Nursing management of Myasthenia Gravis Today’s topic is Nursing Management for clients with myasthenia gravis.

Pathophysiology – Myasthenia Gravis (MG) A chronic progressive disorder of the peripheral nervous system affecting transmission of nerve impulses to voluntary muscles Etiology: unknown An autoimmune process triggers formation of autoantibodies that decrease number of acetylcholine receptors and widen gap between axon ending and muscle fiber in neuromuscular junction

Pathophysiology Muscle contraction is hindered because IgG autoantibodies prevent acetylcholine from binding with receptors at neuromuscular junction Onset is slow precipitated by emotional stress, hormonal disturbance (pregnancy, thyroid disturbance), infection/vaccination, trauma, surgery, temp extremes, excessive exercise

Etiology Associated with continued production of autoantibodies by thymus gland in 75% of cases family history of autoimmune disorders are implicated

Clinical Manifestations Muscle weakness Double vision (diplopia) weak eyelids (unilateral ptosis) Difficulty speaking or smiling Difficulty chewing and swallowing

Specific clinical manifestations

Assessment of Labs/Diagnostics Arterial Blood Gas & Pulmonary function tests For respiratory compromise Electromyography (EMG) Decreased amplitude when motor neurons are stimulated Confirming diagnosis IV administration of edrophonium chloride (Tensilon) Allows acetylcholine to bind with its receptors and temporarily improves symptoms Weakness returns after effects of Tensilon are discontinued

Problems with MG Ineffective airway clearance Impaired verbal communication Activity intolerance

Interventions Focuses on medication management with anticholinesterases neostigmine (Prostigmin) pyridostigmine (Mestinon) Immunosuppressant corticosteroids, azathioprine (Imuran), and cyclosporine (Neoral) Anti-inflammatory medications Thymectomy Plasmapheresis Removes IgG (antiacetylcholine) antibodies Atropine sulfate for cholinergic crisis

Interventions Maintain effective breathing pattern and airway clearance Assess for respiratory distress Monitor meals and teach client to bend head slightly forward while eating and drinking to improve swallowing Teach client to avoid exposure to infections Teach client to effectively coughing, use chest physiotherapy and incentive spirometry Provide adequate nutrition Schedule meds 30-45 minutes before eating for peak muscle strength Offer food frequently in small amounts that are easy to chew and swallow (soft or semisolid) Promote improved physical mobility with referrals to physical therapy and/or occupational therapy Provide eye care: instill artificial tears; use a patch over one eye for double vision; wear sunglasses to protect eyes from bright lights

Client education Take medication on time and keep prescriptions filled Plan rest periods and conserve energy, plan major activities early in day, schedule activities during peak medication effect Avoid extremes of hot and cold, exposure to infections, emotional stress and meds that may worsen or precipitate an exacerbation (alcohol, sedatives, and local anesthetics) Recognize and report signs of crises Use alternative methods of communication if needed

Evaluation: Desired Outcomes Maintain Muscle function Minimize side effects of medications Minimize complications of MG (myasthenic or cholinergic crises) Maintain quality of life

Comparison of myasthenia and cholinergic crises Myasthenia Crisis Cholinergic Crisis Failure to take medication as prescribed or medication too low Over dose of anticholinesterase medications resulting in increased Acetylcholine at the receptor sites

Evaluation Maintain optimal muscle function Be free from side effects of medications Client maintains patent airway and breathing without aspiration Maintain activities of daily living with assistance Demonstrates adequate coping skills for managing chronic and debilitating illness

References Rangel-Castillo, L, Gopinath, S., & Robertson, C.S. (2009). Management of intracranial hypertension. Neurologic Clinics, 26(2), 521-541. Ignatavicius, D. D. & Workman, M. L. (2010). Medical-surgical nursing: patient-centered collaborative care (6th ed.). St. Louis, MO: Saunders Elsevier. Lewis, S. L., Heitkemper, M. M., Dirksen, S. R., & Bucher, L. (2014). Medical-surgical nursing: Assessment & management of client problems (9th ed.). St. Louis, MO: Mosby Hogan, M., Dentlinger, N.C., & Ramdin, V. (2014). Medical- surgical: nursing pearson nursing reviews and rationales (3rd ed.). Boston, MA: Pearson.