題目

The least appropriate option is D, as reducing the dose of short-acting depolarizing muscle relaxants is not recommended; these agents should generally be avoided in myasthenia gravis patients due to the risk of prolonged neuromuscular blockade and unpredictable response. Myasthenia gravis is characterized by autoimmune destruction of acetylcholine receptors, resulting in a decreased number of functional postsynaptic receptors and increased sensitivity to nondepolarizing neuromuscular blocking agents. This necessitates reduced dosing and careful perioperative monitoring with train-of-four peripheral nerve stimulation to prevent postoperative respiratory failure and ensure safe extubation. Preoperative evaluation of acetylcholinesterase inhibitor dosage is appropriate, as continuing pyridostigmine perioperatively is recommended to maintain neuromuscular function and avoid respiratory distress, but excessive dosing may precipitate cholinergic crisis. Perioperative monitoring with quantitative train-of-four is standard practice to guide neuromuscular blockade and recovery, given the high risk of postoperative respiratory failure in myasthenic patients. Short-acting depolarizing muscle relaxants (e.g., succinylcholine) should generally be avoided in myasthenia gravis. Patients on cholinesterase inhibitors have reduced plasma cholinesterase activity, leading to unpredictable and often prolonged effects of depolarizing agents, and dose reduction does not reliably mitigate this risk. The Society of Critical Care Medicine and other expert reviews recommend avoiding succinylcholine and instead using reduced doses of nondepolarizing agents with neuromuscular monitoring.