Airway distensibility and volume recruitment with lung inflation in COPD

Baldi, S.; Dellacà, Raffaele L.; Govoni, Leonardo; Torchio, Roberto; Aliverti, Andréa; Pompilio, Pasquale; Corda, Luciano; Tantucci, Claudio; Gulotta, Carlo; Brusasco, Vito; Pellegrino, Riccardo

doi:10.1152/japplphysiol.00147.2010

Cited by 29 publications

(20 citation statements)

References 35 publications

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“…These data suggest that airflow limitation and/or airway collapse are less common in patients with the lowest airway elastic fibres content. One may speculate that lowered elastic fibres content reduces airway wall compliance thereby increasing airway wall stiffness, which indeed has been observed in COPD [33] and even in asthma [34]. Hence, in the presence of COPD lowered airway elastic fibres content may even represent a protective mechanism against airflow limitation.…”

Section: Discussionmentioning

confidence: 86%

Extracellular matrix composition in COPD

et al. 2012

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Extracellular matrix (ECM) composition has an important role in determining airway structure. We postulated that ECM lung composition of chronic obstructive pulmonary disease (COPD) patients differs from that observed in smoking and nonsmoking subjects without airflow obstruction.We determined the fractional areas of elastic fibres, type-I, -III and -IV collagen, versican, decorin, biglycan, lumican, fibronectin and tenascin in different compartments of the large and small airways and lung parenchyma in 26 COPD patients, 26 smokers without COPD and 16 nonsmoking control subjects.The fractional area of elastic fibres was higher in non-obstructed smokers than in COPD and nonsmoking controls, in all lung compartments. Type-I collagen fractional area was lower in the large and small airways of COPD patients and in the small airways of non-obstructed smokers than in nonsmokers. Compared with nonsmokers, COPD patients had lower versican fractional area in the parenchyma, higher fibronectin fractional area in small airways and higher tenascin fractional area in large and small airways compartments. In COPD patients, significant correlations were found between elastic fibres and fibronectin and lung function parameters.Alterations of the major ECM components are widespread in all lung compartments of patients with COPD and may contribute to persistent airflow obstruction.

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Section: Discussionmentioning

confidence: 86%

Extracellular matrix composition in COPD

et al. 2012

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“…As published previously, we believe that this decrease in distensibility is due to a combination of intrinsic remodeling of the airway walls and progressive parenchymal destruction. 11,15 We extended this knowledge by demonstrating that the association between emphysema and global airway distensibility remained after adjustment for relevant covariates, such age and sex. We believe that this adjustment is important because studies have shown differences in airway diameter changes with lung infl ation by sex and age in healthy lungs 24 and by age in diseased lungs.…”

Section: Airway Distensibility Across Groupsmentioning

confidence: 78%

“…In fact, Baldi et al 15 demonstrated the relationship between emphysema and distensibility only after albuterol administration. Similarly, we validated this association in the postbronchodilator cohort (e- Table 3).…”

Section: Discussionmentioning

confidence: 99%

“…COPDGene subjects were evaluated in one to two visits, with questionnaires and pulmonary function tests usually done before scanning. Based on prior data showing an association between airway distensibility measured by forced oscillation technique and emphysema after bronchodilation with albuterol, 15 we analyzed data in a subset of 73 subjects who had CT imaging performed within 3 h of albuterol inhalation. We called this group the postbronchodilator cohort.…”

Section: Study Populationmentioning

confidence: 99%

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Association Between Airway Caliber Changes With Lung Inflation and Emphysema Assessed by Volumetric CT Scan in Subjects With COPD

Díaz

Come

Ross

et al. 2012

Chest

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A defi ning characteristic of COPD is expiratory airfl ow limitation due to intrinsic remodeling of the small airways and their dynamic collapse during forced exhalation. 1 In a normal lung, infl ation results in a predictable increase in airway caliber because of the interdependence of parenchyma and airways (the relative change in airway diameter is linearly related with the cube root of lung volume). 2 Emphysema alters this relationship by disrupting airway-parenchymal interdependence. Early work in small animals demonstrated that methacholine-induced bronchoconstriction was increased in elastase models of emphysema, 3 suggesting that the bronchoconstrictive effect of airway smooth muscle activation is opposed by the Background: An increase in airway caliber (airway distensibility) with lung infl ation is attenuated in COPD. Furthermore, some subjects have a decrease in airway caliber with lung infl ation. We aimed to test the hypothesis that airway caliber increases are lower in subjects with emphysemapredominant (EP) compared with airway-predominant (AP) CT scan subtypes. Additionally, we compared clinical and CT scan features of subjects with (airway constrictors) and without a decrease in airway caliber. Methods: Based on GOLD (Global Initiative for Chronic Obstructive Lung Disease) stages and CT scan subtypes, we created a control group (n 5 46) and the following matched COPD groups (n 5 23 each): GOLD-2-AP, GOLD-2-EP, GOLD-4-AP, and GOLD-4-EP. From the CT scans of all 138 subjects, we measured emphysema, lung volumes, and caliber changes in the third and fourth airway generations of two bronchi. We expressed airway distensibility (ratio of airway lumen diameter change to lung volume change from end tidal breathing to full inspiration) as a global or lobar measure based on normalization by whole-lung or lobar volume changes. Results: Global distensibility in the third and fourth airway generations was signifi cantly lower in the GOLD-2-EP and GOLD-4-EP groups than in control subjects. In GOLD-2 subjects, lobar distensibility of the right-upper-lobe fourth airway generation was signifi cantly lower in those with EP than in those with AP. In multivariate analysis, emphysema was an independent determinant of global and lobar airway distensibility. Compared with nonconstrictors, airway constrictors experienced more dyspnea, were more hyperinfl ated, and had a higher percentage of emphysema. Conclusions: Distensibility of large-to medium-sized airways is reduced in subjects with an EP CT scan subtype. Emphysema seems to alter airway-parenchyma interdependence.

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“…The control group exhibited little variation (fig. 4); this was most likely associated with a physiological response involving the airway epithelium, nerves, mediators and bronchial smooth muscle [6,10,37]. The greater (fig.…”

Section: Impedance Modulusmentioning

confidence: 99%

Respiratory Impedance and Response to Salbutamol in Healthy Individuals and Patients with COPD

Costa¹,

Faria²,

Mango³

et al. 2014

Respiration

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Background: Recent studies suggested that the bronchodilator response depends on airway obstruction. The forced oscillation technique (FOT) may help improve our understanding of the changes in respiratory mechanics that occur after the application of a bronchodilator. Objectives: We aimed to (1) assess the response to salbutamol and to compare the impedance changes in healthy individuals and COPD patients, (2) investigate the effects of airway obstruction on this response and (3) evaluate the utility of the FOT as a complementary measurement to assess the response to the bronchodilator. Methods: Twenty-five healthy individuals and 82 patients with COPD were assessed with the FOT followed by spirometry before and after the use of salbutamol. Results: The changes exhibited by the COPD subgroups were greater than in the healthy individuals (p < 0.05). Increased obstruction resulted in decreased reductions in mean resistance and increased improvements in mean reactance (p < 0.001). In addition, the bronchodilation reduced the ventilation heterogeneity and the impedance modulus in all COPD stages (p < 0.05). The correlation coefficients for the spirometric and FOT changes were low (0.21-0.38). Conclusions: In the initial phases of COPD (stage I), the effects of bronchodilation are greater than in healthy volunteers. The bronchodilator use improved the oscillatory mechanics in all of the studied groups of COPD patients. These improvements are reduced in more advanced phases of airway obstruction (II, III and IV). The FOT provides information that complements the data supplied by spirometry, contributing to an improvement in the evaluation of the bronchodilator response in COPD.

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Airway distensibility and volume recruitment with lung inflation in COPD

Cited by 29 publications

References 35 publications

Extracellular matrix composition in COPD

Extracellular matrix composition in COPD

Association Between Airway Caliber Changes With Lung Inflation and Emphysema Assessed by Volumetric CT Scan in Subjects With COPD

Respiratory Impedance and Response to Salbutamol in Healthy Individuals and Patients with COPD

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