Guillain-Barre Syndrome Flashcards
(8 cards)
What is Guillain Barre Syndrome
An acute immune mediated, pre junctional, ascending demyelinating polyneuropathy affecting sensory, motor and autonomic nerves
What is the underlying pathology of Guillain Barre Syndrome
Autoantibody damage to the myelin sheath or less commonly the axon itself, typically associated with antiganglioside or other antiglycolipid antibodies
What are possible triggers for Guillain Barre Syndrome
Gastrointestinal infection especially campylobacter
Respiratory infection such as influenza and COVID 19
Other viruses such as Zika, CMV, EBV and HIV
Protozoal illnesses
What are the clinical features of Guillain Barre Syndrome
Acute Onset of symptoms and signs
Recovery is variable ranging from full recovery to prolonged disability (there is also a relapsing remitting form)
Motor Features:
Typically an ascending symmetrical weakness (a flaccid areflexic paralysis) which can ascend to involve the respiratory muscles causing respiratory failure and also to cause facial nerve palsies with bulbar weakness and ophthalmoplegia (paralysis / weakness of muscles controlling eye movement)
Sensory Features:
Ascending sensory impairment associated with pain and paraesthesia
Autonomic Features:
Arrhythmias, Labile BP, Urinary Retention, Paralytic Ileua, Hyperhidrosis, Sudden Death
Miller Fisher Syndrome:
Is a variant typified by ataxia, ophthalmoplegia +/- respiratory and limb weakness
What investigations can be used to support the diagnosis of Guillain Barre Syndrome
MRI of Spine: In Guillain Barre Syndrome this will show selective anterior spinal nerve root enhancement with gadolinium
Lumbar Puncture: Will have a normal cell count and glucose but raised protein (although protein can also be normal in the early stages of the disease)
Nerve conduction studies: the results will depend on the subtype, in demyelination which is the majority of cases there will be a reduction in conduction velocity. While in rarer cases with axonal loss there will be a reduction in compound action potential size
Antiganglioside aka antiglycolipid antibodies may be present, especially in a axonal loss varient.
What specific considerations are there when anaesthetising a patient recovering from Guillain-Barre Syndrome
Airway:
Bulbar Weakness, poor cough, risk of aspiration
Intubation will be required and may need RSI
May still have tracheostomy in situ, as may still require ventilatory support or assistance with secretion clearance
Respiratory:
Increased risk of pneumonia secondary to aspiration and poor ventilatory function, this will require a full assessment including history, nature of secretion, temperature, chest auscultation, treating as required and delaying non urgent surgery as necessary
Significantly reduced ventilatory capacity which may require post operative non invasive or invasive ventilation
Cardiovascular:
Autonomic Instability i.e. labile BP (and increased sensitivity to vasoactive drugs) risk of arrhythmia, likely to require invasive monitoring and cardiac output monitoring to guide fluid administration.
Prolonged illness with multiple canulations may make IV access tricky
Neurological:
Neuropathic Pain is common and the patient may already be on antineuropathic drugs +/- opioids. Post operative pain relief may need a considered plan.
Pharmacology:
Suxamethonium is contraindicated due to the risk of hyperkalaemia as there is upregulation of extra junctional nicotinic receptors
There is also increased sensitivity to non depolarising neuromuscular blocking drugs which can result in prolonged paralysis and hence a reduce dose should be considered
There is an increased sensitivity to the respiratory depressant effect of opioids given the potential presence of an existing respiratory compromise.
Haematology:
Risk of DVT due to prolonged immobility, hence consideration to thromboprophylaxis is required.
Cutaneomusculoskeletal:
Prolonged illness may be associated with significant weight loss making position and padding of areas at risk of damage paramount.
Renal:
May have altered renal function affecting drug choices and dosing.
What specific treatments are available for Guillain-Barre Syndrome?
IV Ig
Plasma Exchange
Give the forced vital capacity (FVC) (ml/kg), maximum inspiratory pressure (cmH2O), and maximum expiratory pressure (cmH2O) values that would warrant consideration of intubation in a patient with GBS
FVC 20ml/kg
Maximal inspiratory pressure (PI max) <30cmH2O (this is a measure of inspiratory muscle strength)
Maximal Expiratory Pressure (PE max) <40cmH2O (this is a measure of expiratory muscle strength)
N.B. bear in mind that the patient’s ability to protect their own airway in the context of bulbar weakness, as well as the above, would warrant consideration of intubation
