title: The effect of pulsatile cardiopulmonary bypass on the need for haemofiltration in patients with renal dysfunction undergoing cardiac surgery.
abstract: The aim of our study was to investigate the effects of pulsatile cardiopulmonary bypass (CPB) on renal function and the need for haemofiltration in patients with preoperative renal impairment undergoing cardiac surgery.
  
  
  
  Clinical data were collected prospectively for patients undergoing cardiac surgery with pulsatile CPB (Group A, n=66) and compared to matched patients with standard non-pulsatile CPB (Group B, n=66). Patients included in the study had mild renal impairment and at least moderate risk from surgery as defined by logistic EuroSCORE. Emergency operations were excluded.
  
  
  
  Patients in Groups A and B had similar age (71 ± 10 versus 70 ± 10 years), sex distribution, mean preoperative renal function (creatinine clearance 63.9 ± 28 versus 67.7 ± 27.3 ml/min) and overall risk profile as predicted by the logistic EuroSCORE (8 ± 8.3 versus 11.05±13.3, p=0.122). Intraoperative variables were comparable with respect to bypass and cross-clamp times (96 ± 37 minutes and 64 ± 28 minutes versus 103 ± 40 minutes and 70 ± 33 minutes in Groups A and B, respectively). A smaller proportion of patients in Group A (4.5% versus 15%, p=0.076) required haemofiltration in the postoperative period. Postoperative mortality was low in both groups (Group A 1.54% versus Group B 3.03%, p=1.00).
  
  
  
  Within the limitations imposed by retrospective analyses, our study demonstrates that pulsatile CPB may confer a reno-protective effect in higher-risk patients with pre-existing mild renal dysfunction undergoing cardiac surgery.
authors.affiliation: Cardiothoracic Surgery, Papworth Hospital, Cambridge.
authors.forename: Shakil
authors.initials: S
authors.lastname: Farid
authors.affiliation: Cardiothoracic Surgery, Papworth Hospital, Cambridge.
authors.forename: Hannah
authors.initials: H
authors.lastname: Povey
authors.affiliation: Clinical Perfusion Services, Papworth Hospital, Cambridge.
authors.forename: Simon
authors.initials: S
authors.lastname: Anderson
authors.affiliation: Cardiothoracic Surgery, Papworth Hospital, Cambridge.
authors.forename: Samer A M
authors.initials: SA
authors.lastname: Nashef
authors.affiliation: Cardiothoracic Surgery, Papworth Hospital, Cambridge y.abuomar@nhs.net.
authors.forename: Yasir
authors.initials: Y
authors.lastname: Abu-Omar
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D006348:Cardiac Surgical Procedures; D002315:Cardiopulmonary Bypass; D005260:Female; D006440:Hemofiltration; D006801:Humans; D007668:Kidney / Q000503:physiopathology*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies
keywords: cardiac surgery; haemofiltration; pulsatile cardiopulmonary bypass; renal dysfunction; renal failure