Plasma Dynamic Viscosity Determined by NMR

Resumo

A nuclear magnetic resonance (NMR) based experimental procedure to determine the dynamic viscosity (η) in blood plasma solutions is presented. An equation relating η and the transverse proton magnetic relaxation rate (\(1/T_{2}\)) is obtained after considering plasma an extremely diluted water solution of albumin with no long range hydrodynamics interactions among macromolecules, and a fast exchange of water molecules between the free and associated water. Carr–Purcell–Meiboom–Gill pulse sequence was used to measure the transverse proton magnetic relaxation time (T₂) in a magnetic resonance console coupled to one homogeneous magnetic system (0.095 T). A η value of 1.68 ± 0.08 mPa s was obtained in 20 control samples, which statistically matched the value obtained in the same samples using an Ostwald viscometer (1.61 ± 0.04 mPa s). η was determined in 172 patients with multiple myeloma (2.47 ± 0.15 mPa s) and 72 with sickle cell disease (2.45 ± 0.24 mPa s) showing a statistically significant increase over the control individuals. The results show the utility of this NMR method to estimate dynamic viscosity in plasma for medical purposes, and a comparison with other methods is done.