Assessment and treatment of airflow obstruction in patients with chronic obstructive pulmonary disorder: a guide for the clinician

ABSTRACT

Introduction: Chronic obstructive pulmonary disorder (COPD) is a common cause of disability, morbidity and mortality worldwide. Early diagnosis and adequate treatment maintained over time are crucial to reducing these harmful consequences.

Areas covered Persistent, not reversible and naturally progressive airflow obstruction is the functional hallmark of COPD. Therefore, in the presence of individual and environmental risk factors, with or without reported suggestive symptoms, simple spirometry must be performed enough quickly to objectify an obstructive ventilatory defect and assist physicians in making a diagnosis of COPD. Then, to cope with the heterogeneity of COPD patients, more specific functional tests and imaging techniques should be implemented to better define the underlying prevalent disease and its severity. That is necessary to decide whether to introduce ICS and establish the initial level of the treatment with just one or two bronchodilators, to control and freeze, when possible, the underlying pathological process.

Expert opinion: The objective assessment of airflow obstruction is mandatory to make a diagnosis of COPD, but the prevalent disease sustaining the disorder should also be investigated to select a targeted therapy, because main determinants of airflow obstruction can be different in COPD patients and may differently respond to treatment.

KEYWORDS:

• COPD
• tidal expiratory flow limitation
• bronchodilators

Article highlights

• COPD is better defined as a functional disorder characterized by chronic, irreversible and naturally progressive airflow obstruction, sustained by either fibrosing chronic bronchiolitis, with or without centrilobular emphysema, or panlobular emphysema.

• These diseases are different for pathology, lung mechanics alterations, gas-exchange abnormalities, main determinants of airflow obstruction and functional and clinical response to treatment, explaining the marked heterogeneity of COPD patients.

• Significant airflow obstruction is more correctly detected by the reduction of the FEV₁/VC ratio below the lower limit of normality (LLN), so avoiding false negative in younger and false positive in older individuals, as compared with a fixed cut-off value. Using in the same way the FEV₁/FVC ratio is easier but less sensitive.

• Early diagnosis objectively based on simple spirometry is highly desirable because the lung function decline in terms of mean annual loss of FEV₁ is greater and the current treatments are more effective to control it in the presence of a mild-to-moderate degree of airflow reduction severity (GOLD stage 1 and 2).

• Bronchial responsiveness after acute administration of bronchodilator must be assessed and it is consistently observed as significant in about 20% of COPD patients. FEV₁ significant increase may identify either flow or volume responders in COPD patients, influencing the choice of the treatment. Isolated FVC and IC significant increases are also considered as a functional response clinically useful.

• Tidal expiratory flow limitation should be investigated (both in a supine and seated position) in highly symptomatic COPD patients and those with nocturnal and/or in early morning symptoms.

• Evaluation of nature and severity of the prevalent underlying disease in COPD patients, using adequate functional tests and sometimes imaging tools, needs to be performed to personalize their pharmacologic treatment.

• Adopting a simple BERN algorithm can be very useful to establish the appropriateness of long-term ICS therapy on top of a bronchodilator(s) in a given COPD patient. Single or dual bronchodilator treatment should be chosen according to the achievement of predetermined both patient-related outcomes and physician-related functional objectives.

• Endoscopic lung volume reduction, after optimizing pharmacologic treatments and rehabilitation programs can be offered to highly selected COPD patients with the advanced emphysematous disease to improve symptoms (essentially chronic dyspnea), exercise tolerance and health-related quality of life and in case, to reduce acute COPD exacerbations, so possibly prolonging survival.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

A reviewer on this manuscript has performed consulting, served on advisory boards, or received travel reimbursement from Amphastar, AstraZeneca, Boehringer Ingelheim, Cipla, Chiesi, GlaxoSmithKline, Mylan, Novartis, Pearl, Sunovion and Theravance. This reviewer has conducted multicenter clinical research trials for some 40 pharmaceutical companies. Peer reviewers on this manuscript have no other relevant financial or other relationships to disclose.

Additional information

Funding

This paper was not funded.