Reducing Greenhouse Gas Emissions and Modifying Nitrous Oxide Delivery at Stanford: Observational, Pilot Intervention...

Area of Science:

• Environmental Science
• Medical Anesthesiology

Background:

• Inhalational anesthetics like nitrous oxide (N₂O) are significant greenhouse gas emitters in healthcare.
• N₂O's long environmental half-life and low potency necessitate large storage volumes, increasing leak potential.
• Stanford Health Care (SHC) analyzed N₂O emissions to target waste reduction.

Purpose of the Study:

• To quantify N₂O pollution at SHC.
• To evaluate the effectiveness of using E-cylinders for N₂O storage and delivery in ambulatory surgery centers to reduce system-wide emissions.

Main Methods:

• Phase 1: Analyzed 2022 N₂O purchase and delivery data (Epic EHR) at SHC.
• Phase 2: Pilot study at Campus A using E-cylinders, weighing them weekly and comparing to delivery data over 5 weeks.
• Phase 3: Replicated methodology at Campus B.

Main Results:

• In 2022, 90.5% of purchased N₂O (7,436,566.8 L) was wasted at SHC, costing $57,285.
• Pilot studies at Campuses A and B showed minimal N₂O use from E-cylinders, far less than three cylinders combined.
• N₂O use from E-cylinders closely matched delivery data, indicating reduced waste.

Conclusions:

• Transitioning N₂O delivery from centralized storage to point-of-care E-cylinders drastically reduced waste and costs.
• Results support analyzing N₂O storage systems and considering E-cylinder implementation to lower healthcare emissions.
• Reduced N₂O waste contributes to SHC's goal of a 50% reduction in scope 1 and 2 emissions by 2030.