Acartürk Tunçay E, et al. - Researchers sought to determine the utility of neutrophil-to-lymphocyte ratio (NLR) as an infectious exacerbation marker in patients with chronic respiratory failure (CRF) ascribed to COPD. Since NLR displayed simplicity and cost-effectiveness, it was considered as an attractive option as an exacerbation marker in COPD patients with CRF. In addition, considering antibiotic treatment was recommended in this group of patients with NLR ≥3.54, peripheral eosinophilia levels <2%, and subjective symptoms.