Clinical epidemiological characteristics of nitrous oxide abusers: A single‐center experience in a hospital in China

PURPOSE: This study investigated the clinical epidemiological characteristics of nitrous oxide (N(2)O) abusers in a hospital in China, which have not been systematically reported. METHODS: The characteristics of patients abusing N(2)O who were examined and treated at the Affiliated Hospital of Xuzhou Medical University from January 2017 to December 2020 were analyzed. RESULTS: A total of 61 patients (average age: 21.7 ± 3.2 years; 42 male and 19 female) were enrolled; 60.7% of the patients had an education level of high school or lower, and most (59.0%) had no stable occupation. The mean exposure time was 8.5 ± 7.7 months (range: 1–36 months). Only 52.5% of the abusers reported the physician of the relevant exposure history at the first time of visiting the doctor. The main clinical type was mixed (49.2%). The most common clinical manifestation was distal limb numbness (80.3%). The most frequent outcome was peripheral neuropathy (59%) and subacute combined degeneration (36%). Serum homocysteine level was elevated in 67.5% (27/40) of the patients, while 44.4% (20/45) showed reduced vitamin B12. Note that 61% (22/36) showed abnormal signals in the posterior or lateral funiculus of the spinal cord, and 97% (31/32) of the patients showed peripheral nerve damage by electromyography. In all cases, symptoms were alleviated after halting N(2)O intake and receiving nutritional neurotherapy. CONCLUSIONS: N(2)O abuse can lead to nervous system damage, especially peripheral nerve and spinal cord damage. A full understanding of its clinical epidemiological characteristics is helpful for clinicians to make a timely and clear diagnosis.