title: Comparison of two electromyographical endotracheal tube systems for intraoperative recurrent laryngeal nerve monitoring: reliability and side effects.
abstract: BACKGROUND
  Recurrent laryngeal nerve (RLN) monitoring systems should be reliable and safe. Monitoring via electromyographical systems on an endotracheal tube (ETT) is widely spread. The MagStim™ system consists of an adhesive electrode to be fixed on an endotracheal tube. The Xomed™ endotracheal tube provides integrated electrodes. Reliability and side effects had never been compared. As both systems have very different morphological properties, we hypothesized that there might be differences in reliability and the incidence of side effects.
  
  
  METHODS
  In a retrospective quality management analysis of 118 patients (MagStim™ electrode, 57 patients; Xomed™ ETT, 61 patients), we compared laryngeal side effects according to the Chilla score and detection rate of the RLN.
  
  
  RESULTS
  Both systems had comparable detection rates of the RLN above 95%. Both electrode systems seemed to have similar reliability. Difficulties to detect the nerve were observed in seven patients (four with MagStim, three with Xomed). In the group with the Xomed™ ETT, significantly less mild laryngeal side effects were observed.
  
  
  CONCLUSIONS
  Both MagStim™ and Xomed™ ETT were reliable in detecting the RLN. The Xomed™ ETT, however, might cause milder laryngeal side effects compared with the MagStim™ electrode.
authors.affiliation: Department of Anaesthesiology, University of Erlangen-Nuremberg, Krankenhausstr 12, 91054, Erlangen, Germany. t.birkholz@gmx.de
authors.forename: Torsten
authors.initials: T
authors.lastname: Birkholz
authors.forename: Christina
authors.initials: C
authors.lastname: Saalfrank-Schardt
authors.forename: Andrea
authors.initials: A
authors.lastname: Irouschek
authors.forename: Peter
authors.initials: P
authors.lastname: Klein
authors.forename: Sven
authors.initials: S
authors.lastname: Albrecht
authors.forename: Joachim
authors.initials: J
authors.lastname: Schmidt
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D015331:Cohort Studies; D004576:Electromyography / Q000295:instrumentation* / Q000379:methods; D005260:Female; D006801:Humans; D007431:Intraoperative Complications / Q000517:prevention & control; D007442:Intubation, Intratracheal / Q000295:instrumentation* / Q000379:methods*; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000295:instrumentation* / Q000379:methods; D016105:Parathyroidectomy / Q000009:adverse effects / Q000379:methods; D012009:Recurrent Laryngeal Nerve / Q000502:physiology*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric; D013965:Thyroidectomy / Q000009:adverse effects / Q000379:methods; D016896:Treatment Outcome; D055815:Young Adult