Absence Of Airflow Limitation Research Articles

Small airway function measured using forced expiratory flow between 25% and 75% of vital capacity and its relationship to airflow limitation in symptomatic ever-smokers: a cross-sectional study

BackgroundChronic obstructive pulmonary disease (COPD) is diagnosed and its severity graded by traditional spirometric parameters (forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) and FEV1, respectively) but these...

Pre-chronic obstructive pulmonary disease: a pathophysiologic process or an opinion term?

Current guidelines does not include current or former smokers who do not have spirometric airflow limitation in their diagnostic or therapeutic algorithms for chronic obstructive pulmonary disease (COPD). The purpose of this review is to outline the burden of respiratory morbidity in this population and to discuss the potential utility of their classification as pre-COPD. It is increasingly clear that patients with a history of exposure to cigarette smoke or other environmental pollutants may have substantial lung pathology and respiratory impairment even in the absence of airflow limitation, as detected by spirometry. Not all of these patients will develop airflow limitation, but many will have considerable respiratory morbidity and a comparable prognosis to those with classical, spirometrically defined COPD. The use of the term pre-COPD may allow for the identification of these individuals in order to target preventive and earlier therapeutic strategies. Spirometry is not adequately sensitive to identify many current and former smokers and other exposed populations with significant lung pathology and respiratory symptoms. Though the pathologic processes present in these patients differ, the earlier identification of this pre-COPD population may foster the development of more effective and disease-modifying treatments.

Treatment Trials in Young Patients with Chronic Obstructive Pulmonary Disease and Pre-Chronic Obstructive Pulmonary Disease Patients: Time to Move Forward.

Chronic obstructive pulmonary disease (COPD) is the end result of a series of dynamic and cumulative gene-environment interactions over a lifetime. The evolving understanding of COPD biology provides novel opportunities for prevention, early diagnosis, and intervention. To advance these concepts, we propose therapeutic trials in two major groups of subjects: "young" individuals with COPD and those with pre-COPD. Given that lungs grow to about 20 years of age and begin to age at approximately 50 years, we consider "young" patients with COPD those patients in the age range of 20-50 years. Pre-COPD relates to individuals of any age who have respiratory symptoms with or without structural and/or functional abnormalities, in the absence of airflow limitation, and who may develop persistent airflow limitation over time. We exclude from the current discussion infants and adolescents because of their unique physiological context and COPD in older adults given their representation in prior randomized controlled trials (RCTs). We highlight the need of RCTs focused on COPD in young patients or pre-COPD to reduce disease progression, providing innovative approaches to identifying and engaging potential study subjects. We detail approaches to RCT design, including potential outcomes such as lung function, patient-reported outcomes, exacerbations, lung imaging, mortality, and composite endpoints. We critically review study design components such as statistical powering and analysis, duration of study treatment, and formats to trial structure, including platform, basket, and umbrella trials. We provide a call to action for treatment RCTs in 1) young adults with COPD and 2) those with pre-COPD at any age.

Comparison between quantitative computed tomography, scintigraphy, and anatomical methods for prediction of postoperative FEV1 and DLCO: effects of chronic obstructive pulmonary disease status and resected lobes.

BackgroundPostoperative assessment of pulmonary function is important for estimating the risk of thoracic surgery and long-term disability following pulmonary resection, including predicted postoperative (ppo) forced expiratory volume (FEV) in one second (ppoFEV1) and percent predicted lung diffusion capacity for carbon monoxide (ppo%DLCO) estimation. The ppo values were compared using four different estimation methods between chronic obstructive pulmonary disease (COPD) and non-COPD patients and according to the resected lobe.MethodsThis prospective study included 59 eligible patients requiring single lobectomy and succeeded in performing pulmonary function tests at 3 and 12 months after lobectomy. The ppoFEV1 and ppo%DLCO were compared with poFEV1 and po%DLCO obtained at 3 and 12 months after lobectomy. The ppo values were estimated using the four usual methods: the 19-segment anatomical technique (S), perfusion scintigraphy (Q), quantitative CT (CT), and quantitative CT with low attenuation volume (CTLAV) subtraction.ResultsFor non-COPD and COPD patients, the smallest mean difference between ppo and po values was observed by S for FEV1 and %DLCO. Based on the resected lobe, the smallest mean difference was observed by (I) Q for right upper lobectomy (RUL) excluding %DLCO at 12 months by S, (II) S for left upper lobectomy (LUL), (III) CT and CTLAV for right lower lobectomy (RLL), and (IV) CT and CTLAV for left lower lobectomy (LLL) at 12 months. The ppo values calculated by S for RUL (FEV1 at 3 and 12 months and %DLCO at 3 months) and by all four methods for LLL (FEV1 and %DLCO at 3 months) were smaller than the po values.ConclusionsThe S method is adequate for calculating ppoFEV1 and ppo%DLCO when patients are classified as non-COPD and COPD. However, S sometimes overestimates the ppoFEV1 and ppo%DLCO when patients are classified according to the resected lobe. The CTLAV method may be the method of choice instead of S for calculating ppoFEV1 and ppo%DLCO in patients who undergo lung lobectomy despite the presence or absence of airflow limitation.

The contribution of FEV1 and airflow limitation on the intensity of dyspnea and leg effort during exercise. Insights from a real-world cohort.

RationaleThe effort required to cycle and breathe intensify as power increases during incremental exercise. It is currently unclear how changes in FEV1 in the presence or absence of airflow limitation) impacts the intensity of dyspnea and leg effort. This is clinically important as the improvement in FEV1 is often the target for improving dyspnea.ObjectivesTo investigate the relationship between dyspnea (D), leg effort, power (P), and FEV1 with and without airflow limitation using direct psychophysical scaling performed during incremental exercise testing to symptom limited capacity.MethodsRetrospective analysis of consecutive patients over the age of 35 referred for cardio‐pulmonary exercise testing at McMaster University Medical Centre from 1988–2012.The modified Borg scale was used to measure dyspnea throughout incremental exercise testing.Measurements and results38,788 patients were included in the analysis [Mean Age 58.6 years (SD ±11.8), Males 61%, BMI 28.1 kg/m2 (SD ±5.1), FEV1 was 2.7 L (SD ±0.85), 95% predicted (SD ±20.4), FVC 3.4 L (SD ± 1.0), 94% predicted (SD ±17.0)], and 10.9% had airflow limitation (AL, FEV1/FVC < 70%). In a nonlinear regression analysis, the intensity of dyspnea increased in a positively accelerating manner with power and as the FEV1% predicted decreased: Dyspnea = 0.06 * Power1.03 * FEV1%Pred−0.66(r = .63). The intensity of leg effort increased with power and declining quadricep strength and FEV1% predicted: Leg Effort = 0.06 * Power1.22 * Quad−0.56*FEV1%Pred−0.39(r = .73). There was no independent effect of AL on dyspnea of leg effort.ConclusionPower, quadriceps strength and FEV1 are the dominant factors contributing to dyspnea and leg effort, irrespective of the degree of airflow limitation.

Chronic Cough and Phlegm in Subjects Undergoing Comprehensive Health Examination in Japan - Survey of Chronic Obstructive Pulmonary Disease Patients Epidemiology in Japan (SCOPE-J).

PurposeThe purpose of this study was to estimate the prevalence of subjects with chronic cough and phlegm and describe their characteristics including the presence or absence of airflow limitation among the general population in Japan.Subjects and MethodsThis was an observational cross-sectional survey targeting multiple regions of Japan. Subjects aged 40 years or above who were undergoing comprehensive health examination were recruited. The existence of chronic cough and phlegm, airflow limitation, and treatment for respiratory diseases were examined. Chronic cough and phlegm were defined as having both symptoms for at least 3 months of the year and for at least 2 consecutive years, or as receiving any treatment for chronic bronchitis at the time of recruitment. Airflow limitation was defined as forced expiratory volume in 1 s/forced vital capacity (FEV1/FVC) less than 0.7.ResultsIn a total of 22,293 subjects, 380 subjects (1.7%) had chronic cough and phlegm. Among these 380 subjects, 21.8% received treatment for a respiratory disease, and 11.6% had airflow limitation. Compared to subjects without both chronic cough and phlegm but with airflow limitation, subjects with chronic cough and phlegm without airflow limitation were younger, more likely to be current smokers (39.6%), and had higher total scores on a chronic obstructive pulmonary disease (COPD) assessment test (CAT). Scores of CAT questions 1–4 (cough, phlegm, chest tightness, breathlessness, respectively) were higher in subjects with chronic cough and phlegm regardless of airflow limitation.ConclusionThis study demonstrated that subjects identified to have chronic cough and phlegm in comprehensive health examination settings were symptomatic, while most of them did not receive any treatment for respiratory diseases and did not have airflow limitation. Screening subjects for chronic cough and phlegm in a comprehensive health examination followed by a detailed examination of screened subjects could be an effective approach for better management of chronic cough and phlegm. Smoking cessation should be included in the management, in consideration that around 40% of subjects with chronic cough and phlegm were current smokers.

Diffuse granulomatous disease: looking inside and outside the lungs

A 39-year-old woman presented with a 6-month history of breathlessness, productive cough and painful lumps on her lower legs. She had suffered with recurrent rhinosinusitis and frequent infections of the...

Effect of airflow limitation on acute exacerbations in patients with destroyed lungs by tuberculosis.

History of treatment for tuberculosis (TB) is a risk factor for obstructive lung disease. However, it has been unclear whether the clinical characteristics of patients with destroyed lung by TB differ according to the presence or absence of airflow limitation. The objective of the study was to evaluate differences in acute exacerbations and forced expiratory volume in 1 second (FEV1) decline in patients with destroyed lung by TB according to the presence or absence of airflow limitation. We performed a retrospective cohort study and enrolled patients with destroyed lung by TB. The presence of airflow limitation was defined as FEV1/forced vital capacity (FVC) < 0.7. One hundred and fifty-nine patients were enrolled, and 128 (80.5%) had airflow limitation. The proportion of patients who experienced acute exacerbation was higher in patients with airflow limitation compared to those without (89.1 vs. 67.7%, respectively; P = 0.009). The rate of acute exacerbation was higher in patients with airflow limitation (IRR, 1.19; 95% CI, 1.11-1.27). Low body mass index (X vs. X + 1; HR, 0.944; 95% CI, 0.895-0.996) in addition to airflow limitation (HR, 1.634; 95% CI, 1.012-2.638), was an independent risk factor for acute exacerbation. The annual decline of FEV1 was 2 mL in patients with airflow limitation and 36 mL in those without (P < 0.001). In conclusion, the presence of airflow limitation is an independent risk factor for acute exacerbation in patients with the destroyed lung by TB.

Chronic bronchitis before age 50 years predicts incident airflow limitation and mortality risk

Background:Previous studies on the relationship of chronic bronchitis to incident airflow limitation and all-cause mortality have provided conflicting results, with positive findings reported mainly by studies that included populations of...

Comparison of the Structural and Inflammatory Features of COPD and Asthma Giles F. Filley Lecture

At least three conditions contribute to COPD. (1) Chronic bronchitis (mucous hypersecretion) is an inflammatory condition in which CD8+ T-lymphocytes, neutrophils, and CD68+ monocytes/macrophages predominate. The condition is defined clinically by the presence of chronic cough and recurrent increases in bronchial secretions sufficient to cause expectoration. There is enlargement of mucus-secreting glands and goblet cell hyperplasia, which can occur in the absence of airflow limitation. (2) Adult chronic bronchiolitis (small or peripheral airways disease) is an inflammatory condition of small bronchi and bronchioli in which there are predominantly CD8+ and pigmented macrophages. The functional defect is difficult to detect clinically but may be recognized by sophisticated tests of small airway function. There is mucous metaplasia, enlargement of the mass of bronchiolar smooth muscle, and loss of alveolar attachments. (3) Emphysema is an inflammatory condition of the alveoli in which T-lymphocytes, neutrophils, and pigmented alveolar macrophages are involved, associated with the release of excessive amounts of elastases. It is defined anatomically by permanent, destructive enlargement of airspaces distal to terminal bronchioli without obvious fibrosis. In contrast, asthma is a clinical syndrome characterized by allergic inflammation of bronchi and bronchioli in which CD4+ (helper) T-lymphocytes and eosinophils predominate. There is increased production and release of interleukin (IL)-4 and IL-5, which is referred to as a Th2-type response. There is usually increased tracheobronchial responsiveness to a variety of stimuli, and the condition is usually manifest as variable airflow obstruction. While differences between COPD and asthma have been highlighted, new data are emerging that indicate there may also be similarities.