Airway responsiveness to exercise and ultrasonically nebulized distilled water in children: relationship to clinical and functional characteristics.
We studied the bronchial response to exercise and ultrasonically nebulized distilled water (UNDW) challenge in 19 normal controls (3 females and 16 males; age 6-13 years) and in 44 asthmatic children (12 females and 32 males; age 6-13 years) in order (1) to determine the sensitivity and specificity of the two challenges and (2) to evaluate the relationship between bronchial responses and clinical and functional characteristics. A 20% fall in FEV1 was regarded as a significant bronchial response. The specificity of both challenges was high (100%), whereas the sensitivity of exercise (77.3%) was twice that of UNDW (38.6%). The combination of the two challenges increased the sensitivity to 81.8%. There was no correlation between the magnitude of bronchial response to exercise and UNDW (rs = -0.03; p greater than 0.05). Exercise responders were not different from nonresponders in regard to gender, age, resting lung function, length of asthmatic history and treatment requirement to control symptoms. However, the UNDW responders were different from nonresponders in regard to age (p less than 0.05) and length of asthmatic history (p less than 0.001). Children younger than 9 years old are unlikely to show a bronchial response to UNDW inhalation, since only 9.5% of them developed a significant bronchoconstriction. We suggest that the two stimuli recognize some different pathways or subjects have basic biological differences.
Foresi
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Istituto di Clinica Medica, Università Cattolica S. Cuore, Roma, Italia.
Corbo
G M
GM
Valente
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D000293:Adolescent; D001249:Asthma / Q000503:physiopathology*; D001980:Bronchi / Q000503:physiopathology*; D001985:Bronchial Provocation Tests; D002648:Child; D015444:Exercise; D005260:Female; D006801:Humans; D008297:Male; D009330:Nebulizers and Vaporizers; D014465:Ultrasonics; D014867:Water
D014867:Water