Comparison of bronchial reactivity to ultrasonically nebulized distilled water, exercise and methacholine challenge test in asthmatic children.
We studied the responses to ultrasonically nebulized distilled water (UNDW) challenge, exercise challenge and methacholine challenge in asthmatic children. Fifty-four asthmatic and fourteen nonasthmatic control children participated in this study. The UNDW inhalation test was by the methodology described by Anderson. The average output of water was approximately 3.0 mL/min (SD = .1) and inhalation times were 30 seconds, one minute, two minutes and four minutes. Some subjects performed exercise challenge on a bicycle ergometer and methacholine challenge by an Astrograph technique. Twenty-three of 54 asthmatic patients (42.6%) and none of the controls showed a fall in FEV1 greater than 20% with UNDW challenge. The fall in FEV1 with UNDW correlated with that induced by exercise challenge (r = .89) and Log Dmin, which may reflect bronchial sensitivity (r = .70). Our method is not sensitive enough for detecting bronchial hyperresponsiveness in all asthmatic children. Bronchoconstriction induced by UNDW has a similar mechanism of action as exercise and methacholine.
Obata
T
T
Department of Allergy, National Children's Hospital, Tokyo, Japan.
Iikura
Y
Y
D000280:Administration, Inhalation; D000293:Adolescent; D001249:Asthma / Q000175:diagnosis / Q000503:physiopathology*; D001985:Bronchial Provocation Tests / Q000379:methods*; D016084:Bronchoconstriction; D002648:Child; D015444:Exercise; D005260:Female; D006801:Humans; D008297:Male; D016210:Methacholine Chloride; D014867:Water
D014867:Water; D016210:Methacholine Chloride