A case of an emergency surgery in a 74-year-old man with free air in the abdomen highlights anesthetic challenges in the management of patients with myasthenia gravis. The underlying pathophysiology of myasthenia gravis is typically an autoimmune-mediated destruction of acetylcholine receptors in the neuromuscular junction, resulting in easy fatigability and weakness. The diagnosis of myasthenia gravis is established via electromyography studies and the identification of antibodies specific to myasthenia gravis. Medical treatment of myasthenia gravis involves steroids, immune modulators, plasmapheresis, and symptomatic treatment with acetylcholinesterase inhibitors. Many patients can achieve long-term cure with surgical thymectomy. Patients with myasthenia gravis present an anesthetic challenge because they can have other comorbid autoimmune diseases, compromised respiratory status, and atypical reactions to neuromuscular blockade, with resistance to succinylcholine and exquisite sensitivity to neuromuscular blockade. Potential anesthetic modifications include regional anesthesia and avoidance of neuromuscular blockade. When neuromuscular blockade is used, careful monitoring of and titration of muscle relaxation are paramount. Myasthenic patients are at high risk of requiring postoperative ventilation. Potential emergencies specific to myasthenia gravis are myasthenic crisis and cholinergic crisis, which can be difficult to distinguish and which may require emergent invasive airway management.
KeywordsMyasthenia gravis Autoimmune disease Neuromuscular blockade Thymectomy Myasthenic crisis
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