title: Increasing mean arterial pressure during cardiac surgery does not reduce the rate of postoperative acute kidney injury.
abstract: BACKGROUND
  We hypothesized that the optimization of renal haemodynamics by maintaining a high level of mean arterial blood pressure (MAP) during cardiopulmonary bypass (CPB) could reduce the rate of acute kidney injury (AKI) in high-risk patients.
  
  
  METHODS
  In this randomized, controlled study, we enrolled 300 patients scheduled for elective cardiac surgery under cardiopulmonary bypass. All had known risk factors of AKI: serum creatinine clearance between 30 and 60 ml/min for 1.73 m(2) or two factors among the following: age >60 years, diabetes mellitus, diffuse atherosclerosis. After a standardized fluid loading, the MAP was maintained between 75-85 mmHg during CPB with norepinephrine (High Pressure, n=147) versus 50-60 mmHg in the Control (n=145). AKI was defined by a 30% increased of serum creatinine (sCr). We further tested others definitions for AKI: RIFLE classification, 50% rise of sCr and the need for haemodialysis.
  
  
  RESULTS
  The pressure endpoints were achieved in both the High Pressure (79 ± 6 mmHg) and the Control groups (60 ± 6 mmHg; p<0.001). The rate of AKI did not differ by group (17% vs. 17%; p=1), whatever the criteria used for AKI. The length of stay in hospital (9.5 days [7.9-11.2] vs. 8.2 [7.1-9.4]) and the rate of death at day 28 (2.1% vs. 3.4%) and at six months (3.4% vs. 4.8%) did not differ between the groups.
  
  
  CONCLUSIONS
  Maintaining a high level of MAP (on average) during normothermic CPB does not reduce the risk of postoperative AKI. It does not alter the length of hospital stay or the mortality rate.
authors.affiliation: Department of Anesthesia and Surgical Intensive Care, LUNAM Université, Université d'Angers, Angers, Larrey, France.
authors.forename: A
authors.initials: A
authors.lastname: Azau
authors.affiliation: Department of Anesthesia and Surgical Intensive Care, LUNAM Université, Université d'Angers, Angers, Larrey, France.
authors.forename: P
authors.initials: P
authors.lastname: Markowicz
authors.affiliation: Department of Anesthesia and Surgical Intensive Care, LUNAM Université, Université d'Angers, Angers, Larrey, France.
authors.forename: J J
authors.initials: JJ
authors.lastname: Corbeau
authors.affiliation: Department of Anesthesia and Surgical Intensive Care, LUNAM Université, Université d'Angers, Angers, Larrey, France.
authors.forename: C
authors.initials: C
authors.lastname: Cottineau
authors.affiliation: Department of Anesthesia and Surgical Intensive Care, LUNAM Université, Université d'Angers, Angers, Larrey, France.
authors.forename: X
authors.initials: X
authors.lastname: Moreau
authors.affiliation: Department of Cardiac Surgery, LUNAM Université, Université d'Angers, Angers, Larrey, France.
authors.forename: C
authors.initials: C
authors.lastname: Baufreton
authors.affiliation: Department of Anesthesia and Surgical Intensive Care, LUNAM Université, Université d'Angers, Angers, Larrey, France lbeydon.angers@invivo.edu.
authors.forename: L
authors.initials: L
authors.lastname: Beydon
mesh_terms: D058186:Acute Kidney Injury / Q000097:blood / Q000209:etiology / Q000401:mortality / Q000503:physiopathology; D000368:Aged; D000369:Aged, 80 and over; D062186:Arterial Pressure; D002315:Cardiopulmonary Bypass / Q000009:adverse effects*; D003324:Coronary Artery Disease / Q000097:blood / Q000401:mortality / Q000503:physiopathology / Q000601:surgery; D003920:Diabetes Mellitus / Q000097:blood / Q000401:mortality / Q000503:physiopathology / Q000601:surgery; D017558:Elective Surgical Procedures / Q000009:adverse effects*; D005260:Female; D006801:Humans; D007902:Length of Stay; D008297:Male; D011183:Postoperative Complications / Q000097:blood / Q000473:pathology / Q000503:physiopathology; D011446:Prospective Studies; D015996:Survival Rate
keywords: acute kidney injury; arterial pressure; cardiac surgery; cardiopulmonary bypass; primary prevention