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.