Examination of venous chamber structure assuming liquid layer separation

Abstract

In continuous renal replacement therapy, the venous chamber (VC) is a site of frequent coagulation due to a longer blood retention time and air contact. In our hospital, the VC fluid level is controlled at a high level to separate the layer between the blood and replenishment fluid; however, this requires adjustment of the fluid levels every few hours and is unstable. In this study, using an in vitro system, we evaluated the liquid layer separation conditions with six types of VC to investigate the VC structure that would enable stable liquid layer separation. In addition, the blood retention of the different VC structures was evaluated. As a result, the conditions for the formation of liquid-layer separation were that the blood inlet should be placed below the replenishment fluid inlet and that the fluid level should be controlled above the replenishment fluid inlet. Among the VC that satisfied both conditions, Prismaflex Sepxiris set, which has a replenishment fluid inlet that is connected to lower than of the VC, consider to be the safest and most stable of the current VC because of its low possibility of filter wetting and large volume until the liquid layer separation is resolved by the inflow of air bubbles.