In response to Polly Toynbee’s article (The NHS leads the world in green healthcare. But it faces a political roadblock, 21 October), I wish to clarify a point she made about the use of anaesthetic gases. Desflurane is indeed the anaesthetic gas with the greatest carbon footprint, but is by no means the most common. Recent data indicates that it is only used in around 10% of general anaesthetics. However, in hospitals where it is used it may still account for the largest share of the anaesthetic-related carbon footprint.

All of the commonly used anaesthetic gases (desflurane, sevoflurane and isoflurane) are greenhouse gases, but desflurane has been found to have a global warming potential around 20 times greater than the same amount of sevoflurane, which is much more commonly used. Additionally, because desflurane is a less potent drug, more of it is required to keep a patient unconscious – further increasing its climate impacts.

All anaesthetic gases are all equally effective at keeping patients fully unconscious during surgery. Furthermore, there are options such as total intravenous anaesthesia (general anaesthetic drugs given into a vein via a drip) and regional anaesthesia (local anaesthetic used to numb an area of the body) that avoid the use of anaesthetic gases completely.

So why use desflurane? Due to its chemical properties, it wears off slightly quicker than some alternatives – but the difference is usually only a few minutes and it does not generally result in the patient returning to the ward or going home from hospital any sooner. Anaesthetists have become increasingly aware of their environmental impacts in recent years, resulting in desflurane use more than halving. Its use will continue to fall as most anaesthetists restrict it to specific clinical circumstances and many are “ditching the desflurane” altogether. But there is still much progress to be made.

The Royal College of Anaesthetists has published a helpful resource called Your Anaesthetic and the Environment. I would encourage anyone due to have surgery to read this and explore their options with their anaesthetist to help us further reduce our carbon footprint.

Dr Li Fang

Senior anaesthetic trainee and sustainability fellow, North West School of Anaesthesia