The Approach to a Patient with a Myasthenic Crisis in an Intensive Care Unit

Abstract

Myasthenia gravis (MG) is an autoimmune disorder characterized by fatigable skeletal muscle weakness resulting from an antibody-mediated reaction against acetylcholine receptors. The authors present a case of a myasthenic crisis to highlight differential diagnosis and treatment specificities to consider in the critical care setting.

A 69-year-old man with no prior relevant medical history was diagnosed with MG following a 2-month history of recent ocular palsy. Symptoms evolved rapidly with out-of-proportion asthenia when chewing and later difficulty walking due to extreme muscle weakness. He presented to the emergency room with acute respiratory failure and was admitted to the intensive care unit. High-dose glucocorticoid and intravenous immune globulin were initiated with a paucity of clinical response followed by plasma exchange. Orotracheal intubation for respiratory support was necessary.

The patient had a remarkable clinical response to plasma exchange and was extubated in 48 h. After extubation, noninvasive ventilation was initiated. Pulmonary rehabilitation guaranteed the extubation success. Rituximab therapy was started, and the patient was discharged 15 days after hospital admission with an unremarkable neurological examination.

A precipitating factor was not identified. In our diagnostic workup, the patient also presented with pernicious anemia with anti-intrinsic factor antibodies that raised suspicion of an autoimmune polyglandular syndrome, but no clinical thyroid disease or diabetes was diagnosed.