Evaluation of neuromuscular blocker use in myasthenia gravis patients undergoing rapid sequence intubation

Myasthenia gravis (MG) pathophysiology and drug-drug interactions with cholinesterase inhibitors can make patients both relatively sensitive and resistant to neuromuscular blocking agents (NMBAs). NMBA dose adjustments in MG patients undergoing rapid sequence intubation (RSI) are described in anesthesia literature but not outside of the operating room (OR). This study sought to characterize NMBA use in MG patients undergoing RSI outside of the OR.

Retrospective, observational, multicenter study of MG patients undergoing RSI outside of the OR from January 2011-September 2023. Patient demographics, NMBA used and dose, and post-intubation monitoring were collected. Data are reported descriptively.

Forty-four cases were included; median age 74 years (IQR 59.8-81.0), 31.8% receiving pyridostigmine, 88.6% intubated for respiratory failure, 81.8% received rocuronium. Only 11 cases (25%) had an NMBA dose adjustment. No cases experienced inadequate paralysis. Of the 24 cases (54.5%) with monitoring within the expected NMBA recovery timeframe, 75% had documented recovery. Of these, only one case had an NMBA dose adjustment. Five cases (11.4%) experienced possible prolonged paralysis based on study definitions; one case with NMBA dose adjustment.

Most cases did not receive an NMBA dose adjustment for MG. There were limited neurologic and neuromuscular assessments available post-intubation. Cases of possible prolonged paralysis were identified. The necessity of adjusting NMBA doses in MG patients undergoing RSI remains unclear and warrants further study. Clinicians should be aware of the potential for unpredictable NMBA response in MG and need for timely monitoring and sedation and analgesia in the immediate post-intubation period.