Introduction The air trap chamber used in continuous renal replacement therapy (CRRT) often causes clot formation due to gas interface, blood stasis and turbulent flow. The designs of this chamber vary widely. Few studies have quantitatively evaluated ex-vivo quasi blood stasis for different chamber types. Methods Flow retention characteristics at 20, 30, 40, 50, and 60 s in a top-feed chamber (where blood flow enters vertically from the top and passes through a mesh within the air trap chamber with a chamber 12 mL in volume) and a side-feed chamber (where blood flow enters from the side and bottom, without a mesh filter, with a flow deviator and 6mL chamber volume) were evaluated using a 30% glycerin and iodine povidone-solution. Still images of the chambers at each time point were converted to 8-bit grayscale using Image J software (ver.1.54, Maryland, U.S.), with a brightness threshold in the range of 1-80 to compare the two chamber designs. Results Both chambers showed a decrease in the values of the highlighted areas over time; however, from 20 s, the side-feed chamber showed significantly lower values of the highlighted areas compared with the top-feed chamber. Similar to the findings at 20 s, significant differences in the values of the highlighted areas, favored the side-feed chamber and persisted at 30, 40, 50, and 60 s. Furthermore, pseudo-blood remained superficially in the top-feed chamber, while the side-feed chamber exhibited vortex flow, less stasis, turbulence and stagnation. Conclusion The two chambers tested emptied of pseudo blood at different rates, with varying retention characteristics, with the side-feed chamber showed less pseudo-blood retention at all time points assessed.

S. Karger AG, Basel.

简介 连续肾脏替代疗法（CRRT）中使用的空气陷阱室由于气液界面、血液停滞和湍流，常常会导致凝血。这些房间的设计差异很大。很少有研究对不同类型的房间进行体外准血液停滞的定量评估。 方法 使用30%甘油和碘伏溶液来评价顶进式房间（其中血液从顶部垂直进入，并通过空气陷阱室内的网孔，在12毫升体积的房间里流过）以及侧进式房间（其中血液从侧面和底部进入，没有网孔过滤器、流量偏离器且容积为6毫升）在20秒、30秒、40秒、50秒和60秒时的流体滞留特性。使用Image J软件（版本1.54，马里兰州，美国），将各时间点房间的静止图像转换为8位灰度图，并设置亮度阈值在1-80范围内，以便比较两种设计。 结果 两个房间随时间推移显示高亮区域数值下降；然而从20秒开始，侧进式房间的高亮区域数值明显低于顶进式房间。类似于20秒时的结果，在30秒、40秒、50秒和60秒时，两种设计之间的高亮区域数值也存在显著差异，并且优势依然在侧进式房间一边。 此外，在顶进式房间里伪血液停留在表面层，而侧进式房间则显示涡流流动，较少的停滞现象、湍流以及滞留。结论 两个测试的房间以不同的速率清空了伪血液，具有不同的滞留特性，并且在所有评估的时间点上，侧进式房间显示出较低的伪血液保留量。

S. Karger AG, 巴塞尔。