title: Arterial oxygenation and oxygen delivery after hemoglobin-based oxygen carrier infusion in canine hypovolemic shock: a dose-response study.
abstract: OBJECTIVE
  To compare effects of 6% hetastarch (Hextend) and hemoglobin-based oxygen carrier hemoglobin glutamer-200 (Hb-200) (bovine; Oxyglobin) on hemodynamics, arterial oxygen content, and systemic oxygen delivery in a canine hemorrhagic shock model.
  
  
  METHODS
  Randomized laboratory investigation.
  
  
  METHODS
  University surgical research facility.
  
  
  METHODS
  Twenty-four anesthetized healthy, adult, mongrel dogs (28 +/- 1 kg; 7 female, 17 male).
  
  
  METHODS
  Dogs were instrumented for determinations of heart rate, arterial, central venous, pulmonary arterial, and pulmonary arterial occlusion pressures, and cardiac index. Total solids, colloid oncotic pressure, arterial oxygen content, Hb, lactate, pH, and blood gases were analyzed in blood samples. Recordings were made before, after 1 hr of hemorrhagic shock, and immediately and 3 hrs after infusion of either 30 mL/kg hetastarch (group 1), 10 mL/kg Hb-200 + 20 mL/kg hetastarch (group 2), 20 mL/kg Hb-200 + 10 mL/kg hetastarch (group 3), or 30 mL/kg Hb-200 (group 4).
  
  
  RESULTS
  Hemorrhage (35 +/- 1 mL/kg) reduced mean arterial pressure to 50 mm Hg and caused significant decreases in total Hb, mean pulmonary arterial pressure, cardiac index and systemic oxygen delivery, increases in heart rate and systemic vascular resistance, and lactic acidosis. In group 1, hetastarch infusion was accompanied by increases of pulmonary arterial pressure, cardiac index, and blood oxygen extraction above baseline, and decreases of systemic vascular resistance, total Hb, total solids, arterial oxygen content, and systemic oxygen delivery below baseline (p <.05). Other data returned to baseline. In groups 2 to 4, hemodynamic functions (except pulmonary arterial pressure) recovered, yet neither total Hb (i.e., plasma and red blood cell Hb) nor arterial oxygen content increased despite increases in plasma Hb of 2 to 5 g/dL and proportionate increases in total solids. Systemic oxygen delivery improved dose-dependently with Hb-200 but did not return to baseline (p <.05), reaching values comparable to hetastarch group only at 30 mL/kg Hb-200. In all groups, oxygen extraction remained above baseline. Metabolic acidosis and lactatemia resolved significantly faster in groups 2 to 4, and colloid oncotic pressure after resuscitation was greater in groups 2 to 4 than in controls (p <.05).
  
  
  CONCLUSIONS
  In hemorrhagic shock, Hb-200 infusion may not improve oxygen delivery more than hetastarch, likely due to hemodilution caused by its high colloid oncotic pressure, but may facilitate diffusive oxygen transport to tissues.
authors.affiliation: School of Veterinary Medicine, Department of Clinical Studies, University of Pennsylvania, Kennett Square, PA, USA.
authors.forename: Bernd
authors.initials: B
authors.lastname: Driessen
authors.forename: Jonathan S
authors.initials: JS
authors.lastname: Jahr
authors.forename: Fedor
authors.initials: F
authors.lastname: Lurie
authors.forename: Mohammad S
authors.initials: MS
authors.lastname: Golkaryeh
authors.forename: Robert A
authors.initials: RA
authors.lastname: Gunther
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001802:Blood Substitutes / Q000494:pharmacology*; D004285:Dogs; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D006454:Hemoglobins; D006895:Hydroxyethyl Starch Derivatives / Q000494:pharmacology*; D008297:Male; D010100:Oxygen / Q000378:metabolism*; D011897:Random Allocation; D012769:Shock / Q000628:therapy*
chemical_list: D001802:Blood Substitutes; D006454:Hemoglobins; D006895:Hydroxyethyl Starch Derivatives; C402601:hemoglobin glutamer-200; D010100:Oxygen