title: Cold-induced fluid extravasation during cardiopulmonary bypass in piglets can be counteracted by use of iso-oncotic prime.
abstract: OBJECTIVE
  Hypothermic cardiopulmonary bypass is associated with increased fluid extravasation. This study aimed to compare whether iso-oncotic priming solutions, in contrast to crystalloids, could reduce the cold-induced fluid extravasation during cardiopulmonary bypass in piglets.
  
  
  METHODS
  Three groups were studied: the control group (CT group; n = 10), the albumin group (Alb group; n = 7), and the hydroxyethyl starch group (HES group; n = 7). Prime (1000 mL) and supplemental fluid were acetated Ringer solution, 4% albumin, and 6% hydroxyethyl starch, respectively. After 1 hour of normothermic cardiopulmonary bypass, hypothermic cardiopulmonary bypass (cooling to 28 degrees C within 15 minutes) was initiated and continued to 90 minutes. Fluid needs, plasma volume, changes in colloid osmotic pressure in plasma and interstitial fluid, hematocrit levels, and tissue water content were recorded, and protein masses and fluid extravasation rates were calculated.
  
  
  RESULTS
  Colloid osmotic pressure in plasma decreased immediately after the start of cardiopulmonary bypass in the CT group but remained stable in the Alb and HES groups. Colloid osmotic pressure in interstitial fluid tended to decrease in the CT group and remained unchanged in the Alb group, whereas a slight increase was observed in the HES group. Immediately after the start of cooling, fluid extravasation rates increased from 0.15 +/- 0.10 to 0.64 +/- 0.12 mL . kg -1 . min -1 in the CT group, whereas no such increase was observed in the Alb and HES groups. The changes in fluid extravasation rates were reflected by corresponding changes in tissue water content.
  
  
  CONCLUSIONS
  The use of albumin or hydroxyethyl starch as prime to preserve the colloid osmotic pressure during cardiopulmonary bypass causes a reduction in the cold-induced fluid extravasation compared with that seen with crystalloids. Albumin seems more effective than hydroxyethyl starch to limit cold-induced fluid shifts during cardiopulmonary bypass.
authors.affiliation: Department of Anesthesia and Intensive Care, University of Bergen, Haukeland University Hospital, Bergen, Norway.
authors.forename: Marit
authors.initials: M
authors.lastname: Farstad
authors.forename: Venny Lise
authors.initials: VL
authors.lastname: Kvalheim
authors.forename: Paul
authors.initials: P
authors.lastname: Husby
mesh_terms: D000418:Albumins / Q000494:pharmacology; D000818:Animals; D002199:Capillary Permeability / Q000187:drug effects; D002315:Cardiopulmonary Bypass / Q000379:methods*; D000077324:Crystalloid Solutions; D045604:Extracellular Fluid / Q000187:drug effects; D006895:Hydroxyethyl Starch Derivatives / Q000494:pharmacology; D007036:Hypothermia, Induced / Q000379:methods*; D007552:Isotonic Solutions / Q000494:pharmacology; D008833:Microcirculation / Q000187:drug effects; D023421:Models, Animal; D009997:Osmotic Pressure / Q000187:drug effects; D010952:Plasma Substitutes / Q000494:pharmacology*; D013552:Swine; D014882:Water-Electrolyte Balance / Q000187:drug effects*
chemical_list: D000418:Albumins; D000077324:Crystalloid Solutions; D006895:Hydroxyethyl Starch Derivatives; D007552:Isotonic Solutions; D010952:Plasma Substitutes; C028570:Ringer's acetate