Xiao-Hua Zhang,1,2 Ming-Feng Han,2 Xiao-Bao Teng,2 Jing-Feng Shi,2 Xiao-Ling Xu1,3 

1Cheeloo College of Medicine, Shandong University, Jinan, 250000, Shandong, People’s Republic of China; 2Department of Respiratory and Critical Care Medicine, The Second People’s Hospital of Fuyang City, Fuyang, Anhui, 236015, People’s Republic of China; 3Department of Respiratory and Critical Care Medicine, the First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, 230001, People’s Republic of China

Correspondence: Xiao-Ling Xu, Cheeloo College of Medicine, Shandong University, No. 44 of Wenhua West Road, Lixia District, Jinan, Shandong, 250000, People’s Republic of China, Tel +86 18963789002, Email xxlahh08@163.com

Objective: This study aimed to assess the predictive value of the neutrophil-lymphocyte ratio (NLR), C-reactive protein/albumin ratio (CAR), and serum amyloid A (SAA) in predicting acute exacerbations of chronic obstructive pulmonary disease (AECOPD) complicated by respiratory failure (RF).
Methods: A retrospective study was conducted on 198 patients with AECOPD in the Respiratory Department of No. 2 People’s Hospital of Fuyang City from December 2022 to May 2023. Patients were categorized into two groups: an experimental group with the presence of RF (n = 70) and a control group with no RF present (n = 128). Baseline characteristics and inflammatory marker levels were compared between the two groups, and their impact on the risk of readmission within one year was analyzed to assess the predictive value of NLR, CAR, and SAA in patients with AECOPD and RF.
Results: The experimental group exhibited significantly higher levels of white blood cells, neutrophils, C-reactive protein (CRP), SAA, NLR, and CAR compared to the control group. Additionally, the experimental group had a higher one-year readmission rate, with statistically significant differences. The areas under the receiver operating characteristic (ROC) curve for NLR, CAR, and SAA in predicting AECOPD with RF were 0.705, 0.659, and 0.656, respectively. When combined, the ROC area under the curve for these three markers increased to 0.717, which was statistically significant.
Conclusion: The combined assessment of NLR, CAR, and SAA offers a reliable reflection of systemic inflammation and holds predictive value for AECOPD with RF.

Keywords: acute exacerbation of chronic obstructive pulmonary disease, C-reactive protein/albumin ratio, neutrophil-lymphocyte ratio, predictive value, serum amyloid A