title: Impact of continuous intraoperative neuromonitoring on autonomic nervous system during thyroid surgery.
abstract: BACKGROUND
  Continuous intraoperative neuromonitoring (CIONM) via vagal nerve stimulation (VNS) is a new option for recurrent laryngeal nerve (RLN) protection during thyroid surgery. The aim of this study was to evaluate the safety of VNS for CIONM and to assess its effects on the autonomic nervous system (ANS) through analyzing heart rate variability (HRV).
  
  
  METHODS
  In a prospective, nonrandomized controlled study 5 patients received VNS for CIONM and 5 were operated on with conventional intermittent intraoperative neuromonitoring (IONM). HRV was analyzed in accord with patient-specific reference values.
  
  
  RESULTS
  VNS resulted in significantly altered ANS balance. Relative parasympathetic activity increased during VNS. Yet, no relevant cardiac arrhythmias or hemodynamic alterations were observed during VNS.
  
  
  CONCLUSIONS
  HRV analysis revealed a distinct impact of VNS for CIONM on ANS balance. VNS caused parasympathetic predominance that was not countered by increased sympathetic activity.
authors.affiliation: Department of General and Visceral Surgery, Robert-Bosch-Hospital, Stuttgart, Germany. christoph.ulmer@rbk.de
authors.forename: Christoph
authors.initials: C
authors.lastname: Ulmer
authors.forename: Colin
authors.initials: C
authors.lastname: Friedrich
authors.forename: Andrea
authors.initials: A
authors.lastname: Kohler
authors.forename: Fabian
authors.initials: F
authors.lastname: Rieber
authors.forename: Tarkan
authors.initials: T
authors.lastname: Basar
authors.forename: Michael
authors.initials: M
authors.lastname: Deuschle
authors.forename: Klaus-Peter
authors.initials: KP
authors.lastname: Thon
authors.forename: Wolfram
authors.initials: W
authors.lastname: Lamadé
mesh_terms: D000328:Adult; D001341:Autonomic Nervous System / Q000503:physiopathology*; D004576:Electromyography; D005260:Female; D006042:Goiter / Q000601:surgery; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods*; D010275:Parasympathetic Nervous System / Q000503:physiopathology; D011446:Prospective Studies; D013959:Thyroid Diseases / Q000601:surgery*; D016606:Thyroid Nodule / Q000601:surgery; D013965:Thyroidectomy; D014630:Vagus Nerve; D014826:Vocal Cord Paralysis / Q000503:physiopathology*