Relationship between lactate-to-albumin ratio and 28-day mortality in patients with exacerbation of chronic obstructive pulmonary disease admitted to the Intensive Care Unit

Aim To explore the predictive value of lactate-to-albumin ratio (LAR) on 28-day mortality in patients with exacerbation of chronic obstructive pulmonary disease (AECOPD) admitted to the Intensive Care Unit (ICU). Methods According to ICD-9 and ICD-10 diagnosis codes, patients diagnosed with AECOPD in the Medical Information Mart for Intensive Care IV (v.2.2) database were selected. The primary endpoint was 28-day mortality after ICU admission. We used receiver operating characteristic (ROC) curve, Kaplan-Meier (K-M) survival curve, logistic regression analyses and subgroup analysis to assess predictive power of LAR. Results 606 patients were included in this study. The 28-day mortality was 29.7%. The area under the ROC curves (AUC) for LAR were 0.641 [95% confidence interval (CI) 0.592-0.689], which was comparable with OASIS (AUC: 0.662; 95% CI 0.616-0.709; p = 0.471) and SOFA (AUC: 0.660; 95% CI 0.612-0.708; p = 0.500). The cutoff value of LAR was 0.645 by ROC curve. The high-LAR group showed a bad prognosis in K-M analysis (p < 0.001). Multivariate logistic regression shown that LAR was significantly associated with a poor outcome (odds ratio: 1.77; 95% CI 1.16-2.71; p = 0.008). Subgroup analysis showed no significant interaction of LAR with each subgroup (p for interaction: 0.175-0.775). Conclusion LAR is a rational and easily accessible marker, which is remarkably associated with 28-day mortality in ICU patients with AECOPD.