Relationship between quasi-static pulmonary hysteresis and maximal airway narrowing in humans

Brusasco, Vito; Pellegrino, Riccardo; Violante, Benedetto; Crimi, Emanuele

doi:10.1152/jappl.1992.72.6.2075

Cited by 47 publications

(43 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Among them are the volume history effects of the deep breath preceding the forced expiratory manoeuvre on the bronchial tone and, thus, calibre [94][95][96][97][98], and the inability of these parameters to detect whether tidal breathing is flow limited or not [99][100][101][102]. The FEV1/VC ratio should not be used to determine the severity of an obstructive disorder, until new research data are available.…”

Section: Severity Classificationmentioning

confidence: 99%

Interpretative strategies for lung function tests

Pellegrino¹

2005

European Respiratory Journal

Self Cite

4,918

4,636

View full text Add to dashboard Cite

Section: Severity Classificationmentioning

confidence: 99%

Interpretative strategies for lung function tests

Pellegrino¹

2005

European Respiratory Journal

Self Cite

4,918

4,636

View full text Add to dashboard Cite

“…Airway narrowing is caused by smooth muscle constriction, mucosal oedema, secretion of (proteinaceous) fluid into the airway lumen, and airway inflammation. Mechanical factors, such as loss of lung recoil forces, have, furthermore, been shown to influence airway dimensions [60,61]. Smooth muscle constriction directly narrows airway diameter, whereas accumulation of liquid within the airway wall during an inflammatory process increases wall thickness, thereby inducing airway obstruction as luminal area decreases [62].…”

Section: Pathophysiology and Role Of Surfactant In Airway Obstructionmentioning

confidence: 99%

The role of pulmonary surfactant in obstructive airways disease

Hohlfeld

Fabel²,

Hamm³

1997

Eur Respir J

View full text Add to dashboard Cite

Pulmonary surfactant research has an increasing impact on treatment considerations in adult respiratory disorders, above all acute respiratory distress syndrome (ARDS). Obstructive airways diseases have only been sporadically addressed in this respect. In the last decade, direct and circumstantial evidence for surfactant as a contributing factor in the regulation of airway calibre has emerged.Morphologically, a bronchiolar surfactant layer has been demonstrated, whereby the airways are mostly supplied by alveolar surfactant components via the mucociliary escalator. Functionally, prevention of airway film collapse and collapse of the airway walls are important surfactant properties in maintaining airway stability. In addition to its surface activity, airway surfactant improves bronchial clearance and regulates airway liquid balance, thus indirectly modulating airway wall thickness and airway diameter. Surfactant has furthermore been shown to modulate the function of respiratory inflammatory cells. Its immunomodulatory activity includes suppression of cytokine secretion and transcription factor activation. This may be of importance in the inflammatory network of asthma.Thus, dysfunction of surfactant in obstructive lung disease might be one of the mechanisms leading to increased airway resistance, which is commonly thought to be due to narrowing of airways under humoral and nervous control. In animal models of asthma, surfactant dysfunction was demonstrated, which was possibly due to protein inhibition. Furthermore, surfactant therapy seems to be capable of preventing allergen-induced bronchoconstriction. Human studies on surfactant impairment in obstructive airways diseases are still scarce but the data available are consistent with animal studies.Antiobstructive pharmacotherapy, mainly with corticosteroids, might influence and improve airway surfactant balance, but the exact mechanisms and the overall effect of pharmacotherapy on surfactant function in obstructive airways disease has to be further elucidated. Our knowledge about the role of pulmonary surfactant in obstructive airways disease is still limited, but there is convincing evidence that pulmonary surfactant plays a role in keeping the airways open.

show abstract

“…A major factor governing energy dissipation into the airway wall during stretching relates to the degree of airway smooth muscle contraction (29). An increase in airway caliber by DI is therefore taken as an indicator to bronchial smooth muscle relaxation and is particularly noticeable when bronchoconstriction has been acutely induced by methacholine or histamine inhalation (30,31). Altogether, the current findings on the effects of DI at baseline are consistent with significant airway smooth muscle tone in children, as indicated in other studies by the effect of beta-adrenergic agonists (32,33).…”

Section: Discussionmentioning

confidence: 99%

Post-Exercise Airway Narrowing in Healthy Primary School Children

Marchal

Werts

Vu³

et al. 2008

Pediatr Res

View full text Add to dashboard Cite

Changes in lung function after exercise in healthy primary school children have mostly been described in field studies. More complete description and insight into relevant mechanisms may be provided in lung function laboratory. The aim was to describe airway caliber and response to deep inhalation (DI) after exercise in healthy primary school children. Respiratory resistance (Rrs) by the forced oscillation technique and spirometry were measured before and after exercise in 50 healthy primary school children. The Rrs response to DI was assessed in 31 subjects, assuming a significantly larger decrease in Rrs after exercise would attest relief of exerciseinduced airway smooth muscle contraction. Measurements were taken before, 5 min (E5) and 15 min (E15) after exercise. Significantly larger Rrs and lower forced expiratory volume in 0.5 s were observed at E5 versus baseline or E15 (p Ͻ 0.05). DI induced significant decrease in Rrs (p ϭ 0.01) that was not different between E5 and baseline. Healthy primary school children exhibit changes in Rrs and spirometry after exercise indicating small but significant airway narrowing. The response to DI similar at baseline and E5 suggests airway narrowing from hyperemia in the bronchial wall rather than airway smooth muscle constriction. T here is considerable interest in assessing the airway response to exercise in children because of the clinical impact of exercise triggered asthma attacks (1,2). Field studies in unselected primary school children have described the distribution of lung function changes after exercise (3,4) or tested prevalence of exercise induced bronchoconstriction (EIB) in relation with respiratory symptoms (5,6). In these studies, the response was expressed as largest fall in forced expiratory volume in 1 s (FEV1) within 10 -15 min of exercise cessation (3,4) or considered positive when peak expiratory flow decreased 15% or more (5,6). To the best of our knowledge, whether significant change in airway caliber occurs in healthy children during the recovery from exercise has not been documented. In the context of a lung function laboratory, the airway response to exercise may be characterized more thoroughly and indications obtained relative to potential mechanisms. The respiratory resistance (Rrs) measured by the forced oscillation technique (FOT) is considered a good proxy to airway caliber above a few herz (7). It is particularly relevant to pediatric studies, as it requires minimal cooperation. Forced expiratory volume in 0.5 s (FEV0.5) has been suggested more sensitive than FEV1 to airway caliber in young children because of their high rate of lung emptying (8). FEV0.5 could also prove useful in school children who are known to have higher FEV1 to forced vital capacity ratio than adults. In addition, the tracking of time variations of Rrs has the potential to identifying mechanisms of bronchoconstriction by assessing change induced by a deep inhalation (DI) (9,10). When acute bronchoconstriction has been pharmacologically induced in a context ...

show abstract

Relationship between quasi-static pulmonary hysteresis and maximal airway narrowing in humans

Cited by 47 publications

References 0 publications

Interpretative strategies for lung function tests

Interpretative strategies for lung function tests

The role of pulmonary surfactant in obstructive airways disease

Post-Exercise Airway Narrowing in Healthy Primary School Children

Contact Info

Product

Resources

About