Hypo-osmolar aerosol induces hyperventilation in chronic non-asthmatic rhinitics.
The effect of a hypo-osmolar aerosol on transcutaneous O2 and CO2 time course (PtcO2, PtcCO2) was investigated in subjects affected by chronic non-atopic rhinitis, without any history of asthmatic symptoms and no airways hyper-responsiveness. Twelve normal subjects and 12 subjects affected by chronic idiopathic rhinitis, who had normal responsiveness to both hypo-osmolar aerosol and methacholine challenge as measured by the decrease in FEV1 (mean FEV1 decrease = 5% and PC20 > 16 mg, respectively) were studied. By means of a transcutaneous mono-electrode, it was possible to study the time course of PtcO2 and PtcCO2 during and after a 5-min inhalation of ultrasonically nebulized distilled water (output 2 ml/min-1). A significant decrease in PtcCO2 and increase in PtcO2 were observed during the challenge in rhinitics as compared with normal subjects [maximum decrease and maximum increase expressed as mean value (+/- SD) were -22% (+/- 6.9) and +12.6% (+/- 7.2), respectively]. No significant changes in either PtcCO2 and PtcO2 were observed after the test. The results of this study suggest that patients affected by idiopathic chronic rhinitis with absence of bronchial hyper-responsiveness may present a hyperventilatory response to the inhalation of hypo-osmolar aerosol; the mechanism of such a response might be due to an upregulation of the irritant receptors of the upper airways.
Cogo
A L
AL
Institute of Infectious and Respiratory Diseases, University of Ferrara, Italy.
Ferrari
M
M
Fugagnoli
A
A
Micheletto
C
C
Ciaccia
A
A
D000293:Adolescent; D000328:Adult; D000336:Aerosols / Q000009:adverse effects*; D000704:Analysis of Variance; D001785:Blood Gas Monitoring, Transcutaneous; D001985:Bronchial Provocation Tests; D002908:Chronic Disease; D005260:Female; D006801:Humans; D006985:Hyperventilation / Q000097:blood / Q000209:etiology*; D008168:Lung / Q000503:physiopathology*; D008297:Male; D009994:Osmolar Concentration; D012220:Rhinitis / Q000097:blood / Q000503:physiopathology*; D013147:Spirometry
D000336:Aerosols