Neuromuscular blocker reversal in a patient with myasthenia gravis or suspected pseudocholinesterase deficiency: key considerations?

• A. Myasthenia gravis decreases sensitivity to nondepolarizing agents.
• B. Succinylcholine is preferentially used in myasthenia gravis.
• C. Myasthenia gravis increases sensitivity to nondepolarizing agents; use careful dosing and TOF monitoring; reversal should be titrated.
• D. TOF monitoring is unnecessary.

Answer: (C)

In myasthenia gravis, there are fewer functional nicotinic receptors at the neuromuscular junction, so the patient is more susceptible to blockade from nondepolarizing neuromuscular blockers. That means you need to use smaller doses and rely on objective monitoring to judge how complete the blockade is and when it’s wearing off. Because recovery can be unpredictable, reversal should be guided and titrated rather than given in a fixed amount. Train-of-four monitoring provides a direct readout of receptor occupancy and helps you avoid both residual weakness and over-reversal.

If pseudocholinesterase deficiency is a concern, that primarily affects depolarizing agents like succinylcholine, which would have a prolonged duration. This reinforces the preference for nondepolarizing agents in such scenarios and underlines the need for careful dosing and monitoring of reversal with a cholinesterase inhibitor, adjusted to the TOF response, to ensure a safe and complete recovery of neuromuscular function. The key point is that MG increases sensitivity to nondepolarizing blockers, so dosing must be careful and reversal must be titrated with objective monitoring.