A patient with myasthenia gravis showing lower sensitivity to rocuronium and earlier recovery of train-of-four responses on electromyography compared to acceleromyography: a case report

Abstract

BACKGROUND: Although newly developed electromyographic devices have been introduced in anesthetic practice, reports on their use in patients with myasthenia gravis (MG) are lacking. We describe electromyographic monitoring combined with acceleromyography in a myasthenic patient. CASE PRESENTATION: A 55-year-old female underwent robot-assisted thoracoscopic thymothymectomy due to MG associated with thymoma. At general anesthesia induction, 0.13 mg/kg of rocuronium completely suppressed the acceleromyographic train-of-four (TOF) response, enabling tracheal intubation. However, the electromyographic TOF count remained at 4. Intraoperatively, rocuronium was administered whenever the acceleromyographic TOF count reached 1, which was consistently delayed compared to the electromyographic TOF count of 1. After surgery, sugammadex 2 mg/kg was administered following confirmation of a TOF count of 2 on both monitors, which enabled successful extubation in the operating room. CONCLUSIONS: This case suggests that combining electromyography with acceleromyography might be more beneficial than electromyography or acceleromyography alone in myasthenic patients, until further evidence is available.