PURPOSE: We propose a novel method to evaluate the efficacy of a pressurized metered dose inhaler (pMDI) in combination with a spacer, by not only considering the total dose extractable from the spacer but also the dependence of dose on the volume available for aerosol inhalation. METHODS: We studied volume-dependence of aerosol concentration during extraction from two commonly used plastic spacers (150 ml AerochamberPlus; 750 ml Volumatic) after a single puff of a 100 microg salbutamol pMDI (HFA-Ventolin), using laser photometric measurements. RESULTS: After a delay of is in each spacer, the aerosol peak dose for AerochamberPlus was 2-fold that for Volumatic (p < 0.001), with the peak appearing well within the first 0.5 L even for the largest spacer. The opposite dose relationship is reached when considering total cumulative dose, which was 2-fold higher for Volumatic than for AerochamberPlus (p < 0.001); >95% of total cumulative dose was extracted well within 3 L for the largest spacer. The 2-fold cumulative dose relationship was confirmed by chemical assay on an absolute filter [AerochamberPlus: 21.4+/-3.2 (SD) microg; Volumatic: 43.8+/-9.1 (SD) microg]. CONCLUSIONS: Actual aerosol dose available to patients during inhalation via spacers can only be done on the basis of a quantification of aerosol peak dose and cumulative dose as a function of extracted volume.
PURPOSE: We propose a novel method to evaluate the efficacy of a pressurized metered dose inhaler (pMDI) in combination with a spacer, by not only considering the total dose extractable from the spacer but also the dependence of dose on the volume available for aerosol inhalation. METHODS: We studied volume-dependence of aerosol concentration during extraction from two commonly used plastic spacers (150 ml AerochamberPlus; 750 ml Volumatic) after a single puff of a 100 microg salbutamol pMDI (HFA-Ventolin), using laser photometric measurements. RESULTS: After a delay of is in each spacer, the aerosol peak dose for AerochamberPlus was 2-fold that for Volumatic (p < 0.001), with the peak appearing well within the first 0.5 L even for the largest spacer. The opposite dose relationship is reached when considering total cumulative dose, which was 2-fold higher for Volumatic than for AerochamberPlus (p < 0.001); >95% of total cumulative dose was extracted well within 3 L for the largest spacer. The 2-fold cumulative dose relationship was confirmed by chemical assay on an absolute filter [AerochamberPlus: 21.4+/-3.2 (SD) microg; Volumatic: 43.8+/-9.1 (SD) microg]. CONCLUSIONS: Actual aerosol dose available to patients during inhalation via spacers can only be done on the basis of a quantification of aerosol peak dose and cumulative dose as a function of extracted volume.
Authors: E Dompeling; A M Oudesluys-Murphy; H M Janssens; W Hop; J G Brinkman; R N Sukhai; J C de Jongste Journal: Arch Dis Child Date: 2001-02 Impact factor: 3.791
Authors: J H Wildhaber; S G Devadason; M J Hayden; R James; A P Dufty; R A Fox; Q A Summers; P N LeSouëf Journal: Eur Respir J Date: 1996-09 Impact factor: 16.671
Authors: Didier Cataldo; Shane Hanon; Rudi V Peché; Daniel J Schuermans; Jean M Degryse; Isabelle A De Wulf; Karin Elinck; Mathias H Leys; Peter L Rummens; Eric Derom Journal: Adv Ther Date: 2022-01-26 Impact factor: 3.845