Physical Agents in Bronchial Provocation Tests: Nebulized Hyperosmolar Aerosol
Probably the most important development leading to the recognition that abnormal osmolarity of the respiratory tract is a potent stimulus that can provoke airway narrowing was the introduction of ultrasonic nebulizers in the 1960s. Since these nebulizers produce dense aerosols (usually in excess of 3 ml of aerosol per minute), with a large proportion of respirable droplets , they were considered superior to the nebulizers and humidifiers available at that time [18–20]. However, it became apparent that inhalation of ultrasonically nebulized aerosols could be associated both with an increase in airway resistance [11, 22, 23, 30] and a decrease in arterial oxygen tension [23, 29] in patients with chronic bronchitis [11, 23], chronic obstructive airways disease [22, 29] and asthma [6, 11]. The use of ultrasonically nebulized aerosols specifically for the purpose of diagnosis and assessment of bronchial hyperresponsiveness was investigated in the 1970s by Allegra et al. [1, 3] and Allegra and Bianco , who used ultrasonically nebulized water to challenge patients with asthma. In 1981, Schoeffel et al.  extended these findings by demonstrating that the response to ultrasonically nebulized aerosols is largely determined by the osmolarity of the aerosol and that hyperosmolar aerosols are also potent agents for provoking airway narrowing in asthmatic subjects.
KeywordsPhysical Agent Droplet Size Distribution Asthmatic Subject Bronchial Hyperresponsiveness Mass Median Aerodynamic Diameter
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- 1.Allegra L, Bianco S, Petrigini G, Robuschi M (1974) Lo Sforzo muscolare e la nebulizzazione ultrasonica die H2O come tests di provocazione aspecifica del broncospasmo. In: Pasargiklian, Bocca (eds) Progressi in medicina respiratoria `74. Edizioni scientifiche terme e grandi alberghi di Sirmione, Sirmione, p 81Google Scholar
- 2.Allegra L, Bianco S (1980) Non-specific bronchoreactivity obtained with an ultrasonic aerosol of distilled water. Eur J Respir Dis 61: 41–49Google Scholar
- 3.Allegra L, Robuschi M, Bianco S (1975) Tests di provocazione bronchiale aspecifica. In: Mellillo, Pisaneschi (eds) Attide110 Congresso Nazionale dell’Associazione Italiani Aerosol in Medicina. Terme di Tabiano, Salsomaggiore, pp 107–121Google Scholar
- 4.Anderson SD, Smith CM (1989) The use of non-isotonic aerosols for evaluating bronchial hyperresponsiveness. In: Spector S (ed) Provocative challenge procedures: background and methodology. Futura, Mount Kisco, pp 227–252Google Scholar
- 8.Belcher NG, Lee TH, Rees PJ (1989) Airway responsiveness to hypertonic saline, exercise and histamine challenges in bronchial asthma. Eur J Respir Dis 2: 44–48Google Scholar
- 15.Eschenbacher WL, Gravelyn TR (1988) Mediator release after local osmolar challenge to the airways. In: Armour CL, Black JL (eds) Mechanisms in asthma: pharmacology, physiology and management. Liss, New York, pp 355–363Google Scholar
- 17.Finney MJB, Anderson SD, Black JL (1989) Terfenadine modifies airway narrowing induced by the inhalation of non-isotonic aerosols in subjects with asthma. Am Rev Respir Dis (in press)Google Scholar
- 25.Schoeffel RE, Anderson SD, Altounyan REC (1981) Bronchial hyperreactivity in response to inhalation of ultrasonically nebulized solutions of distilled water and saline (Br Med J 283: 1285–1287Google Scholar
- 27.Smith CM, Anderson SD (1990) Provocation tests for asthma using non-isotonic aerosols. J Allergy Clin Immunol (in press)Google Scholar
- 28.Smith CM, Anderson SD (1989) Inhalation challenge using hypertonic (4.5%) saline in asthmatic subjects: a comparison with responses to hyperpnoea, methachohne and water. Eur Respir J (in press)Google Scholar
- 31.Wolfsdorf J, Swift DL, Avery ME (1969) Mist therapy reconsidered; an evaluation of the respiratory deposition of labelled water aerosols produced by jet and ultrasonic nebulizers. Paediatrics 43: 799–808Google Scholar