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 mechanical forces in hemolysis. Specific attention is focused on the effects of shear and pressure. An experimental apparatus consisting of a rotational viscometer, compression chamber, and heat exchanger was prepared to apply multiple mechanical forces to a blood sample. The rotational viscometer, in which bovine blood was subjected to shear rates of 0, 500, 1,000, and 1,500 s(-1), was set in the compression chamber and pressurized with an air compressor at 0, 200, 400, and 600 mm Hg. The blood temperature was maintained at 21 degrees C and 28 degrees C. 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 strongly related to pressure when high shear rates are applied to the erythrocytes. 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 dynamics.