Aerosol recovery from large-volume reservoir delivery systems is highly dependent on the static properties of the reservoir
In this study, the role of electrostatic fields on aerosol recovery from a system with a large collapsible reservoir (30 L) was investigated. In addition, the efficacy of the reservoir method for bronchial challenge procedures was assessed in vivo. Aerosol recovery was determined by measuring the fraction of aerosol (0.05% 99mTc-tagged human albumin solution) retrieved from the reservoir. Before aerosol recovery experiments, electrostatic fields in the reservoir were measured. Aerosol recovery varied significantly with wall thickness of the reservoir and presence of an antistatic coating (range 6.0-70.3%). A close inverse relationship was found between the mean electrostatic field in the reservoir and aerosol recovery. The nebulized provocative concentration of histamine causing a 20% fall in forced expiratory volume in one second in asthmatics was found to be approximately half that of a standard method when compared with the reservoir system (mean ratio 2.24 (95% confidence interval, 1.60-3.12)). Recovery from an aerosol delivery system with a relatively large collapsible aerosol reservoir was highly dependent on the electrostatic field in the reservoir. In these systems the use of electrostatic field dissipative material for the reservoir is therefore recommended.
Increase in allergen‐specific IgE and ex vivo Th2 responses after a single bronchial challenge with house dust mite in allergic asthmatics
To cite this article: van de Pol MA, Lutter R, van Ree R, van der Zee JS. Increase in allergen‐specific IgE and ex vivo Th2 responses after a single bronchial challenge with house dust mite in allergic asthmatics.Allergy 2012; 67: 67–73.
Aerosol deposition in automatic dosimeter nebulization.
A new dosimeter nebulization method was studied in 10 asthmatics and 8 normal volunteers by delivering fixed doses of 99mTc-traced radioaerosol in 0.2 s periods of tidal breathing. Two separate inspiratory phases were studied with the onset of nebulization, when in the earlier phase 15% and in the later phase 60% of tidal volume was inhaled. Further, bronchodilator administration was analogically assessed in the asthmatics. In healthy subjects, the total lung deposition was 17% greater in the earlier phase (p less than 0.005) than in the later one. In asthmatics, the difference was not significant. The losses of aerosol outside the lower respiratory tract were minimized, in the mouthwashing 0.3% and in the exhaled air 1.4%. The onset of nebulization (early or late) had no significant effect on bronchodilation with salbutamol in asthmatics. We conclude that the present dosimeter method is useful for efficient delivery of radioaerosols and drugs, and for standardization of bronchoprovocation.