Emissions risk of general anaesthetic

USING local instead of general anaesthetic for hip and knee surgery and other operations could cut greenhouse gas emissions, a new study has found.

Drugs used for general anaesthetics contain greenhouse gases such as nitrous oxide, which can stay in the atmosphere for up to 114 years and contribute to global warming.

Switching the one million annual hip and knee replacement operations in the US to local anaesthetic would save the equivalent of 7.3 million miles driven in a car, according to the study, which was based on a one-year experiment at a hospital in New York and published in the journal Regional Anesthesia & Pain Medicine.

Surgeons at the Hospital for Special Surgery in New York carried out 96 per cent of their hip and knee replacements using local anaesthesia in 2019, and estimated they saved the equivalent of 60,500 car miles.

That compared to an average of 75 per cent normally done under general anaesthesia.

Although the greenhouse gases used in anaesthesia last just a fraction of the time in the atmosphere compared to carbon dioxide, some are thousands of times more potent, and scientists say that reducing the impact on the environment in the near future is crucial.

Anaesthetic gases account for between 50-60 per cent of the carbon footprint of an operating theatre in the US as less than 5 per cent of the gases are inhaled by the patient, leaving the rest to enter the atmosphere.

The study also highlighted that local anaesthetic is often preferable in terms of giving patients a shorter hospital stay, more effective pain relief and fewer side effects, although its authors acknowledged it is not always suitable.

“Although the extent of the contribution of healthcare-related activities to climate change is uncertain, healthcare professionals do have a responsibility and the means to decrease our carbon footprint by reducing our use and emissions of greenhouse gases,” said Dr Christopher Wu, an anaesthetist of the Hospital for Special Surgery and one of the authors of the study.

It came as the Government was warned that the NHS is not doing enough to cut its environmental impact. The health service has the biggest carbon footprint in the public sector, contributing 6.3 per cent of the country’s emissions, and using the same amount of water as Estonia.

The parliamentary environmental audit committee called on the NHS and Public Health England to eliminate coal and oil powered heating, to tackle fluorinated gases such as those used in asthma inhalers and to speed up a switch to electric vehicles.

The biggest single source of emissions within the health service is pharmaceutical production; one year of kidney dialysis emits greenhouse gases equivalent to seven return flights between London and New York.