Affiliations: Laboratory of Clinical Hemorheology, Dept. of Internal Medicine, Academic Medical Center, 1105 A2 Amsterdam, the Netherlands
Note: [] Paper read at the 7th European Conference on Clinical Haemorheology, Symposium: Contrast Media, Southampton, 1991 and reviewed in accordance with the Guidelines of Clinical Hemorheology.
Abstract: The in vitro hemorheological effects of three new, so called low osmolar, radio-contrast media (CM) were compared. Two of the CM were non-ionic compounds, Iohexol and Iopamidol, the third one was the ionic dimer Ioxaglate. Their osmolalities varied from 574 to 679 mosmol/kg. with viscosities from 4.8 to 7.5 mPa.s. Red blood cell (RBC) aggregation (syllectometry and calCulation of the aggregation factor, AF), RBC deformability (ektacytometry and calculation of the Taylor factor, Tk), plasma viscosity as well as low and high shear viscosity of various blood-CM mixtures were measured. Changes in these parameters, induced by various grades of dilution and/or hyperosmolality were related to changes in morphological parameters, found in an earlier, comparable study. It was shown that, in contrast to both non-ionic CM and despite its own hyperosmolality, Ioxaglate had no effect on RBC morphology and caused less deterioration of RBC deformability and aggregation than hyperosmolar saline. So far no explanation has been found for this phenomenon. Transformation from normal RBC biconcave morphology to echinocytes due to a hyperosmolar environment was invariably associated with a decrease in elongation index (more rigid cells), disturbance of rouleau formation and an abnormal sylleetogram. The values of AF and Tk were not always consistent with the other parameters reflecting RBC aggregation and deformability.
