Bench experiments to investigate the effect of nitrous oxide cracking technology in ideal circumstances

Abstract

Bench experiments to investigate the effect of nitrous oxide cracking technology in ideal circumstancesNitrous oxide (N 2 O) is a potent greenhouse gas, and occupational exposure has potential health impacts for healthcare staff [1,2]. Although the use of N 2 O can often be

Implementing nitrous oxide cracking technology in the labour ward to reduce occupational exposure and environmental emissions: a quality improvement study*

“…The environmental monitoring phase of the project (November 2021–May 2022) was undertaken on the low‐risk, midwifery‐led Manchester Birth Centre at Wythenshawe Hospital, which has consistently sized rooms (6.1 m × 5.6 m) with O 2 /N 2 O terminal units (Schrader valves) at either end of the room. As in our bench experiment, the infrared N 2 O detector was positioned equidistant (3.1 m) from the piped O 2 /N 2 O terminal units at a height of 1.3 m (analogous to a member of staff sitting in the room) [13], and configured to log readings every 2 min. The equipment was set up as soon as possible following the admission of the parturient.…”

“…The challenges we identified included that different sized rooms might have different ambient dilution; use of delivery devices (i.e. mouthpiece and facemask) varied between parturients; ambient N 2 O concentrations can change rapidly [13]; some parturients received additional analgesia (e.g. epidural); some parturients were transferred to the operating theatre for delivery; and parturients presented at different stages of labour.…”

“…Removal of N 2 O manifolds and minimising its clinical use are the most important approaches, overall, to mitigating the atmospheric emission of healthcare-related N 2 O [12]. Where N 2 O is used, catalytic destruction, also known as `cracking´has the potential to mitigate both occupational exposure and environmental impacts by breaking N 2 O down into (non-greenhouse gas) N 2 and O 2 [4,13].…”

“…1), which demonstrated a substantial reduction in ambient N 2 O concentrations under experimental conditions [13], consistent with the manufacturer's data that over 99% of N 2 O is destroyed [14]. However, we noted that the effectiveness of the technology would depend on what proportion of the N 2 O delivered to the patient was then exhaled into the scavenging system, thereby entering the device [12, 13]. Bearing in mind the potential challenges with achieving this in the setting of labour, we designed a quality improvement project based on environmental monitoring of N 2 O levels and staff feedback to investigate whether using the MDU and Ultraflow demand valve could reduce N 2 O release in practice.…”

Towards zero carbon healthcare: anaesthesia

“…Catalytic destruction technology (known as “cracking”), in which a catalyst breaks down the N 2 O exhaled by the patient into nitrogen and oxygen, offers a way to reduce its environmental impact when used as an analgesic (eg, in labour),28 but the proportion of gas “cracked” depends on the proportion of exhaled breath that can be directed into the machine, eg, via a facemask.…”