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Updated: Jun 23, 2026

Electrically Evoked Stapedius Reflex Measurements in Cochlear Implantation and Its Application in the Postoperative Fitting Process
07:00

Electrically Evoked Stapedius Reflex Measurements in Cochlear Implantation and Its Application in the Postoperative Fitting Process

Published on: June 21, 2024

Dose-dependent suppression of the electrically elicited stapedius reflex by general anesthetics in children

Mark W Crawford1, Michelle C White, Evan J Propst

  • 1Department of Anesthesia and Pain Medicine, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada. mark.crawford@sickkids.ca

Anesthesia and Analgesia
|April 18, 2009
PubMed

Insights

Volatile anesthetics increase evoked stapedius reflex threshold (ESRT) measurements in children undergoing cochlear implantation. Propofol had minimal effect, and ECAP was unaffected, suggesting volatile anesthetics should be avoided for intraoperative ESRT measurement.

Area of Science:

  • Anesthesiology
  • Otolaryngology
  • Neuroscience

Background:

  • Cochlear implants require precise stimulation limits for effective hearing restoration.
  • Intraoperative evoked stapedius reflex threshold (ESRT) and evoked compound action potential (ECAP) guide these stimulation limits.
  • Anesthetic agents can potentially influence electrophysiological measurements during surgery.

Purpose of the Study:

  • To investigate the dose-related effects of common anesthetics (sevoflurane, desflurane, isoflurane, propofol) on intraoperative ESRT and ECAP in pediatric cochlear implant surgery.
  • To determine the impact of volatile anesthetics versus propofol on these auditory nerve responses.

Main Methods:

  • A randomized study of 44 children (6 months to 17 years) undergoing cochlear implantation.
  • Children received sevoflurane, desflurane, isoflurane, or propofol.
  • ESRT and ECAP were measured at varying anesthetic concentrations, analyzed via repeated-measures ANOVA.

Main Results:

  • ESRT significantly increased with higher concentrations of volatile anesthetics (sevoflurane, desflurane, isoflurane).
  • Volatile anesthesia abolished the stapedius reflex in over half of the participants.
  • Propofol showed minimal impact on ESRT, and ECAP remained unaffected by all tested anesthetics.

Conclusions:

  • Volatile anesthetics dose-dependently suppress the stapedius reflex, potentially leading to overestimated comfort levels during cochlear implantation.
  • Using volatile anesthetics for intraoperative ESRT measurement may result in postoperative discomfort and hinder patient adaptation to the implant.
  • Avoidance of volatile anesthetics is recommended when measuring ESRT during cochlear implant procedures.
Abstract

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