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Background: Ultrasonically nebulized distilled water (UNDW) is thought to cause bronchospasm via changing the preciliary fluid osmolarity and thus, yielding to mediator release from mast cells or through the activation of cholinergic reflex. Sodium chromoglycate (SCG) known to inhibit mediator release from mast cells and neurogenic activation of bronchial submucousa is considered capable of preventing water induced bronchospasm.
Methods: Thirteen atopic asthmatic patients observed to be hyperreactive to UNDW are included in this study to test this hypothesis. SCG was inhaled by the patients and FEV1 was evaluated 30, 60 and 90 minutes post-inhalation. One week later the same procedure was repeated on the same patients by inhalation of placebo normal saline. Then 2-8 ml of distilled water was inhaled by the patients and FEV1 was measured again.
Results: Before UNDW inhalation, FEV1 was similar between the study and placebo groups whereas it was significantly higher in the study group after UNDW inhalation than that in placebo group (p<0.01).
Conclusions: SCG was considered to be effective in early and late response to UNDW in asthmatic patients. In this circumtance, SCG may have protective effect against bronchial hyperreactivity againts mist of water and air humidity in the ligths of our study.