title: Microcirculatory parameters after isotonic and hypertonic colloidal fluid resuscitation in acute hemorrhagic shock.
abstract: BACKGROUND
  Volume resuscitation is one of the primary therapeutic goals in hemorrhagic shock, but data on microcirculatory effects of different colloidal fluid resuscitation regimen are sparse. We investigated sublingual mucosal microcirculatory parameters during hemorrhage and after fluid resuscitation with gelatin, hydroxyethyl starch, or hypertonic saline and hydroxyethyl starch in pigs.
  
  
  METHODS
  To induce hemorrhagic shock, 60% of calculated blood volume was withdrawn. Microvascular blood flow was assessed by laser Doppler velocimetry. Microcirculatory hemoglobin oxygen saturation was measured with a tissue reflectance spectrophotometry, and side darkfield imaging was used to visualize the microcirculation and to quantify the flow quality. Systemic hemodynamic variables, systemic acid base and blood gas variables, and lactate measurements were recorded. Measurements were performed at baseline, after hemorrhage, and after fluid resuscitation with a fixed volume regimen.
  
  
  RESULTS
  Systemic hemodynamic parameters returned or even exceeded to baseline values in all three groups after fluid resuscitation, but showed significantly higher filling pressures and cardiac output values in animals treated with isotonic colloids. Microcirculatory parameters determined in gelatin and hydroxyethyl starch resuscitated animals, and almost all parameters except microvascular hemoglobin oxygen saturation in animals treated with hypertonic saline and hydroxyethyl starch, were restored after treatment.
  
  
  CONCLUSIONS
  Hemorrhaged pigs can be hemodynamically stabilized with either isotonic or hypertonic colloidal fluids. The main finding is an adequate restoration of sublingual microcirculatory blood flow and flow quality in all three study groups, but only gelatin and hydroxyethyl starch improved microvascular hemoglobin oxygen saturation, indicating some inadequate oxygen supply/demand ratio maybe due to a better restoration of systemic hemodynamics in isotonic colloidal resuscitated animals.
authors.affiliation: Department of Anesthesiology and Critical Care Medicine, Innsbruck Medical University, Innsbruck, Austria.
authors.forename: Stephan
authors.initials: S
authors.lastname: Maier
authors.forename: Carmen
authors.initials: C
authors.lastname: Holz-Hölzl
authors.forename: Werner
authors.initials: W
authors.lastname: Pajk
authors.forename: Hanno
authors.initials: H
authors.lastname: Ulmer
authors.forename: Christian
authors.initials: C
authors.lastname: Hengl
authors.forename: Martin
authors.initials: M
authors.lastname: Dünser
authors.forename: Thorsten
authors.initials: T
authors.lastname: Haas
authors.forename: Corinna
authors.initials: C
authors.lastname: Velik-Salchner
authors.forename: Dietmar
authors.initials: D
authors.lastname: Fries
authors.forename: Andreas
authors.initials: A
authors.lastname: Greiner
authors.forename: Walter
authors.initials: W
authors.lastname: Hasibeder
authors.forename: Hans
authors.initials: H
authors.lastname: Knotzer
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D003102:Colloids / Q000494:pharmacology; D005440:Fluid Therapy / Q000379:methods*; D005780:Gelatin / Q000494:pharmacology; D006439:Hemodynamics; D006895:Hydroxyethyl Starch Derivatives / Q000494:pharmacology; D008833:Microcirculation / Q000502:physiology*; D009060:Mouth Floor / Q000098:blood supply*; D012151:Resuscitation / Q000379:methods; D012462:Saline Solution, Hypertonic / Q000494:pharmacology; D012771:Shock, Hemorrhagic / Q000503:physiopathology* / Q000628:therapy*; D013552:Swine
chemical_list: D003102:Colloids; D006895:Hydroxyethyl Starch Derivatives; D012462:Saline Solution, Hypertonic; D005780:Gelatin