Rare case of Nitrous oxide-induced polyneuropathy, pancytopenia and pulmonary embolism: A report

"Nitrous oxide commonly known as "laughing gas" is an odorless, colorless, non-flammable. It leads to a state of euphoria, explaining its nickname. Nitrous oxide is the least potent inhalational anesthetic classically used in anaesthesia for over 150 years for its analgesic and anxiolytic properties."

Studies report significant neurological, hematological and psychiatric side effects, generally related to an induced functional vitamin B12 deficiency, however the recreational nitrous oxide effect in young population is yet to be evaluated. A case study reports prognosis of recreational N2O abuse complications in a 22 year old female. The findings are published in the Journal of Medical Case Reports.

The findings of the case study are

• Investigators report a differential diagnosis of a 22-year-old woman of North African origin who experienced an exceptional combination of polyneuropathy, bilateral pulmonary embolism and severe pancytopenia related to vitamin B12 deficiency and hyperhomocysteinemia induced by recreational nitrous oxide use.

• After treatment with vitamin B12 supplementation and intensive rehabilitative management, the patient progressively regained the ability to walk and her biological parameters gradually returned to normal.

• The pathophysiological mechanisms related to a decrease in vitamin B12 activity are the reduction of products needed for synthesis of deoxyribonucleic acid, carbohydrate or fatty acids, and the increase of hyperhomocysteinemia.

• Other mechanisms involving a direct action of N2O are also suspected.

Researchers added that in the current study it was first important to exclude the most probable origins for each of these conditions, which explains the extensive assessments that were carried out. In the absence of a diagnosis that better explains the onset of these conditions, the diagnosis of nitrous oxide-induced polyneuropathy, pancytopenia and pulmonary embolism was retained.

Though the occurrence of these conditions and their physiological pathway have already been described in the literature in the recent years. The newness of this particular case is that this young patient experienced simultaneously severe pancytopenia, bilateral pulmonary embolism and polyneuropathy related to vitamin B12 deficiency and hyperhomocysteinemia induced by recreational nitrous oxide use.

In conclusion "This case report brings elements to support our knowledge about pathological pathway, recovery and prognosis of recreational N2O abuse complications. The general and medical population should be aware to the serious consequences of this type of consumption."

Reference: Parein, G., Bollens, B. Nitrous oxide-induced polyneuropathy, pancytopenia and pulmonary embolism: a case report. J Med Case Reports 17, 350 (2023). https://doi.org/10.1186/s13256-023-04075-w