An under-occluded roller pump is less hemolytic than a centrifugal pump

Area of Science:

• Biomedical Engineering
• Cardiovascular Devices
• Hemodynamics

Background:

• Hemolysis, the destruction of red blood cells, is a critical concern in cardiopulmonary bypass.
• Roller pumps (RP) and centrifugal pumps (CP) are commonly used, but their impact on hemolysis varies.
• Optimizing pump settings is essential to minimize blood trauma.

Purpose of the Study:

• To quantify and compare the hemolysis generated by roller pumps at various occlusion levels against a centrifugal pump.
• To test the hypothesis that different roller pump occlusion settings and centrifugal pumps produce similar levels of hemolysis.

Main Methods:

• Five identical closed-loop circuits were established, each with a different pump configuration: a centrifugal pump and a roller pump at four distinct occlusion settings.
• Circuits were primed with bovine blood, and pumps operated at a consistent flow rate (4.5 L/min) and afterload (250 mmHg) for three hours.
• Index of Hemolysis (IH) was measured and compared across all configurations using ANOVA.

Main Results:

• Under-occluded roller pump settings produced significantly lower Index of Hemolysis (IH) compared to the centrifugal pump.
• The centrifugal pump did not show a significantly greater IH than the roller pump set to a barely non-occlusive setting.
• Adjusting roller pump occlusion settings appears to be a viable method for reducing blood damage.

Conclusions:

• Modifying roller pump occlusion settings, particularly reducing occlusion, can lead to a lower Index of Hemolysis (IH) than traditional settings or centrifugal pumping.
• This suggests that roller pumps, when adjusted appropriately, may offer advantages in minimizing blood trauma during extracorporeal circulation.
• Further investigation into optimal roller pump parameters is warranted to enhance hemocompatibility.