Myasthenia Gravis Research Paper

Introduction Myasthenia gravis is a neuromuscular autoimmune disorder that affects the skeletal muscles in the body. This disorder is mainly characterized by periods of weakness in the body. The Latin meaning for myasthenia gravis is grave muscle weakness (Lewis 2007). In the United States the prevalence rate is 14 per 100,000 (Lewis 2007) myasthenia gravis can affect any age, but normally it affects people over the age of 50 (Lewis 2007) The mortality rate from myasthenia gravis has declined from 42% in the early 1960 to 6% in the 1970s (Levine 2011). Currently with advances in treatment, most people with myasthenia gravis have a 4% mortality rate and usually caused by other conditions (Levine 2011). Myasthenia Gravis …show more content…
Myasthenia crisis affects the respiratory muscles in the upper airway (Levine 2011). A physical sign a patient is experiencing a crisis is patients will use there accessory muscles to breathe and lack the ability to count to 20 (Levine 2011). Inspiratory function is determined by vital capacity (VC) and negative inspiratory force NIF (Levine 2011). A VC less than 1 L or a NIG less than 20cm H20 is an indicator for respiratory weakness (Levine 2011). A positive expiratory force (PEF) of less than 40cm H2O may be an indicator for a crisis (Levine 2011). The patient exhibiting any of the above findings is clinically appropriate for mechanical ventilation (Levine …show more content…
Drug therapy for myasthenia gravis includes corticosteroids, immunosuppressant and anticholinesterase drugs. Anticholinesterase drugs like neostigmine and pyridostigme, are designed to improve function at the neuromuscular junction (Lewis 2007). Immunoglobulin (IVIg) and plasma exchange are drug therapies used for severe myasthenia gravis or crisis (Behan & Chaudri 2008). Patients can be a candidate for surgery. The presence of the thymus appears to enhance the myasthenia gravis. Thymoma is found in 15% of patients with mysasthenia gravis and 32% in patients with myasthenic crisis (Behan & Chaudri 2008). Thus removing the thymus gland, especially if a thymoma is present, will produce improved results for a majority of patients (Behan & Chaudri 2008). If the patient is experiencing a myasthenic crisis then respiratory support is imperative for these patients. Two-thirds to 90% of all patients in a crisis must be intubated and mechanically ventilated (Behan & Chaudri 2008). If the patient is about to have a crisis, elective intubation is a preferred practice instead of doing an emergent one. Once the patient is intubated, the settings should be placed with tidal volumes of 8-10cm/kg and pressure support of 8-15cm H2O to prevent atelectasis and minimize the work of breathing (Behan & Chaudri