Impact of hypoalbuminemia on mortality in critically ill patients requiring continuous renal replacement therapy

Background: This study aimed to assess the association of hypoalbuminemia with mortality in critically ill patients requiring continuous renal replacement therapy (CRRT). Methods: This is a retrospective cohort study of critically ill patients receiving CRRT from December 2006 through November 2015 in a tertiary referral hospital in the United States. We used logistic regression to assess serum albumin at CRRT initiation as predictors for 90-day mortality. Results: A total of 911 patients requiring CRRT were included in this study. The mean serum albumin at CRRT initiation was 3.0 ± 0.7 g/dL. The 90-day mortality was 57%. Serum albumin levels of ≤2.4, 2.5–2.9, 3.0–3.4, and ≥ 3.5 g/dL were noted in 24%, 29%, 24%, and 23% of patients, respectively. In adjusted analysis, serum albumin ≤2.4 g/dL compared with serum albumin of ≥3.5 g/dL was significantly associated with higher 90-day mortality with OR of 1.57 (95% CI 1.02–2.42). Serum albumin 2.5–2.9 and 3.0–3.4 g/dL were not associated with higher mortality. Sensitivity analysis in patients requiring CRRT in the setting of acute kidney injury showed consistent results. Conclusion: Approximately three out of four patients had hypoalbuminemia (<3.5 g/dL) at CRRT initiation. However, only severe hypoalbuminemia <2.5 g/dL was significantly associated with higher mortality.