Differences inaerosol output andairways responsiveness between theDeVilbiss 40and45 handheldnebulisers

Background - TheDeVilbiss 40glass hand heldnebulisers havebeenwidelyusedfor airways responsiveness testing in epidemiological surveys ofasthma.Thesenebulisers havebeensuperseded insome recentstudies bytheDeVilbiss 45plastic handheldnebulisers withtheassumption thattheyare interchangeable. Thisstudy comparedthe aerosoloutputsof the DeVilbiss 40andDeVilbiss 45nebulisers andinvestigated whethertherewas any difference intheinvivomeasurementsof airways responsiveness whenusingthetwo nebuliser types. Methods - Theaerosol outputofsixDeVilbiss40andsixDeVilbiss 45nebulisers was calculated byweightlossper actuation, theusualmethodofcalibrating nebuliser output,and comparedwiththe true amount ofaerosol obtained measuredby a fluoride tracertechnique. Airwaysresponsiveness was measuredtwicein13 asthmatic patients underidentical conditions bytheYanprotocol usingDeVilbiss