title: Isoflurane in contrast to propofol promotes fluid extravasation during cardiopulmonary bypass in pigs.
abstract: BACKGROUND
  A highly positive intraoperative fluid balance should be prevented as it negatively impacts patient outcome. Analysis of volume-kinetics has identified an increase in interstitial fluid volume after crystalloid fluid loading during isoflurane anesthesia. Isoflurane has also been associated with postoperative hypoxemia and may be associated with an increase in alveolar epithelial permeability, edema formation, and hindered oxygen exchange. In this article, the authors compare fluid extravasation rates before and during cardiopulmonary bypass (CPB) with isoflurane- versus propofol-based anesthesia.
  
  
  METHODS
  Fourteen pigs underwent 2 h of tepid CPB with propofol (P-group; n = 7) or isoflurane anesthesia (I-group; n = 7). Fluid requirements, plasma volume, colloid osmotic pressures in plasma and interstitial fluid, hematocrit levels, and total tissue water content were recorded, and fluid extravasation rates calculated.
  
  
  RESULTS
  Fluid extravasation rates increased in the I-group from the pre-CPB level of 0.27 (0.13) to 0.92 (0.36) ml·kg·min, but remained essentially unchanged in the P-group with significant between-group differences during CPB (pb = 0.002). The results are supported by corresponding changes in interstitial colloid osmotic pressure and total tissue water content.
  
  
  CONCLUSIONS
  During CPB, isoflurane, in contrast to propofol, significantly contributes to a general increase in fluid shifts from the intravascular to the interstitial space with edema formation and a possible negative impact on postoperative organ function.
authors.affiliation: * Research Fellow, Department of Anesthesia and Intensive Care, † Research Fellow, ‡ Research Assistant, § Associate Professor, Section for Thoracic Surgery, Department of Heart Disease, Haukeland University Hospital, Bergen, Norway. ‖ Post-doctor, Department of Anesthesia and Intensive Care, # Professor, Department of Clinical Medicine, University of Bergen, Haukeland University Hospital.
authors.forename: Hege Kristin
authors.initials: HK
authors.lastname: Brekke
authors.forename: Stig Morten
authors.initials: SM
authors.lastname: Hammersborg
authors.forename: Steinar
authors.initials: S
authors.lastname: Lundemoen
authors.forename: Arve
authors.initials: A
authors.lastname: Mongstad
authors.forename: Venny Lise
authors.initials: VL
authors.lastname: Kvalheim
authors.forename: Oddbjørn
authors.initials: O
authors.lastname: Haugen
authors.forename: Paul
authors.initials: P
authors.lastname: Husby
mesh_terms: D018685:Anesthetics, Inhalation / Q000494:pharmacology*; D018686:Anesthetics, Intravenous / Q000494:pharmacology*; D000818:Animals; D002315:Cardiopulmonary Bypass / Q000379:methods*; D004195:Disease Models, Animal; D004487:Edema / Q000139:chemically induced; D005260:Female; D005440:Fluid Therapy / Q000706:statistics & numerical data*; D006400:Hematocrit / Q000706:statistics & numerical data; D007530:Isoflurane / Q000494:pharmacology*; D007552:Isotonic Solutions / Q000008:administration & dosage; D008297:Male; D009997:Osmotic Pressure / Q000187:drug effects; D010953:Plasma Volume / Q000187:drug effects; D015742:Propofol / Q000494:pharmacology*; D000077331:Ringer's Solution; D013552:Swine
chemical_list: D018685:Anesthetics, Inhalation; D018686:Anesthetics, Intravenous; D007552:Isotonic Solutions; D000077331:Ringer's Solution; D007530:Isoflurane; D015742:Propofol