Eosinophil count and clinical outcome in patients with acute exacerbation of Chronic obstructive pulmonary disease.

Introduction: We examined the association of blood eosinophil counts at the time of AECOPD hospitalization with the risk of ICU admission as well as the hospital lengths of stay and mortality. Methods: In the current retrospective study, the association between blood eosinophil counts in COPD patients at the time of AECOPD hospitalization and the risk of subsequent ICU admission as well as mortality was assessed. The chi-squared test and t-test were used to compare categorical and continuous variables. The statistical significance level was set at 0.05. Kaplan-Meier curves for mortality as well as ICU admission up to 40 days after discharge from the index hospitalization were constructed using the determined optimal eosinophil threshold derived above and for the predetermined ≥ 300 vs < 300 cells/μL threshold. All analyses were performed using SPSS version 19. Results: Antibiotic prescription was significantly associated with increased ICU admission (OR = 1.57; confidence interval [95% CI] = 1.02-2.42. Patients with higher FEV1 had decreased ICU admission (OR = 0.98, 95% CI = 0.97-1.01, p = 0.1) as well as all-cause mortality compared (OR = 0.98, 95% CI= 0.92-1.04, p = 0.58). There were significantly greater mortality rates for patients with higher ESR (OR = 1.02, CI =1.01-1.03, p = 0.01) and CRP (OR = 1.02, 95% CI = 1.01-1.03, p = 0.01). There were significantly lower ICU admission rates for patients with higher FVC (OR = 0.97, 95% CI = 0.95-0.98, p = 0.002). Conclusions: Blood eosinophil count could help determine the risk of ICU admission as well as mortality in COPD patients at the time of hospitalization.