Topic
Second gas effect
About: Second gas effect is a research topic. Over the lifetime, 25 publications have been published within this topic receiving 528 citations.
Papers
TL;DR: The uptake of halothane given in constant concentration (1 per cent) was shown to be more rapid in a mixture with 70 per cent N2O than in one with 10 per centN2O, demonstrating that the uptake of a gas is influenced by the constituents of the mixture of which it is a component.
Abstract: The uptake of halothane given in constant concentration (1 per cent) was shown to be more rapid in a mixture with 70 per cent N2O than in one with 10 per cent N2O. This demonstrates that the uptake of a gas is influenced by the constituents of the mixture of which it is a component. Changes in the c
117 citations
TL;DR: When an anesthetic such as halothane (second gas) is administered with nitrous oxide (first gas) the rate of rise of alveolar Halothane is more rapid than when it is given alone.
Abstract: When an anesthetic such as halothane (second gas) is administered with nitrous oxide (first gas) the rate of rise of alveolar halothane is more rapid than when it is given alone. This “second gas effect” has been attributed to the increased volume of inspired gas which results from the large volume
83 citations
TL;DR: The results indicate that, at high concentrations, N2O neither facilitated the increase of FA nor enhanced the uptake of a companion gas, and the "second gas effect" is not a valid concept.
Abstract: To determine whether the "second gas effect" is valid, we determined the pharmacokinetics of 02% enflurane with or without 80% N2 O (n = 7 each) under controlled constant volume ventilation in 14 young healthy male patients before their operations The alveolar (end-tidal) concentration (FA) and in
64 citations
TL;DR: In the present study, groups of six normocapnic patients were given one of three gas mixtures via a nonrebreathing system and the existence of and the basis for the concentration and second gas effects were explored.
Abstract: In the present study, we explored both the existence of and the basis for the concentration and second gas effects. Groups of six normocapnic patients were given one of three gas mixtures via a nonrebreathing system: 65% nitrous oxide (N2O) plus 4% desflurane; 5% N2O plus 4% desflurane; or 65% N2O p
40 citations
TL;DR: It is shown that in the standard diagram gas uptake is incomplete, there is ambiguity over functional residual capacity (FRC), equilibration with blood is inadequately represented and there is no representation of recirculation of anaesthetic.
Abstract: During induction with high inspired concentrations of nitrous oxide, net uptake of gas produces a contraction in volume and a concentrating effect. In turn, this results in concentration and second gas effects. Most explanations of these effects are based on the common "rectangle" diagram devised by Stoelting and Eger and contain several inconsistencies which are explored here in order to produce a more accurate description. It is shown that in the standard diagram gas uptake is incomplete, there is ambiguity over functional residual capacity (FRC), equilibration with blood is inadequately represented and there is no representation of recirculation of anaesthetic. Compensation for loss of volume may be by means of an increased inspired ventilation, decreased expired ventilation or reduction in lung volume. Numerous accounts in the literature (including those based on the standard diagram) focus on the former mechanism at constant FRC. This has produced an unbalanced picture in which it is often implied that extra gas is routinely drawn into the lungs to replace that taken up. Significant compensation by this means cannot occur, for example when a constant volume ventilator is used. In discussing concentration and second gas effects, it is necessary to give a balanced view of the alternative mechanisms of compensation or to revert, as above, to a simple statement of the principle of conservation of volume.
32 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2019 | 1 |
| 2018 | 1 |
| 2011 | 1 |
| 2008 | 1 |
| 2006 | 3 |
| 2003 | 1 |