Arihan, OkanWernly, BernhardLichtenauer, MichaelFranz, MarcusKabisch, BjoernMuessig, JohannaJung, Christian2025-05-102025-05-1020181932-620310.1371/journal.pone.01916972-s2.0-85041031473https://doi.org/10.1371/journal.pone.0191697https://hdl.handle.net/20.500.14720/7633Wernly, Bernhard/0000-0003-4024-0220; Masyuk, Maryna/0000-0003-2856-6893; Lichtenauer, Michael/0000-0001-8403-3931; Kelm, Malte/0000-0003-0060-1052; Jung, Christian/0000-0001-8325-250XPurpose Blood urea nitrogen (BUN) was reported to be associated with mortality in heart failure patients. We aimed to evaluate admission BUN concentration in a heterogeneous critically ill patient collective admitted to an intensive care unit (ICU) for prognostic relevance. Methods A total of 4176 medical patients (67 +/- 13 years) admitted to a German ICU between 2004 and 2009 were included. Follow-up of patients was performed retrospectively between May 2013 and November 2013. Association of admission BUN and both intra-hospital and longterm mortality were investigated by Cox regression. An optimal cut-off was calculated by means of the Youden-Index. Results Patients with higher admission BUN concentration were older, clinically sicker and had more pronounced laboratory signs of multi-organ failure including kidney failure. Admission BUN was associated with adverse long-term mortality (HR 1.013; 95% CI 1.012 +/- 1.014; p< 0.001). An optimal cut-off was calculated at 28 mg/dL which was associated with adverse outcome even after correction for APACHE2 (HR 1.89; 95% CI 1.59 +/- 2.26; p< 0.001), SAPS2 (HR 1.85; 95% CI 1.55 +/- 2.21; p< 0.001) and several parameters including creatinine in an integrative model (HR 3.34; 95% CI 2.89 +/- 3.86; p< 0.001). We matched 614 patients with admission BUN > 28 mg/dL to case-controls <= 28mg/dL corrected for APACHE2 scores: BUN above 28 mg/dL remained associated with adverse outcome in a paired analysis with the difference being 5.85% (95% CI 1.23 +/- 10.47%; p = 0.02). Conclusions High BUN concentration at admission was robustly associated with adverse outcome in critically ill patients admitted to an ICU, even after correction for co-founders including renal failure. BUN might constitute an independent, easily available and important parameter for risk stratification in the critically ill.eninfo:eu-repo/semantics/openAccessArticle131Q2Q129370259WOS:000423416600082