Myasthenic Gravis Crisis in an 85-Year-Old Male Requiring Emergent Intubation and Plasmapheresis

Myasthenia gravis (MG) is a chronic autoimmune neuromuscular disorder caused by autoantibodies targeting acetylcholine receptors at the neuromuscular junction, leading to impaired synaptic transmission and muscle weakness. Myasthenic crisis (MC) is a life-threatening complication characterized by severe respiratory muscle weakness, often necessitating emergent airway management and intensive care. Common triggers for MC include infections, stress, medication changes, and underlying malignancies. Standard management includes ventilatory support, immunomodulatory therapies such as plasmapheresis or intravenous immunoglobulin (IVIG), and corticosteroids. We present the case of an 85-year-old male with a history of ocular MG on pyridostigmine, Parkinson's disease on carbidopa/levodopa, and colorectal adenocarcinoma on active chemoradiation. He presented to the emergency department with three days of worsening facial weakness, dysphagia, dysarthria, and respiratory distress. Examination revealed significant bulbar weakness, inability to clear secretions, and hypoxia despite noninvasive ventilatory support. His negative inspiratory force (NIF) deteriorated from -12 to -10, prompting emergent intubation for airway protection. Given his ongoing respiratory failure, he underwent plasmapheresis with subsequent clinical improvement. He remained intubated for four days, completed six sessions of plasmapheresis, and was transitioned to rehabilitation upon discharge. This case highlights the unpredictable nature of MC, emphasizing the need for early recognition and timely intervention in the emergency setting. It highlights the importance of multidisciplinary management, including neurology and critical care, and the role of plasmapheresis as a rapid and effective therapeutic option for severe MG exacerbations.