Association of lactate dehydrogenase to albumin ratio with new-onset acute respiratory distress syndrome and all-cause mortality in patients with sepsis: a retrospective cohort study based on the MIMIC-IV database.

objectiveThe lactate dehydrogenase (LDH)-to-albumin (ALB) ratio (LDAR) has been widely recognized as a prognostic biomarker; however, its association with the incidence of new-onset acute respiratory distress syndrome (ARDS) and subsequent outcomes among patients with sepsis remains insufficiently characterized. This study utilized data from the Medical Information Mart for Intensive Care-IV(MIMIC-IV)database to elucidate the relationship between LDAR and the occurrence of ARDS, as well as short- and long-term mortality, in individuals with sepsis.

methodsAdult patients diagnosed with sepsis were identified from the MIMIC-IV database. Participants were stratified into quartiles based on log₂-transformed LDAR (log₂LDAR). Multivariable logistic regression and restricted cubic spline (RCS) analyses were employed to evaluate the association between log₂LDAR and new-onset ARDS. Among patients with ARDS, Cox proportional hazards models and RCS analyses were applied to examine the association between log₂LDAR and all-cause mortality (ACM). The primary endpoint was the occurrence of new-onset ARDS; secondary endpoints included 30-day, 90-day, and one-year ACM.

results2,775 septic patients were included, with an incidence of new-onset ARDS of 40.39% (1,121/2,775). After adjustment for potential confounders, patients in the highest quartile of log₂LDAR (Q4) demonstrated a markedly higher likelihood of developing ARDS compared with those in the lowest quartile (Q1) (OR = 1.529, 95% CI: 1.165–2.009, p = 0.002). RCS analysis revealed a linear positive association between log₂LDAR and ARDS occurrence. Among patients with ARDS, elevated log₂LDAR was associated with increased mortality risk: as a continuous variable, it was correlated with 30-day (HR = 1.169, 95% CI: 1.064–1.284, p < 0.001), 90-day, and one-year ACM; as a categorical variable, the 30-day ACM risk in the highest quartile was 2.125-fold that of the lowest quartile (HR = 2.125, 95% CI: 1.464–3.086, p < 0.001), with similar trends observed for 90-day and one-year ACM. RCS analysis indicated a nonlinear relationship between log₂LDAR and ACM. Subgroup analyses and sensitivity analyses excluding patients who developed ARDS within 6 h of intensive care unit (ICU) admission further confirmed the robustness of the aforementioned associations.

conclusionAn elevated LDAR represents an important indicator of increased ARDS risk among patients with sepsis and is associated with unfavorable short- and long-term survival outcomes in those with sepsis-associated ARDS.

trial registrationNot applicable. CLINICAL TRIAL NUMBER: Not applicable.