Guillain-Barre Syndrome

Guillain-Barre syndrome - also known as acute post-infective polyneuritis - is a disease of the peripheral nervous system, affecting the nerves to the arms, legs, head and trunk, but not the brain or spinal cord. An autoimmune reaction following an acute infection Affects peripheral nerve myelin Causes acute, rapid sergmental demyelination of peripheral nerves and some cranial nerves Not inherited, Genetic factors may make some people more likely to develop autoimmune conditions. Complete recovery may take upto 2 years Death may occur in 3-8 % of patients and it is due to respiratory failure, autonomic dysfunction, sepsis or pulonary emboli

Pathophysiology Myelin sheath covers nerves, insulates, speeds conduction of impulses Myelin produced by Schwann cell In Guillain-Barre Syndrome Schwann cell spared – mylination later becomes possible. Cell mediated immune attack on myelin sheath Inflammation of the myelin  destruction of the myelin

Clinical Manifestations Initial ly headache, vomiting, fever Back and limb pain Followed by paralysis Starts as tingling and numbness followed by increasing weakness. Paralysis is progressive and ascending May have a sudden onset and affect all four limbs at once. The degree of paralysis varies. H/O viral illness in the previous few weeks Weakness in all the limbs symmetrical Paresthesias in the feet and hands

Begins with muscle weakness and diminished reflexes of the lower extremities Upward Progression of the above symptoms over several days to one month May lead to quadriplegia Respiratory muscles may be affected leading to respiratory failure About 25% of patients may require mechanical ventilation within 18 days of symptom onset.Clinical Manifestations Sensory symptoms : paraesthesias of the hands and feet and pain related to the demyelination of sensory fibers

Blindness – optic nerve demyelination Bulbar muscle weakness – 9th and 10th nerve demyelination 10th nerve involvement – autonomic dysfunction – instability of the cardiovascular system. Leading to tachycardia, bradycardia, hypertension or orthostatic hypotension Autonomic dysfunction – rapidly resolves Guillain-Barre Syndrome does not affect cognitive function or level of consciousness.

Diagnosis CSF proteins elevated without any change in the other cells more than 45 mg//dL within 3 weeks Evoked potential sutdies demonstrate a progressive loss of nerve conduction velocity Abnormalities of F waves (absence, dispersion , impersistence) in at least two limbs Motor nerve conduction block, or slowing (motor nerve conduction velocity below 80% of normal

Medical Management A medical emergency Intensive care unit management Ventilatory support may be needed Prevent complications of immobility Plasmapheresis – IVIG Continuous ECG monitoring For tachycardia and hypertension – beta blockers Hypotension – IV fluid

Nursing interventions Maintain respiratory function : incentive spirometer, chest physiotherapy, monitor vital capacity, early intervention and mechanical ventilation if vital capacity is < 12 to 15 ml/Kg for 4 to 6 hours or if patient is not able to clear secretions BP and heart rate assessed frequently – if autonomic dysfunction – intervene Enhance physical mobility : extremities that are paralysed splinted in functional position; physiotherapy, prevent bed sore

Cheking with spirometer whether Respiratory muscles are being weakened

Treatment Options Corticosteriods:  Steroids have been used to try to increase muscle usage, but no evidence supports this therapy . Plasmapheresis (Plasma Exchange): Approximately 200 to 250mL/kg of plasma is exchanged over 7-14 days to filter out possible antibodies and harmful substances in the blood.  This treatment has been shown to provide improvement for only a small population of patients . Intravenous immunoglobulin: Injections of high dosages of human immunoglobulin (0.4 g/kg per day for 5 days) have been found to be somewhat effective for a small population of patients. Antibiotics:  Possible early treatment with erythromycin may help produce a shorter duration of illness if the patient has campylobacter associated GBS . Rehabilitation: Physical therapy to improve muscle tone and strength as well as counseling is the major form of treatment.