Ecological footprint of salbutamol administration by metered-dose inhaler versus nebulisation in acute asthma: a life-cycle assessment

Objective The scientific evidence indicates little or no difference in the effectiveness or cost of using of metered-dose inhalers (MDIs) versus nebulisation to treat acute asthma in the emergency department (ED). However, the use of MDIs raises questions of environmental impact. Our objective was to compare the ecological footprint of salbutamol administered by MDI versus nebulisation.

Design Life cycle assessment in which we inventoried and quantified the resources extracted and pollutants emitted by each therapeutic option, from the manufacturing of medication and equipment to their disposal by incineration.

Setting EDs of the CHU de Québec-Université Laval (Canada).

Participants Not applicable.

Main outcome measures Each item of life cycle inventory data was translated into CO2-equivalent emissions (CO2eq) using the IPCC2021/GWP100 method. Results were estimated for the administration of one and three treatments of 800 µg of salbutamol by MDI and 5 mg by nebulisation (standard doses for adults and children ≥ 24 kg).

Results One and three ED-administered treatments with salbutamol emit respectively 1.9 and 4.0 kg of CO2eq via MDI versus 0.9 and 1.0 kg via nebulisation, which corresponds to 5.5 and 11.6 km and to 2.7 and 2.8 km travelled in a subcompact car. Each series of eight inhalations from an MDI releases 1.1 kg of CO2eq due to emission of the hydrofluoroalkane propellant.

Conclusions Considering the absence or minimal difference in clinical effectiveness, this study suggests that nebulisation may be a more eco-efficient administration route than MDIs in the emergency treatment of asthma.