Devadason, S.G.

spacer filter group aerosol delivery children group i variability aerosol filter dose delivery study nebuchamber within-subject variability group ii within-subject plastic spacers plastic child face mask volumatic metal within-subject cv device budesonide asthma babyhaler filter doses charge /spacer effect dose variability spacer devices actuation administration procedure inhalation pmdi /spacer combinations sample asthmatic correlation analysis administration procedure result devadason sg metal spacer month inhaler difference astra medication dose inhalers period pmdi /spacers parent score crossover study inhalation technique princess margaret hospital devadason plastic spacer asthmatic children factor variation amount janssen instruction salbutamol assessment randomized mouth patient respir diary volume polycarbonate material pmdi /spacer meansd run-in period study medication