title: Miniaturized versus conventional cardiopulmonary bypass and acute kidney injury after cardiac surgery.
abstract: BACKGROUND
  Acute kidney injury (AKI) is a serious complication after coronary artery bypass grafting (CABG). There are conflicting reports whether a miniaturized cardiopulmonary bypass (MCPB) system is associated with a lower AKI incidence compared with conventional cardiopulmonary bypass (CCPB). It is unknown if AKI risk factors differ between the two groups. We assessed if MCPB decreases AKI after CABG and compared the risk factors between both groups.
  
  
  METHODS
  Sixty-eight Asian patients presenting for elective CABG at a tertiary heart centre were enrolled. They were randomly assigned to MCPB (n=34) or CCPB group (n=34) and followed up in a single-blinded, prospective, randomized, controlled trial. The primary outcome was Acute Kidney Injury Network stage 1 AKI.
  
  
  RESULTS
  The AKI incidence was 21.5% and was not significantly different between patients undergoing MCPB versus CCPB (21.9% versus 21.2%, p=0.948). The first CPB haematocrit was independently associated with AKI in the MCPB group (Relative Risk [RR]=0.484, 95% Confidence Interval [CI]=0.268-0.876, p=0.016); post-operative blood loss and inflammation were independently associated with AKI in the CCPB group (RR=1.005, 95%CI=1.003-1.007, p<0.001; RR=1.018, 95%CI=1.010-1.028, p<0.001).
  
  
  CONCLUSIONS
  The MCPB system is not associated with a lower incidence of AKI in Asian patients undergoing CABG. Risk factors for AKI differed between patients using the MCPB and CCPB systems.
authors.affiliation: Department of Anaesthesiology, Singapore General Hospital, Singapore Department of Cardiovascular and Metabolic Disorders, Duke-National University of Singapore Graduate Medical School, Singapore rnsctlk@gmail.com.
authors.forename: S T H
authors.initials: ST
authors.lastname: Chew
authors.affiliation: Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
authors.forename: R R G
authors.initials: RR
authors.lastname: Ng
authors.affiliation: Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
authors.forename: W
authors.initials: W
authors.lastname: Liu
authors.affiliation: Department of Cardiac, Thoracic and Vascular Surgery, National University Heart Centre, Singapore.
authors.forename: S G
authors.initials: SG
authors.lastname: Goh
authors.affiliation: Department of Cardiac, Thoracic and Vascular Surgery, National University Heart Centre, Singapore.
authors.forename: M G
authors.initials: MG
authors.lastname: Caleb
authors.affiliation: Yong Loo Lin School of Medicine, National University of Singapore, Singapore Department of Anaesthesia, National University Health System, Singapore.
authors.forename: L K
authors.initials: LK
authors.lastname: Ti
mesh_terms: D058186:Acute Kidney Injury / Q000209:etiology / Q000628:therapy; D000368:Aged; D002315:Cardiopulmonary Bypass / Q000295:instrumentation / Q000379:methods; D001026:Coronary Artery Bypass / Q000009:adverse effects*; D004311:Double-Blind Method; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D008904:Miniaturization; D011183:Postoperative Complications / Q000628:therapy*; D011446:Prospective Studies
keywords: acute kidney injury; cardiopulmonary bypass; coronary artery bypass grafting; miniaturized; risk factors