COPD exacerbations: definitions and classifications

The most recent update of the international NHLBI/WHO Global Initiative for Chronic
\nObstructive Lung Disease (GOLD) guidelines defines chronic obstructive pulmonary disease
\n(COPD) with respect to its pulmonary and extrapulmonary (systemic) components, but
\ndoes not mention exacerbations in the main definition, even though they are the main cause
\nof medical intervention and admission to hospital in these patients. In the same guidelines,
\nan exacerbation of COPD is separately defined as ‘an event in the natural course of the
\ndisease characterised by a change in the patient’s baseline dyspnoea, cough and/or sputum that is
\nbeyond normal day-to-day variations, is acute in onset, and may warrant a change in regular medication
\nin a patient with underlying COPD’. The latest GOLD guidelines also provide a classification
\nof the severity of the exacerbations of COPD based on clinical parameters to drive
\nthe necessity and the type of antibiotic therapy.
\nSimilarly, the latest update of the Canadian Thoracic Society (CTS) recommendations for
\nthe management of COPD defines an exacerbation of COPD as ‘a sustained worsening of dyspnoea,
\ncough or sputum production leading to an increase in the use of maintenance medications and/
\nor supplementation with additional medications’. The term ‘sustained’ implies a change from
\nbaseline lasting 48 h or more. In addition, COPD exacerbations are defined as either purulent
\nor non-purulent on the assumption that this is helpful in predicting the need for antibiotic
\ntherapy. Again, in a strict analogy to the latest GOLD guidelines, the CTS update
\nalso provides a classification of the severity of purulent exacerbations of COPD, recognising
\nboth simple and complicated purulent COPD exacerbations, based on the presence of clinical
\nrisk factors that either increase the likelihood of treatment failure or are more likely to
\nbe associated with more virulent or resistant bacterial pathogens.
\nAlthough both the GOLD and CTS definitions and classifications of the severity of COPD
\nexacerbations may provide a useful practical tool for clinical studies, they have not been formally
\nvalidated in clinical trials and are rather cumbersome and difficult to use in clinical
\npractice. Other definitions derived from the literature are also used and are discussed below.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.