Aerosol delivery from spacers in wheezy infants: a daily life study

The aims of this study were to assess and compare dose delivery and dose va riability of pressurized metered dose inhalers (pMDI)/spacers in wheezy inf ants in daily life and to investigate factors influencing aerosol delivery. In an open randomized crossover study in 25 wheezy infants aged 5-26 months , a metal spacer (Nebuchamber(R)), a detergent coated (DC) and a non-deterg ent coated (nonDC) plastic spacer (Babyhaler(R)) were tested at home for 7 days each. Budesonide (200 mug b.i.d.) was administered via a Nebuchamber o r fluticasone (125 mug b.i.d.) via a Babyhaler. Aerosol was trapped in filt ers, positioned between the spacer and face mask. Cooperation was scored on diary cards. Electrostatic charge (ESC) of the spacers was measured. Evalu ations of the administration technique were made from video recordings. Median (range) dose delivery of the filters expressed as per cent (%) of no minal dose, was 34% (3-59), 23% (1-49), and 41% (12-55) for the Nebuchamber , nonDC-Babyhaler, and DC-Babyhaler respectively. Considerable dose variabi lity was found, median (range) within-subject dose variability, expressed a s coefficient of variation, for the Nebuchamber (49% (15-249)) was signific antly higher when compared,vith both nonDC- (36% (12-325)) and DC-Babyhaler s (27% (10-122)), for which dose variabilities were similar. Detergent coating was effective to reduce electrostatic charge, and to incr ease dose delivery, but had no effect on dose variability. Bad cooperation was an important cause for high dose variability for all spacers (r=0.5-0.6 , p<0.02). Many mistakes were made during the administration procedure.