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.

Subcutaneous emphysema of the chest wall: a case with unusual presentation.

Subcutaneous emphysema (SE) is the presence of air or other gas in the subcutaneous tissue and is generally associated with pneumothorax and/or pneumomediastinum. We describe an unusual presentation of SE of the chest wall without radiological evidence of pneumothorax or pneumomediastinum, which aetiopathogenesis remains open to several hypotheses in spite of an accurate clinical study.