A nurse is caring for a patient with myasthenia gravis who is experiencing increased muscle weakness, difficulty swallowing, and drooping eyelids. The physician suspects an impending myasthenic crisis. What is the most critical intervention the nurse should anticipate to prevent further complications?

Rationale: A. Encourage the patient to perform muscle strengthening exercises is incorrect because during a myasthenic crisis, the patient’s muscles are severely weakened. Exercise could increase fatigue and worsen respiratory compromise. B. Administer intravenous immunoglobulin (IVIG) as prescribed is correct because IVIG is used to rapidly improve neuromuscular transmission and reduce the severity of a myasthenic crisis. The most critical concern is preventing respiratory failure, which can occur if the crisis progresses, so prompt immunotherapy is essential. C. Increase the dosage of oral pyridostigmine is incorrect because oral medications may not act quickly enough during a crisis, and excessive dosing can sometimes worsen weakness due to cholinergic crisis. Immediate interventions like IVIG or plasmapheresis are prioritized. D. Provide a high-calorie diet to improve energy levels is incorrect because, although nutrition is important, it does not address the acute threat of respiratory compromise or severe muscle weakness seen in a myasthenic crisis.