Mitigating the systemic loss of nitrous oxide: a narrative review and data-driven practice analysis

Given the negative health impacts of climate change, clinicians have a fundamental responsibility to take an active role in mitigating the environmental impact of their practices. Inhaled anaesthetics are potent greenhouse gases, including nitrous oxide (N2O), with their long atmospheric lifetime, high global warming potential, and ozone-depleting properties. However, few clinicians realise that losses from central N2O supply systems account for the vast majority of overall N2O consumption in healthcare. Central N2O supply systems are standard in most facilities, compounding the impact of these under-recognised, unnecessary greenhouse gas emissions. We review the environmental impact of N2O in healthcare, offer N2O utilisation data from 47 hospitals in the USA, and provide clinician-targeted guidance for mitigating these widespread N2O emissions. Consistent with findings from the UK and Australia, data from two large US healthcare systems reveal significant nonclinical N2O losses of 47.2–99.8% of total procured N2O. As illustrated in one quaternary medical centre, the transition from central to portable supply systems reduced overall N2O consumption by 97.6%. To date, this mitigation initiative has been successfully implemented at over 25 hospitals in our system. Raising awareness of this considerable source of healthcare-specific N2O emissions empowers clinicians to spearhead facility-level engagement and action. As healthcare leaders, clinicians should advocate for decarbonisation of clinical practices and systems while ensuring high-quality patient care.