Clinical Features, Etiology and Outcomes of Community-Acquired Pneumonia in Patients with Chronic Obstructive Pulmonary Disease

Abstract

BackgroundCommunity-acquired pneumonia (CAP) is a frequent complication of chronic obstructive pulmonary disease (COPD), but previous studies are often contradictory.ObjectivesWe aimed to ascertain the characteristics and outcomes of CAP in patients with COPD as well as to determine the risk factors for mortality and Pseudomonas aeruginosa pneumonia in COPD patients with CAP. We also describe the etiology and outcomes of CAP in COPD patients receiving chronic oxygen therapy at home and those receiving inhaled steroids.MethodsAn observational analysis of a prospective cohort of hospitalized adults with CAP (1995–2011) was performed.ResultsWe documented 4121 CAP episodes, of which 983 (23.9%) occurred in patients with COPD; the median FEV1 value was 50%, and 57.8% were classified as stage III or IV in the GOLD classification. Fifty-eight per cent of patients were receiving inhaled steroids, and 14.6% chronic oxygen therapy at home. Patients with COPD presented specific clinical features. S. pneumoniae was the leading causative organism overall, but P. aeruginosa was more frequent in COPD (3.4 vs. 0.5%; p<0.001). Independent risk factors for case-fatality rate in patients with COPD were multilobar pneumonia, P. aeruginosa pneumonia, and high-risk PSI classes. Prior pneumococcal vaccination was found to be protective. FEV1 was an independent risk factor for P. aeruginosa pneumonia.ConclusionsCAP in patients with COPD presents specific characteristics and risk factors for mortality. Prior pneumococcal vaccine has a beneficial effect on outcomes. P. aeruginosa pneumonia is associated with low FEV1 values and poor prognosis.

Is COPD associated with increased mortality and morbidity in hospitalized pneumonia? A systematic review and meta‐analysis

“…In addition, that meta-analysis focused exclusively on mortality, the other clinically important outcomes including length of hospital stay, ICU admission and need for mechanical ventilation were not investigated. Furthermore, several studies 16,19,27 with conflicting results have recently been published. In contrast to the previous metaanalysis, our meta-analysis provides evidence that co-morbid COPD is not associated with increased mortality.…”

“…All cohort studies ascertained the diagnosis of CAP based on chest radiographic findings, whereas the two case-control studies identified the cases of CAP according to the International Classification of Diseases (ICD-10) codes. Eight cohort studies confirmed the presence of COPD by spirometric criteria, 15,[18][19][20]23,[26][27][28] whereas the case-control studies 16,29 and one cohort study 17 identified COPD patients through medical records. The main characteristics of the included studies are summarized in Table 1.…”

“…Data on length of hospital stay were available in eight cohort studies 15,[17][18][19][20][26][27][28] and one case-control study. 16 No statistical difference was found in cohort studies (MD, 0.11; 95% CI: −0.42 to 0.64; P = 0.68; I 2 = 21%) (Supplementary Figure S1), but the case-control study indicated that COPD was associated with longer hospital stay (9 vs 8 days, P < 0.001).…”

“…Seven cohort studies 15,[17][18][19][20]23,27 provided data on ICU admission. COPD was not associated with more frequent ICU admission (RR, 0.97; 95% CI: 0.70-1.35; P = 0.87; I 2 = 65%) (Supplementary Figure S2).…”

“…Five studies 15,17,20,26,27 reported the need for mechanical ventilation. Of these, one 26 was conducted in ICU patients (30.1 vs 21.4%, P = 0.05), and the other four studies showed no statistical difference between groups (RR, 0.91; 95% CI: 0.71-1.16; P = 0.44; I 2 = 4%) (Supplementary Figure S3).…”