Changes of extremity and laryngeal muscle electromyographic amplitudes after intravenous administration of vecuronium

Yongbing Shi, Vivian Hou, Anne Tucker, James Cohen

Research output: Contribution to journalArticlepeer-review

10 Scopus citations


To compare electromyographic (EMG) amplitude changes in extremity and laryngeal muscles after vecuronium administration and study the effects of topical lidocaine on laryngeal EMG in a swine model. Study Design: Prospective animal study. Methods: Electrically evoked EMG activities were recorded from the vocalis muscles (directly and via an EMG endotracheal tube) and from the flexor digitorum muscles before and after intravenous vecuronium administration. EMG amplitudes were followed for 30 minutes after vecuronium injection together with monitoring of limb twitches to train-of-four stimulation. The testing was repeated after a 30-minute wash-out period and with topical lidocaine. Results: EMG amplitude recovery occurred sooner and more quickly in flexor digitorum muscle than in vocalis muscles. Reappearance of four twitches corresponded to EMG amplitude recovery to about 80% of the baseline in flexor digitorum muscles and to about halfbaseline size in vocalis muscles. EMG amplitudes were generally lower at the start of the second round testing than the first round, with somewhat slower recovery in vocalis muscles. Conclusions: In contrast to reports by others in human studies, extremity muscles seem to be more resistant to vecuronium at 0.1 mg/kg than laryngeal muscles in the swine. Reappearance of four twitches corresponds to 50% of laryngeal EMG recovery and indicates adequate condition for monitoring electrically evoked laryngeal EMG activities. This study is inconclusive regarding the effects of topically applied lidocaine on laryngeal EMG amplitudes. Translation of these data to humans should be done with caution.

Original languageEnglish (US)
Pages (from-to)2156-2160
Number of pages5
Issue number12
StatePublished - Dec 2008


  • Laryngeal EMG
  • Nondepolarizing muscle relaxant
  • Thyroid surgery

ASJC Scopus subject areas

  • Otorhinolaryngology


Dive into the research topics of 'Changes of extremity and laryngeal muscle electromyographic amplitudes after intravenous administration of vecuronium'. Together they form a unique fingerprint.

Cite this