Objective
To compare modelled lung delivery of rescue medication via different valved spacers with facemask with the goal of providing optimum patient care while minimizing potential carbon footprint
Method
Four different spacer types were evaluated by breathing simulator (tidal volume=155-mL, I:E ratio=1:2, rate=25 cycles/min). The facemask of each spacer (n=3) was attached to an anatomical model and the airway coupled to a breathing simulator via a filter to capture drug particles that penetrated as far as the carina. 5-actuations of salbutamol (Ventolin† Evohaler) were delivered at 30-s intervals and recovered from specific locations in the aerosol pathway by HPLC. Comparisons were then made on drug delivery data looking at potential dose to the lungs for each pMDI/spacer. This potential delivery was then equated to a potential relative carbon footprint based upon published claims1 that Ventolin has a carbon footprint of 28 kg CO2 per inhaler.
Results
Conclusion
Medication delivery can vary significantly depending on the pMDI/spacer system which will have implications on the carbon footprint. In this case, the use of the AeroChamber Plus* Flow-Vu* spacer could potentially reduce the carbon footprint by up to five-fold compared to other spacers. By maximizing the amount of each puff reaching the lungs the patient is likely to be able to achieve relief sooner. This will reduce the number of puffs needed and as a result reduce the carbon footprint of the inhaler.