Laughing gas — nitrous oxide — does not increase the risk of a heart attack when used as an anesthetic during surgery or soon afterward, new research has found.
 

In a new study published in the journal Anesthesiology, medical investigators with Washington University School of Medicine in St. Louis who tracked 500 surgery patients found no increased heart risks tied to nitrous oxide anesthesia.
 

"It's been known for quite a while that laughing gas inactivates vitamin B12 and, by doing so, increases blood levels of the amino acid homocysteine," said lead researcher Peter Nagele, M.D., assistant professor of anesthesiology and genetics. "That was thought to raise the risk of a heart attack during and after surgery, but we found no evidence of that in this study."

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Nitrous oxide is used during general anesthesia because by itself the drug isn't strong enough to keep patients unconscious during surgical procedures.
 

The study was funded, in part, by the National Institutes of Health