A more sustainable NHSBMJ 2019; 366 doi: https://doi.org/10.1136/bmj.l4930 (Published 02 August 2019) Cite this as: BMJ 2019;366:l4930
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Van Hove and Leng raise some very valuable points (BMJ 2019;366:14930) on how the healthcare sector could reduce the environmental impact of metered dose inhaler (MDI) propellants and anaesthetic gases. One tool already used by anaesthetists concerned by the impact of inhaled anaesthesia shows how, with support from the sector and the pharmaceutical industry, clinicians could realise “quick wins” on the NHS’s carbon footprint which van Hove and Leng identify.
When we buy lightbulbs, we look for A++ rating labels which indicate low energy consumption. However, when faced with pharmaceuticals there is no such rating. Although a variety of matrices exist, such as the Process Mass Intensity (the ratio of mass of raw materials to API; typically 50-150), they are rarely included in product literature for clinicians to consider.
The propellants used in MDIs – either HFA-134a (Tetraflouroethane, norflurane) or HFA-227ea (heptaflouropropane, apaflurane) – have a Global Warming Potential (GWP) 1430 and 3200 times that of CO2. The CO2 equivalence (CO2e) of a 200 actuation Ventolin Evohaler inhaler has been calculated by GSK to be around 28 kg, or 141 g/puff, and, despite the launch of their inhaler recycling scheme in 2011, by 2017, 58% of users still binned used inhalers with domestic waste.
In anaesthesia, a mobile app has been developed to help clinicians to understand the impact of regularly used gases (including sevoflurane, isoflurane and desflurane). The Anaesthesia Impact Calculator allows clinicians to calculate and compare the CO2e of inhaled anaesthesia agents and carrier gases.
To the knowledge of the Alliance, there are currently no similar apps for MDIs. Although details of the propellants are found in summaries of product characteristics, their impact is not quantified. The NICE patient self-guide leaflet addresses the CO2e of inhaler actuations and expresses it in relation to dry powder inhalers and car travelling, but it’s not clear where the figure of 500 g CO2e per actuation comes from.
To achieve the system-wide approach van Hove and Leng require, we need sector wide collaboration - including from pharmaceutical companies - to develop systems like the EU Energy Rating labels, and the Anaesthesia Impact Calculator. Doctors must be informed of the sustainability (or otherwise) of their practice at the moment of decision-making.
If they were rated today, MDIs and inhalational agents would carry red Ds and DPIs a green A++.
Dr Tom Pierce, UK Health Alliance on Climate Change
Competing interests: Tom Pierce: Environmental Advisor to the Royal College of Anaesthetists. Laurence Bourton: Communications Manager, UK Health Alliance on Climate Change (cc: firstname.lastname@example.org)
Van Hove and Leng, of NICE, are right to call for a more sustainable NHS, but wrong when they say that a system-wide approach is required to move us towards a carbon neutral healthcare system. More than that will be needed.
In fact, it will be impossible to achieve a carbon neutral system until the wider economy is decarbonised. 58% of the system's carbon footprint derives from the supply chain of goods and services, and a substantial part of emissions that are attributed to 'core' activities comes from such things as hospital electricity use, or staff transport. Unless and until the electricity grid is decarbonised, electricity use within the health and social care system will always have an associated carbon footprint.
The continuation of civilisation depends on us reaching net zero carbon emissions as soon as possible. The legal time limit of 2050 is probably too late. So a more important question than whether dry powder inhalers can substitute for metered dose inhalers is what the NHS can do to accelerate the necessary wider decarbonisation, and whether we can reduce the carbon intensity of healthcare fast enough, or whether we need also to cut back on supply of healthcare as well. It is increasingly accepted that in the wider economy we will have to consume less to achieve net zero. This is likely to be the case in health care as well.
That then raises the question as to which interventions are too carbon costly, in relation to the health gains, to be affordable. No one surely would be better placed than NICE to start calculating the carbon cost per QALY of different interventions, and to start the debate as to which of them can, and cannot, be afforded, if we are to keep our planet habitable.
Competing interests: No competing interests
While some breath-actuated metered dose inhalers (MDIs) may be of a similar price to dry powder inhalers (DPIs), as referenced within this article, because of the far greater use of plain metered dose inhalers MDIs within the NHS, there is a considerable cost to making a switch to dry powder inhalers. A rough calculation, based on the latest available primary care prescribing data (April - June 2019) for just salbutamol for all CCGs in England and for the numbers of prescriptions and costs for each type of inhaler gives the following (sourced from ePACT2, NHS Business Services Authority):
Number of items of MDIs = 4,624,000. Cost = £8,389,000. Average cost per item = £1.81
Number of items of DPIs = 171,300. Cost = £771,000. Average cost per item = £4.50.
So, switching all MDIs to DPIs will cost approximately £12.4M a quarter or just short of £50M a year.
CCGs do not have this money and it would need to be provided from central reserves to have primary care prescribing make this switch.
Competing interests: No competing interests