title: Circulating blood volume determination using electronic spin resonance spectroscopy.
abstract: There have been numerous methods proposed to measure the circulating blood volume (CBV). Nevertheless, none of them have been massively and routinely accepted in clinical diagnosis. This study describes a simple and rapid method, on a rabbit model, using the dilution of autologous red cells labeled with a nitroxide radical (Iodoacetamide-TEMPO), which can be detected by electronic spin resonance (ESR) spectroscopy. Blood samples were withdrawn and re-injected using the ears' marginal veins. The average CBV measured by the new method/body weight (CBV(IAT)/BW) was 59 +/- 7 mL/kg (n = 33). Simultaneously, blood volume determinations using the nitroxide radical and (51)Cr (CBV(Cr)) were performed. In the plot of the difference between the methods (CBV(IAT) - CBV(Cr)) against the average (CBV(IAT) + CBV(Cr))/2, the mean of the bias was -1.1 +/- 6.9 mL and the limits of agreement (mean difference +/-2 SD) were -14.9 and 12.7 mL. Lin's concordance correlation coefficient p(c) = 0.988. Thus, both methods are in close agreement. The development of a new method that allows a correct estimation of the CBV without using radioactivity, avoiding blood manipulation, and decreasing the possibility of blood contamination with similar accuracy and precision of that of the "gold standard method" is an innovative proposal.
authors.affiliation: Departamento de Fisicomatemática y LANAIS "Radicales Libres en Biología y Medicina", Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina. gfacorro@ffyb.uba.ar
authors.forename: Graciela
authors.initials: G
authors.lastname: Facorro
authors.forename: Ana
authors.initials: A
authors.lastname: Bianchin
authors.forename: José
authors.initials: J
authors.lastname: Boccio
authors.forename: Alfredo
authors.initials: A
authors.lastname: Hager
mesh_terms: D000818:Animals; D001775:Blood Circulation; D001811:Blood Volume Determination / Q000379:methods*; D003497:Cyclic N-Oxides; D004578:Electron Spin Resonance Spectroscopy; D007460:Iodoacetamide; D011817:Rabbits; D013113:Spin Labels
chemical_list: D003497:Cyclic N-Oxides; D013113:Spin Labels; C003959:TEMPO; D007460:Iodoacetamide