Search results for "FEV1"
showing 10 items of 132 documents
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 Lack of the Bronchoprotective and Not the Bronchodilatory Ability of Deep Inspiration Is Associated with Airway Hyperresponsiveness
2001
In healthy subjects, deep inspiration (DI) acts both as a bronchodilator and a bronchoprotector. The latter is impaired in asthmatics. We have now evaluated whether the lack of bronchoprotection is related to bronchial hyperresponsiveness (BHR), and whether the bronchodilatory effect is also lost in asthmatics. Ten healthy subjects (PC20 > 75 mg/ml), 12 asthmatics with moderate to severe BHR (PC20 < 1 mg/ml), 14 asthmatics with mild to borderline BHR (1 < PC20 < 25 mg/ml), and 10 rhinitics with mild to borderline BHR (1 < PC20 < 25 mg/ml) underwent single-dose methacholine provocations inducing at least 20% reduction in FEV1 after 20 min of DI inhibition. To measure the bronchodilatory effe…
Predicting hypoxia in cystic fibrosis patients during exposure to high altitudes
2006
Abstract Background For patients with cystic fibrosis (CF)-related partial respiratory insufficiency and reduced arterial oxygen tension at ground level, the mild hypobaric environment on commercial jet aircraft poses the risk of severe hypoxemia. Thus, physicians should be able to estimate the extent of in-flight hypoxia. Objectives To derive tools for estimating the expected drop in arterial oxygen partial pressure (paO 2 ) and oxygen saturation (saO 2 ) in young adult CF patients with mild to moderate airway obstruction during exposure to the hypobaric conditions aboard commercial aircraft and to test the predictive power of a hypobaric chamber simulation. Methods Blood gases of 12 CF pa…
Serum low density lipoprotein subclasses in asthma
2013
Summary Background The levels of serum low-density lipoproteins (LDL) have been implicated in the inflammatory cascade in a murine model of asthma. Recent findings suggest that LDL may modulate the inflammatory state of the asthmatic airways in humans. Objective We explored whether LDL subclasses are associated with the occurrence and severity of asthma. Methods 24 asthmatics (M/F: 11/13) and 24 healthy individuals, with normal BMI and absence of metabolic syndrome, matched for age and gender. Serum concentrations of LDL subclasses were distributed as seven bands (LDL-1 and -2 defined as large, least pro-inflammatory LDL, and LDL-3 to −7 defined as small, most pro-inflammatory LDL), using t…
Serum lipoproteins are not associated with the severity of asthma
2018
Abstract Background Asthma is a chronic inflammatory disorder of the bronchi with a complicated and largely unknown pathogenesis . In this context, an emerging role is attributed to the apolipoproteins which serve as structural components of plasma lipoproteins . Low density lipoproteins (LDL) may be involved in the inflammatory pathways of the asthmatic airways; in particular, small dense LDL (sdLDL) particles were associated with increased oxidative susceptibility compared to medium and large sized LDL. In our previous study, we found a positive correlation between forced expiratory volume 1 s (FEV 1) % predicted and larger LDL particles (LDL-1), and an inverse correlation between FEV1% p…
Do childhood respiratory infections continue to influence adult respiratory morbidity?
2008
The aim of the present study was to examine the influence of childhood respiratory infections on adult respiratory health. In 1992-1994, the European Community Respiratory Health Survey recruited community based samples of 20-44-yr-old people from 48 centres in 22 countries. Study participants completed questionnaires and underwent lung function testing. On average, 8.9 yrs later, 29 centres re-investigated their samples using similar methods. Mixed effects models comprising an estimate for the random variation between centres were used to evaluate the relevant associations. In total, 9,175 patients participated in both studies, of whom 10.9% reported serious respiratory infections (SRI) be…
Specific IgE against Staphylococcus aureus enterotoxins: an independent risk factor for asthma.
2012
The role of IgE in patients with severe asthma is not fully understood.We sought to investigate whether IgE to Staphylococcus aureus enterotoxins might be relevant to disease severity in adult asthmatic patients.Specific IgE antibody concentrations in serum against enterotoxins, grass pollen (GP), and house dust mite allergens and total IgE levels were measured in adult cohorts of 69 control subjects, 152 patients with nonsevere asthma, and 166 patients with severe asthma. Severe asthma was defined as inadequately controlled disease despite high-dose inhaled corticosteroids plus at least 2 other controller therapies, including oral steroids.Enterotoxin IgE positivity was significantly great…
Expiratory airflow obstruction due to tracheostomy tube: A spirometric study in 50 patients
2018
OBJECTIVES Tracheostomy is commonly used in intensive care units and in head and neck departments. Airway obstruction due to occluded cuffless tracheostomy tubes themselves remains unknown, although capping trials are commonly used before decannulation. The aim of this study was to evaluate the extent to which airway obstruction can be caused by occluded cuffless tubes in patients who underwent head and neck surgery. DESIGN Prospective Research Outcome. SETTINGS University teaching hospital. PARTICIPANTS Fifty patients requiring transient tracheostomy after head and neck surgery. MAIN OUTCOME MEASURES A flow-volume loop (FVL) through the mouth using a portable spirometer, with the occluded …
Longitudinal analysis of endurance and respiratory function from a natural history study of Morquio A syndrome
2015
Objectives: Baseline data from the Morquio A Clinical Assessment Program (MorCAP) revealed that individuals with Morquio A syndrome show substantial impairment in multiple domains including endurance and respiratory function (Harmatz et al., Mol Genet Metab, 2013). Here, 1- and 2-year longitudinal endurance and respiratory function data are presented.Methods: Endurance was assessed using the 6-minute walk test (6MWT) and the 3-minute stair climb test (3MSCT). Respiratory function was evaluated by measuring forced vital capacity (PVC) and maximum voluntary ventilation (MW). Data were analyzed using repeated measures ANCOVA models. Annualized estimates of change were determined using model es…
Determinants of bronchial hyperresponsiveness in subjects with rhinitis.
2005
Subjects with rhinitis but without asthma may have coexisting bronchial hyperresponsiveness, although the reasons for this are uncertain. To evaluate the factors that determine BHR in rhinitis we examined 410 patients with symptomatic rhinitis with forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) ≥ 80% of the predicted value. In all subjects a skin prick test (SPT) was performed, a determination of total serum IgE and an eosinophils count in the blood. Of the 410 subjects we found that 161 (39.3%) exhibited a methacholine PD20 of 800 mg or less (Group A), whereas 249 (60.7%) had a methacholine PD20 more of 800 mg (Group B). Despite the matched mean values for FEV…