Abstract:
:Early experience suggests that lung volume reduction surgery improves exercise tolerance as measured by the 6-min walk distance in patients with emphysema. To identify the physiologic mechanism(s) by which lung volume reduction surgery improved exercise, we performed progressive cardiopulmonary exercise testing, including rest and peak exercise blood gas determinations, on 21 consecutive patients before and 3 mo after lung volume reduction surgery. Maximal work (median, range, % change) increased 17.5 watts (-13 to +44 watts, 46%, p < 0.05), maximal oxygen consumption increased 0.16 L/min (-0.17 to +0.48, 25%, p < 0.05), maximal ventilation increased 6.6 L/min (-7 to +26 L/min, 27%, p < 0.05), and the dead space/tidal volume ratio at peak exercise decreased 0.07 (-0.22 to +0.09, 12%, p < 0.05), exclusively as a result of an increase in the tidal volume. After lung volume reduction surgery heart rate decreased at the point of isowatt exercise, from 115 to 111 beats/min (p < 0.05). No difference was observed in the other physiologic variables measured at isowatt exercise. In 13 patients exercised while breathing room air, the alveolar-to-arterial O2 difference increased, and the arterial O2 tension decreased from rest to peak exercise both before and after the operation, but significant changes in this response were not observed after surgery. The primary problem limiting exercise performance in these patients was the limited ventilatory capacity as 16 and 13 of the 21 subjects developed acute respiratory acidemia at peak exercise before and after surgery, respectively. Lung volume reduction surgery in patients with severe emphysema improved maximal ventilation, thereby improving maximal exercise performance.
journal_name
Am J Respir Crit Care Medauthors
Benditt JO,Lewis S,Wood DE,Klima L,Albert RKdoi
10.1164/ajrccm.156.2.9611032subject
Has Abstractpub_date
1997-08-01 00:00:00pages
561-6issue
2 Pt 1eissn
1073-449Xissn
1535-4970journal_volume
156pub_type
杂志文章abstract::During dynamic hyperinflation, the ventilatory pump is facing increased demand because it must overcome the intrinsic positive end-expiratory pressure (PEEPi) and decreased capacity since it must operate at a dynamically increased end-expiratory lung volume (EELV). The aim of this study was to evaluate the relative pr...
journal_title:American journal of respiratory and critical care medicine
pub_type: 杂志文章
doi:10.1164/ajrccm.156.2.9611073
更新日期:1997-08-01 00:00:00
abstract:RATIONALE:There is a need to develop novel noninvasive imaging biomarkers that help to evaluate antiinflammatory asthma treatments. OBJECTIVES:To investigate whether the extent of the segmental lung edema measured noninvasively using turbo-inversion recovery-magnitude magnetic resonance imaging (TIRM MRI) corresponds ...
journal_title:American journal of respiratory and critical care medicine
pub_type: 临床试验,杂志文章
doi:10.1164/rccm.201310-1825OC
更新日期:2014-03-15 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
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journal_title:American journal of respiratory and critical care medicine
pub_type: 杂志文章
doi:10.1164/ajrccm.155.2.9032210
更新日期:1997-02-01 00:00:00
abstract:RATIONALE:Congenital central hypoventilation syndrome (CCHS), a unique disorder of respiratory control associated with Hirschsprung disease (HSCR) and tumors of neural crest origin, results from polyalanine repeat expansion mutations in the paired-like homeobox (PHOX)2B gene in more than 90% of cases, and alternative P...
journal_title:American journal of respiratory and critical care medicine
pub_type: 杂志文章
doi:10.1164/rccm.200602-305OC
更新日期:2006-11-15 00:00:00
abstract:RATIONALE:Density-based morphometric studies have demonstrated decreased capillary density in infants with bronchopulmonary dysplasia (BPD) and in BPD-like animal models, leading to the prevailing view that microvascular development is disrupted in BPD. OBJECTIVE:To perform a comprehensive analysis of the early and la...
journal_title:American journal of respiratory and critical care medicine
pub_type: 杂志文章
doi:10.1164/rccm.200506-927OC
更新日期:2006-01-15 00:00:00
abstract:RATIONALE:Sublingual allergen-specific immunotherapy is gaining popularity for treatment of allergic diseases, but underlying immunological mechanisms are unresolved. OBJECTIVES:To perform detailed immunological investigation of sublingual house dust mite (HDM) immunotherapy. METHODS:A 12-month randomized double-blin...
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.200905-0686OC
更新日期:2009-11-15 00:00:00
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journal_title:American journal of respiratory and critical care medicine
pub_type: 杂志文章
doi:10.1164/ajrccm.159.5.9808047
更新日期:1999-05-01 00:00:00
abstract::Partial liquid ventilation (PLV) has been shown to be an effective means of improving oxygenation in the injured lung. However, little is known about how approach to ventilation during PLV affects gas exchange and pulmonary mechanics. We hypothesized that gas exchange and pulmonary mechanics would be best with positiv...
journal_title:American journal of respiratory and critical care medicine
pub_type: 杂志文章
doi:10.1164/ajrccm.159.4.9711021
更新日期:1999-04-01 00:00:00
abstract:RATIONALE:The rapid diagnosis of pulmonary tuberculosis (TB) is difficult when acid fast bacilli (AFB) cannot be detected in sputum smears. OBJECTIVES:Following a proof of principle study, we examined in routine clinical practice whether individuals with sputum AFB smear-negative TB can be discriminated from those wit...
journal_title:American journal of respiratory and critical care medicine
pub_type: 临床试验,杂志文章,多中心研究
doi:10.1164/rccm.200904-0557OC
更新日期:2009-10-01 00:00:00
abstract::To investigate patterns of testing for human immunodeficiency virus (HIV) infection in tuberculosis patients, we obtained data from the tuberculosis registry and from medical records of 500 tuberculosis patients in Los Angeles County. Sixty-three percent of tuberculosis patients were tested for HIV infection, and mult...
journal_title:American journal of respiratory and critical care medicine
pub_type: 杂志文章
doi:10.1164/ajrccm.155.1.9001340
更新日期:1997-01-01 00:00:00
abstract::Rationale: To detect pulmonary arterial hypertension (PAH) at any early stage is a promising approach to optimize the outcome. Objectives: To investigate the impact of school ECG-based screening on detecting idiopathic or heritable (I/H)-PAH in the general pediatric population. Methods: This was a nationwide survey of...
journal_title:American journal of respiratory and critical care medicine
pub_type: 杂志文章
doi:10.1164/rccm.201802-0375OC
更新日期:2019-06-01 00:00:00
abstract:RATIONALE:There are no accepted blood-based biomarkers in chronic obstructive pulmonary disease (COPD). Pulmonary and activation-regulated chemokine (PARC/CCL-18) is a lung-predominant inflammatory protein that is found in serum. OBJECTIVES:To determine whether PARC/CCL-18 levels are elevated and modifiable in COPD an...
journal_title:American journal of respiratory and critical care medicine
pub_type: 临床试验,杂志文章,多中心研究
doi:10.1164/rccm.201008-1220OC
更新日期:2011-05-01 00:00:00
abstract::The nasal antiinflammatory effects produced by maintenance treatment with topical steroids include reduced production of cytokines. The present study explored nasal mucosal effects induced during the first 9 h after a single dose of topical budesonide. Nine subjects with allergic rhinitis due to birch or timothy polle...
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.162.5.9910094
更新日期:2000-11-01 00:00:00
abstract::Hydrogen peroxide (H2O2) is known to play an important role in airway homeostasis. For this reason its levels and thus its synthesis and consumption are important mechanisms for controlling airway functions. We have identified the major macromolecular consumer of H2O2 in sheep airway secretions to be lactoperoxidase (...
journal_title:American journal of respiratory and critical care medicine
pub_type: 杂志文章,评审
doi:10.1164/rccm.2206018
更新日期:2002-12-15 00:00:00
abstract::Survival is linked to the histopathologic distinction between usual interstitial pneumonia (UIP) and nonspecific interstitial pneumonia (NSIP), the most commonly encountered fibrotic idiopathic interstitial pneumonia. We retrospectively compared the prognostic significance of histopathologic diagnoses, baseline pulmon...
journal_title:American journal of respiratory and critical care medicine
pub_type: 杂志文章
doi:10.1164/rccm.200210-1245OC
更新日期:2003-09-01 00:00:00
abstract::At present there is some indirect evidence for increased nocturnal inflammation in patients suffering from nocturnal asthma: 1. Circulating eosinophil numbers and activation, as reflected by increased levels of ECP and EDN and low-density eosinophils, are increased at night. 2. Circulating histamine levels are increas...
journal_title:American journal of respiratory and critical care medicine
pub_type: 杂志文章,评审
doi:10.1164/ajrccm/150.5_Pt_2.S83
更新日期:1994-11-01 00:00:00
abstract::Pharyngeal dilator muscle activation (GGEMG) during wakefulness is greater in patients with obstructive sleep apnea (OSA) than in healthy control subjects, representing a neuromuscular compensatory mechanism for a more collapsible airway. As previous work from our laboratory has demonstrated a close relationship betwe...
journal_title:American journal of respiratory and critical care medicine
pub_type: 杂志文章
doi:10.1164/ajrccm.164.11.2102048
更新日期:2001-12-01 00:00:00
abstract::It is controversial whether mutations in cystic fibrosis transmembrane conductance regulator intrinsically dysregulate inflammation. We characterized passage 2 human tracheobronchial epithelial cell cultures morphologically and physiologically and determined whether cytokine production or nuclear factor-kappaB activat...
journal_title:American journal of respiratory and critical care medicine
pub_type: 杂志文章
doi:10.1164/rccm.200207-765OC
更新日期:2004-03-01 00:00:00
abstract:RATIONALE:In a pulmonary process characterized by spatially heterogeneous loss of aeration, the impairment of gas exchange is expected to depend on the regional distribution of perfusion relative to that of aeration. OBJECTIVES:To investigate how regional aeration, shunt, and perfusion are interrelated at different le...
journal_title:American journal of respiratory and critical care medicine
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更新日期:2008-02-01 00:00:00
abstract::Although numerous reports have described the improvement in PAO2 in patients in the prone position, the underlying mechanism has yet to be determined. Some authors have suggested this phenomenon may be related to an increase in functional residual capacity (FRC); however, no previous studies have described positional ...
journal_title:American journal of respiratory and critical care medicine
pub_type: 杂志文章
doi:10.1164/ajrccm.156.4.9601042
更新日期:1997-10-01 00:00:00
abstract::Aeroallergens such as Amb a I from short ragweed are important in the development of allergic airway disease. We tested the ability of a human monoclonal immunoglobulin-A (IgA) antibody specific for Amb a I (A-IgA) to modulate airway responsiveness and lung eosinophilia after airway challenge with nebulized Amb a I or...
journal_title:American journal of respiratory and critical care medicine
pub_type: 杂志文章
doi:10.1164/ajrccm.158.2.9801014
更新日期:1998-08-01 00:00:00
abstract::The present study was designed to examine whether clenbuterol (CLEN) could reduce dexamethasone (DEX)-induced diaphragm dysfunction. We studied four groups of New Zealand white (NZW) rabbits, each receiving one of the following daily injections subcutaneously for 2 wk: saline (control), DEX 3 mg/kg, DEX 3 mg/kg + CLEN...
journal_title:American journal of respiratory and critical care medicine
pub_type: 杂志文章
doi:10.1164/ajrccm.154.6.8970370
更新日期:1996-12-01 00:00:00
abstract::The blood beryllium lymphocyte proliferation test is used in medical surveillance to identify both beryllium sensitization and chronic beryllium disease. Approximately 50% of individuals with beryllium sensitization have chronic beryllium disease at the time of their initial clinical evaluation; however, the rate of p...
journal_title:American journal of respiratory and critical care medicine
pub_type: 杂志文章
doi:10.1164/rccm.200402-190OC
更新日期:2005-01-01 00:00:00
abstract:RATIONALE:Few studies have examined associations between exposure to air pollution and childhood lung function after implementation of strict air quality regulations in the 1990s. OBJECTIVES:To assess traffic-related pollution exposure and childhood lung function. METHODS:We geocoded addresses for 614 mother-child pa...
journal_title:American journal of respiratory and critical care medicine
pub_type: 杂志文章
doi:10.1164/rccm.201506-1058OC
更新日期:2016-04-15 00:00:00
abstract:RATIONALE:Current thinking accredits eosinophils with preeminent contributions to allergic airway responses, including a major role in the development of airway remodeling, a process thought to significantly contribute to airway dysfunction. However, direct evidence in support of this notion is limited and often contro...
journal_title:American journal of respiratory and critical care medicine
pub_type: 杂志文章
doi:10.1164/rccm.200905-0736OC
更新日期:2011-01-15 00:00:00
abstract::Sepsis is the most common cause of death in patients in the intensive care unit. Genome-wide gene expression analysis can provide insights into the molecular alterations of sepsis. Total mRNA was extracted from the livers of 6 uninfected control mice and 60 septic mice after infusion of either live Escherichia coli or...
journal_title:American journal of respiratory and critical care medicine
pub_type: 杂志文章
doi:10.1164/rccm.200211-1278OC
更新日期:2004-05-15 00:00:00
abstract::The epidemiologic characteristics of lung cancer in Taiwan differ from those in other parts of the world in low male-to-female ratio, the high percentage of adenocarcinoma, and the relatively high percentage of nonsmokers who are victims. To investigate possible correlation between p53 gene alteration and the unique c...
journal_title:American journal of respiratory and critical care medicine
pub_type: 杂志文章
doi:10.1164/ajrccm.150.6.7952630
更新日期:1994-12-01 00:00:00
abstract::The hereditary thrombophilias are a group of inherited conditions that predispose to thrombosis. Heritable deficiencies of the endogenous anticoagulants protein C, protein S, and antithrombin have been recognized for some years, but their prevalence, even among patients with familial thrombosis, is low. The recent dis...
journal_title:American journal of respiratory and critical care medicine
pub_type: 杂志文章,评审
doi:10.1164/ajrccm.158.5.9712022
更新日期:1998-11-01 00:00:00
abstract::Tumor-associated angiogenesis is important for tumor growth and metastasis. Interleukin (IL)-8 was recently reported to be an important angiogenic factor both in vitro and in vivo. In this study we evaluated, for the first time, IL-8 messenger RNA (mRNA) expression in non-small-cell lung cancer (NSCLC), using real-tim...
journal_title:American journal of respiratory and critical care medicine
pub_type: 杂志文章
doi:10.1164/ajrccm.162.5.2002108
更新日期:2000-11-01 00:00:00