Guillain- Barre Syndrome Flashcards
what is gullian- barre syndrome?
- acute symmetrical paralytic polyneuropathy
what does GBS affect?
- affects the peripheral nervous system via ascending weakness
what are the possible triggers of GBS?
- bacterial and viral infections
e.g., camplobacter jejuni, cytomegalovirus, espstein- barr virus
what is the underlying mechanism of GBS?
- molecular mimicry
what is molecular mimicry?
- where the B cells of the immune system creates antibodies against the antigens on the pathogen that is causing the proceeding infection
what do the antibodies that the B cells produce also match? what does this target?
- also matches the proteins on the nerve cells
- targets myelin sheath or nerve axon causing damage to nerve cells and hence causing neuropathy and symptoms
what does GBS predominantly affect?
- affects the schawnn cells
- gradual destruction
or the axons of peripheral nerves
is there a cure for the condition? what can it be described as?
- no cure for the condition, only ways to manage the condition
- described as auto- immune
what is the classic GBS onset?
- ascending sensorimotor neuropathy
what are the symptoms like?
- can range from mild to severe
- very varied
what can severe cases of GBS result in?
- respiratory paralysis
- anatomic dysfunction
what does GBS start as?
- starts as monopathy presentation
what are the 5 main symptoms of GBS?
- symmetrical ascending weakness
- lack of sensation
- lack of reflexes
- lack of function
- neuropathic pain
what is the time period where symptoms normally start within?
- normally start within 4 weeks of the infection
what can GBS progress to?
- can progress to cranial nerves
- causes facial nerve weakness
when do the symptoms peak?
- symptoms peak at 2-4 weeks
how long does the recovery period last?
- lasts months to years
what are the 3 phases of GBS?
- acute
- plateau
- recovery
what does the acute phase involve? what is the time frame?
- rapid onset of symptoms
- escalating over a period of days to weeks
what does the plateau stage involve?
- stabilisation of symptoms
- no further deterioration
what does the recovery phase involve?
- gradual improvement
- full recovery may lead to residual deficits
how is GBS normally diagnosed?
- diagnosed based on medical history, physical exam and tests like CSF examination and electrodiagnostic studies
what investigations support the diagnosis of GBS?
- nerve conduction signals (reduced signal)
- lumbar puncture (high CSF with normal cell count and glucose)
what two features are required for diagnosis?
- progressive bilateral weakness of arms and legs (initially, only legs may be involved) - ascending motor weakness
- absent or decreased tendon reflexes in affected limbs
how long does the progressive phase last for?
- from days to 4 weeks
- normally under 2 weeks
what can result from GBS? what does this mean?
- autonomic dysfunction
- nerves of ANS are damaged
what can be a result of cranial nerve involvement? what is affected?
- bilateral facial palsy
- usually affects vision
what are the five features that strongly support the diagnosis?
- relative symmetry of symptoms
- relatively mild sensory symptoms and signs (absent in pure motor variant)
- muscular or radicular back/ limb pain
- increased CSF
- electrodiagnostic features of motor or sensorimotor neuropathy
what are the two first line of treatment?
- intravenous immunoglobulin (IVIg)
- plasma exchange
what does plasma exchange help with?
- helps to remove antibodies
why is IVIg and plasma exchange effective?
- because they are strong steroid based anti- inflammatory treatments
what are the steroids you could use in treatment?
- plasmapheresis
- DVT prophylaxis
why would you use DVT prophylaxis?
- prevents blood clots as pulmonary embolism is the leading cause of death via GBS
what are the two pathways you can enter the hospital with GBS?
- come into hospital with understanding of neurological problem so neuro screening requested
- other patients may have unclear signs
when would you admit a patient to ICU?
when one or more is present:
- rapid progression of weakness
- severe autonomic or swallowing dysfunction
- evolving respiratory distress
- EGRIS > 4
when would you start treatment of GBS?
when one or more present:
- inability to walk >10m independently
- rapid progression of weakness
- severe autonomic or swallowing dysfunction
- respiratory insufficiency
what are the four main factors to monitor for?
- muscle strength
- respiratory function
- swallowing function
- autonomic function
what should you look for in respiratory function?
- weak cough
- unable to clear secretions
- tone
when is it especially important to monitor swallowing function?
- if bulbar symptoms present
what should you include when monitoring autonomic function?
- blood pressure
- heart rate/ rhythm
- bladder/ bowel control
what percentage of GBS patients fully recover?
- 80%
what percentage of GBS patients have some neurological disability?
- 15%
what percentage of GBS patients die?
- 5% die
what are the 15 early complications of GBS?
- chocking
- cardiac arrhythmias
- infections
- deep vein thrombosis
- pain
- delirium
- depression
- urinary retention
- constipation
- corneal ulceration
- dietary deficiency
- hyponatraemia
- pressure ulcers
- compression neuropathy
- limb contractures
what is cardiac arrhythmias?
- abnormal heart rhythm
what are the 8 key features of general intensive care?
- assisted cough
- proper nutritional support
- insulin infusion
- adequate positioning
- anticoagulants and compression stockings
- maintenance of the functional position of limbs
- early rehabilitation
- psychological support
what could GBS patients suffer from?
- respiratory muscle weakness
- reduced inspiration and expiration
what would respiratory muscle weakness lead to? (3)
- airway protection loss
- ineffective cough
- several pulmonary complications
what effects the ability to clear secretions in GBS patients? (2)
- bulbar palsy
- dysautonomia
what does a reduced clearance of secretions cause?
- higher risk of respiratory failure and pulmonary infections
what should you monitor for bulbar palsy and dysautonomia?
- heart rate
- blood pressure
- respiratory rate
what is bulbar palsy?
- affects the brainstem’s motor neurons especially those used for speech and swallowing
how often are patients monitored? what is monitored?
- monitored every 3-4 hours
- monitored on forced vital capacity
what is forced vital capacity?
- maximum air volume exhaled after a deep breath
what are you monitoring in the FVC measurement? what do you compare it to?
- check for reduction in 20 to 25% of forced vital capacity
- compare to guidelines
what percentage of GBS patients have affected respiratory muscles?
- 40% of patients
what do the affected respiratory muscles lead to?
- causes neuromuscular respiratory failure in 25%
when is it especially vital to evaluate respiratory muscle involvement?
- vital in those with rapid onset weakness in the bulbar/ shoulder girdle muscles
why would you evaluate respiratory muscle involvement?
- evaluate to see if there is a need for mechanical ventilation
what other tests should be completed to monitor respiratory muscle function?
- beside pulmonary function tests
what are other cardinal features of GBS?
- autonomic disturbances
what are the important symptoms to note of failing respiration? (5)
- rapid and significant muscle weakening
- facial muscle weakness
- bulbar palsy
- shallow/ rapid breathing
- reduced breath sounds
what are other signs of failing respiration? (3)
- staccato speech
- inability to count above 10
- low FVC of 1 litre
what are some other symptoms of respiratory failure? (6)
- dysautonomia
- tachycardia
- brow sweating
- paradoxical breathing
- mental clouding
- somnolence
what are some laboratory markers of failing respiration on ABG? (3)
- oxygen saturation less than 92%
- p02 < 8kPa
- C02 > 6kPa
what is the measurement of FVC indicative of failing respiration?
- FVC 30% of FVC from baseline within 24 hours
- inconsistent/ failing values of FVC at a single test session
how does FVC indicate diaphragmatic weakness?
- decline in vital capacity by more than 15-20% in the supine position indicates diaphragmatic weakness
what monitoring should you do every 4 hours? (5)
- FVCs
- pulse
- blood pressure
- respiratory rate
- Sp02
when should you monitor FVC every 1-2 hours?
- when FVC is below 20mL/ Kg BW
what FVC will prompt urgent intensive care? what will this care involve?
- value of less than 15mL/kg should prompt urgent care referral
- would include endotracheal intubation in anticipation of potential respiratory arrest
what should you check if clinical or laboratory signs of failing respiration are present? what does this give a sense of?
- check for ABGs
- sense of acidity and homeostatic imbalance
