Nitrous Oxide Exposure

During 2023 the royal college of midwifes sent out a letter to all registered midwifery staff informing them of their employers duties to ensure that they are not exposed to Nitrous oxide levels above the safe limit. In short, we needed to look at how we upgrade our 1980’s building infrastructure to ensure thee safety of our staff. The timeline for this started way back in 2017 when we took the decision to install the purair 750 made by MEC ltd. These were installed by a sub-contractor and maintained by the in house team. Rightly or wrongly the system was left in this way until 2023 when the letter from RCM landed and many trusts withdrew Entonox as a form of pain relief until systems were put into place. Our trust set up a incident management team that worked to ensure mitigations were in place to protect staff whilst in estates, we started to formulate a design to ensure that we did not put staff at risk. Within 7 days we had installed low level extract fans in each delivery room that had to be manually turned on when entonox was being used. This design has since progressed and now each extract fan is individually controlled by a nitrous oxide sensor situated at low level within the room. This activates the fan and brings in air from the corridor at high level down across the patient and out at low level. This has also increased the air change rates within all delivery rooms and achieved cross flow ventilation within the room, further protecting staff. The system also allows us to log via the BMS the nitrous oxide levels for all rooms and also alert midwifery team of any rooms where the levels become too high for use in that room to continue. Liaison with clinical teams has also enabled the delivery unit to switch to re-breather masks that when connected to the purair 750 collect much more of the exhaled gas.