Biomarkers for the diagnosis and monitoring of nitrous oxide intoxication: objectives and methodology of the SFBC Working Group.

The recreational use of nitrous oxide (N2O) is an emerging public health issue. Chronic N2O abuse may result in various clinical symptoms, encompassing neurological, psychiatric and cardiovascular outcomes. Despite the difficulties for the laboratory investigation of N2O intoxication, there is currently no guidelines in France to help both clinicians and biologists use appropriate biomarkers for the diagnosis and monitoring of patients with clinical symptoms potentially related to N2O intoxication. A multi-disciplinary Working Group, carried out under the auspices of the French Society of Clinical Biology (SFBC) and in collaboration with the French Societies of Emergency Medicine (SFMU), Analytical Toxicology (SFTA), Hemostasis and Thrombosis (SFTH), Vitamins and Biofactors (SFVB), and the French Federation of Neurology (FFN), was recently implemented to elaborate practical guidelines. The methodology of the Working Group is based on the critical analysis of the literature, and raising concerns and objectives are grouped into five working packages. The present manuscript primarily aims to expound upon the methodology and objectives of the ongoing SFBC Working Group on N2O.