During which event along a CPB run is the highest embolic count per minute recorded?

The highest embolic count per minute during a cardiopulmonary bypass (CPB) run is recorded during the short filling of the beating heart. This phase involves an intricate interplay of hemodynamics as fluid is being introduced back into the heart while it is still in a state of contraction.

During this time, the rapid changes in pressure and volume lead to increased turbulence and shear stress within the vascular system. This turbulence can dislodge atheromatous debris or thrombus that may have formed, particularly in the aorta or other significant vessels. Furthermore, when blood flow is altered during CPB, various factors such as air bubbles, fibrin clots, or particulate matter can become dislodged or mobilized, contributing to an increased embolic load.

Understanding the dynamics of embolic events is essential in perfusion practice, as this knowledge guides clinicians in mitigating the risk of embolic complications, which can lead to serious neurological and organ-related issues post-surgery. It's crucial to note that the other phases, such as aortic cannulation or the start of CPB, can also present risks for embolic events, but the specific physiological conditions during the short filling lead to a notably higher count per minute.