Microcirculatory parameters after isotonic and hypertonic colloidal fluid resuscitation in acute hemorrhagic shock.
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To induce hemorrhagic shock, 60% of calculated blood volume was withdrawn.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.
Maier
Stephan
S
Department of Anesthesiology and Critical Care Medicine, Innsbruck Medical University, Innsbruck, Austria.
Holz-Hölzl
Carmen
C
Pajk
Werner
W
Ulmer
Hanno
H
Hengl
Christian
C
Dünser
Martin
M
Haas
Thorsten
T
Velik-Salchner
Corinna
C
Fries
Dietmar
D
Greiner
Andreas
A
Hasibeder
Walter
W
Knotzer
Hans
H
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
D003102:Colloids; D006895:Hydroxyethyl Starch Derivatives; D012462:Saline Solution, Hypertonic; D005780:Gelatin