title: High dose propofol enhances red cell antioxidant capacity during CPB in humans.
abstract: OBJECTIVE
  To compare low vs. high dose propofol and isoflurane on red cell RBC antioxidant capacity in patients during aortocoronary bypass surgery (ACBP).
  
  
  METHODS
  Twenty-one patients, for ACBP, were anesthetized with sufentanil 0.5-10 microg x kg(-1) and isoflurane 0-2%; ISO = control; n = 7), or sufentanil 0.3 microg x kg(-1), propofol 1-2.5 mg x kg(-1) bolus then 100 microg x kg(-1) min(-1) before, and 50 microg x kg(-1) x min(-1) during CPB (LO; n = 7), or sufentanil 0.3 microg x kg(-1), propofol 2-2.5 mg x kg(-1) bolus then 200 microg x kg(-1) x min(-1) (HI; n = 7). Venous blood was drawn pre- and post-induction, after 30 min CPB, 5, 10, and 30 min of reperfusion, and 120 min post-CPB to measure red cell antioxidant capacity (malondialdehyde (MDA) production in response to oxidative challenge with t-butyl hydrogen peroxide) and plasma propofol concentration. Pre- induction blood samples were analyzed for antioxidant effects of nitrates on red cells. The tBHP concentration response curves for RBC MDA in ISO, LO and HI were determined.
  
  
  RESULTS
  Preoperative nitrate therapy did not effect RBC MDA production. Perioperative RBC MDA production was similar in ISO and LO groups. Sustained intraoperative decrease in RBC MDA was seen with propofol 8.0+/-2.4 - 11.8+/-4.5 microg x ml(-1) in HI (P<0.05-0.0001). MDA production vs. log plasma propofol concentration was linear in HI dose.
  
  
  CONCLUSIONS
  During CPB, RBC antioxidant capacity is enhanced and maintained with HI dose propofol. Propofol, at this dose, may prove useful in protecting against cardiopulmonary ischemia-reperfusion injury associated with ACBP.
authors.affiliation: Department of Anaesthesia, University of British Columbia, Vancouver, Canada. daansley@unixg.ubc.ca
authors.forename: D M
authors.initials: DM
authors.lastname: Ansley
authors.forename: J
authors.initials: J
authors.lastname: Sun
authors.forename: W A
authors.initials: WA
authors.lastname: Visser
authors.forename: J
authors.initials: J
authors.lastname: Dolman
authors.forename: D V
authors.initials: DV
authors.lastname: Godin
authors.forename: M E
authors.initials: ME
authors.lastname: Garnett
authors.forename: A K
authors.initials: AK
authors.lastname: Qayumi
mesh_terms: D000328:Adult; D000368:Aged; D018686:Anesthetics, Intravenous / Q000494:pharmacology*; D000975:Antioxidants / Q000494:pharmacology*; D002315:Cardiopulmonary Bypass; D004912:Erythrocytes / Q000187:drug effects* / Q000378:metabolism; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D015227:Lipid Peroxidation / Q000187:drug effects; D008297:Male; D008315:Malondialdehyde / Q000032:analysis; D008875:Middle Aged; D015742:Propofol / Q000494:pharmacology*
chemical_list: D018686:Anesthetics, Intravenous; D000975:Antioxidants; D008315:Malondialdehyde; D015742:Propofol