Gao LL, Yu JQ, Liu Q, et al. - The safety and analgesic effect of the fixed nitrous oxide/oxygen mixture for trauma patients in the emergency department (ED) were evaluated. In this double-blind, randomized study of 60 patients, conventional pain treatment plus a mixture of 65% nitrous oxide/oxygen (the treatment group) or the conventional pain treatment plus oxygen (control group) were provided to the patients. In the treatment group vs oxygen group, both patients' (8.0 [7.0–9.0] vs 4.0 [2.0–6.0]) and physicians’ (8.5 [8.0–9.0] vs. 4.0 [3.0–6.0]) satisfaction scores were significantly higher. Further, there appeared no serious adverse events. Findings thereby support self-administered nitrous oxide/oxygen mixture in the ED for moderate-to-severe traumatic pain as safe and efficacious.