The blood lactate/serum albumin ratio might represent a good prognostic indicator of 28-day mortality in patients with acute respiratory distress syndrome: a retrospective observational study

Abstract

Abstract Background Acute respiratory distress syndrome (ARDS) is an acute inflammatory lung injury with a high mortality rate. However, previous ARDS prognostic scoring systems or predictors have been limited by complex formulas that are relatively expensive and inconvenient to obtain. Thus, this study aimed to explore the clinical significance of the blood lactate/serum albumin ratio (LAR) in assessing the prognosis of ARDS patients and compare it with other indicators related to 28-day mortality in ARDS patients. Methods We conducted a single-center retrospective study involving patients who fulfilled the Berlin definition of ARDS between 2016 and 2021. Clinical data were collected from medical records within 24 hours after ARDS diagnosis. The LAR, neutrophil-to-lymphocyte ratio, and monocyte-to-lymphocyte ratio (MLR) were calculated. The primary clinical outcome was 28-day mortality. The risk factors for 28-day mortality were determined using logistic regression analysis. The receiver operating characteristic curve was used to evaluate the area under the curve (AUC). Results A total of 276 ARDS patients met the inclusion criteria and were divided into surviving and nonsurviving groups according to 28-day mortality. There were significant differences in the Acute Physiologic Assessment and Chronic Health Evaluation II scores, Sequential Organ Failure Assessment scores, MLRs, and LARs between the surviving and nonsurviving groups. The AUC for the LAR was 0.790 (P < 0.001), whereas the AUCs for the Acute Physiologic Assessment and Chronic Health Evaluation II score, Sequential Organ Failure Assessment score, neutrophil-to-lymphocyte ratio, and MLR were 0.584, 0.599, 0.524, and 0.587, respectively. After grouping according to an LAR optimal cutoff value of 0.07, 28-day mortality was significantly higher in the high-LAR group than in the low-LAR group (47.18 vs 12.69, P < 0.001). Conclusions The LAR is an independent risk factor for 28-day mortality in ARDS patients and can be used to assess the severity of ARDS to a certain extent, making it superior to other commonly used indicators.