The prognostic utility of Lactate/Albumin*Age score in septic patient with normal lactate level.

ABSTRACT

Background: A previous study has shown that the lactate/albumin*age (LAA) score is useful for predicting mortality in patients with sepsis admitted to the ICU. We aimed to evaluate the clinical significance of the LAA score in patients with sepsis who presented to the emergency department (ED). Methods: This retrospective observational study used data from the Korean Shock Society Registry collected between January 2017 and December 2021. The prognostic performance of the LAA score for predicting the 28-day mortality was evaluated. Lactate and albumin levels were measured immediately after arrival to the ED. Results: Of the 5346 patients with sepsis, data from 3240 were analyzed. The area under the receiver operating characteristic curve (AUROC) of the LAA score (0.737, 95 % confidence interval (CI) 0.716-0.757), was higher than that of lactate (0.699, 95 % CI 0.677-0.720, p < 0.001), lactate/albumin (LA) ratio (0.730, 95 % CI 0.709-0.751, p = 0.016), and Sequential Organ Failure Assessment (SOFA) score (0.698, 95 % confidence interval 0.676-0.720, p = 0. 004), and Acute Physiology and Chronic Health Evaluation (APACHE) II scores (0.672; 95 % confidence interval 0.649-0.694, p < 0.001). The optimal cut-off value for the LAA score was 119.9. In the Kaplan-Meier analysis according to the optimal cutoff value, the 28-day mortality rates were higher in the high LAA score group (log-rank test, p < 0.001). The LAA score was independently associated with 28-day mortality in the multivariate Cox proportional hazards model (adjusted hazard ratio 2.07, 95 % CI 1.76-2.43, p < 0.001). In the normal (<2 mmol/L) lactate group, the AUROC value for LAA score was higher than LA ratio (normal group 0.674 vs 0.634, p < 0.004). In patients over 65 years old, LAA score (0.731) showed a higher AUROC value than LA ratio (0.725). (p < 0.001). Conclusion: The LAA score may be used as an independent predictor of mortality in patients with sepsis in the emergency department. Our results show that it performs better than serum lactate alone, LA ratio, and SOFA and APACHE II scores. While this suggests that the LAA could provide clinicians with a useful tool for timely early intervention and care planning in patients with a poor prognosis, further validation in large multicenter prospective studies are necessary to confirm its reliability and practicality as a readily available and objective biomarker.