title: Pilot alternating treatment design study of the splanchnic metabolic effects of two mean arterial pressure targets during cardiopulmonary bypass.
abstract: BACKGROUND
  The arterial pressure target for optimal splanchnic function during cardiopulmonary bypass (CPB) is uncertain. Thus, we aimed to compare the effects of two different arterial pressure targets during CPB on trans-splanchnic oxygenation, acid-base regulation, and splanchnic interleukin-6 (IL-6) and interleukin-10 (IL-10) flux.
  
  
  METHODS
  Sixteen patients undergoing cardiac surgery with CPB in a university affiliated hospital were subjected to a prospective alternating treatment design interventional study. We measured arterial and hepatic vein blood gases, electrolytes, IL-6, and IL-10 while targeting a mean arterial pressure (MAP) of between 60 and 65 mm Hg for 30 min, a MAP of between 80 and 85 mm Hg for 30 min (using norepinephrine infusion), and finally 60-65 mm Hg MAP target for 30 min.
  
  
  RESULTS
  The MAP targets were achieved in all patients [65 (4), 84 (4), and 64 (3) mm Hg, respectively; P<0.001] with a greater dose of norepinephrine infusion during the higher MAP target (P<0.001). With longer time on CPB, hepatic vein O2 saturation decreased, while magnesium, lactate, glucose, IL-6, and IL-10 increased independent of MAP target. The decrease in hepatic vein saturation was greater as the temperature increased (re-warming). Overall, there was trans-splanchnic oxygen, chloride, lactate, and IL-6 removal during CPB (P<0.001) and carbon dioxide, bicarbonate, glucose, and IL-10 release (P<0.001). Such removal or release was not affected by the MAP target.
  
  
  CONCLUSIONS
  Targeting of a higher MAP during CPB by means of norepinephrine infusion did not affect splanchnic oxygenation, splanchnic acid-base regulation, or splanchnic IL-6 or IL-10 fluxes. Australian and New Zealand Clinical Trial Registry ACTRN 12611001107910.
authors.affiliation: Department of Anaesthesia, Austin Hospital, 145 Studley Road, Heidelberg, Melbourne, VIC 3084,Australia.
authors.forename: L
authors.initials: L
authors.lastname: McNicol
authors.forename: M
authors.initials: M
authors.lastname: Lipcsey
authors.forename: R
authors.initials: R
authors.lastname: Bellomo
authors.forename: F
authors.initials: F
authors.lastname: Parker
authors.forename: S
authors.initials: S
authors.lastname: Poustie
authors.forename: G
authors.initials: G
authors.lastname: Liu
authors.forename: A
authors.initials: A
authors.lastname: Kattula
mesh_terms: D000136:Acid-Base Equilibrium / Q000187:drug effects / Q000502:physiology; D000368:Aged; D000369:Aged, 80 and over; D062186:Arterial Pressure / Q000187:drug effects / Q000502:physiology*; D002245:Carbon Dioxide; D006348:Cardiac Surgical Procedures; D002315:Cardiopulmonary Bypass; D004305:Dose-Response Relationship, Drug; D005260:Female; D006503:Hepatic Veins / Q000378:metabolism; D006801:Humans; D016753:Interleukin-10 / Q000097:blood; D015850:Interleukin-6 / Q000097:blood; D007430:Intraoperative Care / Q000379:methods; D008297:Male; D008875:Middle Aged; D009638:Norepinephrine / Q000008:administration & dosage* / Q000494:pharmacology; D010100:Oxygen / Q000097:blood; D010865:Pilot Projects; D011446:Prospective Studies; D013152:Splanchnic Circulation / Q000187:drug effects / Q000502:physiology*; D014662:Vasoconstrictor Agents / Q000008:administration & dosage* / Q000494:pharmacology
chemical_list: D015850:Interleukin-6; D014662:Vasoconstrictor Agents; D016753:Interleukin-10; D002245:Carbon Dioxide; D010100:Oxygen; D009638:Norepinephrine