A patient with myasthenia gravis may develop respiratory insufficiency after surgery, with some patients requiring intubation and mechanical ventilation. This can be a real problem if the myasthenia gravis has gone undiagnosed prior to surgery.
Risk factors for respiratory complications:
(1) severe bulbar involvement (significant dysarthria and/or dysphagia)
(2) use of muscle relaxants
(3) failure to closely monitor neuromuscular function while using muscle relaxants, with doses higher than required to achieve adequate blockade
Complications associated with muscle relaxants can be avoided by:
(1) not using muscle relaxants
(2) the use of sugammadex to reverse
(3) the use of an acetylcholinesterase inhibitor to reverse
Some patients with myasthenia may have a reduced number of functional acetylcholine receptors. This can be associated with:
(1) relative resistance to succinylcholine, causing unpredictable blockade
(2) delayed reversal with an acetylcholinesterase inhibitor
