title: Cardiopulmonary bypass time as a risk factor for acute renal failure.
abstract: OBJECTIVE
  Acute renal failure following heart surgery is a major complication. The aim of this study was to evaluate if duration of cardiopulmonary bypass (CPB) is an important factor that influences kidney dysfunction.
  
  
  METHODS
  One hundred and sixteen patients from a single center referred for heart surgery were evaluated. Demographic factors, clinical data, operative and postoperative variables were evaluated. Serum creatinine and creatinine clearance were calculated until the fifth postoperative day. Acute renal failure was defined as the requirement of dialysis therapy. Patients were divided into two groups, the CPB<70min Group, patients with CPB duration equal to or less than 70 minutes and the CPB<90min Group, patients with CPB duration equal to or more than 90 minutes.
  
  
  RESULTS
  The median increases in serum creatinine were 0.18 + 0.41(CPB<70min) and 0.42 + 0.44 (CPB>90min p=0.005). Dialysis was indicated in 1.3% (CPB<70min) and 12.5% 90min - p = 0.018). The odds ratio for dialysis was 1.12 (95% CI; 1.00-1.20) for CPB>90min. There was no significant difference in mortality (5.2 versus 7.5%, p = 0.631).
  
  
  CONCLUSIONS
  The greatest likelihood of developing kidney failure after heart surgery is observed when CPB is at least 90 minutes, although creatinine clearance was not significantly altered between the groups studied.
authors.affiliation: Hospital de Base de Bauru, SP. taniguchi@sbccv.org.br
authors.forename: Fábio Papa
authors.initials: FP
authors.lastname: Taniguchi
authors.forename: Ademar Rosa de
authors.initials: AR
authors.lastname: Souza
authors.forename: Antonio Sérgio
authors.initials: AS
authors.lastname: Martins
mesh_terms: D058186:Acute Kidney Injury / Q000209:etiology*; D002315:Cardiopulmonary Bypass / Q000009:adverse effects*; D001026:Coronary Artery Bypass; D003404:Creatinine / Q000097:blood; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D006435:Renal Dialysis; D013997:Time Factors
chemical_list: D003404:Creatinine