Determination of the relationship between inflammatory markers and emergency department clinical course and mortality in patients admitted with COPD exacerbation

AIM: This study aimed to evaluate the relationship between complete blood count–derived inflammatory markers, including Neutrophil-to-Lymphocyte Ratio (NLR), Platelet-to-Lymphocyte Ratio (PLR), Monocyte-to-Lymphocyte Ratio (MLR), and composite inflammatory indices—Systemic Immune-Inflammation Index (SII), Systemic Inflammation Response Index (SIRI), Aggregate Systemic Inflammation Index (AISI), Pan-Immune-Inflammation Value (PIV), Multiple Inflammatory Index (MII)—and the emergency department clinical course, need for mechanical ventilation (MV), recurrent admissions, mortality in patients with acute exacerbation of Chronic Obstructive Pulmonary Disease (COPD). METHODS: This prospective observational study was conducted between January 1 and April 30, 2025. A total of 221 consecutive patients diagnosed with acute exacerbation of COPD according to the Global Initiative for Chronic Obstructive Lung Disease 2025 criteria were included. Demographic data, vital signs, modified Medical Research Council (mMRC) dyspnea scale scores, COPD Assessment Test (CAT) scores, and inflammatory markers calculated from laboratory data were recorded. Clinical outcomes included hospital admission, need for MV, 30-day readmission, and mortality. RESULTS: Of the patients, 51.6% were hospitalized and 11.3% developed 30-day mortality. Hospitalized patients had higher mMRC and CAT scores, neutrophil counts, NLR, and SII values, while oxygen saturation (SpO₂), pH, monocyte, and eosinophil levels were lower. Patients requiring MV showed higher mMRC, CAT, and NLR values. Patients with 30-day readmission had higher CAT scores, neutrophil counts, and lactate levels. In the mortality group, SpO₂, pH, hemoglobin levels were lower, whereas respiratory rate, glucose and PaCO₂ were higher. No significant association was observed between clinical outcomes and SIRI, AISI, PIV, MII. CONCLUSION: The findings indicate that NLR may be associated with hospital admission and the need for MV in COPD exacerbations, while SII appears to be related only to hospitalization decisions. Other composite inflammatory indices seem to have limited prognostic value. Larger studies with longer follow-up may help clarify their clinical relevance. Keywords: COPD, inflammation, NLR, SII