title: Impact of a new definition of acute kidney injury based on creatinine kinetics in cardiac surgery patients: a comparison with the RIFLE classification.
abstract: OBJECTIVE
  Acute kidney injury (AKI) after cardiac surgery is associated with adverse patient outcome. A new definition and staging system for AKI based on creatinine kinetics (CKs) has been proposed recently. Their proponents hypothesize that early absolute increases in serum creatinine (sCr) after kidney injury are superior to percentage increases, especially in patients with chronic kidney disease (CKD). The aims of our study were to measure agreement between CK definition and the current consensus definition [risk, injury, failure, loss and end-stage renal disease (RIFLE) system], and to compare time to diagnosis and prognostic value between both systems.
  
  
  METHODS
  Retrospective cohort study. Agreement on AKI diagnosis by both classifications, time to diagnosis and prognostic value of both systems were compared in cardiac surgeries performed during a 6-year period (2002-2007) in a single centre.
  
  
  RESULTS
  We found substantial agreement between both classifications (0.67). More patients were diagnosed with AKI by the CK definition than by RIFLE criteria both globally (28.2 vs 13.9%) and in every category (16.5 vs 8.4% for CK-1 vs RIFLE-R; 8.4 vs 3.6% for CK-2 vs RIFLE-I and 3.2 vs 2.0% for CK-3 vs RIFLE-F). Time to diagnosis was shorter for the CK definition (1.8 vs 2.5 days). Prognostic value in terms of information about in-hospital death and need for renal replacement was comparable between classifications.
  
  
  CONCLUSIONS
  In cardiac surgery, the CK definition and classification system showed substantial agreement with the current standard, was more sensitive than RIFLE and detected AKI earlier without loss of prognostic information.
authors.affiliation: Departments of Cardiac Surgery, Hospital Universitario Ramón y Cajal, IRYCIS, Madrid, Spain European University of Madrid, Madrid, Spain josemanuel.garrido@salud.madrid.org jmgarridoccv@gmail.com.
authors.forename: Jose M
authors.initials: JM
authors.lastname: Garrido
authors.affiliation: Anaesthesia and Reanimation, Hospital Universitario Ramón y Cajal, IRYCIS, Madrid, Spain CIFRA Consorcio FRA Comunidad de Madrid, Madrid, Spain.
authors.forename: Angel M
authors.initials: AM
authors.lastname: Candela-Toha
authors.affiliation: Anaesthesia and Reanimation, Hospital Universitario Ramón y Cajal, IRYCIS, Madrid, Spain.
authors.forename: Diego
authors.initials: D
authors.lastname: Parise-Roux
authors.affiliation: CIFRA Consorcio FRA Comunidad de Madrid, Madrid, Spain Nephrology, Hospital Universitario Ramón y Cajal, IRYCIS, Madrid, Spain.
authors.forename: Mayte
authors.initials: M
authors.lastname: Tenorio
authors.affiliation: Clinical BIostatistics Unit, Hospital Universitario Ramón y Cajal, IRYCIS, Madrid, Spain CIBER Epidemiología y Salud Pública, Madrid, Spain.
authors.forename: Victor
authors.initials: V
authors.lastname: Abraira
authors.affiliation: CIFRA Consorcio FRA Comunidad de Madrid, Madrid, Spain Biochemistry, Hospital Universitario Ramón y Cajal, IRYCIS, Madrid, Spain.
authors.forename: Jose M
authors.initials: JM
authors.lastname: Del Rey
authors.affiliation: Anaesthesia and Reanimation, Hospital Universitario Ramón y Cajal, IRYCIS, Madrid, Spain.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Prada
authors.affiliation: Departments of Cardiac Surgery, Hospital Universitario Ramón y Cajal, IRYCIS, Madrid, Spain.
authors.forename: Andrea
authors.initials: A
authors.lastname: Ferreiro
authors.affiliation: CIFRA Consorcio FRA Comunidad de Madrid, Madrid, Spain Nephrology, Hospital Universitario Ramón y Cajal, IRYCIS, Madrid, Spain Department of Medicine, School of Medicine, Universidad de Alcalá de Henares, Madrid, Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: Liaño
mesh_terms: D058186:Acute Kidney Injury / Q000145:classification* / Q000175:diagnosis / Q000209:etiology; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D003404:Creatinine / Q000097:blood*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007677:Kidney Function Tests; D008297:Male; D011183:Postoperative Complications; D011379:Prognosis; D012189:Retrospective Studies; D012720:Severity of Illness Index; D013997:Time Factors
chemical_list: D003404:Creatinine
keywords: Acute kidney injury; Cardiac surgery; Cardiac surgery outcomes; Complications