Horizontal flow chambers have a shorter residence time in the chamber than vertical flow chambers

Abstract

Introduction : The venous air trap (V) chamber used in blood purification systems is a possible source of coagulation during blood purification. In this study, the fluid residence time of differently shaped V-chambers was evaluated in simulated experiments. Methods : The Prismaflex and ACH-Σ consoles were evaluated. The time from the injection of 1 mL of dye into the V-chamber to its disappearance was measured three times each, and the average values were compared. Additionally, the flow of fluids in the V-chamber was evaluated visually. Results: The fluid residence time in the V-chamber was significantly shorter in the Prismaflex group (p＜0.01). Moreover, visual evaluation showed that the fluid in the Prismaflex V-chamber flowed uniformly as a swirl. In contrast, in the ACH-Σ V-chamber, the fluid flowed unevenly pulsating only at the bottom, and stagnation was observed in the upper layer of the chamber liquid surface. Conclusion : It was suggested that structural differences in the V-chamber may affect the retention in the V-chamber.