Delta Neutrophil Index and Other Hematologic Parameters in Acute Exacerbations of COPD: A Retrospective Study

<b>Background:</b> Chronic obstructive pulmonary disease (COPD) is an increasing cause of morbidity and mortality worldwide, and acute exacerbations are the major health issues in COPD patients. In this study, we aimed to investigate the role of the delta neutrophil index (DNI) with other hematologic parameters in managing and guiding COPD patients admitted with acute exacerbations. <b>Methods:</b> In this retrospective study, COPD patients treated internally in pulmonology clinic, intensive care unit, and anesthesiology and reanimation unit with acute exacerbation between May 2021 and December 2023 were investigated. Records from daily visits were evaluated retrospectively. Patients were divided into two groups according to the causative organism: bacterial or nonbacterial. <b>Results:</b> Patients with cardiac failure were found to have significantly higher median DNI values (<i>p</i> : 0.026), whereas patients with other comorbidities that were not individually recorded have substantially lower median DNI values (<i>p</i> : 0.026). White blood cell (WBC), neutrophil, immature granulocyte values (both absolute value and percent), thrombocyte, platelet-lymphocyte ratio (PLR), neutrophil-lymphocyte ratio (NLR), C-reactive protein (CRP), procalcitonin, positive blood culture, positive systemic inflammatory response syndrome (SIRS) criteria, and sepsis were significantly higher in patients with bacterial acute exacerbation. Hospitalization duration was also significantly longer in the same group (<i>p</i> : 0.006). No statistically significant correlation was found between median DNI values and early mortality rate (within 28 days), readmission within 30 days and 6 months. <b>Conclusion:</b> In this study, we have shown that the serum procalcitonin level, WBC, NLR, and PLR measurement can be used to distinguish bacterial and nonbacterial COPD exacerbations. The DNI revealed no prognostic predictive value regarding early mortality, mechanic ventilation need, or readmission in 30 days and 6 months.