Abstract:
:The mechanisms of exertional dyspnea relief in response to supplemental oxygen (O2) in chronic airflow limitation (CAL) are not precisely known and are likely multifactorial. To explore factors contributing to the relief of dyspnea after oxygen administration, 11 patients with severe CAL (FEV1.0 = 39 +/- 3% predicted, mean +/- SEM) and mild hypoxemia (resting PaO2 = 74 +/- 2 mm Hg) breathed room air (RA) and 60% O2 during exercise at approximately 50% of their maximal incremental exercise capacity. Breathlessness ratings (Borg scale), endurance time, respiratory drive (change in mouth occlusion pressure over the first 0.1 s of inspiration, P0.1), ventilation (VE), breathing pattern, operational lung volumes, gas exchange, and metabolic parameters were compared during RA and 60% O2. PaO2 at exercise cessation during RA and 60% O2 was 65 +/- 3 mm Hg and 226 +/- 12 mm Hg, respectively (p < 0.001). With 60% O2, the mean of individual Borg/time slopes fell significantly (p < 0.05) by 23 +/- 12% and was associated with a 35 +/- 11% increase (p < 0.01) in endurance time (r = -0.64, p < 0.05). During 60% O2, slopes of P0.1 and lactate over time also fell significantly (p < 0.05), whereas delta PaCO2/time did not change significantly. At a standardized time near end-exercise, Borg, VE, and P0.1 changed during 60% O2 by -0.8 +/- 0.3 (p < 0.05), -4.1 +/- 2.0 L/min (p = 0.07), and -1.3 +/- 0.5 cm H2O/s (p < 0.05), respectively. Slopes of Borg/VE, Borg/lactate, and VE/lactate were essentially superimposable during tests on RA and O2: Borg, lactate, and VE all fell proportionally during hyperoxia. In patients with CAL and mild exercise hypoxemia, relief of exertional breathlessness during hyperoxia is explained by reduced ventilatory demand in association with reduced blood lactate levels.
journal_name
Am J Respir Crit Care Medauthors
O'Donnell DE,Bain DJ,Webb KAdoi
10.1164/ajrccm.155.2.9032190subject
Has Abstractpub_date
1997-02-01 00:00:00pages
530-5issue
2eissn
1073-449Xissn
1535-4970journal_volume
155pub_type
临床试验,杂志文章,随机对照试验abstract::To elucidate the apparent contradictions in vascular remodeling in the lungs of patients with idiopathic pulmonary fibrosis, we evaluated alveolar vascularity in relation to the various degrees of fibrosis in surgically biopsied lungs of usual interstitial pneumonia. Alveolar capillary endothelial cells were intensely...
journal_title:American journal of respiratory and critical care medicine
pub_type: 杂志文章
doi:10.1164/rccm.200308-1111OC
更新日期:2004-06-01 00:00:00
abstract::Several modalities of ventilatory support have been proposed to gradually withdraw patients from mechanical ventilation, but their respective effects on the outcome of weaning from mechanical ventilation are not known. We conducted a randomized trial in three intensive care units in mechanically ventilated patients wh...
journal_title:American journal of respiratory and critical care medicine
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1164/ajrccm.150.4.7921460
更新日期:1994-10-01 00:00:00
abstract::Pleural disease both before and after organ transplantation has important implications. Pleural effusions are common in candidates for heart, liver, and kidney transplantation. A thoracentesis is not mandatory in these patients, but it should be performed if clinical or radiologic features suggest that the effusion is...
journal_title:American journal of respiratory and critical care medicine
pub_type: 杂志文章,评审
doi:10.1164/ajrccm.153.3.8630560
更新日期:1996-03-01 00:00:00
abstract:INTRODUCTION:Proteinases with a disintegrin and a metalloproteinase domain (ADAMs) have not been well studied in COPD. We investigated whether ADAM9 is linked to COPD in humans and mice. METHODS:ADAM9 blood and lung levels were measured in COPD patients versus controls, and air- versus cigarette smoke (CS)-exposed wil...
journal_title:American journal of respiratory and critical care medicine
pub_type: 杂志文章
doi:10.1164/rccm.201711-2300OC
更新日期:2018-06-04 00:00:00
abstract:RATIONALE:Very little is known about airways that are too small to be visible on thoracic multidetector computed tomography but larger than the terminal bronchioles. OBJECTIVES:To examine the structure of preterminal bronchioles located one generation proximal to terminal bronchioles in centrilobular and panlobular em...
journal_title:American journal of respiratory and critical care medicine
pub_type: 杂志文章
doi:10.1164/rccm.201602-0278OC
更新日期:2017-03-01 00:00:00
abstract::Critical illness is not a discrete disease state or syndrome. It is the culmination of a multiplicity of heterogeneous disease states and their varied health trajectories leading to extreme illness that requires advanced life support in a distinct geographic location in the hospital. It is a marker of newly acquired o...
journal_title:American journal of respiratory and critical care medicine
pub_type: 杂志文章,评审
doi:10.1164/rccm.201704-0815ED
更新日期:2017-12-01 00:00:00
abstract:RATIONALE:Patients with severe asthma (SA) are less responsive to the beneficial effects of corticosteroid (CS) therapy, and relative CS insensitivity has been shown in airway smooth muscle cells (ASMC) from patients with SA. OBJECTIVES:We investigated whether there was a defect in the actions of the glucocorticoid re...
journal_title:American journal of respiratory and critical care medicine
pub_type: 杂志文章
doi:10.1164/rccm.201402-0314OC
更新日期:2015-01-01 00:00:00
abstract::To determine the status of activation of lymphocytes and the role of cytokines on the inflammatory response of the bronchial mucosa in toluene diisocyanate (TDI) asthma, we performed a quantitative analysis of bronchial biopsies obtained from 15 subjects with TDI-induced asthma and seven normal control subjects. Marke...
journal_title:American journal of respiratory and critical care medicine
pub_type: 杂志文章
doi:10.1164/ajrccm.151.3.7533600
更新日期:1995-03-01 00:00:00
abstract:RATIONALE:As of April 2015, participants in the Danish Lung Cancer Screening Trial had been followed for at least 5 years since their last screening. OBJECTIVES:Mortality, causes of death, and lung cancer findings are reported to explore the effect of computed tomography (CT) screening. METHODS:A total of 4,104 parti...
journal_title:American journal of respiratory and critical care medicine
pub_type: 杂志文章,随机对照试验
doi:10.1164/rccm.201505-1040OC
更新日期:2016-03-01 00:00:00
abstract::The objective of this study was to evaluate the effectiveness of an asthma education program on morbidity, knowledge, and compliance with inhaled corticosteroid treatment using a prospective, randomized, controlled, one-year-before/one-year-after protocol. After rigorous optimization of asthma therapy under the care o...
journal_title:American journal of respiratory and critical care medicine
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1164/ajrccm.155.5.9154850
更新日期:1997-05-01 00:00:00
abstract:RATIONALE:Roflumilast is a therapeutic agent in the treatment of chronic obstructive pulmonary disease (COPD). It has antiinflammatory effects; however, it is not known whether it can affect a biologic pathway implicated in COPD pathogenesis and progression. The self-propagating acetyl-proline-glycine-proline (AcPGP) p...
journal_title:American journal of respiratory and critical care medicine
pub_type: 杂志文章,随机对照试验
doi:10.1164/rccm.201503-0543OC
更新日期:2015-10-15 00:00:00
abstract::Regular short-acting inhaled beta-agonist therapy is of uncertain benefit in patients with chronic obstructive pulmonary disease (COPD). We conducted a randomized, concealed, double-blind, placebo-controlled crossover trial in two periods, each of 3-mo duration, involving 53 patients with a smoking history of > 20 pac...
journal_title:American journal of respiratory and critical care medicine
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1164/ajrccm.163.1.2004214
更新日期:2001-01-01 00:00:00
abstract::We reported that systemic keratinocyte growth factor (KGF) given before bone marrow transplantation (BMT) prevents allogeneic T cell-dependent lung inflammation assessed on Day 7 post-BMT, but the antiinflammatory effects of KGF were impaired in mice injected with both T cells and conditioning regimen of cyclophospham...
journal_title:American journal of respiratory and critical care medicine
pub_type: 杂志文章
doi:10.1164/ajrccm.162.5.2002053
更新日期:2000-11-01 00:00:00
abstract::To better understand strategies for recruiting and maintaining lung volume in acute lung injury, we examined relationships between steady-state lung volume and cumulative cyclic recruitment/derecruitment volume history and the quasi-static pressure-volume curve, in an animal saline lavage lung injury model. Small-volu...
journal_title:American journal of respiratory and critical care medicine
pub_type: 杂志文章
doi:10.1164/rccm.200305-614OC
更新日期:2004-04-15 00:00:00
abstract::Noninflammatory structural alterations, variously referred to as airway remodeling, are well documented in the asthmatic airway. However, the pathogenesis of these alterations, the importance of airway remodeling in generating the asthma phenotype, and the natural history of airway remodeling responses have not been a...
journal_title:American journal of respiratory and critical care medicine
pub_type: 杂志文章
doi:10.1164/ajrccm.164.supplement_2.2106070
更新日期:2001-11-15 00:00:00
abstract:RATIONALE:Chronic infection with Burkholderia cepacia complex bacteria in cystic fibrosis is associated with accelerated decline in pulmonary function and increased mortality. Clinical implications of the recently characterized genomovar VI, B. dolosa, are unknown. OBJECTIVES:Characterization of impact of B. dolosa on...
journal_title:American journal of respiratory and critical care medicine
pub_type: 杂志文章
doi:10.1164/rccm.200503-344OC
更新日期:2006-02-15 00:00:00
abstract:RATIONALE:The relation between birth weight and respiratory symptoms and asthma in children remains unclear. Previous studies focused on a relation at separate ages. A longitudinal analysis may lead to a better understanding. OBJECTIVES:To estimate the effect of birth weight on the development and course of respirator...
journal_title:American journal of respiratory and critical care medicine
pub_type: 杂志文章
doi:10.1164/rccm.200610-1441OC
更新日期:2007-05-15 00:00:00
abstract::Bronchoalveolar lavage (BAL) is increasingly used in the pediatric age group. However, normal values for BAL fluid (BALF) constituents are lacking. As part of an investigation to define reference values in children, we studied lymphocyte surface markers of BALF in 28 children 3 to 16 yr of age without bronchopulmonary...
journal_title:American journal of respiratory and critical care medicine
pub_type: 杂志文章
doi:10.1164/ajrccm.152.1.7599820
更新日期:1995-07-01 00:00:00
abstract::Female Fisher 344 rats (n = 25) were inoculated intrapleurally with a single 20-mg dose of (JM-100) fibrous glass. The mean length (2.2 microns) and width (0.15 microns) of the fibrous glass particles was within respirable range. Following inoculation, the rats were killed at timed intervals ranging from 2 to 430 d fr...
journal_title:American journal of respiratory and critical care medicine
pub_type: 杂志文章
doi:10.1164/ajrccm.150.2.8049840
更新日期:1994-08-01 00:00:00
abstract:RATIONALE:Surfactant protein D (SP-D), a 43-kD collectin, is synthesized and secreted by airway epithelia as a dodecamer formed by assembly of four trimeric subunits. We have previously shown that the quaternary structure of SP-D can be altered during inflammatory lung injury through its modification by S-nitrosylation...
journal_title:American journal of respiratory and critical care medicine
pub_type: 杂志文章
doi:10.1164/rccm.201004-0654OC
更新日期:2011-04-01 00:00:00
abstract:RATIONALE:Inhaled human insulin (INH; Exubera [human insulin (recombinant DNA origin) Inhalation Powder]) causes small changes in pulmonary function and increases in insulin antibodies compared with subcutaneous (SC) insulin. OBJECTIVES:To investigate the relationship between changes in pulmonary function and insulin ...
journal_title:American journal of respiratory and critical care medicine
pub_type: 杂志文章,多中心研究,随机对照试验
doi:10.1164/rccm.200512-1861OC
更新日期:2006-06-01 00:00:00
abstract::The human pleural space is lined by a single layer of mesothelial cells, the intracellular pH (pH(i)) of which has never been investigated. In the present study, the intrinsic buffering power of H+ ions (beta(i)) and the pH(i) regulatory systems were investigated in primary cultures of human pleural mesothelial cells ...
journal_title:American journal of respiratory and critical care medicine
pub_type: 杂志文章
doi:10.1164/ajrccm.155.2.9032200
更新日期:1997-02-01 00:00:00
abstract:RATIONALE:The allergen inhalation challenge is used in clinical trials to test the efficacy of new treatments in attenuating the late-phase asthmatic response (LAR) and associated airway inflammation in subjects with allergic asthma. However, not all subjects with allergic asthma develop the LAR after allergen inhalati...
journal_title:American journal of respiratory and critical care medicine
pub_type: 杂志文章
doi:10.1164/rccm.201701-0110OC
更新日期:2018-02-15 00:00:00
abstract::Dobutamine has been proposed as a means of disclosing a pathologic oxygen supply (DO2) dependency in critically ill patients. Like other catecholamines, however, dobutamine might increase cellular metabolism, so that oxygen consumption (VO2) would increase regardless of the presence or absence of a supply dependency. ...
journal_title:American journal of respiratory and critical care medicine
pub_type: 杂志文章
doi:10.1164/ajrccm.150.1.8025780
更新日期:1994-07-01 00:00:00
abstract::This study aimed to estimate exposure-response relationships for mesothelioma and environmental exposure to crocidolite. All 4,659 former residents of Wittenoom, Western Australia (WA) who lived there between 1943 and 1993 for at least 1 mo and were not directly employed in the crocidolite industry, were followed-up t...
journal_title:American journal of respiratory and critical care medicine
pub_type: 杂志文章
doi:10.1164/ajrccm.157.1.96-11086
更新日期:1998-01-01 00:00:00
abstract::The Pulmonary Complications of HIV Infection Study is a prospective, multicenter, observational study evaluating pulmonary disease among HIV-infected persons. For approximately 52 mo, 1,182 HIV-infected subjects were followed. All participants were evaluated for pulmonary disease on a predetermined schedule. There wer...
journal_title:American journal of respiratory and critical care medicine
pub_type: 杂志文章,多中心研究
doi:10.1164/ajrccm.155.1.9001290
更新日期:1997-01-01 00:00:00
abstract::Phosphodiesterase (PDE)-5 degrades guanosine 3',5'cyclic monophosphate (cGMP) and its inhibitor sildenafil citrate (Viagra) treats erectile dysfunction by smooth muscle relaxation through elevated cGMP. Sildenafil was examined in two guinea pig models of airways disease: guinea pigs exposed to LPS or sensitized guinea...
journal_title:American journal of respiratory and critical care medicine
pub_type: 杂志文章
doi:10.1164/rccm.200211-1372OC
更新日期:2004-01-15 00:00:00
abstract::Cryptogenic fibrosing alveolitis has been reported to be associated with an increased risk of lung cancer. However, it has recently become apparent that cigarette smoking may be a risk factor for cryptogenic fibrosing alveolitis as well as for lung cancer, and so may confound the association between these conditions. ...
journal_title:American journal of respiratory and critical care medicine
pub_type: 杂志文章
doi:10.1164/ajrccm.161.1.9906062
更新日期:2000-01-01 00:00:00
abstract::Nitrogen dioxide (NO2) is a common indoor and outdoor air pollutant that may induce deterioration of respiratory health. In this study the effects of repeated daily exposure to NO2 on airway antioxidant status, inflammatory cell and mediator responses, and lung function were examined. Healthy nonsmoking subjects were ...
journal_title:American journal of respiratory and critical care medicine
pub_type: 临床试验,杂志文章
doi:10.1164/ajrccm.159.2.9711068
更新日期:1999-02-01 00:00:00
abstract::Damage to the airway epithelium is one prominent feature of chronic asthma. Corticosteroids induce apoptosis in inflammatory cells, which in part explains their ability to suppress airway inflammation. However, corticosteroid therapy does not necessarily reverse epithelial damage. We hypothesized that corticosteroids ...
journal_title:American journal of respiratory and critical care medicine
pub_type: 杂志文章
doi:10.1164/ajrccm.164.10.2103013
更新日期:2001-11-15 00:00:00