Tschaikowsky et al developed method for measuring blood volume after injection of hydroxyethyl starch. This allows for a rapid determination of the blood volume without need of radioisotopes. The authors are from the University of Erlangen-Numberg in Germany.
Patient selection: adults from 20 to 76 years of age
Procedure:
(1) A blood sample is collected as baseline.
(2) Haemofusin (Pharmacia) is a 10% solution of hydroxyethyl starch (HES) in isotonic saline. A volume is infused intravenously into the patient through a central line.
(3) After the blood has been distributed a second blood sample is collected, with measurement of the patient's hematocrit.
(4) Plasma is separated from the baseline and post-distribution blood samples. 0.6 mL of plasma from each sample is hydrolyzed by boiling with 0.15 mL of concentrated hydrochloric acid for 7 minutes. The acid is then neutralized with 0.55 mL of 3.33 M Tris buffer.
(5) The hydrolysis will break the starch down with release of glucose. The glucose concentration in both samples is measured and reported in mg/dL.
blood volume in mL =
= 3082 * (mL of HES injection IV) / (((plasma glucose after injection HES) - (plasma glucose before HES)) * (1 - (hematocrit as a decimal fraction)))
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