Myasthenia Gravis

 Describe myasthenia gravis  Signs and Symptoms of the disease  Describe the treatments available Purpose and Objectives

An autoimmune disease in which a person’s antibodies are against the acetylcholine receptor (AChR). IgG antibody is against the AChR on the muscle cells, which in turn blocks the binding of acetylcholine. This disease causes muscle weakness and fatigue. It results from a defect in the nerve impulse transmission at the neuromuscular junction. It affects the muscles of the face, lips, tongue, neck, and throat. (Carpenter, 2010) What is Myasthenia Gravis?

Myasthenia Gravis

Signs & Symptoms Patient may present with….  Weak eye closure, ptosis,  Skeletal (voluntary) muscle weakness and fatigue  Blank facial expression  Weak neck muscle (might be too weak to hold head straight)  Weak respiratory muscles

 Exact cause is unknown.  Could be caused by an autoimmune response, inadequate muscle fiber response to acetylcholine.  Myasthenia gravies affects 1 in 25,000 people at any age, but more common in ages  It is more common in women. (Carpenter, 2010)

Diagnostic test/labs  Chest X rays and MRI- check for the presence of thymoma.  Tensilon test- doctor administers edrophonium via IV injection and then have the patient performs a series of voluntary movement.  Blood test to check for the presence of IgG antibody.  Neurological examination  Electromyography- to check muscles and nerves

Treatments  Anticholinesterase drugs- neostigmine and pyridostigmine (helps muscles & nerves communicate better)  steroids and immunosuppressant therapy –azathioprine, cyclosporine, and cyclophosphamide  These drugs do NOT cure the disease; however, it improves the symptoms.  Rest  Eye patch for patients experiencing diplopia.  Avoid stress and prolong heat exposure to avoid symptoms.  Thymectomy

Between 1915 to1966, the prevalence of people with MG as about 1 in 200,000, and 70% of the patients with MG died as a result of respiratory failure or pneumonia. However, with the improvement of anticholinesterase, the prevalence of MG was about 1 in 20,000 and death rate dropped to a 30% by (Grob, Brunner, Namba, Pagala, 2008)

According to a study done in Germany, patients who have a thymectomy are more likely to experience less symptoms than those who are treated with other treatments. The study was done with 172 participants, and those who had a thymectomy had a bigger improvement than those who did not. (Bachmann 2008)

Prognosis & Outcomes  Unfortunately, there is no known cure for myasthenia gravis; however, a patient is able to experience no symptoms as long as medications are taken as prescribed.

Nursing diagnosis  Risk for aspiration r/t muscle weakness

Nursing intervention  Monitor respiratory rate, depth and effort.  Auscultate lung sounds before and after feedings  Check gag reflex and ability to swallow before feeding patient.  Feed patient slowly and allow enough time to chew  Keep head elevated at about 30 or 45 degrees

Medical interventions  Write prescriptions such as anticholinesterase drugs (neostigmine and pyridostigmine)  Provide thymectomy- in patients with thymoma and those who have anti- AChR antibodies because it kills the cells that produce such antibodies.  Provide plasma exchange in which dangerous antibodies are removed from the blood.

Patient case scenario  Patient was a 53 year old female who was admitted to ER after a severe allergic reaction to Mestinon. She stated that she developed a rash throughout her whole body after two hours of taking the medication for myasthenia gravis. The rash was red and palpable. It first started on her back and then it extended to her whole body. Patient took Benadryl to treat the rash at home, but it did not work. Then she came to the hospital.

Nursing interventions for case scenario  Monitor temperature  Assessing skin for edema, erythema, moisture, and appearance  Administering medicine  Assessing vital signs

Medical interventions  Write prescription stop the rash such as Solumedrol  Write prescription for anticoagulation such as Fragming  Provide immunoglobin therapy (since patient has MG)

 Myasthenia gravis results from a defect from  A). Antibodies  B). neuromuscular junction  C).plasma membrane  D). muscle

NCLEX style questions  Which type of antibody is involved in Myasthenia gravis? a). IgG b). IgA c). IgB d).IgM

 Which type of muscle is affected by MG? A). Smooth B). Cardiac C). Skeletal D). nervous

 A patient who is prescribed anticholinesterase drugs for MG asks the nurse what will medication do. What is nurse’s best response? A). This medication will cure MG B). This medication will relieve the pain that results with MG C. this medication will help the cells of the muscles and nerves communicate better D). This medication will relieve the inflammation

Myasthenia gravis is curable A. False B. True

References  Huether S., McCance K., (2012) Understanding Pathophysiology. (5 th edition). St. Louis, Missouri. Elesvier.  Carpenter D. (2010) Atlas of Pathophysiology. Springhouse, California. Springhouse.  Bachman K. (2008). Thymectomy is more effective than conservative treatment for myasthenia gravis regarding outcome and clinical improvement. April 2009, Vol 145, issue 4, pages Retrieved from SrZrTES3xn.6 SrZrTES3xn.6  Grob, D., Brunner, N., Namba, T. and Pagala, M. (2008), Lifetime course of myasthenia gravis. Muscle Nerve, 37: 141–149. doi: /mus.2095 retrieved from