title: Kinetic estimated glomerular filtration rate and acute kidney injury in cardiac surgery patients.
abstract: OBJECTIVE
  To determine how a formula to estimate kinetically changing glomerular filtration rate (keGFR) relates to serum creatinine changes and to compare the discriminatory ability of keGFR to that of perioperative change in serum creatinine to predict acute kidney injury (AKI) and mortality.
  
  
  METHODS
  Retrospective cohort study at a single-tertiary-care Midwestern university hospital of 4022 patients admitted to the intensive care unit between January 2006 and January 2012 immediately after cardiac surgery.
  
  
  RESULTS
  Of 4022 patients, 1031 (25.6%) developed at least AKI stage 1 and 1106 (27.5%) developed AKI-min. Patients who developed AKI stage 1 or AKI-min had a greater decrease in keGFR, both by absolute amounts and by percentage. After adjusting for other factors with logistic regression, keGFR had good discrimination (c statistic = 0.787 and 0.749, respectively) in predicting AKI and operative mortality.
  
  
  CONCLUSIONS
  Despite no change in immediate perioperative serum creatinine levels, keGFR fell and this predicted subsequent AKI. Using keGFR enables identification of patients who, despite unchanged postoperative creatinine, incur clinically significant kidney injury based on reduction in GFR and increased mortality.
authors.affiliation: Anesthesiology & Critical Care, Mayo Clinic, Rochester, MN.
authors.forename: Troy G
authors.initials: TG
authors.lastname: Seelhammer
authors.affiliation: University of Michigan, Ann Arbor, MI.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Maile
authors.affiliation: Anesthesiology & Critical Care, Mayo Clinic, Rochester, MN.
authors.forename: Michael
authors.initials: M
authors.lastname: Heung
authors.affiliation: University of Michigan, Ann Arbor, MI.
authors.forename: Jonathan W
authors.initials: JW
authors.lastname: Haft
authors.affiliation: University of Michigan, Ann Arbor, MI.
authors.forename: Elizabeth S
authors.initials: ES
authors.lastname: Jewell
authors.affiliation: University of Michigan, Ann Arbor, MI. Electronic address: engorenm@med.umich.edu.
authors.forename: Milo
authors.initials: M
authors.lastname: Engoren
mesh_terms: D058186:Acute Kidney Injury / Q000097:blood*; D000368:Aged; D006348:Cardiac Surgical Procedures / Q000401:mortality*; D015331:Cohort Studies; D015897:Comorbidity; D003404:Creatinine / Q000097:blood*; D003920:Diabetes Mellitus / Q000453:epidemiology; D005260:Female; D005919:Glomerular Filtration Rate; D006333:Heart Failure / Q000453:epidemiology; D006785:Hospitals, University; D006801:Humans; D006973:Hypertension / Q000453:epidemiology; D007677:Kidney Function Tests; D016015:Logistic Models; D008171:Lung Diseases / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000453:epidemiology; D011183:Postoperative Complications / Q000097:blood*; D012189:Retrospective Studies; D012307:Risk Factors; D062606:Tertiary Care Centers
chemical_list: D003404:Creatinine
keywords: Acute kidney injury; Cardiac surgery; Creatinine clearance; Glomerular filtration rate; Mortality; Prediction