Search results for "Air trapping"
showing 10 items of 10 documents
Effects of allergen exposure on methacholine and AMP-induced air trapping in pollen-sensitive subjects
2011
Summary Background The effect of pro-inflammatory stimuli on bronchoconstrictor-induced air trapping has not been studied. Objective To determine the effect of natural allergen exposure, a pro-inflammatory stimulus, on methacholine- and adenosine 5′-monophospate (AMP)-induced air trapping. Methods Airway responsiveness to methacholine and AMP before and during the pollen season was obtained in 25 subjects with pollen allergy and in 10 healthy controls. The response was expressed by the sensitivity (PC 20 value) and by the slope and intercept of the FVC values recorded at each step of the challenge against the corresponding FEV 1 values. Results The slope and intercept FVC versus FEV 1 value…
The effect of challenge method on methacholine-induced changes in sensitivity and air trapping
2010
Summary Background The methacholine challenge test performed with the tidal breathing method induces a greater fall in FEV 1 than the dosimeter method; however, the effect of the challenge method on methacholine-induced fall in FVC has not been investigated. Objective To determine the influence of the challenge method on methacholine-induced changes in FEV 1 and FVC. Methods Airway responsiveness to methacholine was determined by dosimeter method and tidal breathing method in 37 subjects with suspected asthma. The dosimeter was modified to deliver an identical volume to that obtained with the tidal breathing method and the same nebulizer model was used for the two challenges. The response w…
The bronchodilation response to deep inspiration in asthma is dependent on airway distensibility and air trapping
2011
In healthy individuals, deep inspirations (DIs) have a potent bronchodilatory ability against methacholine (MCh)-induced bronchoconstriction. This is variably attenuated in asthma. We hypothesized that inability to bronchodilate with DIs is related to reduced airway distensibility. We examined the relationship between DI-induced bronchodilation and airway distensibility in 15 asthmatic individuals with a wide range of baseline lung function [forced expired volume in 1 s (FEV1) = 60–99% predicted]. After abstaining from DIs for 20 min, subjects received a single-dose MCh challenge and then asked to perform DIs. The effectiveness of DIs was assessed by the ability of the subjects to improve …
The role of small airways in monitoring the response to asthma treatment: what is beyond FEV1?
2009
The definition of asthma has evolved from that of an episodic disease characterized by reversible airways constriction to a chronic inflammatory disease of the airways, with at least partially reversible airway constriction. Increasing evidence supports the notion that small and large airways play a central role in asthma pathophysiology with regard to inflammation, remodeling and symptoms. The contribution of the distal airways to the asthma phenotype carries implications for the delivery of inhaled medications to the appropriate areas of the lung and for the monitoring of the response to asthma treatment. Asthma control is evaluated on the basis of symptoms, lung function and exacerbation…
Hyperpolarized helium-3 gas magnetic resonance imaging of the lung.
2003
3He magnetic resonance imaging (MRI) is capable of producing new and regional information on normal and abnormal lung ventilation. The basis of 3He MRI involves "optical pumping" to hyperpolarize the 3He nuclei by photon angular momentum transfer. The hyperpolarized gas is administered via inhalation. 3He is an inert, nontoxic noble gas and absorbed in less than 0.1%. Imaging consists of a four-step protocol. 1) Gas density 3He MRI with high spatial resolution displays the distribution of a 3He bolus in a 10-second breath-hold. An almost homogeneous distribution is regarded as normal. Patients with lung diseases show multiple ventilation defects. 3He MRI has been shown to be more sensitive …
Effects of cigarette smoke on methacholine- and AMP-induced air trapping in asthmatics.
2014
Abstract Objective: No information is available on the effect of cigarette smoke on bronchoconstrictor-induced air trapping in asthma. The aim of this study was to evaluate the additional influence of smoking on methacholine- and adenosine 5'-monophosphate (AMP)-induced air trapping in subjects with asthma.Airway responsiveness to methacholine and AMP, bronchial (J'awNO) and alveolar (CANO) nitric oxide (NO) and exhaled breath condensate pH were measured in 68 adults (23 current smokers with asthma, 23 non-smokers with asthma and 22 current or former smokers with chronic obstructive pulmonary disease; COPD). The degree of air trapping induced by each bronchoconstrictor agent was expressed b…
Assessing and accessing the small airways; implications for asthma management
2013
Despite the wealth of experience in the management of asthma, the disease remains inadequately controlled in some patients, who face long-term respiratory impairment and disability. The disease has been characterised as an inflammatory condition affecting first the larger airways and eventually the smaller airways, but there is evidence that peripheral airway involvement defines a particular and more severe phenotype of asthma. For this reason, assessing functional and biological parameters reflective of small airways involvement is important prognostically. No assessment method is universally and directly representative of peripheral airway function, but the traditional spirometric tests, …
Relationship between sleep disturbances and peripheral airway abnormalities in COPD patients
2017
Background: Individuals with COPD experience sleep disturbances due to the impact of symptoms on quality of sleep. Aim: To test the hypothesis that, in COPD, sleep disturbances are linked to peripheral airway abnormalities. Methods: An investigational study is being performed at the University of Palermo, Italy. The impact of breathing problems on quality of sleep during the previous week is measured with the COPD and Asthma Sleep Impact Scale (CASIS) questionnaire. Airway resistances by impulse oscillometry (IOS) assesses peripheral airway abnormalities. Lung function evaluation includes static and dynamic lung volume measurements. To rule out the risk of having obstructive sleep apnea, th…
Lung ventilation- and perfusion-weighted Fourier decomposition magnetic resonance imaging: In vivo validation with hyperpolarized3He and dynamic cont…
2012
The purpose of this work was to validate ventilation-weighted (VW) and perfusion-weighted (QW) Fourier decomposition (FD) magnetic resonance imaging (MRI) with hyperpolarized (3)He MRI and dynamic contrast-enhanced perfusion (DCE) MRI in a controlled animal experiment. Three healthy pigs were studied on 1.5-T MR scanner. For FD MRI, the VW and QW images were obtained by postprocessing of time-resolved lung image sets. DCE acquisitions were performed immediately after contrast agent injection. (3)He MRI data were acquired following the administration of hyperpolarized helium and nitrogen mixture. After baseline MR scans, pulmonary embolism was artificially produced. FD MRI and DCE MRI perfus…
Akute oder chronische Transplantat-Abstoßung? - HRCT des Thorax bei Patienten nach Lungentransplantation
2001
Purpose: Aim of the study was to evaluate the postoperative changes in patients with single (SLTX) or double lung transplantation (DLTX) with HRCT and to correlate those findings with the clinical diagnosis. Material and methods: 29 patients with SLTX (n = 14) or DLTX (n=15) were observed for more than 6 years after transplantation by HRCT (n =82). CT examinations were performed in inspiration and expiration (n=70) with a slice thickness of 1 mm and a feed of 10 mm. The image material was evaluated by 2 experienced radiologists in consensus. Criteria for acute rejection at HRCT were: ground glass opacities and focal air trapping in expiration. Criteria for chronic transplant rejection were:…