Expert: Ronald Levy, M.D. - 9/5/2011

Question
I read that laughing gas as well as being used in dentistry is also administered along with general anesthesia a lot of the time during surgeries. I read that it can be relatively free of a lot of side effects however when it is used in higher doses it can cause nausea and vomiting. Is that because of side effects of the gas itself or because of hypoxia when to much is given?

Answer
Laughing gas is actually nitrous oxide and it is used often in general anesthetics. It doesn't actually cause laughing, rather disinhibition. I think the laughing is more suggestive than anything else. The nausea is a property of the gas and has nothing to do with hypoxia since anesthesia machines are designed to not allow you to give a hypoxic mixture. Because of the emtic effects of nitrous oxide, many anesthesiologists avoid using it.

Ronald Levy, MD
Professor of Anesthesiology
UTMB-Galveston