Effects of two low osmolality contrast media on red blood cell filterability and aggregation in vitro.

The in vitro effects of ionic ioxaglate and non-ionic iopamidol were compared. Filtration measurements were carried out on an hemorheometer; erythrocyte aggregation was evaluated by means of an erythrocyte aggregometer, and red blood cell morphology was observed with an optical microscope. Ioxaglate and iopamidol reduced erythrocyte filterability to the same extent; by contrast neither ionic nor non-ionic contrast media significantly modified aggregation or shape of red blood cells. The decrease of erythrocyte deformability observed in this study may cause clotting in catheters or syringes during angiographies investigations.