An 80‐year‐old woman with diabetes, hypertension, and hypothyroidism was admitted with 1 week of generalized weakness. She also reported persistent left‐sided neck pain. In the office, her systolic blood pressure was 240 mm Hg, and her primary physician referred her to the emergency department. The physical exam was notable for diaphoresis, left‐sided neck tenderness, and hypoxia. Neurologic exam was normal. Lab studies showed a white blood cell count of 11.3. The chest x‐ray demonstrated an elevated right hemidi‐aphragm. Head CT and head/neck CTA revealed atherosclerotic changes. Echocardiogram showed a normal ejection fraction. She was admitted to the medical floor, where her hypertensive urgency was managed with a combination of intravenous and oral antihypertensive medications. Her generalized weakness and hypoxia worsened. Pulmonary CTA revealed right basilar atelectasis but was negative for pulmonary embolism. A respiratory viral panel was negative. On hospital day 4, she complained of cough and was empirically started on moxifloxacin for pneumonia. Her respiratory status declined—an arterial blood gas showed 7.20/107/78. The patient was transferred to the intensive care unit and intubated for hypercarbic and hypoxic respiratory failure. In the absence of an explanation for her respiratory failure, a diagnosis of a neuromuscular disorder was considered, and methylprednisolone was started empirically. Soon after, her acetylcholine receptor antibody, specific for myasthenia gravis, measured 40.07 (normal < 0.03). Pyridostigmine was started. She was then treated with both intravenous immunoglobulin and plasma‐pheresis and was extubated on hospital day 28. She was subsequently discharged to acute rehabilitation on pyridostigmine and a steroid taper.
Myasthenia gravis, an autoimmune disorder affecting the neuromuscular junction, classically presents with focal weakness, ocular dysfunction, and bulbar symptoms. However, it may go unrecognized, particularly in the elderly, as was the case here. This patient was in myas‐thenic crisis, with severe respiratory muscle weakness, resulting in hypercarbic hypoxic respiratory failure. Crises may be initiated by respiratory illness or certain medications, but the trigger is often unknown.
Although acute respiratory failure is a common condition seen by hospitalists, its underlying etiology can be elusive. This challenging case demonstrates the importance of considering a neuromuscular disease in the setting of hypercarbic hypoxic respiratory failure in the absence of overt central nervous system depression or a history of severe chronic lung disease.
B. Gentilesco ‐ none; K. Lee ‐ none
To cite this abstract:Gentilesco B, Lee K. Myasthenia Gravis Presenting with Acute Respiratory Failure. Abstract published at Hospital Medicine 2011, May 10-13, Dallas, Texas. Abstract 285. Journal of Hospital Medicine. 2011; 6 (suppl 2). https://www.shmabstracts.com/abstract/myasthenia-gravis-presenting-with-acute-respiratory-failure/. Accessed January 26, 2020.