Korean J Anesthesiol.  1988 Oct;21(5):753-758. 10.4097/kjae.1988.21.5.753.

The Second Gas Effect During Induction of Anesthesia in Children

• Kim SD
• Ko H

• KMID: 2239448
• DOI: http://doi.org/10.4097/kjae.1988.21.5.753

Abstract

To evaluate the second gas effect during induction of clinical anesthesia, the ratios of the end-tidal to the inspired concentration of halothane (FET/F1) were measured in 21 children in ASA class 1. The children were divided into three groups: gorup I received 100 % O2 and 1% halothane, group II received 70% N2O, 30% O2 and 1% halothane simultaneously, and group III received 1% halothane and 100% O2 for 5 min, followed by 70% N2O, 30% O2 and 1% halothane. With or without N2O, the increases of FET/F1 were significant 3min after inhalation of halothane. The increase in FET/F1 compared with the previous value, was insignificant in gorup I, and significant for 7min and 5min in groups II and III respectively. Compared with gorup I, the remarkable second gas effect in gorup II was noticed 7 min after induction and continued during the study, but in group III, it was noticed only 9 min after induction, and disappeared rapidly. The second gas effect in this study might be due to the concentrating effect by the uptake of N2O.

Keyword

The second gas effect; FET/F1 ratio; Nitrous oxide

MeSH Terms

Anesthesia*
Child*
Halothane
Humans
Inhalation
Nitrous Oxide
Halothane
Nitrous Oxide