Decommissioning Piped Nitrous Oxide in Health Care Facilities

• Nitrous oxide is an anesthetic gas (used for anesthetic purposes as well as carrier gas for other volatile anesthetics) with a high global warming potential (GWP).  Therefore, reducing or even eliminating its use in the hospital operations significantly can reduce GHG emissions footprint of the hospital.
• Since Nitrous Oxide is relatively cheap, high purchases (due to high use or leakages) rarely get noticed and a key emissions hotspot often remains ‘invisible’.
• However, during carbon accounting, the proportion of nitrous oxide emissions in the overall hospital facility’s footprint becomes visible and can therefore be addressed.
• There is a need to reduce the risk of exposure to staff due to leakages along the gas pipes, which can affect the body’s nervous system under long-term exposure.

While tracking the greenhouse gas (GHG) emissions for the Aga Khan University Hospital, Nairobi (AKUH,N), it was noticed that emissions from anesthesia accounted for 20% of Scope 1 and 2 emissions, while nitrous oxide made up more than 95% of anesthetic gas emissions. While concerted efforts were in place to reduce other sources of operational emissions, including installing a solar photovoltaic (PV) system to reduce electricity in Scope 2, the interventions did not yet involve any solutions for the clinical practices. 

Therefore, since nitrous oxide is a high GWP gas and a single emissions source responsible for huge hospital emissions, it was resolved that the hospital would decommission piped nitrous in the hospital to reduce the impact of clinical practices on overall GHG emissions for the hospital.

This process was initiated in mid-2022, by providing portable Entonox bottles to one Operating Room as a pilot and engaging all relevant stakeholders. Over the course of 2022, the changes were implemented in all Operating Rooms. Piped nitrous oxide was finally completely switched off in June 2023.

Several key learnings from this process in AKUH, N can be useful to consider to implement similar interventions.

Key learning: Importance of stakeholder engagement

All stakeholders need to buy in and understand the reasons behind implementing changes to processes, otherwise the solution will face resistance from key users. In this case the clinical teams, facilities teams, as well as supply chain and management.

Key learning: Working with anesthesiology

The anaesthesiology team was key stakeholder to the project after it was highlighted that the use of piped nitrous oxide contributed greatly to the AKUH,N climate footprint. Without their support, as the users of aesthetic gases, this project would not have been possible. They worked closely with the facilities team and OR team to train each other on handling of the portable tanks, replacement, installation of regulators and storage. Facilities team also provided trolleys to ensure the cylinders were safely secured and spanners for replacement of regulators when replacing the cylinders.

Key learning: Identifying alternatives

Prior to implementing the changes, alternative solutions needed to be identified that will replace the incumbent solution without any hitches, as to ensure patient safety and health provision at all times. Piloting was required to ensure efficacy and effectiveness of the replacement. Piloting started with one Operating Room using the portable cylinders for 4 weeks and after positive feedback a decision was made to isolate the piped nitrous and use portable cylinders in all the 6 ORs of AKUH,N.