title: Risk factors for failure of continuous veno-venous hemodialysis in the treatment of acute renal failure following cardiac surgery.
abstract: OBJECTIVE
  To evaluate the risk factors for failure of continuous veno-venous hemodialysis (CVVHD) in the treatment of acute renal failure (ARF) after cardiac surgery.
  
  
  METHODS
  Adult patients without any prior pre-operative history of chronic renal failure who underwent CVVHD after cardiac surgery in our medical center from January 2005 to December 2008 were divided into a success or a failure group. All selected patients' pre-, intra-, and post-operative data were retrospectively analyzed. ARF was described as post-operative urinary output of less than 0.5ml/kg/h and/or a 50% increase in baseline BUN and serum creatinine levels.
  
  
  RESULTS
  Fifty-two adult patients (accounting for 3.04%) who underwent CVVHD after cardiac surgery were entered into this study. Thirty-six patients survived, with a mortality rate of 30.8%. Pre-operative mean left ventricular ejection fraction (LVEF) in the success group was higher than that in the failure group (46±9% versus 40±7%, p=0.0220). Mean duration of oliguria until dialysis in the failure group was significantly longer than that in the success group (22.1±6.9h versus 11.6±2.5h, p<0.0001). Through univariate analysis and multivariate logistic regression, independent risk factors for failure of CVVHD in the treatment of post-operative ARF included pre-operative LVEF (OR=0.635, 95% CI 0.358-0.852) and duration of oliguria until dialysis (OR=2.442, 95% CI 1.563-5.768).
  
  
  CONCLUSIONS
  Pre-operative impaired left ventricular function is an important risk factor for failure of CVVHD in the treatment of ARF after cardiac surgery. The sooner CVVHD is instituted the better prognosis may be.
authors.affiliation: Dept. of Thoracic Cardiovascular Surgery of Tongji Hospital of Tongji University, Shanghai, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Ji
authors.forename: YunQing
authors.initials: Y
authors.lastname: Mei
authors.forename: XiSheng
authors.initials: X
authors.lastname: Wang
authors.forename: Jing
authors.initials: J
authors.lastname: Feng
authors.forename: JianZhi
authors.initials: J
authors.lastname: Cai
authors.forename: YiFeng
authors.initials: Y
authors.lastname: Sun
authors.forename: Wusha
authors.initials: W
authors.lastname: Dewei
mesh_terms: D058186:Acute Kidney Injury / Q000628:therapy*; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D006801:Humans; D009846:Oliguria; D011183:Postoperative Complications; D011379:Prognosis; D006435:Renal Dialysis / Q000592:standards*; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate; D017211:Treatment Failure; D016896:Treatment Outcome; D016277:Ventricular Function, Left