Respiratory and pulmonary vascular modifications induced by methacholine inhaled challenge in 20 asthmatic outpatients were studied non invasively by means of echo-Doppler. Eight healthy volunteers were studied as a control group. A significant reduction in oxemia (-22 mmHg) as a hyperreactive marker (PD15O2) was observed in asthmatics and it was strictly related to PD20FEV1(r = 0.82 and p <0.005). Again in asthmatics we observed a significant increase in sPAP (from 27±2 to 39±9 mmHg) evaluated by means of echo-Doppler: This variation was time related to hypoxic phase. Hypoxemia lasted 9±5 minutes but neither this index nor the basal lung function or the methacholine challenge results were related to the echo-Doppler measurements which were useful for evaluating the pulmonary vascular response. Finally our study suggests that: a) a significant decrease in oxemia was strictly related to the bronchial response in asthmatics; b) a transient increase in sPAP was present and time related to hypoxia only asthmatics; C) the lack of relationship among vascular and bronchial response was probably due to different distribution of ventilatory and vascular reflexes in each subject.
|Translated title of the contribution||Non invasive assessment of physiopathologic events during methacholine inhaled test in asthmatics|
|Number of pages||7|
|Publication status||Published - 1993|
ASJC Scopus subject areas
- Pulmonary and Respiratory Medicine