RESUMO
Hemorheological and hemodynamic effects of high molecular weight polyethylene oxide (PEO) solutions have been studied in vitro and in vivo at 30 experimental dogs. The rheological behaviour of the PEO solutions and of blood samples has been assessed by rotational viscometers at 20 degrees C, 25 degrees C and 37 degrees C. An addition of PEO solutions to the blood in vitro has modified its rheological behavior, depending on the shear rates, concentration and temperature. Saline with aqueous PEO solutions at the concentration of 500 ppm has been infused into the blood circulation of the experimental dogs to achieve the total concentration in blood of 20-30 ppm. The following parameters cardiac output, mean arterial blood pressure, central venous pressure, pulse frequency, blood volume flow in the femoral artery, total vascular resistance and blood viscosity before and after the infusion of PEO solutions have been studied. The main observed effect was a decrease of the hemodynamic resistance in the cardiovascular system up to 40% below the baseline after infusion of PEO solutions.
