Just What Is A COPD Exacerbation?

Recently, a novel pilot study was conducted using what is called a “system network analysis” to determine whether the variables measured during COPD exacerbations, could help generate a new way of defining COPD exacerbations. A total of 69 variables were studied, including clinical, laboratory, microbiology, cytokines, and imaging. These were analyzed during 72 hours of hospitalizations and 3 months following discharge from the hospital.

The results of the study helped to describe the relationship between COPD and comorbidities (or the simultaneous presence of other chronic diseases or conditions besides COPD in a patient), and the potential role of a B-cell immune response.

One finding was that, during an exacerbation, the connection between lung function and cytokine expression of inflammation was disrupted, and each process or function became independent from the other.

A second set of findings was that, in addition to the presence of cough and sputum, there was a measurable increase in the perception of dyspnea (breathlessness). Additionally, the respiratory rate was higher during the acute phase of the event, there was a large increase in the blood levels of C-reactive protein (CRP), and the levels were directly related to the severity of the exacerbation. A high white blood cell count also was often present in exacerbations.

Though the study was conducted on a relatively small group of patients (a total of 14 individuals) and did not provide for baseline measurements of these individuals prior to their exacerbations, and also did not compare their data to a control group of patients without COPD, the study is thought to be significant because it may provide the impetus for further research using integrative analytical techniques to provide a better definition of COPD exacerbations and to gain deeper insights into the effect of interventions on the pattern of response.

In the words of Bartolome R. Celli, the author of an article on this study published in the European Respiratory Journal, “It is time we stop defining a COPD exacerbation only by its symptoms. The tools are available to be more precise and following the guidance provided by Galileo >300 years ago, to measure what is measurable and make measurable what is not.”