PLoS ONE (Jan 2018)

Blood Urea Nitrogen (BUN) is independently associated with mortality in critically ill patients admitted to ICU.

  • Okan Arihan,
  • Bernhard Wernly,
  • Michael Lichtenauer,
  • Marcus Franz,
  • Bjoern Kabisch,
  • Johanna Muessig,
  • Maryna Masyuk,
  • Alexander Lauten,
  • Paul Christian Schulze,
  • Uta C Hoppe,
  • Malte Kelm,
  • Christian Jung

DOI
https://doi.org/10.1371/journal.pone.0191697
Journal volume & issue
Vol. 13, no. 1
p. e0191697

Abstract

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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.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 long-term mortality were investigated by Cox regression. An optimal cut-off was calculated by means of the Youden-Index.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; p28 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).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.