Six-hour lactate clearance outperforms initial lactate for predicting 28-day mortality in older emergency department patients with sepsis

Older adults with sepsis face a high risk of death, and emergency clinicians need early biomarkers to stratify that risk at the bedside. The work, published in BMC Emergency Medicine, also examined the lactate-to-albumin ratio (LAR) and found it performed substantially less well in this population.

The researchers enrolled patients aged 65 years or older who presented to the emergency department with sepsis between June and December 2023. Of 272 older adults screened, 223 met the eligibility criteria. The team measured initial serum lactate, serum albumin, and follow-up lactate levels at six and 24 hours. The primary outcome was 28-day all-cause mortality. Predictive performance was compared using area under the receiver operating characteristic curve (AUROC) analysis, with pairwise AUROC comparisons performed using the DeLong test in a complete-case analysis, and decision curve analysis (DCA) used to assess potential clinical benefit.

In the complete-case analysis of 176 patients, six-hour lactate clearance showed the highest discriminative performance, with an AUROC of 0.77 (95% confidence interval 0.66–0.87). This was comparable to 24-hour lactate clearance (AUROC 0.76) and six-hour LAR clearance (AUROC 0.76), and significantly better than initial lactate, which reached an AUROC of only 0.58 (p = 0.02). Initial LAR (AUROC 0.61) and 24-hour LAR clearance (AUROC 0.54) demonstrated limited discriminative performance.

Decision curve analysis added a clinically oriented perspective on which biomarker strategy might help decisions. The DCA showed greater net clinical benefit for identifying failure to achieve adequate lactate clearance, defined as less than 20%, at both six and 24 hours, compared with treat-all or treat-none strategies across clinical threshold probabilities of 10% to 27%. The authors concluded that dynamic lactate-based biomarkers, particularly six-hour lactate clearance, demonstrated good prognostic performance, and that DCA supported greater net clinical benefit for serial lactate monitoring in older patients with sepsis.

Several caveats frame these findings. The study was a single-center retrospective cohort with a modest complete-case sample of 176 patients, and the analysis relied on complete cases, which may introduce selection effects if missing follow-up lactate values were not random. The AUROC confidence interval for the leading measure is wide, spanning 0.66 to 0.87, so the precision of the estimate is limited. As an observational study, the results describe associations with 28-day mortality rather than proving that serial lactate monitoring changes outcomes; a decision curve analysis models potential net benefit under assumed threshold probabilities and does not by itself establish clinical effectiveness. The article was shared early as a peer-reviewed, accepted version subject to further edits before the final Version of Record.

Subject of Research: Prognostic value of lactate, lactate clearance and the lactate-to-albumin ratio for predicting 28-day mortality in older emergency department patients with sepsis.

Article Title: Prognostic value of lactate, lactate clearance, and lactate-to-albumin ratio for predicting 28-day mortality in older patients with sepsis in the emergency department

Article References: Sanguanwit, P., Tunkittiwanitkul, N., & Danpukdee, T. (2026). Prognostic value of lactate, lactate clearance, and lactate-to-albumin ratio for predicting 28-day mortality in older patients with sepsis in the emergency department. BMC Emergency Medicine. https://doi.org/10.1186/s12873-026-01825-z

Image Credits: AI Generated

DOI: 10.1186/s12873-026-01825-z

Keywords: sepsis, lactate clearance, lactate-to-albumin ratio, 28-day mortality, emergency department, older adults, risk stratification, biomarkers, AUROC, decision curve analysis, retrospective cohort, BMC Emergency Medicine