Measuring blood volume with fluorescent-labeled hydroxyethyl starch.

Area of Science:

• Biochemistry
• Hematology
• Medical Diagnostics

Background:

• Accurate blood volume measurement is crucial for patient management, particularly in polycythemia and postoperative care.
• Current methods using radiolabeled albumin or red blood cells have limitations.

Purpose of the Study:

• To develop and validate a novel method for blood volume determination using fluorescent-labeled hydroxyethyl starch.
• To compare the efficacy of this new method against established techniques.

Main Methods:

• Hydroxyethyl starch (Elohaes) was labeled with fluorescein isothiocyanate.
• In vitro and in vivo studies were conducted in patients with suspected polycythemia and those undergoing intensive postoperative care.
• Blood volume was measured via dilution of the fluorescent-labeled starch and compared with radiolabeled albumin and red blood cell methods.

Main Results:

• The fluorescent tag remained stable in vivo, with elimination kinetics similar to the parent compound.
• Blood volume measurements using fluorescent starch were comparable to albumin but significantly different from red blood cell measurements.
• The volume of distribution of fluorescent starch was slightly lower than that of labeled albumin.

Conclusions:

• Fluorescent-labeled hydroxyethyl starch is a valid and sensitive alternative for blood volume measurement.
• This method simplifies the assay procedure and requires doses that do not impact hemodynamic status.
• The technique offers a promising advancement in clinical blood volume assessment.