Abstract
Hypovolemic shock arising during ultrafiltration in hemodialysis patients is one of the most important cardiovascular complications. To maintain mean arterial pressure (MAP), iso- or hyperosmotic solutions are intravenously adminstered to supplement or expand plasma volume. To examine a difference among the hemodynamic responses evoked by rapidly infusing such iso-osmotic solutions, we measured the changes in central venous pressure (CVP), MAP, and heart rate (HR) during acute volume expansion by a Ringer's solution (Ringer) or 5% D-glucose solution (glu) with a volume of 2% body weight in anesthetized rats. The infusion of the Ringer increased MAP gradually, depending upon a rise in CVP during volume expansion. In contrast, during infusion of a 5% D-glu, there were no significant changes in CVP and MAP. Furthermore, to determine whether no significant homodynamic responses by 5% D-glu was due to glucose metabolism, we examined the hemodynamic responses during infusion of 5% L-glu which lacked physiological glycolysis metabolism. There were no significant differences in the CVP and MAP responses between 5% D- and L-glu. Taken together, the Ringer was iso-osmotic and had the similar electrolyte concentrations as the interstitial fluid. On the other hand, the glu had a chemical gradient of glucose against the interstitial fluid, which might rapidly spread into the interstitial space. The above characteristics of the iso-osmotic solutions may explain the different hemodynamic responses. [J Physiol Sci. 2008;58 Suppl:S186]
