A preliminary study to measure plasma volume using hydroxyethyl starch (707.6)

Abstract

Purpose: This study tested the potential of using hydroxyethyl starch (HESPAN) as an indicator to measure plasma volume. Methods: Fifty‐ml of whole blood was collected in tubes containing EDTA from ten subjects (n=10, male=6, female=4) between the ages of 18 and 60. The blood samples were centrifuged at 3000‐rpm for 20 min. The plasma was removed and inserted into an artificial circulation system constructed from Tygon tubing, a central mixing chamber, and a peristaltic pump. For each subject, the initial glucose level was measured using an Accu‐Chek Active glucose monitor. Ten 0.5‐ml aliquots of a 6% HESPAN solution were sequentially added into the system and allowed to circulate for a period of six minutes. Two‐mL plasma samples were withdrawn between the additions of each aliquot, treated with concentrated hydrochloric acid for hydrolysis of the HESPAN starch to glucose monosaccharide units, and neutralized with TRIS buffer. The resulting samples were then used to measure the increase in plasma glucose concentration. Results: A graph was constructed displaying the relationship between HESPAN concentration and increases in plasma glucose levels. It was determined that there was a nearly linear relationship resulting in an r2 value of 0.9395. Conclusions: Using HESPAN, as an indicator may be valid technique to measure plasma volume due to the linear relationship between HESPAN concentration increases in plasma glucose.