Myasthenia Gravis Flashcards
What is Myasthenia Gravis
Myasthenia gravis is an autoimmune disorder affecting the myoneural junction, is characterized by varying degrees of weakness of the voluntary muscles.
Pathophysiology
In MG, the receptors at the muscle surface are destroyed or deformed by antibodies that prevent a normal muscular reaction from occurring.
The causative factor is unknown, but the disorder may have a genetic link
RISK FACTORS:
Female gender and age under 40 years
Male gender and age over 60 years
Other autoimmune disorders
Factors that can worsen myasthenia gravis
Fatigue
Illness/infection
Stress/emotional distress
Extreme heat
Some medications — such as beta blockers, calcium channel blockers, quinine and some antibiotics like cipr and aminoglycosides
Clinical Manifestations
Diplopia and ptosis
Generalized weakness.
Bland facial expression.
Voice impairment and dysphonias
Difficulty chewing/Aspiration
Decreased respiratory capacity
No sensory loss, reflexes normal- because it is a motor disorder
Diagnostic Tests
History and Physical
Edrophonium test:
Injection of the chemical edrophonium (Tensilon) may result in a sudden, although temporary, improvement in muscle strength - an indication that patient may have myasthenia gravis. It could make muscle weakness worse. Must have atropine available to reverse Tensilon
A blood test may reveal the presence of abnormal antibodies.
Ice Pack test- Improve muscle strength
Treatment
Cholinesterase inhibitors-Pyridostigmine ( Mestinon) – most successful for long term treatment. Give 45 min to an 1 hour before a full meal. Can give with a small snack so that way they can eat after med has been able to increase muscle strength to prevent aspiration
Corticosteroids-Prednisone
Immunosuppressant
Plasmapheresis
IV immunoglobulin G
Surgery- removal of thymus gland to decrease ?
SURGICAL MANAGEMENT
Nursing Assessment
Assess for severity of MG
Assess for coping abilities and strategies
Respiratory assessment
Assess muscle strength of face, limbs, swallowing, speech, cough and gag reflexes
Overall Goal
Return of normal muscle endurance
Manage fatigue
Avoid complications
Maintain a quality of life appropriate to the disease process
Nursing management
Maintain adequate ventilation
Continue drug therapy/side effects
Cholinergic vs myasthenic crisis
MC-Is when S/S are getting worse but meds help
Cholinergic- OD of meds increasing acetycholine at receptor sites.
Patient teaching
Diet
Scheduling of medications
Arrange activities requiring less physical effort- In the early morning 2 muscles being stronger
Follow medical regimen and schedule to work with when they will eat excetera
Complications of therapy-teach cholinergic crisis
Community resources
Highlights
Assessment for respiratory and swallowing, Medication scheduling, activities, and patient teaching
