title: Dopexamine improves liver oxygenation during crystalloid resuscitation from experimental hemorrhagic shock.
abstract: OBJECTIVE
  To evaluate the effects of dopexamine administration on hemodynamic variables and tissue oxygen tensions during crystalloid resuscitation from hemorrhagic shock.
  
  
  METHODS
  Randomized, control trial.
  
  
  METHODS
  An animal laboratory at a university center.
  
  
  METHODS
  Twelve piglets, mean weight 22 kg.
  
  
  METHODS
  The animals were anesthetized and bled to a state of hemorrhagic shock and resuscitated, using a crystalloid solution infused at a rate of approximately 2.6 mL/min/kg (total amount 208 mL/kg). Cardiac output and mean arterial pressure (MAP were measured as indicators of volume filling during the 20- to 30-min resuscitation period and during the follow-up period until 80 mins from the start of resuscitation. Dopexamine was administered by infusion at 6 micrograms/kg-min from the start of volume replacement (dopexamine group, n = 6). The rest of the animals (control group, n = 6) were given volume replacement only.
  
  
  RESULTS
  Systemic oxygen transport variables were calculated. Tissue oxygen tensions were continuously recorded from the liver, conjunctival layer, and via subcutaneous and transcutaneous electrodes in the abdominal region. MAP decreased from 119 +/- 2 (SEM) to 44 +/- 2 mm Hg and cardiac output decreased by 77% during the shock period. During resuscitation, cardiac output was restored in both groups. MAP increased close to the baseline during the early resuscitation period and decreased slowly during follow-up. Oxygen delivery remained at 46% of baseline, whereas systemic oxygen consumption was restored during resuscitation in both groups. Liver tissue oxygen tension increased well above baseline during resuscitation in the dopexamine group, and liver tissue oxygen tension was significantly higher than in the control group. After 60 mins of resuscitation, the liver oxygen tension decreased to control group values. None of the other tissue oxygen tensions showed any differences between groups.
  
  
  CONCLUSIONS
  Dopexamine administration during crystalloid resuscitation from hemorrhagic shock was well tolerated and resulted in significant and specific, although transient, improvement in liver oxygenation.
authors.affiliation: Fourth Department of Surgery, Helsinki University Hospital, Finland.
authors.forename: A
authors.initials: A
authors.lastname: Nordin
authors.forename: H
authors.initials: H
authors.lastname: Mäkisalo
authors.forename: L
authors.initials: L
authors.lastname: Mildh
authors.forename: K
authors.initials: K
authors.lastname: Höckerstedt
mesh_terms: D000318:Adrenergic beta-Agonists / Q000494:pharmacology* / Q000627:therapeutic use; D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D000077324:Crystalloid Solutions; D004195:Disease Models, Animal; D004298:Dopamine / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000627:therapeutic use; D007552:Isotonic Solutions; D008099:Liver / Q000187:drug effects* / Q000378:metabolism / Q000503:physiopathology; D008102:Liver Circulation; D010100:Oxygen / Q000378:metabolism*; D010952:Plasma Substitutes / Q000627:therapeutic use*; D011817:Rabbits; D011897:Random Allocation; D012151:Resuscitation / Q000379:methods*; D012771:Shock, Hemorrhagic / Q000378:metabolism / Q000503:physiopathology / Q000628:therapy*; D013552:Swine
chemical_list: D000318:Adrenergic beta-Agonists; D000077324:Crystalloid Solutions; D007552:Isotonic Solutions; D010952:Plasma Substitutes; C046318:dopexamine; D010100:Oxygen; D004298:Dopamine