Abstract
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 language | English |
|---|---|
| Pages (from-to) | 513-519 |
| Number of pages | 7 |
| Journal | Journal of International Medical Research |
| Volume | 33 |
| Issue number | 5 |
| DOIs | |
| Publication status | Published - 2005 |
Keywords
- Breathing systems
- End-tidal concentration
- Fresh gas flow
- Haemodynamic changes
- Isoflurane
- Low-flow anaesthesia
- Vaporizer setting
ASJC Scopus subject areas
- Biochemistry
- Cell Biology
- Biochemistry, medical