title: Cystatin C and glomerular filtration rate in the cardiac surgery with cardiopulmonary bypass.
abstract: OBJECTIVE
  The aim of this study was to compare cystatin C versus creatinine as a marker for acute kidney injury in patients submitted to cardiac surgery with cardiopulmonary bypass.
  
  
  METHODS
  Fifty consecutive patients submitted to coronary artery bypass grafting were studied. Renal function was evaluated by serum cystatin C and creatinine. Blood samples were obtained from each patient at three time points: before operation, and on the first and fifth postoperative days. Glomerular filtration rate (GFR) was calculated by Cockcroft-Gault (CG), Modification of Diet in Renal Disease (MDRD), and Larsson (Cys-GFR) formulas.
  
  
  RESULTS
  Creatinine and GFR by CG and MDRD formulas did not show statistical difference between study times. After renal injury from surgery, there was an increase in cystatin C on the 1st and 5th day after surgery, being significantly different on the 5th postoperative (P<0.01). The GFR by Larson formula was higher in the preoperative time (105.2 +/- 41.0 ml/min) than in the 5th postoperative day (89.5+/- 31.5 ml/min; P<0.012).
  
  
  CONCLUSIONS
  The cystatin C and the Cys-GFR showed significant changes after cardiac surgery when compared with the creatinine and respective GFR calculated by the Cockcroft-Gault and MDRD formulas.
authors.affiliation: Department of Cardiovascular Surgery, FMB - UNESP, Botucatu - SP, Brazil. felicio@fmb.unesp.br
authors.forename: Marcello Laneza
authors.initials: ML
authors.lastname: Felicio
authors.forename: Rubens Ramos de
authors.initials: RR
authors.lastname: Andrade
authors.forename: Yara Marcondes Machado
authors.initials: YM
authors.lastname: Castiglia
authors.forename: Marcos Augusto de Moraes
authors.initials: MA
authors.lastname: Silva
authors.forename: Pedro Thadeu Galvão
authors.initials: PT
authors.lastname: Vianna
authors.forename: Antonio Sergio
authors.initials: AS
authors.lastname: Martins
mesh_terms: D058186:Acute Kidney Injury / Q000175:diagnosis* / Q000209:etiology; D015415:Biomarkers / Q000097:blood; D002315:Cardiopulmonary Bypass / Q000009:adverse effects*; D003404:Creatinine / Q000097:blood*; D055316:Cystatin C / Q000097:blood*; D005260:Female; D005919:Glomerular Filtration Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D013997:Time Factors
chemical_list: D015415:Biomarkers; D055316:Cystatin C; D003404:Creatinine