Hemolysis induced by a Bellofram blood pump; chronic in vitro evaluation

¹ Guthrie Clinic Limited, Sayre, Pennsylvania

In the application of extracorporeal pumping systems to chronic assisted circulation, hemolysis may be an important factor. A reciprocating pump utilizing rolling diaphragms has been tested for production of free plasma hemoglobin. In a recirculating system, 1,500 ml of freshly drawn heparinized dog blood was circulated at a flow rate of 3,000 ml/min against pressures of 100, 200, and 300 mm Hg for from 1 to 24 hr. Hemolysis was determined by a modified benzidine method. Recirculation for 1 hr against a height of 142 cm produced 3.6 mg/100 ml, 1.8 mg/100 ml, and 2.4 mg/100 ml free plasma hemoglobin, respectively, for hemolysis indices of 0.0010– 0.0013. When the same priming volume was recirculated at 3,000 ml/min and 300 mm Hg pressure for 24 hr, the average hourly rate of free hemoglobin accumulation was 0.5 mg/100 ml, an index of 0.0006. These rates of hemolysis are comparable to the estimated normal human production of free plasma hemoglobin. The extremely low rate of hemolysis produced by this pump is related to the noncompressive action of the rolling diaphragms and flap valves. The characteristics of its performance make this pump ideally suited to chronic perfusion.

Submitted on June 18, 1964