title: Microcirculatory effects of a hyperviscous hemoglobin-based solution administered intravenously in dogs with experimentally induced hemorrhagic shock.
abstract: OBJECTIVE
  To determine whether increasing the viscosity of a standard hemoglobin-based oxygen-carrying solution (HBOC) would offset its associated vasoconstrictive effects and result in improved microvascular perfusion in healthy splenectomized dogs with experimentally induced hemorrhagic shock.
  
  
  METHODS
  12 male American Foxhounds.
  
  
  METHODS
  Each dog underwent anesthesia and splenectomy. Shock was induced by controlled hemorrhage until a mean arterial blood pressure of 40 mm Hg was achieved and maintained for 60 minutes. Dogs were then randomly assigned to receive either a standard or hyperviscous HBOC (6 dogs/group). Sidestream dark-field microscopy was used to assess the effects of shock and HBOC administration on the microcirculation of the buccal mucosa and the jejunal serosa. Video recordings of the microcirculation were collected before shock was induced (baseline) and at intervals up to 180 minutes following HBOC administration. Vascular analysis software was used to compute microcirculatory variables.
  
  
  RESULTS
  Compared with baseline findings, hemorrhagic shock resulted in decreases in all microvascular variables in the buccal mucosa and the jejunal serosa. At all time points following HBOC administration, microvascular variables were similar to initial values and no significant differences between treatment groups were detected. At all time points following HBOC administration, blood and plasma viscosities in dogs treated with the hyperviscous solution were significantly higher than values in dogs receiving the standard solution.
  
  
  CONCLUSIONS
  In splenectomized dogs with experimentally induced hemorrhagic shock, administration of a hyperviscous HBOC did not significantly affect microvascular variables, compared with effects of a standard HBOC. Microcirculatory flow returned to baseline values in both treatment groups, suggesting that marked HBOC-associated vasoconstriction did not occur.
authors.affiliation: Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio, 43210.
authors.forename: Ann M
authors.initials: AM
authors.lastname: Peruski
authors.forename: Edward S
authors.initials: ES
authors.lastname: Cooper
authors.forename: Amy L
authors.initials: AL
authors.lastname: Butler
mesh_terms: D000818:Animals; D004285:Dogs; D006439:Hemodynamics; D006454:Hemoglobins / Q000008:administration & dosage / Q000737:chemistry* / Q000494:pharmacology*; D008297:Male; D008833:Microcirculation / Q000187:drug effects*; D012771:Shock, Hemorrhagic / Q000628:therapy*; D013156:Splenectomy; D014661:Vasoconstriction / Q000187:drug effects*; D014783:Viscosity
chemical_list: D006454:Hemoglobins; C402601:hemoglobin glutamer-200