PT  - JOURNAL ARTICLE
AU  - R. Torchio
AU  - A. Antonelli
AU  - C. Gulotta
AU  - E. Crimi
AU  - C. Crimi
AU  - V. Brusasco
AU  - R. Pellegrino
TI  - Effects of thoracic gas compression on airway responsiveness in asthma
DP  - 2012 Sep 01
TA  - European Respiratory Journal
PG  - P865
VI  - 40
IP  - Suppl 56
4099  - http://erj.ersjournals.com/content/40/Suppl_56/P865.short
4100  - http://erj.ersjournals.com/content/40/Suppl_56/P865.full
SO  - Eur Respir J2012 Sep 01; 40
AB  - Background:The response to a bronchial challenge is usually assessed from the changes in the forced expiratory in 1 s (FEV1). Yet this measurement is negatively affected by the thoracic gas compression.Aim:To examine the effects of thoracic gas compression on the dose-response curve to methacholine (MCh) in asthma.Methods: 28 male and 25 female asthmatic patients participated in the study. Methacholine challenge was performed in a flow-type body plethysmograph to compute simultaneously FEV1 and compression-free FEV1 (FEV1PLETH). The doses of MCh that caused a decrease in FEV1 and FEV1PLETH by 20% of control were calculated by linear interpolation of the dose-response curve and transformed into natural logarithm.Results:On average, lnPD20FEV1 was significantly less that lnPD20FEV1PLETH (5.49±0.94 vs. 5.74±1.00, p<0.001). The difference between lnPD20FEV1 and lnPD20FEV1PLETH was positively correlated with absolute TLC (r2=0.40) and height in cm (r2=0.27), and it was larger in males than in females (0.34 vs. 0.14, p<0.001).Conclusions:Thoracic gas compression has a significant effect on airway responsiveness, which depends on absolute lung volume and, thus, anthropometric characteristics.