Sustainability Working Group member Tim Mair has written the following article on reducing carbon emissions using anaesthetic gas capture.
Volatile anaesthetic gases such as isoflurane are potent greenhouse gases that significantly contribute to climate change. Isoflurane, for example, has a warming potential over 100 years which is approximately 510 times that of CO2.
On average, volatile anaesthetic agents contribute about one fifth of the carbon footprint of surgical procedures. Around 3 million tonnes of CO2 equivalent emissions are released from anaesthetic gases each year; this is the same as a car travelling around the globe 540,000 times!
During general anaesthesia, only 5% of volatile anaesthetic agents are metabolised in the body, leaving 95% to be exhaled, emitted into the scavenging system, and subsequently released into the atmosphere or incinerated.
Capture systems, such as SageTech’s anaesthetic gas capture device, provides an innovative circular economy solution to this problem by adsorbing the gases onto a reusable filter. The anaesthetic agents can then be extracted from the filter, purified and potentially re-used.
As part of our attempts to reduce the overall carbon footprint of our hospital, Bell Equine Veterinary Clinic has recently installed a SageTech unit. This was very simply integrated into our current scavenging system, so that the volatile agent is removed from the waste gases prior to them being discharged into the atmosphere.
The downside of this system in equine anaesthesia is that the unit only operates when the horse is connected to the anaesthetic machine; once the horse is removed from the machine and placed in recovery, all of the gases still present in the animal will released into the atmosphere, but this will only be a small proportion of the total volume of volatile anaesthetic agent used during the whole procedure.
This system, coupled with the adoption of a low gas flow anaesthesia technique, will significantly reduce the carbon footprint of our surgical unit.