Elastic behavior of the lung in patients with airway obstruction

Finucane, Kevin E.; Colebatch, H. J. H.

doi:10.1152/jappl.1969.26.3.330

Cited by 120 publications

(67 citation statements)

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“…(10) demonstrated that tantalum-labeled meconium was cleared from the trachea and mainstem bronchi within 1 hr and migrated progressively into the lung periphery with breathing. Whereas physiologic effects of obstruction on lung function have been studied (2,8,12,15,24), little data are available on pulmonary mechanics in animals or infants with acute meconium obstruction. Because of the migration properties of meconium, the physiologic resnonse of obstructive ~henomena in general cannot be extrapo l i e d to the pathophysi~logy of p u l m o~r y function in meconium aspiration.…”

Section: Discussionmentioning

confidence: 99%

Sequential Effects of Acute Meconium Obstruction on Pulmonary Function

et al. 1980

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SummaryThe relationship between pulmonary function and the migration of meconium to distal airways was determined in 10 rabbits (mean weight 2.6 kg) after insumation of a meconium-saline mixture (1-2 ml/kg). Animals were anesthetized, cannulated, intubated, and mechanically ventilated with 100% oxygen. Lung mechanical dysfunction was most severe during the early phase of meconium migration, 15 min postinsumation. Substantial increases in inspiratory lung resistance (RI) and expiratory lung resistance (RE) suggest that the site of obstruction at 15 min was the large airways. A decrease in dynamic lung compliance with unchanged static compliance characterizes the obstruction as partial. At 15 min and thro&hout the migration process, RE was greater than RI, demonstrating a check-valve effect. This phenomenon was substantiated by an increased functional residual capacity (FRC) in all rabbits, presumably due to gas trapping. Secondary to these changes, marked hypoxemia, hypercapnea, and acidosis developed in spite of assisted ventilation with 100% oxygen. At 60 and 120 min postinsufflation, both RI and RE decreased as compared to 15 min. This suggests that the predominant site of obstruction shifted to medium and small airways concomitant with the migration of meconium. Widespread and uneven distribution of meconium still produced significant frequency dependence of lung compliance. Static compliance remained unchanged, indicating that meconium !nnsylvania, USA ing the pathologic process of meconium aspiration have been conducted (I, 10, 11, 19, 21,22). Results have shown that whereas the irritating action of meconium on the pulmonary parenchyma might initiate a chemical or bacterial pneumonitis (4, 21), the importance of inflammation with regard to severe respiratory dysfunction may not be great (1 1). Rather, mechanical airway obstruction by particles of meconium has been shown to play the most important role in the early pathophysiology of MAS (21).Evidence for obstruction and migration of meconium has been supported by roentgenographic methods, where Gooding et a/.(10) demonstrated that tantalum-labeled meconium was cleared from the trachea and mainstem bronchi within 1 hr and migrated progressively into the lung periphery with breathing. Whereas physiologic effects of obstruction on lung function have been studied (2,8,12,15,24), little data are available on pulmonary mechanics in animals or infants with acute meconium obstruction. Because of the migration properties of meconium, the physiologic resnonse of obstructive ~henomena in general cannot be extrapo l i e d to the pathophysi~logy of p u l m o~r y function in meconium aspiration. The purpose of this study is to determine the sequential physiologic efficts bf acute meconium obstruction on pulmonary function as they vary with the migration of meconium to the distal airways. Such data will provide further insight into the pathophysiology and respiratory management of infants with MAS.does not affect surface-active or tissue propries of the lung within 120 ...

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Section: Discussionmentioning

confidence: 99%

Sequential Effects of Acute Meconium Obstruction on Pulmonary Function

et al. 1980

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“…Another possibility is that the radial distending force exerted on airways by the lung parenchyma is reduced at higher lung volumes in asthma, through changes in either parenchymal forces or their coupling with airways (40). Relevant to this, a leftward shift of the pressurevolume curve also occurs in the lungs of patients with asthma and COPD and is believed to result from a disrupted elastin and collagen fiber network (1,41,42). As the lungs inflate, lung elastic recoil pressure increases.…”

Section: Elastic Properties In Obstructive Lung Diseasementioning

confidence: 99%

Elastic Properties of the Central Airways in Obstructive Lung Diseases Measured Using Anatomical Optical Coherence Tomography

Williamson¹,

McLaughlin²,

Noffsinger³

et al. 2011

Am J Respir Crit Care Med

102

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Rationale: Our understanding of how airway remodeling affects regional airway elastic properties is limited due to technical difficulties in quantitatively measuring dynamic, in vivo airway dimensions. Such knowledge could help elucidate mechanisms of excessive airway narrowing. Objectives: To use anatomical optical coherence tomography (aOCT) to compare central airway elastic properties in control subjects and those with obstructive lung diseases. Methods: After bronchodilation, airway lumen area (Ai) was measured using aOCT during bronchoscopy in control subjects (n 5 10) and those with asthma (n 5 16), chronic obstructive pulmonary disease (COPD) (n 5 9), and bronchiectasis (n 5 8). Ai was measured in each of generations 0 to 5 while airway pressure was increased from 210 to 20 cm H 2 O. Airway compliance (Caw) and specific compliance (sCaw) were derived from the transpulmonary pressure (PL) versus Ai curves. Measurements and Main Results: Caw decreased progressively as airway generation increased, but sCaw did not differ appreciably across the generations. In subjects with asthma and bronchiectasis, Caw and sCaw were similar to control subjects and the PL-Ai curves were left-shifted. No significant differences were observed between control and COPD groups. Conclusions: Proximal airway elastic properties are altered in obstructive lung diseases. Although central airway compliance does not differ from control subjects in asthma, bronchiectasis, or COPD, Ai is lower in asthma and the PL-Ai relationship is left-shifted in both asthma and bronchiectasis, suggesting that airways are maximally distended at lower inflating pressures. Such changes reflect alteration in the balance between airway wall distensibility and radial traction exerted on airways by surrounding lung parenchyma favoring airway narrowing. Clinical trial registered with Australian New Zealand Clinical Trials Registry (ACTRN12607000624482).

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“…Loss of elastic recoil of the lung parenchyma has been observed in the lungs of some patients with asthma, even after successful treatment has restored normal lung function [124][125][126]. The structural bases for these changes are not known, although loss of alveolar attachments and peribronchiolar damage to elastin has been reported in cases of fatal asthma [64].…”

Section: Smooth Muscle Shorteningmentioning

confidence: 99%

“…This is probably due to loss of elastic recoil of the lung parenchyma [125] and loss of attachments to the airway wall [143] but may also be due to reduced stiffness of the airway wall. TIDDENS et al [134] studied isolated airways from smokers who underwent surgery.…”

Section: Airway Wall Collapsementioning

confidence: 99%

Clinical relevance of airway remodelling in airway diseases

James¹,

Wenzel²

2007

Eur Respir J

306

214

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Asthma and chronic obstructive pulmonary disease (COPD) are characterised by airflow obstruction, airway remodelling (measurable structural change) and inflammation. The present review will examine the relationship between airway remodelling in these two conditions with respect to symptoms, abnormal lung function, airway hyperresponsiveness and decline in lung function. The potential for remodelling to be a protective response will also be discussed.Asthma is associated with variable symptoms and changes in lung function and also fixed abnormalities of lung function and an increased rate of decline in lung function with age. There is a relative preservation of the relaxed airway lumen dimensions, prominent thickening of the smooth muscle layer and reduced airway distensibility. The severity of asthma is related to the degree of airway remodelling, which is most marked in cases of fatal asthma.In COPD, symptoms are persistent and predictable but also progressive and are related to fixed abnormalities of lung function. Remodelling is associated with narrowing of the airway lumen and an increased thickness of the airway wall, although not usually to the extent seen in asthma. COPD is most often due to smoking where there is also remodelling of the parenchyma that may contribute to symptoms.

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Elastic behavior of the lung in patients with airway obstruction

Cited by 120 publications

References 0 publications

Sequential Effects of Acute Meconium Obstruction on Pulmonary Function

Sequential Effects of Acute Meconium Obstruction on Pulmonary Function

Elastic Properties of the Central Airways in Obstructive Lung Diseases Measured Using Anatomical Optical Coherence Tomography

Clinical relevance of airway remodelling in airway diseases

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