GUILLAIN-BARRE SYNDROME

Acute, frequently severe and fulminant, poly radiculopathy,which is auto immune in nature.Males and females equally affected. More frequent in adults than in children.Variants involving the cranial nerves, pure motor involvement etc are also found. In severe cases, muscle weakness may lead to respiratory failure,with auto nomic involvement and unstable hemodynamics, necessitating ventilatory management
Clinical Manifestations

• Rapidly evolving, progressive, ascending motor paralysis with or without sensory disturbance and with areflexia
• Lower cranial nerves are frequently involved and presented with difficulty in swallowing and maintaining airway
• Bulbar involvement is most frequently manifested as B/L facial paralysis
• Fever and other constitutional symptoms are usually absent
• Diminished DTR with absent proprioception. There may be marked sensory loss
• Bladder dysfunction is late and transient.
• Deep aching pain in muscles and back
• Difficulty in swallowing due to pharyngeal muscle weakness and impaired ventilation due to intercostal muscle paralysis in 30% of cases and they require ventilatory support
• Marked autonomic dysfunction leads to  Wide fluctuations in blood pressure – hypo / hyper tension, Sudden profuse diaphoresis,Peripheral vasoconstriction Resting tachycardia,Cardiac conduction abnormality, Orthostatic hypotension – severe, Thromboembolism due to immobilisation, & sudden death
• Metabolic derangements -Hyponatremia due to excessive ADH secretion

Pathophysiology
The condition is preceded 1-3weeks by a/c infections affecting the respiratory tract or GIT (60-75% cases). Commonly implicated organisms include CMV, Epstein Barr, HIV, Viruses or Mycoplasma pneumoniae or crampylobacter jejuni bacteriae. GBS is also found to be associated with lymphoma and hodgkin’s disease. The basic pathophysiology is, Immune responses to nonself antigens - auto antibodies - misdirected to host nerve tissue - ganglioside damage - demyelination - conduction block.Secondary axonal degeneration  rare, except in chronic cases.

Diagnosis

Essential Criteria

• Progressive weakness of more than one limb due to neuropathy
• Areflexia
• Duration of progression less than 4 weeks

Supportive Criteria

• Relative symmetry
• Mild sensory signs or symptoms
• Cranial nerve involvement, especially bilateral facial weakness
• Recovery begins 2 to 4 weeks after progression ceases
• Autonomic dysfunction
• Absence of fever at onset
• Typical CSF and EMG/nerve conduction studies features.
  

Clinical Features

• Weakness is usually symmetrical
• Sensory signs are mild
• Cranial nerve involvement common
• Autonomic dysfunction common

Laboratory Features

• CSF after 1st week, total protein content is increased (80%)
• White cell count near normal (90%)
• EMG--nerve conduction slowed, suggesting demyelination

Antibodies in GBS
GM1 -   Associated with severe, pure, motor variant
GM1b - Campylobacter jejuni -- severe progression
GQ1b -  Miller Fischer variant

Permanent Neurological sequalae in 7-15% of patients
1) Foot drop 2) Intrinsic muscle weakness3) Sensory ataxia 4) Dysarthria

Differential diagnosis for GBS

• Transverse Myelitis
• Myasthenia Gravis
• Poliomyelitis
• Periodic Paralysis
• Polymyositis
• Acquired hypokalemia
• Botulism
• Porphyric neuropathy
• Toxic neuropathies
• Meningo radiculopathies
• Lyme’s disease,and radiculopathies due to CMV, HIV

Treatment in nutshell.

• Symptomatic
• Good general medical and nursing care including monitoring
• Monitoring of vital capacity and when it is less than 15ml/kg or pharyngeal muscle weakness - early intubation and ventilatory support indicated
• Measurement of ABG - adequacy of ventilation
• Suction clearance of secretions
• Tracheostomy if prolonged ventilation is needed
• Measures to prevent DVT and pulmonary embolism- heparin s/c, graded elastic stocking etc
• Skin care--frequent turning to prevent bed sore
• Chest physiotherapy and correction of electrolytes
• Steroids are not much useful
• Plasmapheresis; Accelerates recovery if performed within 2 weeks of onset of the disease. Within 1 week - most useful. 40-50ml/kg plasma exchange for 4 to 5 days 
•  I/V immunoglobulins 2g/kg 5 daily infusions

ICU monitoring and elective intubation should be considered if  Vital capacity less than 20 mL/kg , Maximal inspiratory pressure worse than -30 cmH2O, Maximal expiratory  pressure less than 40 cmH2O, Reduction of 30% in vital capacity, Maximal inspiratory pressure or Maximal expiratory pressure.

Recovery
 85 to 90% patients recover completely in a few weeks, Death is Mainly due to secondary pulmonary complications, ARDS, emboli etc.Mortality rate is  3 to 8%

Anesthetic Considerations
Patients usually present for elective tracheostomy and are already intubated

Preoperative assessment

• If unintubated assess airway, month, dentition and neck
• Assess bulbar function to prevent aspiration during induction
• Assess respiratory muscle function – vital capacity, mouth occlusion pressures, cough
• Assess autonomic function – ECG, postural hypo tension, excessive sweating
• Correct electrolyte imbalance/hyponatremia

Perioperative Management

 Monitoring : ECG, BP , Invasive and Noninvasive SPO2, PNS Rapid sequence induction if bulbar function is poor, using vecuronium suggested.But suxamethonium is avoided as wide spread denervation may result in hyperkalemia.Controlled ventilation is indicated. Altered function of ANS so compensatory CVS responses may be absent and can cause Profound hypo tension, when there is blood loss, changes in posture or application of positive pressure ventilation.Similarly noxious stimulus can cause hypertension for example laryngoscopy or painful stimulus. Vasopressor adminis tration may cause  exaggerated response. Non depolarizing relaxants requirement is less, and if needed vecuronium is preferred. Regional anaesthetic techniques contraindicated and if at all graded epidural may be beneficial.

Post Operative Management

• Adequate pain relief
• Post operative ventilation continued
• Care of bowel, bladder and skin
• Physiotherapy/prevention of DVT

Ref: http://bestpractice.bmj.com/best-practice/monograph/176/diagnosis/criteria.html,  Millers anaesthesia 6th edition, Harrisons principles 17 th edition, Stoelting anaesthesia and co existing disease 4th edition, E- med; http://www.emedicine.medscape.com,gbs/

HOT ISSUES NOW!

The recent H1N1 pandemic has brought concern and fear about Guillain Barre syndr ome once more. The issues raised were whether swine flu itself can cause GBS? and whether vaccination agaist H1N1 is associated with increased risk of Guillain Barre syndrome? Let us see what CDC, media, authorities, and experts say about this. Like other viral infections, H1N1 infection itself has the potential for triggering an immune reaction leading on to GBS, but the estimated incidence is unknown. The available literature supports the safety of vaccine.This is a controversial issue and the blogger has no personal opinion about this. Follow the links and arrive at a conclusion.

http://www.cdc.gov/h1n1flu/vaccination/gbs_qa.htm
http://www.phac-aspc.gc.ca/alert-alerte/h1n1/faq/faq_rg_h1n1-fvv-eng.php
http://www.cbsnews.com/stories/2009/11/20/earlyshow/health/main5723397.shtml
www.cdc.gov/eid/content/16/3/pdfs/09-1699.pdf
http://www.flutrackers.com/forum/showthread.php?p=343548
http://www.reuters.com/article/idUSTRE50R6IK20090128