1.7 Guillain-Barré

Question 1

a) What is Guillain–Barré syndrome and what are its causes? (3 marks)

c) List the investigations with their findings that may be used to support the diagnosis. (2 marks)

d) What are the specific considerations when anaesthetising a patient recovering from Guillain–Barré syndrome? (9 marks)

Answer 1

What is Guillain–Barré?

> > Acute,
immune-mediated,
pre-junctional,
ascending demyelinating polyneuropathy
affecting sensory, motor and autonomic nerves.

Question 2

What are Guillain–Barré causes?

Answer 2

> > Associated with respiratory
or gastrointestinal infection (especially
Campylobacter) in preceding weeks.

> > Autoimmune in nature –
antibodies attack the
myelin sheath or, more
rarely, the axon itself.

Question 3

b) What are the clinical features of Guillain–Barré syndrome? (6 marks)

Answer 3

1&raquo_space; Variable presentation ***
depending on subtype; different forms associated with immune attack on different parts of the neurone.

Recovery is variable, ranging from full recovery to relapsing, remitting form.

2. > > Motor:
   typically ascending symmetrical weakness
   (flaccid, areflexic paralysis),
   may ascend to involve respiratory muscles
   and also to cause facial nerve palsies
   with bulbar weakness and opthalmoplegia.
3. > > Sensory:
   ascending sensory impairment associated with pain.

4.
» Autonomic:
arrhythmias, labile BP, urinary retention,
paralytic ileus, hyperhydrosis, sudden death.

5.
» Miller Fisher syndrome:
this is a variant typified by
ataxia, areflexia, opthalmoplegia +/− weakness

Question 4

c) List the investigations with
their findings that may be used to
support the diagnosis. (2 marks)

Answer 4

Blood tests:
» Variable, not specific or sensitive: low sodium, renal dysfunction, raised ALT and GGT raised CK.

> > Elevated ESR +/− CRP.

> > Antiganglioside antibodies
(antibodies against a component of the axon itself, increased association with Campylobacter, worse prognosis) in 25%.

> > Serology for Campylobacter, CMV, EBV, HSV or Mycoplasma pneumoniae may be positive.

> > ABG may show development of respiratory failure.

Stool:
» GI infections, especially Campylobacter.

CT brain:
» Normal: to exclude other causes.

MRI spine:
» Selective anterior spinal nerve root **
enhancement with gadolinium.

Lumbar puncture:
» Normal cell count and glucose,
elevated protein levels **
(although even this may be normal early in the disease).

Nerve conduction studies:
» Depends on subtype:
majority show demyelinating pattern, **
some show axonal loss.

Respiratory function tests:
» Reduced vital capacity

Question 5

d) What are the specific considerations when
anaesthetising a patient recovering from Guillain–Barré
syndrome? (9 marks)

Answer 5

Airway:

> > Bulbar weakness, poor cough, increased risk of aspiration.
Intubation required – consider need for rapid sequence induction.

> > May still have tracheostomy in situ if still requiring ventilatory support or assistance with secretion clearance.

Respiratory:

> > Increased risk of pneumonia secondary to aspiration and poor ventilatory function. Make full assessment of this – history, nature of secretions, temperature, chest auscultation. Treat as required, delay non-urgent
surgery if necessary.

> > Significantly reduced ventilatory capacity, assess likelihood of requiring noninvasive or invasive ventilation postoperatively.

Cardiovascular:
» Autonomic instability, labile BP
(with sensitivity to commonly used vasoactive drugs),
risk of arrhythmia.

Invasive monitoring indicated

including cardiac output monitoring to guide fluid administration (ensure full circulation as dehydration will exacerbate lability).

> > Prolonged illness, multiple cannulations, access may be tricky.

Neurological:
» Neuropathic pain common – may already be on antineuropathic drugs +/− opioid analgesia.
Need to plan postoperative pain relief, involve acute
pain team.

Pharmacology:
» Suxamethonium: contraindicated due to risk of hyperkalaemia following the development of extrajunctional nicotinic receptors.

> > Non-depolarising neuromuscular blocking agents: increased sensitivity – reduce dose.

> > Opioids: increased sensitivity to respiratory depressant effect in the presence of existing respiratory compromise, may already be taking opioids and so dose adjustments may be necessary.

Haematology:
» Risk of deep vein thrombosis due to prolonged immobility – continuation of thromboembolic deterrent stockings and pneumatic compression devices and pharmacological prophylaxis (check timing if planning
neuraxial technique).

Cutaneomusculoskeletal:
» Prolonged illness may be associated with weight loss – care with positioning and padding

Renal:
» Check renal function – may dictate drug choices.