Comparative Hemolysis Study of Clinically Available Centrifugal Pumps

Area of Science:

• Biomedical Engineering
• Cardiovascular Devices
• Hemolysis Research

Background:

• Centrifugal pumps are vital for cardiopulmonary bypass and circulatory support.
• Five centrifugal pump models are clinically available in Japan.
• Evaluating blood trauma from these pumps is crucial for patient safety.

Purpose of the Study:

• To conduct a comparative in vitro hemolysis study of five clinically available centrifugal pumps.
• To assess blood trauma under identical operating conditions.
• To identify factors influencing hemolysis in centrifugal pumps.

Main Methods:

• Constructed in vitro hemolysis test circuits for five pump types: BioMedicus BP-80, Sarns Delphin, Isoflow SJM, Nikkiso HPM-15, and Terumo Capiox CX-SP45.
• Operated pumps at 6 L/min against a 120 mm Hg pressure head for 6 hours using fresh bovine blood at 21°C.
• Measured plasma-free hemoglobin and temperature changes at the pump outlet.

Main Results:

• Normalized indexes of hemolysis varied significantly across pumps, with Nikkiso HPM-15 showing the lowest (0.00066 g/100 L) and Sarns Delphin the highest (0.00745 g/100 L).
• Temperature increase at the outlet port was minimal for Nikkiso (1.8°C) and maximal for SJM (3.8°C).
• No direct correlation was found between pump rotational speed (rpm) and the normalized index of hemolysis.

Conclusions:

• Centrifugal pump design and impeller configuration appear to be more critical factors in blood damage than rotational speed.
• The study provides valuable data for selecting centrifugal pumps with lower hemolysis potential.
• Further research into pump design optimization for minimizing blood trauma is warranted.