Changing patterns of nitrous oxide use and environmental awareness among Brazilian anesthesiologists: a nationwide cross-sectional survey

Nitrous Oxide (N 2 O) is a potent greenhouse gas with significant environmental impact and is currently the leading ozone depleting substance in use. Despite its long-standing role in anesthetic practice, data on N 2 O use and the environmental awareness of Brazilian anesthesiologists are scarce. This study aimed to describe patterns of N 2 O use and assess the level of awareness among anesthesiologists regarding its environmental impact. A nationwide cross-sectional survey was conducted among anesthesiologists in a private Brazilian hospital network. The questionnaire addressed the frequency of N 2 O use in adult and pediatric anesthesia, knowledge of its environmental effects, and attitudes toward its continued availability. Of 1,238 eligible anesthesiologists, 941 completed the survey (response rate 76%). Overall, 59.3% (n = 558) reported never using N 2 O in adult patients, while 14.5% (n = 136) reported frequent or constant use. In pediatric patients, 27.5% (n = 259) reported never using N 2 O, and 38.9% (n = 366) reported frequent or constant use. Eighty percent (n = 753) indicated a reduction in N 2 O use since the beginning of their careers, and 34.5% (n = 325) were unaware of its contribution to climate change. Age and years of professional experience were directly proportional to N 2 O use in adults (p < 0.05), while awareness of its environmental impact was inversely associated with use in pediatric cases (p < 0.05). The survey demonstrates a shift toward reduced N 2 O use, particularly among younger anesthesiologists, although substantial use in adult practice remains. Persistent knowledge gaps highlight the importance of targeted education and policy interventions to mitigate environmental impact.