EFFECT OF CRYSTALLOID AND COLLOID SOLUTIONS ON BLOOD RHEOLOGY IN SEPSIS

Sepsis is associated with altered blood theology. Fluid infusion is an essential component of therapy for septic shock. The purpose of this study was to compare the theologic changes associated with saline, alb umin, and hydroxyethyl starch in sepsis. Whole blood was obtained from five normal controls and five patients with severe sepsis. The sample s were centrifuged, and the erythrocytes were resuspended in autologou s plasma or autologous plasma plus the buffy coat at an hematocrit (Ho t) of 40%. The sample was diluted to an Hct of 30%, 20%, and 10% with saline, albumin, or hydroxyethyl starch. Viscosity was measured at low and high shear rates and erythrocyte aggregation was measured by the ratio of viscosity at low to high shear rates. Erythrocyte deformabili ty was assessed by filtration. The viscosity of hydroxyethyl starch wa s greater than saline, albumin, or autologous plasma (p <.01). Erythro cyte viscosity was greater (p <.01) and deformability less (p <.01) in septic blood compared with normals. Dilution with hydroxyethyl starch increased erythrocyte viscosity as compared with saline (p <.01) and albumin (p < .01). Erythrocyte deformability was decreased with both h ydroxyethyl starch (p <.001) and albumin (p ( .05) compared with salin e. Increased erythrocyte aggregation was also observed with hydroxyeth yl starch (p <.05) and albumin (NS) in septic cells when compared with saline. These data indicate that hydroxyethyl starch increases blood viscosity, decreases erythrocyte deformability, and increases erythroc yte aggregation when compared with saline. These changes are less sign ificant with albumin. In patients with sepsis, these effects may furth er compromise the already altered erythrocyte theology.