Neuromuscular monitoring in myasthenic syndrome.
We describe the anaesthetic management of a 72-year-old man with myasthenic syndrome. Pre-operatively, he was treated with 3,4-diaminopyridine and showed a strong hand grip. During general anaesthesia with nitrous oxide and sevoflurane in oxygen, a mechanomyograph and two accelerographs were set up for the hands and left foot to monitor neuromuscular function. Insufficient force and acceleration of contraction with 1 Hz stimulation was observed in the hands. In the foot, the twitches produced by 1 Hz and train-of-four stimulation could barely be detected using the accelerograph, and the train-of-four ratio fluctuated between 70 and 100%. No neuromuscular blocking drugs were used during surgery. After discontinuation of sevoflurane, responses to train-of-four stimulation remained small, but a strong response to tetanic stimulation was observed, with post-tetanic facilitation. Extubation was successful, and recovery from anaesthesia was uneventful. Tetanic stimulation and post-tetanic facilitation are important in monitoring neuromuscular function in patients with myasthenic syndrome whose train-of-four responses are insufficient.
Itoh
H
H
Department of Anaesthesiology and Intensive Care Medicine, Kanazawa University School of Medicine, 13-1 Takara-machi, Kanazawa 920-8641, Japan. hironori@med.kanazawa-u.ac.jp
Shibata
K
K
Nitta
S
S
D000368:Aged; D000769:Anesthesia, Inhalation; D006801:Humans; D015624:Lambert-Eaton Myasthenic Syndrome / Q000503:physiopathology*; D008297:Male; D016343:Monitoring, Intraoperative / Q000379:methods*; D009469:Neuromuscular Junction / Q000503:physiopathology*