Effect of contrast media on RBC filterability studied with nickel mesh filtration

Abstract

Effect of contrast media (CM) on red blood cell (RBC) filterability was studied using a newly developed nickel mesh filtration method. The impact of CM osmolality, viscosity and iodine content on RBC filterability in this system was analyzed. Under isotonic conditions, iothalamate (48 mgI/ml, 1.3 cp) and low osmolality CM, iohexol (101 mgI/ml, 1.8 cp) did not cause any changes in RBC morphology. The RBC suspension of iothalamate was more filterable than that of iohexol because of low viscosity. However, under equal viscosity (iodine content) conditions, iothalamate caused shape change and marked decreases in RBC filterability with a small increase in viscosity (iodine content) from 1.3 cp to 1.7 cp (48 mgI/ml to 98 mgI/ml). This change in viscosity (iodine content) corresponded to a remarkable increase in osmolality from 300 mOsm/kgH₂O to 588 mOsm/kgH₂O. Under similar conditions, iohexol did not induce any discernible shape changes and resulted in a small decrease in filterability. The present study clearly showed that the osmotic effect of CM on RBC filterability is more predominant than the effects of viscosity and iodine content.