Does eosinophilic COPD exacerbation have a better patient outcome than non-eosinophilic in the intensive care unit?

BACKGROUND: COPD exacerbations requiring intensive care unit (ICU) admission have a major impact on morbidity and mortality. Only 10%-25% of COPD exacerbations are eosinophilic. AIM: To assess whether eosinophilic COPD exacerbations have better outcomes than non-eosinophilic COPD exacerbations in the ICU. METHODS: This retrospective observational cohort study was conducted in a thoracic, surgery-level III respiratory ICU of a tertiary teaching hospital for chest diseases from 2013 to 2014. Subjects previously diagnosed with COPD and who were admitted to the ICU with acute respiratory failure were included. Data were collected electronically from the hospital database. Subjects' characteristics, complete blood count parameters, neutrophil to lymphocyte ratio (NLR), delta NLR (admission minus discharge), C-reactive protein (CRP) on admission to and discharge from ICU, length of ICU stay, and mortality were recorded. COPD subjects were grouped according to eosinophil levels (>2% or ≤2%) (group 1, eosinophilic; group 2, non-eosinophilic). These groups were compared with the recorded data. RESULTS: Over the study period, 647 eligible COPD subjects were enrolled (62 [40.3% female] in group 1 and 585 [33.5% female] in group 2). Group 2 had significantly higher C-reactive protein, neutrophils, NLR, delta NLR, and hemoglobin, but a lower lymphocyte, monocyte, and platelet count than group 1, on admission to and discharge from the ICU. Median (interquartile range) length of ICU stay and mortality in the ICU in groups 1 and 2 were 4 days (2-7 days) vs 6 days (3-9 days) (P<0.002), and 12.9% vs 24.9% (P<0.034), respectively. CONCLUSION: COPD exacerbations with acute respiratory failure requiring ICU admission had a better outcome with a peripheral eosinophil level >2%. NLR and peripheral eosinophilia may be helpful indicators for steroid and antibiotic management.