Methylmalonic acid: a specific marker of nitrous oxide intoxication?

Guillaume Grzych, Emeline Gernez, Sylvie Deheul, Isabelle Kim

La Revue de Médecine Interne, volume 43, Issue 3, March 2022, Pages 197-198

We have carefully read the review of the literature by Caré et al. on nitrous oxide toxicity, published in the latest issue of La Revue de Médecine Interne, and applaud the thoroughness of this article. However, as metabolic biochemists, we would like to make a suggestion concerning the use of methylmalonic acid (MMA), described by the authors as a specific biomarker of nitrous oxide intoxication. Indeed, many elements in the literature call into question the specificity of this marker in nitrous oxide intoxication; its use in this context must therefore remain cautious.

1. Increased plasma MA concentration is not specific to nitrous oxide intoxication
2. Absence of increase in plasma MA concentration does not rule out nitrous oxide intoxication
3. The metabolic impact of nitrous oxide on WMA has not been demonstrated.

Link to article: https: //www.em-consulte.com/article/1505824/l-acide-methylmalonique%C2%A0-un-marqueur-specifique-de