Resting Dead Space Fraction as Related to Clinical Characteristics Lung Function and Gas Exchange in Male Patients with Chronic Obstructive Pulmonary Disease

摘要

Measures of forced expired volume in one second % predicted (FEV1%), residual volume to total lung capacity ratio (RV/TLC) and diffusing capacity for carbon monoxide measurements (DLCO) are the standard lung function test for evaluating patients with chronic obstructive pulmonary disease (COPD). The dead space fraction (VD/VT) has been shown to be a robust marker of gas exchange abnormality. However, the use of VD/VT has gradually become less common. As VD/VT measured at rest (VD/VTR) has been successfully used in non-COPD conditions, it was hypothesized that in COPD the VD/VTR was more sensitive than the standard lung function test in correlation with clinical characteristics and gas exchange. This study aimed to test the hypothesis and to identify the variables relevant to VD/VTR.