Abstract:Objective To investigate the clinical value of neutrophil/lymphocyte ratio (NLR) in predicting hypoxemia in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD). Methods A retrospective analysis was performed on the clinical data and laboratory indicators of 130 patients with AECOPD treated in the Second People's Hospital of Anhui Province from January 2020 to December 2021. Based on the arterial partial pressure of oxygen (PaO₂) level, the patients were divided into hypoxemia group (PaO₂<83 mm Hg, n=70) and non-hypoxemia group (PaO₂ ≥ 83 mm Hg, n=60). White blood cell count (WBC), neutrophil count (NEU), lymphocyte count (LYM), monocyte count (MC), platelet count (PLT), red blood cell distribution width (RDW), hypersensitive C-reactive protein (hs-CRP), albumin (ALB), and fibrinogen (FIB) were measured, and NLR was calculated in two groups. ROC curve was used to evaluate the predictive efficacy of hs-CRP, WBC, NLR and FIB in the diagnosis of hypoxemia. Logistic regression was used to analyze the correlation between NLR and hypoxemia. Results NLR in hypoxemia group was significantly higher than that in non-hypoxemia group (13.5±6.7 vs 3.9±1.7, P<0.01) and was negatively correlated with PaO₂ level (r=-0.549, P<0.01). The AUC of NLR for predicting hypoxemia was the largest, followed by hs-CRP, WBC and FIB. Low NLR was an independent risk factor for hypoxemia in patients with AECOPD (OR=15.102,95%CI:3.137-72.688, P=0.001). Conclusion NLR can be a potential biomarker for predicting hypoxemia in patients with AECOPD.