title: Profound haemodilution during normothermic cardiopulmonary bypass influences neither gastrointestinal permeability nor cytokine release in coronary artery bypass graft surgery.
abstract: BACKGROUND
  Cardiopulmonary bypass (CPB) impairs intestinal barrier function and induces systemic inflammation after cardiac surgery. The objective of this study was to evaluate the effect of profound haemodilution (haematocrit 19-21%) during normothermic CPB on gastrointestinal permeability and cytokine release in comparison with a standard haemodilution (haematocrit 24-26%).
  
  
  METHODS
  This was a prospective, controlled, randomized pilot trial of 60 patients without gastrointestinal disease undergoing normothermic CPB (35.5-36 degrees C) for coronary artery bypass graft surgery. Gastrointestinal permeability was measured by the triple-sugar technique (sucrose, lactulose, and mannitol excretion in urine) before and after CPB. Interleukin (IL)-6, IL-10, and tumour necrosis factor alpha (TNFalpha) were quantified using enzyme-linked immunosorbent assays.
  
  
  RESULTS
  Data from 59 patients (19-21% haematocrit, n=28; 24-26% haematocrit, n=31) were analysed. Data on gastrointestinal permeability were available for 47 patients (19-21% haematocrit, n=23; 24-26% haematocrit, n=24), blood samples for cytokine analysis from 59 patients. Mannitol excretion was normal before and after surgery without significant differences between the groups (after operation: 5.4% vs 2.9%, P=0.193). Lactulose and sucrose excretion was within a normal range before surgery and increased afterwards without differences between the groups. IL-6, IL-10, and TNFalpha were elevated after surgery, but there was no difference between the groups [IL-6 (P=0.78), IL-10 (P=0.74), and TNFalpha (P=0.67)].
  
  
  CONCLUSIONS
  Profound haemodilution during normothermic CPB brought about significant changes neither in intestinal permeability nor in cytokine release. It may be concluded that a haematocrit of 19-21% during normothermic CPB does not impair intestinal barrier function and cytokine response in patients without gastrointestinal comorbidity.
authors: Department of Anaesthesiology and Intensive Care Medicine, Charité-Universitätsmedizin Berlin, Campus Virchow-Klinikum and Campus Charité Mitte, Augustenburger Platz 1, 13353 Berlin, Germany.
authors: K
authors: K
authors: Berger
authors: M
authors: M
authors: Sander
authors: C D
authors: CD
authors: Spies
authors: L
authors: L
authors: Weymann
authors: S
authors: S
authors: Bühner
authors: H
authors: H
authors: Lochs
authors: K-D
authors: KD
authors: Wernecke
authors: C
authors: C
authors: von Heymann
mesh_terms: D000368:Aged; D001831:Body Temperature; D002315:Cardiopulmonary Bypass / Q000379:methods*; D001026:Coronary Artery Bypass / Q000379:methods*; D016207:Cytokines / Q000096:biosynthesis*; D004187:Disaccharides; D005260:Female; D041981:Gastrointestinal Tract / Q000503:physiopathology*; D006400:Hematocrit; D006438:Hemodilution / Q000379:methods*; D006801:Humans; D007408:Intestinal Absorption; D007430:Intraoperative Care / Q000379:methods; D008297:Male; D008875:Middle Aged; D010539:Permeability; D010865:Pilot Projects; D011446:Prospective Studies
chemical_list: D016207:Cytokines; D004187:Disaccharides