Abstract

Background: In this study, we investigated whether peripheral eosinophilia, demographic and other laboratory

parameters were effective on six-month mortality in chronic obstructive pulmonary disease (COPD) exacerbations

requiring hospitalization.

Methods: The study is a retrospective, observational study. Between January 2015 and November 2016, a total of 410

patients admitted to the emergency or outpatient services with COPD exacerbation were enrolled. Demographic

characteristics, baseline complete blood count (CBC) parameters, serum albumine, C-reactive protein levels and arterial

blood gas measurements and hospitalization durations were recorded. All hospital admission records up to 1 year before

hospitalization and for 6 months after discharge were reviewed. At the end of 6th month of follow-up, survivals were

investigated. Patients with ≥2% eosinophil ratio in CBC of peripheral blood were classified as eosinophilic COPD

exacerbations, and those with less than 2% eosinophil ratio were classified as neutrophilic exacerbation COPD

exacerbations. The characteristics of the patients with mortality and survived groups were compared.

Results: Of the 410 patients included in the study, 69% were male and mean age was 69 years (min-max: 37- 92 years).

Eighty-seven percent of hospitalizations were made via the emergency service. The mean duration of hospitalization was

6 days (min-max:1-26 days).The 6-month mortality rate after exacerbation was 19% (n=79). The survival rate of those

with peripheral eosinophilia was significantly better (p = 0.004).

Advanced age and male gender were the factors that increased mortality (p = 0.01, and p = 0.04, respectively).

Hemoglobin and serum albumine values were significantly lower (p = 0.001, for both) in the mortality group, while

charlson comorbidity index was significantly higher compared to those who survived (p =0.02). In addition, the number

of severe exacerbations 1 year before admission was higher in the mortality group (p =0.040). Independent variables

associated with mortality were advanced age (HR = 1.030, 95% CI = 1.008-1.054, p = 0.009), peripheral eosinophilia(HR= 0.415, 95% CI = 0.199-0.863, p = 0.018) and male gender (HR = 1.765, 95% CI = 1.023-3.045, p = 0.041).