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.