Chronic obstructive pulmonary disease (COPD) remains a major public health problem. It is the fourth leading cause of chronic morbidity and mortality in the United States, and is projected to rank fifth in 2020 in burden of disease worldwide, according to a study published by the World Bank/World Health Organization. Yet, COPD remains relatively unknown or ignored by the public as well as public health and government officials. In 1998, in an effort to bring more attention to COPD, its management, and its prevention, a committed group of scientists encouraged the U.S. National Heart, Lung, and Blood Institute and the World Health Organization to form the Global Initiative for Chronic Obstructive Lung Disease (GOLD). Among the important objectives of GOLD are to increase awareness of COPD and to help the millions of people who suffer from this disease and die prematurely of it or its complications. The first step in the GOLD program was to prepare a consensus report, Global Strategy for the Diagnosis, Management, and Prevention of COPD, published in 2001. The present, newly revised document follows the same format as the original consensus report, but has been updated to reflect the many publications on COPD that have appeared. GOLD national leaders, a network of international experts, have initiated investigations of the causes and prevalence of COPD in their countries, and developed innovative approaches for the dissemination and implementation of COPD management guidelines. We appreciate the enormous amount of work the GOLD national leaders have done on behalf of their patients with COPD. Despite the achievements in the 5 years since the GOLD report was originally published, considerable additional work is ahead of us if we are to control this major public health problem. The GOLD initiative will continue to bring COPD to the attention of governments, public health officials, health care workers, and the general public, but a concerted effort by all involved in health care will be necessary.

https://www.who.int/respiratory/copd/GOLD_WR_06.pdf

Global strategy for the diagnosis, management, and prevention of chronic obstructive pulmonary disease: GOLD executive summary.

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SERIES “ATS/ERS TASK FORCE: STANDARDISATION OF LUNG FUNCTION TESTING” 

Edited by V. Brusasco, R. Crapo and G. Viegi 

Number 2 in this Series

 [1]: #F13

/pdf/standardisation-of-spirometry-1dkqxgifvl.pdf

Standardisation of spirometry

SERIES “ATS/ERS TASK FORCE: STANDARDISATION OF LUNG FUNCTION TESTING” 

Edited by V. Brusasco, R. Crapo and G. Viegi 

Number 5 in this Series 







This section is written to provide guidance in interpreting pulmonary function tests (PFTs) to medical directors of hospital-based laboratories that perform PFTs, and physicians who are responsible for interpreting the results of PFTs most commonly ordered for clinical purposes. Specifically, this section addresses the interpretation of spirometry, bronchodilator response, carbon monoxide diffusing capacity ( D L,CO) and lung volumes.

The sources of variation in lung function testing and technical aspects of spirometry, lung volume measurements and D L,CO measurement have been considered in other documents published in this series of Task Force reports 1–4 and in the American Thoracic Society (ATS) interpretative strategies document 5.

An interpretation begins with a review and comment on test quality. Tests that are less than optimal may still contain useful information, but interpreters should identify the problems and the direction and magnitude of the potential errors. Omitting the quality review and relying only on numerical results for clinical decision making is a common mistake, which is more easily made by those who are dependent upon computer interpretations.

Once quality has been assured, the next steps involve a series of comparisons 6 that include comparisons of test results with reference values based on healthy subjects 5, comparisons with known disease or abnormal physiological patterns ( i.e. obstruction and restriction), and comparisons with self, a rather formal term for evaluating change in an individual patient. A final step in the lung function report is to answer the clinical question that prompted the test.

Poor choices made during these preparatory steps increase the risk of misclassification, i.e. a falsely negative or falsely positive interpretation for a lung function abnormality or a change …

https://erj.ersjournals.com/content/erj/26/5/948.full.pdf

Interpretative strategies for lung function tests

The Standards for the Diagnosis and Treatment of Patients with COPD document 2004 updates the position papers on chronic obstructive pulmonary disease (COPD) published by the American Thoracic Society (ATS) and the European Respiratory Society (ERS) in 1995 1, 2. Both societies felt the need to update the previous documents due to the following. 1) The prevalence and overall importance of COPD as a health problem is increasing. 2) There have been enough advances in the field to require an update, especially adapted to the particular needs of the ATS/ERS constituency. 3) It allows for the creation of a “live” modular document based on the web; it should provide healthcare professionals and patients with a user friendly and reliable authoritative source of information. 4) The care of COPD should be comprehensive, is often multidisciplinary and rapidly changing. 5) Both the ATS and the ERS acknowledge the recent dissemination of the Global Initiative of Obstructive Lung Disease (GOLD) 3 as a major worldwide contribution to the battle against COPD. However, some specific requirements of the members of both societies require adaptation of the broad GOLD initiative. Those requirements include specific recommendations on oxygen therapy, pulmonary rehabilitation, noninvasive ventilation, surgery in and for COPD, sleep, air travel, and end-of-life. In addition, special emphasis has been placed on issues related to the habit of smoking and its control.

### Goals and objectives

The main goals of the updated document are to improve the quality of care provided to patients with COPD and to develop the project using a disease-oriented approach. To achieve these goals, both organisations have developed a modular electronic web-based document with two components. 1) A component for health professionals that intends to: raise awareness of COPD; inform on the latest advances in the overall pathogenesis, diagnosis, monitoring and management of COPD; and …

https://erj.ersjournals.com/content/erj/23/6/932.full.pdf

Standards for the diagnosis and treatment of patients with COPD: a summary of the ATS/ERS position paper

Chronic obstructive pulmonary disease (COPD) is a common problem in the elderly. The disease is characterised by intermittent worsening of symptoms and these episodes are called acute exacerbations. The best estimate, based on several lines of evidence, is that approximately half of all exacerbations are caused by bacteria. These lines of evidence include studies of lower respiratory tract bacteriology during exacerbations, correlation of airways’ inflammation with results of sputum cultures during exacerbations, analysis of immune responses to bacterial pathogens, and the observation in randomised, prospective, placebo-controlled trials that antibacterial therapy is of benefit. The most important bacterial causes of exacerbations of COPD are nontypeable Haemophilus influenzae, Moraxella catarrhalis, Streptococcus pneumoniae and Chlamydia pneumoniae.

/pdf/chronic-obstructive-pulmonary-disease-4ipss13czj.pdf

Chronic obstructive pulmonary disease

The role of dynamic hyperinflation (DH) in exercise limitation in chronic obstructive pulmonary disease (COPD) remains to be de- fined. We examined DH during exercise in 105 patients with COPD (FEV 1 � 37 � 13% predicted; meanSD) and studied the rela- tionships between resting lung volumes, DH during exercise, and peak oxygen consumption ( O 2 ). Patients completed pulmonary function tests and incremental cycle exercise tests. We measured the change in inspiratory capacity ( ∆ IC) during exercise to reflect changes in DH. During exercise, 80% of patients showed signifi- cant DH above resting values. IC decreased 0.37 � 0.39 L or 14 � 15% predicted during exercise (p � 0.0005), but with large varia- tion in range. ∆ IC correlated best with resting IC, both expressed %predicted (r � � 0.50, p � 0.0005). Peak O 2 (%predicted maxi- mum) correlated best with the peak tidal volume attained (V T standardized as % of predicted vital capacity) (r � 0.68, p � 0.0005), which, in turn, correlated strongly with IC at peak exer- cise (r � 0.79, p � 0.0005) or at rest (r � 0.75, p � 0.0005). The extent of DH during exercise in COPD correlated best with resting IC. DH curtailed the V T response to exercise. This inability to ex- pand V T in response to increasing metabolic demand contributed importantly to exercise intolerance in COPD. Chronic obstructive pulmonary disease (COPD) is a heteroge- neous disorder characterized by dysfunction of the small and large airways, as well as destruction of the lung parenchyma and its vasculature in highly variable combinations. The pathophysiological hallmark of COPD is expiratory flow limi- tation, which, in more advanced disease, occurs even during resting quiet breathing. As a consequence, resting lung vol- ume (functional residual capacity (FRC)) is dynamically, and not statically, determined. During exercise, as ventilatory de- mands increase in flow-limited patients, progressive air trap- ping and further dynamic lung hyperinflation (DH) above al- ready increased resting values is inevitable (1, 2). Recent studies have shown that DH during exercise contributes to perceived respiratory discomfort (3, 4). Indirect evidence of the importance of DH comes from studies that have demon- strated that alleviation of dyspnea following bronchodilator therapy and lung volume reduction surgery (LVRS) was ex- plained, in part, by reduced operating lung volumes (5, 6). However, it is not clear from previous studies to what extent the behavior of operating lung volumes during exercise influ- ences peak exercise capacity in COPD. Moreover, earlier studies have shown wide variability in the extent of DH with V ·

https://www.atsjournals.org/doi/pdf/10.1164/ajrccm.164.5.2012122

Dynamic Hyperinflation and Exercise Intolerance in Chronic Obstructive Pulmonary Disease

Changes in lung hyperinflation, dyspnea, and exercise endurance are important outcomes in assessing therapeutic responses in chronic obstructive pulmonary disease (COPD). Therefore, we studied the reproducibility of Borg dyspnea ratings, inspiratory capacity (IC; to monitor lung hyperinflation), and endurance time during constant-load symptom-limited cycle exercise in 29 patients with COPD (FEV1 = 40 ± 2% predicted; mean ± SEM). Responsiveness was also studied by determining the acute effects of nebulized 500 μ g ipratropium bromide (IB) or saline placebo (P) on these measurements. During each of four visits conducted over an 8-wk period, spirometry and exercise testing were performed before and 1 h after receiving IB or P (randomized, double-blinded). Highly reproducible measurements included: endurance time (intraclass correlation R = 0.77, p 0.6, p < 0.0001); and slopes of Borg ratings over time, ox...

https://www.atsjournals.org/doi/pdf/10.1164/ajrccm.158.5.9804004

Measurement of Symptoms, Lung Hyperinflation, and Endurance during Exercise in Chronic Obstructive Pulmonary Disease

There is considerable intersubject variability in the perceived intensity of breathlessness for a given level of activity among patients with chronic airflow limitation (CAL). To examine possible factors contributing to this variability we compared breathing pattern parameters, dynamic operational lung volumes, and Borg dyspnea ratings in 23 patients with severe CAL and in 10 healthy age-matched normal subjects during cycle ergometry to symptom-limitation. Patients with CAL had significantly (p < 0.01) higher levels of ventilation (% maximal voluntary ventilation) for a given work rate (slope of VE(%MVV)/WR(% pred max) = 1.51 +/- 0.18 versus 0.63 +/- 0.10; mean +/- SEM) and greater dynamic lung hyperinflation (DH) (change [delta] in end-expiratory lung volume [EELVdyn] = +0.31 +/- 0.11 L versus -0.16 +/- 0.22 L). Compared with normal subjects at a standardized VE (30 L/min), the CAL group was more breathless Borg = 4 +/- 1 versus 2 +/- 1, p < 0.01) and hyperinflated (EELVdyn = 75 +/- 3 versus 46 +/- 6% TLC, p < 0.001; end-inspiratory lung volume [EILVdyn] = 85 +/- 3 versus 67 +/- 5% TLC, p < 0.01). Within the CAL group, change in Borg ratings correlated with delta VE(%MVV) (r = 0.77, p < 0.001) and with slope of VE(%MVV)/WR(% pred max) (r = 0.48, p < 0.01). Regression analysis selected delta EILVdyn (or delta inspiratory reserve volume [delta IRVdyn]) from various dynamic ventilatory parameters as the strongest predictor of delta Borg (r = 0.63, p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Exertional Breathlessness in Patients with Chronic Airflow Limitation The Role of Lung Hyperinflation

We wished to determine which resting spirometric parameters best reflect improvements in exercise tolerance and exertional dyspnea in response to acute high-dose anticholinergic therapy in advanced COPD. We studied 29 patients with stable COPD (FEV(1) = 40 +/- 2% predicted [%pred]; mean +/- SEM) and moderate to severe chronic dyspnea. In a double-blind placebo-controlled cross-over study, patients performed spirometry and symptom-limited constant-load cycle exercise before and 1 h after receiving 500 micrograms of nebulized ipratropium bromide (IB) or saline placebo. There were no significant changes in spirometry, exercise endurance, or exertional dyspnea after receiving placebo. In response to IB (n = 58): FEV(1), FVC, and inspiratory capacity (IC) increased by 7 +/- 1%pred, 10 +/- 1%pred, and 14 +/- 2%pred, respectively (p < 0.001), with no change in the FEV(1)/FVC ratio. After receiving IB, exercise endurance time (Tlim) increased by 32 +/- 9% (p < 0.001) and slopes of Borg dyspnea ratings over time decreased by 11 +/- 6% (p < 0.05). Percent change (%Delta) in Tlim correlated best with DeltaIC%pred (p = 0.020) and change in inspiratory reserve volume (DeltaTLC%pred) (p = 0.014), but not with DeltaFVC%pred, DeltaPEFR%pred, or DeltaFEV(1)%pred. Change in Borg dyspnea ratings at isotime near end exercise also correlated with DeltaIC%pred (p = 0.04), but not with any other resting parameter. Changes in spirometric measurements are generally poor predictors of clinical improvement in response to bronchodilators in COPD. Of the available parameters, increased IC, which is an index of reduced resting lung hyperinflation, best reflected the improvements in exercise endurance and dyspnea after IB. IC should be used in conjunction with FEV(1) when evaluating therapeutic responses in COPD.

https://www.atsjournals.org/doi/pdf/10.1164/ajrccm.160.2.9901038

Spirometric Correlates of Improvement in Exercise Performance after Anticholinergic Therapy in Chronic Obstructive Pulmonary Disease

We compared qualitative aspects of the sensory experience of exertional breathlessness in normal subjects and in patients with chronic airflow limitation (CAL) and sought a physiologic rationale for these. Twelve patients (66 +/- 2 yr of age, mean +/- SEM) with severe CAL (FEV1 = 37 +/- 5% predicted) and 12 age-matched normal subjects (FEV1 = 103 +/- 5% predicted) were studied. Perceived inspiratory difficulty (BorgIN), inspiratory effort (esophageal pressure expressed as a fraction of maximal esophageal pressure at isovolume [Pes/PImax]), breathing pattern, and operational lung volumes (end-expiratory/inspiratory lung volumes [EELV/EILV]) were measured during symptom-limited incremental cycle exercise testing and compared at a standard VO2 of 50% predicted maximum in normal subjects and in patients with CAL. Qualitative descriptors of breathlessness were selected immediately after exercise. Breathlessness was qualitatively different between normal subjects and patients with CAL. Both normal subjects and patients with CAL chose descriptors of increased "work/effort" and "heaviness" of breathing; however, only patients with CAL consistently chose descriptors denoting "increased inspiratory difficulty" (75%), "unsatisfied inspiratory effort" (75%), and "shallow breathing" (50%). Stepwise regression analysis identified the ratio of Pes/PImax to VT/predicted VC as the strongest correlate of standardized BorgIN (n = 24, r = 0.86, p < 0.001). This latter measurement, which reflects the relationship between effort and ventilatory output, correlated strongly with dynamic EELV/TLC at isotime (r = 0.78, p < 0.001). In conclusion, the qualitatively discrete respiratory sensations of exertional inspiratory difficulty peculiar to patients with CAL may have their origins in thoracic hyperinflation and the resultant disparity between inspiratory effort and ventilatory output.

Katherine A. Webb

Papers

Dynamic Hyperinflation and Exercise Intolerance in Chronic Obstructive Pulmonary Disease

Measurement of Symptoms, Lung Hyperinflation, and Endurance during Exercise in Chronic Obstructive Pulmonary Disease

Exertional Breathlessness in Patients with Chronic Airflow Limitation The Role of Lung Hyperinflation

Spirometric Correlates of Improvement in Exercise Performance after Anticholinergic Therapy in Chronic Obstructive Pulmonary Disease

Qualitative aspects of exertional breathlessness in chronic airflow limitation: pathophysiologic mechanisms.