Effects of the calcium antagonist tiapamil on pulmonary gas exchange in patients with chronic obstructive pulmonary disease who receive salbutamol

1985 ◽  
Vol 38 (1) ◽  
pp. 96-100
Author(s):  
Matthias Gugger ◽  
A Marco Crivelli ◽  
Renato L Galeazzi ◽  
Hans Bachofen
Keyword(s):  
Chronic Obstructive Pulmonary Disease ◽  
Calcium Antagonist ◽  
Gas Exchange ◽  
Pulmonary Disease ◽  
Pulmonary Gas Exchange ◽  
Chronic Obstructive ◽  
Obstructive Pulmonary Disease

Ventilation-perfusion imbalance and chronic obstructive pulmonary disease staging severity

2009 ◽  
Vol 106 (6) ◽  
pp. 1902-1908 ◽  
Author(s):  
Roberto Rodríguez-Roisin ◽  
Mitra Drakulovic ◽  
Diego A. Rodríguez ◽  
Josep Roca ◽  
Joan Albert Barberà ◽  
...  
Keyword(s):  
Chronic Obstructive Pulmonary Disease ◽  
Gas Exchange ◽  
Pulmonary Disease ◽  
Forced Expiratory Volume ◽  
Pulmonary Gas Exchange ◽  
Airflow Limitation ◽  
Chronic Obstructive ◽  
Obstructive Pulmonary Disease ◽  
Gold Stage ◽  
Stage 1

Chronic obstructive pulmonary disease (COPD) is characterized by a decline in forced expiratory volume in 1 s (FEV1) and, in many advanced patients, by arterial hypoxemia with or without hypercapnia. Spirometric and gas exchange abnormalities have not been found to relate closely, but this may reflect a narrow range of severity in patients studied. Therefore, we assessed the relationship between pulmonary gas exchange and airflow limitation in patients with COPD across the severity spectrum. Ventilation-perfusion (V̇A/Q̇) mismatch was measured using the multiple inert gas elimination technique in 150 patients from previous studies. The distribution of patients according to the GOLD stage of COPD was: 15 with stage 1; 40 with stage 2; 32 with stage 3; and 63 with stage 4. In GOLD stage 1, AaPo2 and V̇A/Q̇ mismatch were clearly abnormal; thereafter, hypoxemia, AaPo2, and V̇A/Q̇ imbalance increased, but the changes from GOLD stages 1–4 were modest. Postbronchodilator FEV1 was related to PaO2 ( r = 0.62) and PaCO2 ( r = −0.59) and to overall V̇A/Q̇ heterogeneity ( r = −0.48) ( P < 0.001 each). Pulmonary gas exchange abnormalities in COPD are related to FEV1 across the spectrum of severity. V̇A/Q̇ imbalance, predominantly perfusion heterogeneity, is disproportionately greater than airflow limitation in GOLD stage 1, suggesting that COPD initially involves the smallest airways, parenchyma, and pulmonary vessels with minimal spirometric disturbances. That progression of V̇A/Q̇ inequality with spirometric severity is modest may reflect pathogenic processes that reduce both local ventilation and blood flow in the same regions through airway and alveolar disease and capillary involvement.

scholarly journals Low resting diffusion capacity, dyspnea, and exercise intolerance in chronic obstructive pulmonary disease

2019 ◽  
Vol 127 (4) ◽  
pp. 1107-1116 ◽  
Author(s):  
Amany F. Elbehairy ◽  
Conor D. O'Donnell ◽  
Asmaa Abd Elhameed ◽  
Sandra G. Vincent ◽  
Kathryn M. Milne ◽  
...  
Keyword(s):  
Chronic Obstructive Pulmonary Disease ◽  
Gas Exchange ◽  
Pulmonary Disease ◽  
Respiratory Mechanics ◽  
Pulmonary Gas Exchange ◽  
Exercise Intolerance ◽  
Chronic Obstructive ◽  
Obstructive Pulmonary Disease ◽  
Mechanical Constraints ◽  
Lower Limit Of Normal

The mechanisms linking reduced diffusing capacity of the lung for carbon monoxide (DlCO) to dyspnea and exercise intolerance across the chronic obstructive pulmonary disease (COPD) continuum are poorly understood. COPD progression generally involves both DlCO decline and worsening respiratory mechanics, and their relative contribution to dyspnea has not been determined. In a retrospective analysis of 300 COPD patients who completed symptom-limited incremental cardiopulmonary exercise tests, we tested the association between peak oxygen-uptake (V̇o2), DlCO, and other resting physiological measures. Then, we stratified the sample into tertiles of forced expiratory volume in 1 s (FEV1) and inspiratory capacity (IC) and compared dyspnea ratings, pulmonary gas exchange, and respiratory mechanics during exercise in groups with normal and low DlCO [i.e., <lower limit of normal (LLN)] using Global Lung Function Initiative reference values. DlCO was associated with peak V̇o2 ( P = 0.006), peak work-rate ( P = 0.005), and dyspnea/V̇o2 slope ( P < 0.001) after adjustment for other independent variables (airway obstruction and hyperinflation). Within FEV1 and IC tertiles, peak V̇o2 and work rate were lower ( P < 0.05) in low versus normal DlCO groups. Across all tertiles, low DlCO groups had higher dyspnea ratings, greater ventilatory inefficiency and arterial oxygen desaturation, and showed greater mechanical volume constraints at a lower ventilation during exercise than the normal DlCO group (all P < 0.05). After accounting for baseline resting respiratory mechanical abnormalities, DlCO<LLN was consistently associated with greater dyspnea and poorer exercise performance compared with preserved DlCO. The higher dyspnea ratings and earlier exercise termination in low DlCO groups were linked to significantly greater pulmonary gas exchange abnormalities, higher ventilatory demand, and associated accelerated dynamic mechanical constraints. NEW & NOTEWORTHY Our study demonstrated that chronic obstructive pulmonary disease patients with diffusing capacity of the lung for carbon monoxide (DlCO) less than the lower limit of normal had greater pulmonary gas exchange abnormalities, which resulted in higher ventilatory demand and greater dynamic mechanical constraints at lower ventilation during exercise. This, in turn, led to greater exertional dyspnea and exercise intolerance compared with patients with normal DlCO.

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.

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