Influence of static pressure and shear rate on hemolysis of red blood cells

The purpose of this study was to investigate the effect of multiple mechani cal forces in hemolysis. Specific attention is focused on the effects of sh eer and pressure. An experimental apparatus consisting of a rotational visc ometer, compression chamber, and heat exchanger was prepared to apply multi ple mechanical forces to a blood sample. The rotational viscometer, in whic h bovine blood was subjected to sheer rates of 0, 500, 1,000, and 1,500 s(- 1), was set in the compression chamber and pressurized with an air compress or at 0, 200, 400, and 500 mm Hg. The blood temperature was maintained at 2 1 degreesC and 28 degreesC. Free hemoglobin at 600 mm Hg was observed to be approximately four times higher than at 0 mm Hg for a shear rate of 1,500 s(-1) (p < 0.05). The results suggest that the increase in hemolysis is str ongly related to pressure when high shear rates are applied to the erythroc ytes. The data acquired in this study will be helpful in the development of artificial organs, where it will facilitate the prediction of hemolysis in flow dynamics analysis, flow visualization, and computational fluid dynami cs.