scholarly journals Investigating the relationships among lung function variables in chronic obstructive pulmonary disease in men

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7829 ◽  
Author(s):  
Ming-Lung Chuang ◽  
I-Feng Lin
Keyword(s):  
Chronic Obstructive Pulmonary Disease ◽  
Lung Function ◽  
Pulmonary Disease ◽  
Lung Volume ◽  
Chronic Obstructive ◽  
Lung Volume Measurements ◽  
Latent Factors ◽  
Air Trapping ◽  
Obstructive Pulmonary Disease ◽  
Volume Measurements

Background In patients with chronic obstructive pulmonary disease (COPD), the independent contributions of individual lung function variables to outcomes may be lower when they are modelled together if they are collinear. In addition, lung volume measurements may not be necessary after spirometry data have been obtained. However, these hypotheses depend on whether forced vital capacity (FVC) can predict total lung capacity (TLC). Moreover, the definitions of hyperinflation and air trapping according to lung function variables overlap and need be clarified. Therefore, the aim of this study was to evaluate the relationships among various lung function parameters to elucidate these issues. Methods Demographic data and 26 parameters of full lung function were measured in 94 men with COPD and analyzed using factor and correlation analyses. Results Factor analysis revealed five latent factors. Inspiratory capacity (IC)/TLC and residual volume (RV)/TLC were most strongly correlated with all other lung volumes. IC/TLC, RV/TLC, and functional residual capacity (FRC)/TLC were collinear and were potential markers of air trapping, whereas TLC%, FRC%, and RV% were collinear and were potential markers of hyperinflation. RV/TLC >0.4 (or IC/TLC <0.4) was comparable with the ratio of forced expiratory volume in one second (FEV1) and FVC <0.7. FVC% and FEV1% were poorly correlated with TLC%. The correlation study showed that TLC%, RV/TLC, and FEV1% could be used to represent individual latent factors for hyperinflation, air trapping, inspiration, expiration, and obstruction. Combined with diffusion capacity%, these four factors could be used to represent comprehensive lung function. Conclusions This study identified collinear relationships among individual lung function variables and thus selecting variables with close relationships for correlation studies should be performed with caution. This study also differentiated variables for air trapping and lung hyperinflation. Lung volume measurements are still required even when spirometry data are available. Four out of 26 lung function variables from individual latent factors could be used to concisely represent lung function.

scholarly journals Mechanisms of gas exchange response to lung volume reduction surgery in severe emphysema

2011 ◽  
Vol 110 (4) ◽  
pp. 1036-1045 ◽  
Author(s):  
George Cremona ◽  
Joan A. Barbara ◽  
Teresa Melgosa ◽  
Lorenzo Appendini ◽  
Josep Roca ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Chronic Obstructive Pulmonary Disease ◽  
Lung Function ◽  
Gas Exchange ◽  
Pulmonary Disease ◽  
Lung Volume ◽  
Chronic Obstructive ◽  
Lung Volume Reduction Surgery ◽  
Lung Volume Reduction ◽  
Obstructive Pulmonary Disease

Lung volume reduction surgery (LVRS) improves lung function, respiratory symptoms, and exercise tolerance in selected patients with chronic obstructive pulmonary disease, who have heterogeneous emphysema. However, the reported effects of LVRS on gas exchange are variable, even when lung function is improved. To clarify how LVRS affects gas exchange in chronic obstructive pulmonary disease, 23 patients were studied before LVRS, 14 of whom were again studied afterwards. We performed measurements of lung mechanics, pulmonary hemodynamics, and ventilation-perfusion (V̇a/Q̇) inequality using the multiple inert-gas elimination technique. LVRS improved arterial Po2 (PaO2) by a mean of 6 Torr ( P = 0.04), with no significant effect on arterial Pco2 (PaCO2), but with great variability in both. Lung mechanical properties improved considerably more than did gas exchange. Post-LVRS PaO2 depended mostly on its pre-LVRS value, whereas improvement in PaO2 was explained mostly by improved V̇a/Q̇ inequality, with lesser contributions from both increased ventilation and higher mixed venous Po2. However, no index of lung mechanical properties correlated with PaO2. Conversely, post-LVRS PaCO2 bore no relationship to its pre-LVRS value, whereas changes in PaCO2 were tightly related ( r2 = 0.96) to variables, reflecting decrease in static lung hyperinflation (intrinsic positive end-expiratory pressure and residual volume/total lung capacity) and increase in airflow potential (tidal volume and maximal inspiratory pressure), but not to V̇a/Q̇ distribution changes. Individual gas exchange responses to LVRS vary greatly, but can be explained by changes in combinations of determining variables that are different for oxygen and carbon dioxide.

Screening of High-risk Patients for Chronic Obstructive Pulmonary Disease in Primary Care: A Narrative Review (Preprint)

2020 ◽  
Author(s):  
Ponrathi Athilingam ◽  
Andrew Bugajski ◽  
Usha Menon
Keyword(s):  
Chronic Obstructive Pulmonary Disease ◽  
Lung Function ◽  
Pulmonary Disease ◽  
Current Knowledge ◽  
Screening Tools ◽  
Chronic Obstructive ◽  
Early Screening ◽  
Obstructive Pulmonary Disease ◽  
Impaired Lung Function ◽  
Risk Patients

UNSTRUCTURED Chronic obstructive pulmonary disease (COPD) predominantly affects older adults, and claimed 3 million lives in 2016, making it the third leading cause of death worldwide. Over 35 million Americans aged 40 or older have lung function consistent with diagnosable COPD. COPD and cardiovascular disease (CVD) have a bidirectional relationship, in that one is a risk factor for developing the other. National and international consortiums recommend early screening of adults at risk of COPD, such as those with CVD. Recommended screening strategies include screening tools to assess symptoms, medical history, and handheld spirometry. Handheld spirometry has high diagnostic accuracy and if impaired lung function is indicated, these patients are referred for pulmonary function testing (PFT), the diagnostic gold standard for COPD. However, there is no clinical consensus for pulmonary screening in people with CVD. Current knowledge relating to the prevalence and incidence of CVD in people with COPD and the mechanisms that underlie their coexistence is key in combating the global burden of COPD.

scholarly journals Alternative methods for assessing bronchodilator reversibility in chronic obstructive pulmonary disease

Thorax ◽  
2001 ◽  
Vol 56 (9) ◽  
pp. 713-720
Author(s):  
J Hadcroft ◽  
P M A Calverley
Keyword(s):  
Chronic Obstructive Pulmonary Disease ◽  
Pulmonary Disease ◽  
Lung Volume ◽  
Tidal Flow ◽  
Airflow Limitation ◽  
Alternative Methods ◽  
Chronic Obstructive ◽  
Flow Limitation ◽  
Inspiratory Capacity ◽  
Obstructive Pulmonary Disease

BACKGROUNDBronchodilator reversibility testing is recommended in all patients with chronic obstructive pulmonary disease (COPD) but does not predict improvements in breathlessness or exercise performance. Two alternative ways of assessing lung mechanics—measurement of end expiratory lung volume (EELV) using the inspiratory capacity manoeuvre and application of negative expiratory pressure (NEP) during tidal breathing to detect tidal airflow limitation—do relate to the degree of breathlessness in COPD. Their usefulness as end points in bronchodilator reversibility testing has not been examined.METHODSWe studied 20 patients with clinically stable COPD (mean age 69.9 (1.5) years, 15 men, forced expiratory volume in one second (FEV1) 29.5 (1.6)% predicted) with tidal flow limitation as assessed by their maximum flow-volume loop. Spirometric parameters, slow vital capacity (SVC), inspiratory capacity (IC), and NEP were measured seated, before and after nebulised saline, and at intervals after 5 mg nebulised salbutamol and 500 μg nebulised ipratropium bromide. The patients attended twice and the treatment order was randomised.RESULTSMean FEV1, FVC, SVC, and IC were unchanged after saline but the degree of tidal flow limitation varied. FEV1 improved significantly after salbutamol and ipratropium (0.11 (0.02) l and 0.09 (0.02) l, respectively) as did the other lung volumes with further significant increases after the combination. Tidal volume and mean expiratory flow increased significantly after all bronchodilators but breathlessness fell significantly only after the combination treatment. The initial NEP score was unrelated to subsequent changes in lung volume.CONCLUSIONSNEP is not an appropriate measurement of acute bronchodilator responsiveness. Changes in IC were significantly larger than those in FEV1and may be more easily detected. However, our data showed no evidence for separation of “reversible” and “irreversible” groups whatever outcome measure was adopted.

Serum heavy metals and lung function in a chronic obstructive pulmonary disease cohort

2017 ◽  
Vol 9 (1) ◽  
pp. 30-35 ◽  
Author(s):  
Jeongwon Heo ◽  
Hyun Sun Park ◽  
Yoonki Hong ◽  
Jinkyeong Park ◽  
Seok-Ho Hong ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Chronic Obstructive Pulmonary Disease ◽  
Lung Function ◽  
Pulmonary Disease ◽  
Chronic Obstructive ◽  
Obstructive Pulmonary Disease
Sign in / Sign up

Export Citation Format

Share Document