Abstract
Background: Valved holding chambers (VHC) differ in aerodynamic characteristics, volume, valve mechanism and facemask fit. Yet they are generally marketed and used with the assumption of being equally effective.
Our aim: was to conduct a financially independent study comparing the drug delivery efficacy of all 6 VHCs available in Finland.
Methods: Four different standardized simulated paediatric breathing patterns were used: A) breathing frequency 25/min and tidal volume 200 ml; B) 25/min and 50 ml; C) 50/min and 200 ml; and D) 50/min and 50 ml. A previously validated test rig (Xu Z, et al. J Aerosol Med Pulm Drug Deliv. 2014;27:S44-54) with VHC cradles and soft anatomical face was used. 200 µg of salbutamol (Ventolin Evohaler 100 µg/dos) was actuated into each spacer with and without facemask. The delivered dose was measured after 8 breathing cycles from a filter that was placed at a distance representing the child’s oral cavity.
Results: Altogether 396 measurements were made. There were marked differences between VHCs regarding to delivered dose (figure). Facemask fit also affected drug delivery dramatically. Differences between VHCs were similar using all four breathing patterns.
Conclusion: The evident difference in drug delivery with VHCs has potentially great consequences regarding successful treatment of children with bronchoconstriction. There is a need for comprehensive and financially independent testing and standardisation of VHCs.
Footnotes
Cite this article as: European Respiratory Journal 2018 52: Suppl. 62, OA340.
This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only).
- Copyright ©the authors 2018