title: Changes in glomerular filtration rate after cardiac surgery with cardiopulmonary bypass in patients with mild preoperative renal dysfunction.
abstract: BACKGROUND
  Cardiac surgery with cardiopulmonary bypass (CPB) is commonly perceived as a risk factor for decline in renal function, especially in patients with preoperative renal dysfunction. There are few data on the effects of CPB on renal function in patients with mild preoperative renal dysfunction. The purpose of this study was to evaluate renal function in patients with pre-existing mild renal dysfunction undergoing cardiac surgery with CPB.
  
  
  METHODS
  In a multicentre study cohort we measured prospectively the glomerular filtration rate (GFR) by radioactive markers both before operation and on the 7th postoperative day in cardiac surgical patients with preoperative serum creatinine >120 micromol l(-1) (n=56). In a subgroup of patients (n=14) in addition to the GFR, the effective renal plasma flow (ERPF) and the filtration fraction (FF) were measured.
  
  
  RESULTS
  While preoperative GFR [77.9 (25.5) ml min(-1)] increased to 84.4 (23.7) ml min(-1) (P=0.005) 1 week after surgery, ERPF did not change [295.8 (75.2) ml min(-1) and 295.9 (75.9) ml min(-1), respectively; P=0.8]. In accordance, the FF increased from 0.27 (0.05) (before operation) to 0.30 (0.04) (Day 7, P=0.01).
  
  
  CONCLUSIONS
  Our results oppose the view that cardiac surgery with CPB adversely affects renal function in patients with preoperative mild renal dysfunction and an uncomplicated clinical course.
authors.affiliation: Cardiothoracic Intensive Care Unit, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands. b.loef@hccnet.nl
authors.forename: B G
authors.initials: BG
authors.lastname: Loef
authors.forename: R H
authors.initials: RH
authors.lastname: Henning
authors.forename: G
authors.initials: G
authors.lastname: Navis
authors.forename: A J
authors.initials: AJ
authors.lastname: Rankin
authors.forename: W
authors.initials: W
authors.lastname: van Oeveren
authors.forename: T
authors.initials: T
authors.lastname: Ebels
authors.forename: A H
authors.initials: AH
authors.lastname: Epema
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D002315:Cardiopulmonary Bypass / Q000009:adverse effects*; D003404:Creatinine / Q000097:blood; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007457:Iodine Radioisotopes; D007483:Iothalamic Acid; D007668:Kidney / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D011446:Prospective Studies; D051437:Renal Insufficiency / Q000150:complications* / Q000503:physiopathology; D017595:Renal Plasma Flow
chemical_list: D015415:Biomarkers; D007457:Iodine Radioisotopes; D007483:Iothalamic Acid; D003404:Creatinine