• Hironori Itoh, Keizo Shibata, and Shunichi Nitta.
• Department of Anesthesiology and Intensive care Medicine, Kanazawa University School of Medicine, 13-1 Takara-machi, Kanazawa 920-8641, Japan. hironori@med.kanazawa-u.ac.jp
• Anesth. Analg. 2002 Jul 1;95(1):109-13, table of contents.

UnlabelledPatients with myasthenia gravis (MG) are hypersensitive to nondepolarizing neuromuscular blocking drugs. Although antibodies to the acetylcholine receptor (AChR) often are observed in MG patients, 10% to 30% of patients do not show an anti-AChR antibody. Little is known about differences in sensitivity to nondepolarizing neuromuscular blocking drugs between MG patients with and without anti-AChR antibody. Hypothesizing that seronegative patients are as sensitive to vecuronium as seropositive patients, we assessed sensitivity in seropositive and seronegative MG patients and in non-MG patients (n = 8 each). During anesthesia with sevoflurane (2.5%) and nitrous oxide (60%) in oxygen, neuromuscular transmission was monitored by measuring the twitch tension of the adductor pollicis muscle with supramaximal stimulation. After baseline measurements, 10 microg/kg IV dose increments of vecuronium were administered sequentially until blockade exceeded 90%. The degree of blockade and onset time after the initial 10 microg/kg of vecuronium were assessed, and doses required to exceed 90% blockade were recorded. In addition, effective doses of 50% and 95% for vecuronium were calculated from a single data point. Both types of MG patients showed increased sensitivity to vecuronium compared with non-MG patients.ImplicationsHypothesizing that seronegative patients are as sensitive to vecuronium as seropositive patients, we assessed sensitivity in seropositive and seronegative myasthenia gravis (MG) patients and in non-MG patients. They were, indeed, both equally sensitive to vecuronium.

22 keywords...

hide…