Since chronic obstructive pulmonary disease (COPD) is a heterogeneous disorder, factors contributing to severe pneumonia may be diverse or different among each phenotypes. However, little information is available on factors contributing to the severity of pneumonia in COPD population. Thus, we compared the demographic characteristics, CT findings, and COPD-related variables between COPD patients with severe pneumonia and those with non-severe pneumonia to verify the factors contributing to severe pneumonia in COPD population.
Retrospective observational study was conducted with prospectively collected database between January 2008 and December 2012. Over study period, total 1502 immunocompetent patients with pneumonia admitted via the emergency department. Of these patients, 190 patients had the diagnosis of COPD, and 29 patients were excluded due to medical condition or disease which may affect lung function.
Of the 161 study population, 114 (70.8%) and 47 patients (29.2%) were classified as a non-severe and severe pneumonia, respectively. Higher ECOG score (odds ratio 1.459; 95% confidence interval 1.004-2.121; P = 0.048) and the presence of pulmonary emphysema on CT scan (odds ratio 2.688; 95% confidence interval 1.024-7.059; P = 0.045) were independently associated with severe pneumonia in COPD patients. However, there was no difference in pulmonary function test, GOLD grade and COPD medication between non-severe and severe pneumonia.
In conclusion, the presence of pulmonary emphysema on CT scan and poor performance status at the time of hospital admission were associated with severe pneumonia in COPD population.