title: Impact of inhalation vs. intravenous anaesthesia on autonomic nerves and internal anal sphincter tone.
abstract: BACKGROUND
  Pelvic intraoperative neuromonitoring (pIONM) aims to identify and spare the autonomic nerves and maintain patients' quality of life. The effect of anaesthetic agents on the pIONM signal is unknown; therefore, the aim of the present study was to compare the influences of inhalation anaesthesia (IA) and total intravenous anaesthesia (TIVA).
  
  
  METHODS
  Twenty rectal cancer patients undergoing open nerve-sparing total mesorectal excision (TME) were assigned to pIONM under either IA or TIVA (n = 10 per group). IA was maintained with sevoflurane and TIVA with propofol. During surgery, pelvic autonomic nerves were electrically stimulated under electromyography (EMG) of the internal anal sphincter (IAS). These triggered EMG signals were analysed.
  
  
  RESULTS
  The absolute EMG amplitude during pIONM increased to 1.20 μV (interquartile range (IQR): 0.94-1.6) for IA and 1.49 μV (IQR: 0.84-2.75) for TIVA (P = 0.002). The relative EMG amplitude increase also was significantly lower for IA (0.59; IQR: 0.30-0.81; TIVA: 0.99; IQR: 0.62-2.5), (P = 0.001).
  
  
  CONCLUSIONS
  This is the first study to compare the influences of IA and TIVA on the autonomic nervous system. While both anaesthetic regimens proved useful for pIONM, TIVA with propofol may provide better signal quality than IA with sevoflurane.
authors.affiliation: Department of Anaesthesiology, University Medicine of the Johannes Gutenberg-University Mainz, Mainz, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Heid
authors.affiliation: Department of General, Visceral and Transplant Surgery, University Medicine of the Johannes Gutenberg-University Mainz, Mainz, Germany.
authors.forename: D W
authors.initials: DW
authors.lastname: Kauff
authors.affiliation: Department of General, Visceral and Transplant Surgery, University Medicine of the Johannes Gutenberg-University Mainz, Mainz, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Lang
authors.affiliation: Department of General, Visceral and Transplant Surgery, University Medicine of the Johannes Gutenberg-University Mainz, Mainz, Germany.
authors.forename: W
authors.initials: W
authors.lastname: Kneist
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001003:Anal Canal / Q000187:drug effects*; D000769:Anesthesia, Inhalation; D000771:Anesthesia, Intravenous; D018685:Anesthetics, Inhalation / Q000494:pharmacology*; D018686:Anesthetics, Intravenous / Q000494:pharmacology*; D017776:Autonomic Pathways / Q000187:drug effects*; D004576:Electromyography; D005260:Female; D006801:Humans; D008297:Male; D008738:Methyl Ethers / Q000494:pharmacology; D008875:Middle Aged; D015742:Propofol / Q000494:pharmacology; D000077149:Sevoflurane
chemical_list: D018685:Anesthetics, Inhalation; D018686:Anesthetics, Intravenous; D008738:Methyl Ethers; D000077149:Sevoflurane; D015742:Propofol