• Megan A F Thomas, Christopher J Ward, Matthew E Sinnott, Thomas W Davies, Jan M Wong, Joanna K L Wong, Gudrun Kunst, Sibtain Anwar, Pan-London Perioperative Audit and Research Network Committee, and Local investigators.
• Department of Anaesthesia, King's College Hospital NHS Foundation Trust, London, UK.
• Br J Anaesth. 2024 Dec 1; 133 (6): 142714341427-1434.

BackgroundNitrous oxide (N2O) is a potent greenhouse gas that contributes significantly to the healthcare sector's carbon footprint. Pre-utilisation losses of N2O are up to 95%. Decommissioning manifolds can reduce these losses.MethodsHospitals in our Greater London research network with at least one active N2O manifold were included in the Nitrous Oxide Manifold and Other Reduction of Emissions (NoMoreGas) study. N2O utilisation data were collected continuously over 5 days and extrapolated over a year, in addition to collecting procurement records from the preceding financial year. The primary outcome was the discrepancy between clinically utilised N2O and the quantity procured by hospitals, referred to as the 'N2O gap'. Secondary outcomes included anaesthetists' self-reported utilisation of N2O and their opinions on manifold decommissioning.ResultsEighteen of 53 hospitals were included. In total, 6 487 200 L of N2O were procured with a median (IQR) of 304 200 (183 600-473 400) L per site. During the 5-day data collection period, sites utilised a median (IQR) of 501 (42-1409) L of N2O. Extrapolating over a year resulted in a median (IQR) annual utilisation of 36 573 (3066-102 857) L per site and a total of 1 175 348 L. This represented an estimated 18% of the N2O procured, suggesting pre-utilisation losses of 5 311 852 L. Among surveyed anaesthetists, 70% (n=309) reported using N2O within the previous year, with one-third (n=97) using it once a week or more. There was widespread support for decommissioning manifolds.ConclusionsConsistent with other reports, the data demonstrate a substantial discrepancy between the quantities of N2O procured and utilised clinically, indicative of significant pre-utilisation losses. Our findings support the decommissioning of N2O manifolds for environmental and economic benefits.Copyright © 2024 British Journal of Anaesthesia. Published by Elsevier Ltd. All rights reserved.

13 keywords...

hide…