American Board of Internal Medicine (ABIM) Certification Practice Exam

What role does plasmapheresis play in treating myasthenic crisis?

1. It helps in long-term management.

2. It is a rescue therapy for refractory cases.

3. It should be avoided.

4. It is the first-line treatment.

The correct answer is: It is a rescue therapy for refractory cases.

Plasmapheresis serves as a rescue therapy for patients experiencing a myasthenic crisis, which is characterized by severe muscle weakness and respiratory failure due to exacerbated myasthenia gravis. This procedure involves the removal of antibodies from the bloodstream that contribute to the dysfunction of the neuromuscular junction in this condition. In acute settings, plasmapheresis can rapidly reduce the levels of these circulating autoantibodies, leading to an improvement in muscle strength and respiratory function in a short time frame. While plasmapheresis is not the first-line treatment—typically, corticosteroids and other immunosuppressive agents might be used in chronic management—the urgent nature of a myasthenic crisis necessitates proactive measures to prevent respiratory compromise. Therefore, it is primarily employed in urgent situations where other treatments have failed or are not rapidly effective. This makes it a vital tool in critical care for managing severe exacerbations of myasthenia gravis.