Effects of colloid solutions on ischemia-reperfusion-induced periosteal microcirculatory and inflammatory reactions: comparison of dextran, gelatin, and hydroxyethyl starch.

OBJECTIVE: To compare the microhemodynamics and possible anti-inflammatory reactions of colloid resuscitation with 4% gelatin, 6% dextran, or 6% hydroxyethyl starch 130/0.4 solutions. DESIGN AND SETTING: A randomized control in vivo animal study in a university research laboratory. ANIMALS: Adult male Wistar rats (280 +/- 20 g). INTERVENTIONS: Sodium pentobarbital-anesthetized animals were subjected to a 60-min complete hindlimb ischemia and a 180-min reperfusion. Volume resuscitation, either with a colloid (dextran, gelatin, or hydroxyethyl starch, 25 mL kg(-1) during 3 hr intravenously) or with lactated Ringer's solution, was initiated 10 min before reperfusion. Fluorescence intravital videomicroscopy was performed before ischemia and 30, 60, 120, and 180 min postresuscitation to quantify the tibial periosteal functional capillary density, the capillary red blood cell velocity changes, and leukocyte rolling and firm adherence in postcapillary venules. In a separate series blood samples were drawn to determine the release of soluble intercellular adhesion molecule-1 (enzyme-linked immunosorbent assay technique), and the surface expression of CD11b (flow cytometry) on peripheral blood granulocytes. MEASUREMENTS AND MAIN RESULTS: Reperfusion significantly increased the leukocyte rolling and firm adhesion (by 2.6 and 7.1-fold, respectively), evoked marked decreases in periosteal functional capillary density and red blood cell velocity (56% and 39%, respectively), and increased the CD11b expression on the circulating leukocytes (by 85%). Hydroxyethyl starch, but not gelatin or dextran pretreatment, significantly inhibited the firm adherence of the leukocytes and reduced the elevated CD11b expression. Hydroxyethyl starch pretreatment also effectively attenuated the decreases in functional capillary density and red blood cell velocity, whereas gelatin and dextran did not improve the microhemodynamics. Finally, ischemia had no direct effect on the soluble intercellular adhesion molecule-1 levels, whereas gelatin treatment increased significantly this parameter. CONCLUSIONS: When compared with gelatin or dextran solutions, hydroxyethyl starch provided a therapeutic advantage in this setting by exerting an inhibitory effect on the ischemia-reperfusion-induced local and systemic leukocyte reactions and the postischemic periosteal microvascular dysfunction.