[The significance of erythrocyte fragment count to predicting hemolysis in roller pumps].
Hemolysis in blood pumps has been measured by various in vitro tests, in which normalized index of hemolysis (NIH) was established. As NIH is complicated and difficult to calculate, erythrocyte fragment count (EFC) is proposed in the present study to predict hemolysis in roller pumps. Five paired in vitro tests were conducted using the POLYSTAN pediatric pump (group A) and COBE pump (group B). Ten whole blood samples (400ml) were circled in the roller pump for 16 hours. Erythrocyte fragments count and plasma-free hemoglobin (FHb) were measured before pumping and every 2 hours through circulation after 4 hours pumping. The morphological changes of erythrocyte were observed by scanning electron microscope. Simple linear regression analysis showed the two groups' EFC and FHb levels increased linearly during a long period of pumping, and the coefficient of determination (R2) was 0.64. These data suggested that Erythrocyte fragments count could be used as an index in evaluating the in vitro hemolytic properties of blood pumps.