Effect of fresh gas flow on isoflurane concentrations during low-flow anaesthesia

J. Y. Park, J. H. Kim, W. Y. Kim, M. S. Chang, J. Y. Kim, H. W. Shin

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)


The effect of fresh gas flow (FGF) on isoflurane concentrations at given vaporizer settings during low-flow anaesthesia was investigated. Ninety patients (American Society of Anaesthesiologists physical status I or II) were randomly allocated to three groups (FGF 1 l/min, FGF 2 l/min and FGF 4 l/min). Anaesthesia was maintained for 10 min with vaporizer setting isoflurane 2 vol% and FGF 4 l/min for full-tissue anaesthetic uptake in a semi-closed circle system. Low-flow anaesthesia was maintained for 20 min with end-tidal isoflurane 1.5 vol% and FGF 2 l/min. FGF was then changed to FGF 1 l/min, FGF 2 l/min or FGF 4 l/min. Measurements during the 20-min period showed that inspired and end-tidal isoflurane concentrations decreased in the FGF 1-l/min group but increased in the FGF 4-l/min group compared with baseline values. No haemodynamic changes were observed. Monitoring of anaesthetic concentrations and appropriate control of vaporizer settings are necessary during low-flow anaesthesia.

Original languageEnglish
Pages (from-to)513-519
Number of pages7
JournalJournal of International Medical Research
Issue number5
Publication statusPublished - 2005
Externally publishedYes


  • Breathing systems
  • End-tidal concentration
  • Fresh gas flow
  • Haemodynamic changes
  • Isoflurane
  • Low-flow anaesthesia
  • Vaporizer setting

ASJC Scopus subject areas

  • Biochemistry, medical
  • Biochemistry
  • Cell Biology


Dive into the research topics of 'Effect of fresh gas flow on isoflurane concentrations during low-flow anaesthesia'. Together they form a unique fingerprint.

Cite this