Second gas effect is classically seen with: (LQ, AIPG 2011)
|A||Halothane and oxygen|
|B||Halothane and nitrous oxide|
|C||Nitrous oxide and oxygen|
|D||Halothane and isoflurane|
Halothane and nitrous oxide
a. Nitrous oxide is given in higher concentration (66%).
b. Uptake of nitrous oxide by blood will create a gradient in drawing more nitrous oxide from machine thus increasing the alveolar concentration more than expected, this is called as concentration effect.
c. If other potent agent like halothane is given along with nitrous oxide by the same mechanism it also increases the concentration of halothane this is called as second gas effect.