title: Incidence and outcomes of acute kidney injury after cardiac surgery using either criteria of the RIFLE classification.
abstract: BACKGROUND
  Adult cardiac surgery is significantly associated with the development of acute kidney injury (AKI). Still, the incidence and outcomes of AKI vary according to its definition. Our retrospective monocentric study comparatively investigates the yield of RIFLE definition, which is based on the elevation of serum creatinine levels (SCr) or the reduction of urine output (UO), taking into account only one or both criteria. Pre- and per-operative risk factors for post-operative AKI were evaluated.
  
  
  METHODS
  All adult patients undergoing cardiac surgery, with or without cardiopulmonary bypass, from April 2008 to March 2009 were included. Clinical, biological and surgical features were recorded. Baseline serum creatinine was determined as its value on day 7 before surgery. Post-operative AKI was diagnosed and scored based upon the highest serum creatinine and/or the lowest urine output.
  
  
  RESULTS
  443 patients (Male/Female ratio, 2.3; median age, 69y) were included, with 221 (49.9%) developing postoperative AKI. Elevated serum creatinine (AKISCr) and oliguria (AKIUO) was observed in 9.7% and 40.2%, respectively. AKI patients had a significantly higher BMI and baseline SCr. In comparison to AKIUO, AKISCr mostly occurred in patients with co-morbidities, and was associated with an increased mortality at 1-year post surgery.
  
  
  CONCLUSIONS
  The use of standard RIFLE definition of AKI in a cohort of 443 patients undergoing cardiac surgery resulted in an incidence reaching 50%. Still, significant discrepancies were found between AKISCr and AKIUO regarding the incidence and outcomes. In line with previous reports, our data questions the utility of urine output as a criterion for AKI diagnosis and management after cardiac surgery.
authors.affiliation: Division of Cardio-vascular and Thoracic Surgery, ULg CHU, Liège, Belgium. mglagny@chu.ulg.ac.be.
authors.forename: Marc-Gilbert
authors.initials: MG
authors.lastname: Lagny
authors.affiliation: Division of Nephrology, University of Liège Hospital (ULg CHU), Avenue de l'Hôpital, 1, B-4000, Liège, Belgium. francois.jouret@chu.ulg.ac.be.
authors.forename: François
authors.initials: F
authors.lastname: Jouret
authors.affiliation: Department of Medical Informatics and Biostatistics, Public Health, ULg, Liège, Belgium. jnkoch@alumni.ulg.ac.be.
authors.forename: Jean-Noël
authors.initials: JN
authors.lastname: Koch
authors.affiliation: Division of Cardio-vascular and Thoracic Surgery, ULg CHU, Liège, Belgium. francine.blaffart@chu.ulg.ac.be.
authors.forename: Francine
authors.initials: F
authors.lastname: Blaffart
authors.affiliation: Department of Medical Informatics and Biostatistics, Public Health, ULg, Liège, Belgium. afdonneau@ulg.ac.be.
authors.forename: Anne-Françoise
authors.initials: AF
authors.lastname: Donneau
authors.affiliation: Department of Medical Informatics and Biostatistics, Public Health, ULg, Liège, Belgium. aalbert@ulg.ac.be.
authors.forename: Adelin
authors.initials: A
authors.lastname: Albert
authors.affiliation: Division of Anaesthesiology, ULg CHU, Liège, Belgium. loroediger@yahoo.fr.
authors.forename: Laurence
authors.initials: L
authors.lastname: Roediger
authors.affiliation: Division of Nephrology, University of Liège Hospital (ULg CHU), Avenue de l'Hôpital, 1, B-4000, Liège, Belgium. jm.krzesinski@chu.ulg.ac.be.
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Krzesinski
authors.affiliation: Division of Cardio-vascular and Thoracic Surgery, ULg CHU, Liège, Belgium. jo.Defraigne@chu.ulg.ac.be.
authors.forename: Jean-Olivier
authors.initials: JO
authors.lastname: Defraigne
mesh_terms: D058186:Acute Kidney Injury / Q000453:epidemiology* / Q000378:metabolism / Q000401:mortality; D000368:Aged; D006348:Cardiac Surgical Procedures; D015331:Cohort Studies; D015897:Comorbidity; D001026:Coronary Artery Bypass; D003324:Coronary Artery Disease / Q000601:surgery; D003404:Creatinine / Q000378:metabolism*; D005260:Female; D006349:Heart Valve Diseases / Q000601:surgery; D019918:Heart Valve Prosthesis Implantation; D006801:Humans; D006973:Hypertension / Q000453:epidemiology*; D007362:Intensive Care Units / Q000706:statistics & numerical data; D007902:Length of Stay / Q000706:statistics & numerical data; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D058386:Mitral Valve Annuloplasty; D009846:Oliguria / Q000453:epidemiology*; D011183:Postoperative Complications / Q000453:epidemiology* / Q000378:metabolism / Q000401:mortality; D012189:Retrospective Studies; D012307:Risk Factors
chemical_list: D003404:Creatinine