Related Experiment Video
Updated: Jul 15, 2026

In Vitro Method to Control Concentrations of Halogenated Gases in Cultured Alveolar Epithelial Cells
Published on: October 23, 2018
Influence of methane on infrared gas analysis of volatile anesthetics
E Mortier1, M Struys, L Versichelen
1University Hospital, Department of Anesthesiology, Gent, Belgium.
Abstract:
Contemporary multigas analyzers determine anesthetic gas concentrations using (near) infrared analysis at either 3.3 or 8-9 microns. Methane also absorbs infrared light at 3.3 microns, but not at 8-9 microns. Consequently, erroneous anesthetic agent readings may result when methane is present in the circuit (e.g. during closed circuit anesthesia), potentially compromising patient safety. We have analyzed in laboratory conditions the influence of different known methane concentrations (100, 500 and 1000 ppm) on the gas-analysis readings provided by some clinical monitoring devices that use infrared absorption for the measurement of inhalation anesthetic concentration. At 3.3 microns wavelength the influence on the measurement of halothane was important, whereas the influence on that of enflurane and isoflurane was less pronounced. For desflurane and sevoflurane measurements, the influence of methane at 3.3 microns wavelength proved to be minimal. At higher wavelengths (8-9 microns) no influence of methane could be demonstrated.
Related Concept Videos
Inductive Effects on Chemical Shift: Overview
Mass Spectrum
Mass Spectrometry: Long-Chain Alkane Fragmentation
Chemical Ionization (CI) Mass Spectrometry
Stages of General Anesthesia
Inhalational Anesthetics: Overview

