How should we define and classify exacerbations in chronic obstructive pulmonary disease?

Abstract

Chronic obstructive pulmonary disease (COPD) is a chronic disorder whose clinical course may be punctuated by exacerbations characterized by a sudden symptom worsening beyond the expected daily variations. Exacerbations bear clinical and prognostic relevance, and may result in marked functional and clinical deterioration. The varying presentations of COPD mean that exacerbations, although more frequent in patients with severe or very severe disease, may occur regardless of the degree of functional impairment. The new Spanish COPD Guideline (GesEPOC) has provided new insights into the management of the disease. The GesEPOC defines various disease phenotypes with different clinical, prognostic and therapeutic implications. One of these phenotypes is the so-called ‘exacerbator’, characterized by the incidence of an increased number of exacerbations (two or more moderate–severe exacerbations in the last year). An exacerbation must be defined by: an increase in symptom intensity occurring after a certain period of time since the last exacerbation (so that treatment failure can be excluded as the cause of the event); and the contribution of social criteria or reasons concerning the choice of therapy. The availability of certain tools to detect exacerbations would enable establishment of a homogeneous definition of exacerbation, and improved diagnosis, a suitable treatment choice and a more appropriate patient selection for clinical studies. Validated clinical questionnaires and biomarkers are the most helpful instruments to reach the above objectives. Following the clinical diagnosis of a COPD exacerbation, associated comorbidities must be evaluated and an etiologic diagnosis must be made, all of which will partially drive the choice of treatment. Once a diagnosis has been made, the severity of the exacerbation should be established in order to define where and how the patient should be treated. Based on the patient’s clinical history, clinical examination and diagnostic tests, the severity will be classified in one of these four degrees: very severe, severe, moderate and mild.

Keywords::

• chronic obstructive pulmonary disease
• clinical definition
• degree of severity
• etiologic diagnosis
• exacerbation
• exacerbator phenotype

Financial & competing interests disclosure

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.

Editorial assistance was provided by Content Ed Net and funded by Novartis, Spain.

Notes

Reproduced with permission from [1].

FEV1: Forced expiratory volume in 1 s.

Adapted with permission from [20].

FEV1: Forced expiratory volume in 1 s.

Adapted with permission from [25].

COPD: Chronic obstructive pulmonary disease; mMRC: Modified Medical

Research Council.

Adapted with permission from [1].

Adapted with permission from [1].