Front Med (Lausanne). 2025 Nov 12;12:1607191. doi: 10.3389/fmed.2025.1607191. eCollection 2025.
ABSTRACT
BACKGROUND AND AIMS: The relationship between serum bicarbonate levels and 28-day mortality in dialysis patients remains unclear. This study aimed to investigate the association between serum bicarbonate levels and short-term mortality in patients undergoing dialysis.
METHODS: This multicenter retrospective cohort study included 4,979 dialysis patients aged 18 years or older from the electronic Intensive Care Unit (eICU) Collaborative Research Database (2014-2015). Serum bicarbonate levels were measured within 24 h of ICU admission. A multivariate Cox regression model was applied to evaluate the association between serum bicarbonate levels and 28-day mortality.
RESULTS: A total of 4,979 patients were analyzed, with a median age of 63 years. Among them, 513 patients (10.3%) died within 28 days. A significant non-linear relationship was observed between serum bicarbonate levels and mortality. Using a two-segment linear regression model, the inflection point was determined to be 30 mmol/L (log-likelihood ratio test, p = 0.029). Below this threshold, serum bicarbonate was inversely associated with 28-day mortality (OR = 0.89, 95% CI: 0.86-0.92, p < 0.0001). Above the threshold, the association was not statistically significant (OR = 1.11, 95% CI: 0.97-1.28, P = 0.1278).
CONCLUSION: Serum bicarbonate levels are non-linearly associated with 28-day mortality in dialysis patients. Levels below 30 mmol/L are linked to an increased risk of death. These findings need to be confirmed in future prospective studies.
PMID:41312462 | PMC:PMC12647071 | DOI:10.3389/fmed.2025.1607191
