The association of serum albumin with 28 day mortality in critically ill patients undergoing dialysis: a secondary analysis based on the eICU collaborative research database.

Background: The relationship between serum albumin and prognosis in critically ill patients has been studied, however, there is a paucity of exploration into non-linear relationships, particularly in critically ill patients undergoing dialysis. This study intends to investigate the association between serum albumin (ALB) and 28 day mortality in critically ill patients undergoing dialysis.

Methods: We conducted a multi-center retrospective cohort study of patients undergoing dialysis by utilising data from the eICU Collaborative Research Database from 208 distinct ICUs across the United States between 2014 and 2015. The study focused on mortality within 28 days of ICU admission. We employed univariate analysis, multi-factor logistic regression, subgroup analysis, curve-fitting, and threshold effect analysis to examine the correlation between ALB levels and 28 day mortality.

Results: Among the 2,315 patients with a median age of 63 years, 205 (8.86%) died within 28 days of ICU admission. When ALB level was < 2.7 g/dL, the mortality decreased with an adjusted odds ratio (OR) of 0.34 (95% CI 0.22-0.51, P < 0.0001) for every 1 increment in the ALB. However, no significant mortality changes were observed when ALB levels were at or above this threshold.

Conclusion: Our study identifies a nonlinear dose-response relationship between serum ALB levels and 28 day mortality in critically ill patients undergoing dialysis, with a specific turning point observed. This finding underscores a significant negative correlation between ALB levels and mortality risk, with lower ALB levels being associated with higher mortality risk in this particular population.