Modification of pediatric lung function measurement by antibacterial filters

: The risk of cross-infection by contaminated lung function equipment can be reduced by the use of antibacterial filters. These filters, however, should have no significant influence on flow measurements. We investigated the effect of a new filter (Pall PF 30) on lung function measurements in 92 children and adolescents with bronchial asthma and cystic fibrosis. In randomized sequence, flow-volume curves and spirometry were registered in the whole body plethysmograph. Values measured with filter correlated closely to those registered without; individual values remained close to the line of identity. With high flow rates, however, there was a minimal tendency towards lower measurements with filter; this damping effect was flow-dependent and remained of a clinically insignificant dimension.