Wyong Hospital is switching from nitrous oxide to methoxyflurane as an alternative pain management option to help reduce greenhouse gas emissions.
Nitrous oxide is a commonly used analgesic for acute pain and minor procedures, particularly in paediatric presentations to the emergency department (ED). However, it is recognised as an environmentally harmful option.
We have undertaken the Methoxyflurane Project with the aim of reducing greenhouse gas emissions through the increased use of methoxyflurane as an alternative to nitrous oxide in appropriate patients attending Wyong Hospital ED.
Our goal was to reduce nitrous oxide use while maintaining – or improving – patient care. Other sites may choose to adopt alternative approaches to analgesia (e.g. intranasal fentanyl) or sedation (e.g. intranasal midazolam or dexmedetomidine).
We selected methoxyflurane because it offers both analgesic and mild sedative effects, allows substitution of one inhalational agent for another with improvement to ED workflows, and has a markedly improved environmental profile.
Methoxyflurane is a significantly more sustainable alternative
Nitrous oxide is one of the 6 major greenhouse gases targeted under the Kyoto Protocol, due to its high global warming potential and atmospheric lifetime exceeding 100 years. It contributes approximately 20% of direct emissions within the Australian health system.
In addition, infrastructure leakage is a significant issue – studies from Australia and the United Kingdom indicate that at least 50%, and in some cases over 70%, of supplied nitrous oxide may be lost prior to clinical administration due to system leaks.
New research from the United Kingdom demonstrates that methoxyflurane is a significantly more environmentally sustainable alternative to nitrous oxide. At a 50:50 use ratio, nitrous oxide produces 117 times greater CO2 emissions (CO2e), highlighting its substantially higher environmental impact.
In addition to environmental benefits, methoxyflurane offers several clinical and operational advantages, including:
- rapid onset of action
- reduced side effects such as nausea and vomiting
- quicker patient recovery
- simplified administration, often without the need for additional staffing or continuous nursing presence, improving workflow efficiency.
Collectively, these findings support the adoption of methoxyflurane in place of nitrous oxide within clinical practice. Implementing this change within Wyong ED presents an opportunity to reduce environmental impact and costs while maintaining safe, effective and efficient patient care.
Using a soft launch approach to practice change
We introduced the project using a soft-launch approach, with a focus on key staff engagement rather than formalised education or large-scale rollout. We conducted engagement with key clinicians informally to raise awareness of methoxyflurane as a clinically appropriate and environmentally preferable alternative. This approach encouraged clinical ownership and supported gradual practice change without the need for structured training sessions or formal education programs.
Following implementation, we monitored the use of both methoxyflurane and nitrous oxide through periodic audit processes. We used these data sources to assess changes in prescribing behaviour, monitor trends over time and evaluate the associated environmental impact.
Through well-established quality and safety frameworks within the ED, we continuously reviewed patient safety and clinical outcomes throughout the project period to ensure that the introduction of methoxyflurane did not adversely affect patient care. Throughout the initiative, no adverse events were reported, supporting the safety and effectiveness of this approach.
Overall, the soft-launch strategy, combined with informal staff engagement and ongoing data monitoring, enabled a low-disruption implementation that supported sustainable practice change while maintaining high standards of patient care. Despite the soft-launch strategy, the rapid uptake of methoxyflurane by clinicians at Wyong ED is consistent with published evidence demonstrating high levels of clinician and patient satisfaction with its use in Australian emergency departments.
Nitrous oxide use reduced by 58%
In 2024, before the introduction of methoxyflurane, Wyong ED purchased 401 breathing circuits for nitrous oxide administration. Following the introduction of methoxyflurane, usage declined markedly, with only 167 breathing circuits purchased during 2025. This represents a 58% reduction in nitrous oxide use. Breathing circuit use has continued to fall, and Wyong ED is now considering the decommissioning of nitrous oxide equipment.
Considering the additional staff time and departmental resources required to administer nitrous oxide, the transition to methoxyflurane has resulted in a direct annual cost saving of $5,400. The environmental benefit has been even more substantial, with an estimated 28,000 kgCO2e reduction, equivalent to approximately 55,000 km of petrol car travel.
Importantly, there have been no reported adverse impacts on patient outcomes associated with this change in clinical practice. Overall, the reduction in nitrous oxide use has delivered meaningful environmental benefits alongside financial savings, without compromising patient care.
