange if unable to walk independently or progressing; VTE prophylaxis, pain control, physio. Steroids are not effective.
- Itu — Falling FVC, bulbar weakness, autonomic instability.
Is there a clerking template for Guillain–Barré syndrome?
Yes — there is a free clerking template for Guillain–Barré syndrome on this page, structured as presenting complaint, red flags asked, history, examination (A–E), investigations, differentials, plan and escalation. You can copy it or download it as a Word document. Jump to the template.
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