Extracorporeal carbon dioxide removal (ECCO2R) is a promising yet limited researched therapy for hypercapnic respiratory failure in acute respiratory distress syndrome and exacerbated chronic obstructive pulmonary disease. Herein, we describe a new mock circuit that enables experimental ECCO2R research without animal models. In a second step, we use this model to investigate three experimental scenarios of ECCO2R: (I) the influence of hemoglobin concentration on CO2 removal. (II) a potentially portable ECCO2R that uses air instead of oxygen, (III) a low-flow ECCO2R that achieves effective CO2 clearance by recirculation and acidification of the limited blood volume of a small dual lumen cannula (such as a dialysis catheter). With the presented ECCO2R mock, CO2 removal rates comparable to previous studies were obtained. The mock works with either fresh porcine blood or diluted expired human packed red blood cells. However, fresh porcine blood was preferred because of better handling and availability. In the second step of this work, hemoglobin concentration was identified as an important factor for CO2 removal. In the second scenario, an air-driven ECCO2R setup showed only a slightly lower CO2 wash-out than the same setup with pure oxygen as sweep gas. In the last scenario, the low-flow ECCO2R, the blood flow at the test membrane lung was successfully raised with a recirculation channel without the need to increase cannula flow. Low recirculation ratios resulted in increased efficiency, while high recirculation ratios caused slightly reduced CO2 removal rates. Acidification of the CO2 depleted blood in the recirculation channel caused an increase in CO2 removal rate. We demonstrate a simple and cost effective, yet powerful, “in-vitro” ECCO2R model that can be used as an alternative to animal experiments for many research scenarios. Moreover, in our approach parameters such as hemoglobin level can be modified more easily than in animal models.

中文翻译：

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用于测试体外二氧化碳消除装置的模拟循环回路

体外二氧化碳去除（ECCO2R）是一种有前途但研究有限的急性呼吸窘迫综合征和慢性阻塞性肺疾病加重的高碳酸血症呼吸衰竭的治疗方法。在这里，我们描述了一种新的模拟电路，它可以在没有动物模型的情况下进行实验性 ECCO2R 研究。第二步，我们使用这个模型来研究 ECCO2R 的三个实验场景：（I）血红蛋白浓度对 CO2 去除的影响。(II) 一种潜在的便携式 ECCO2R，它使用空气代替氧气，(III) 一种低流量 ECCO2R，它通过再循环和酸化小型双腔插管（例如透析导管）的有限血容量来实现有效的 CO2 清除。使用提出的 ECCO2R 模拟，获得了与先前研究相当的 CO2 去除率。该模拟适用于新鲜猪血或稀释的过期人体红细胞。然而，由于更好的处理和可用性，新鲜的猪血是首选。在这项工作的第二步中，血红蛋白浓度被确定为去除 CO2 的重要因素。在第二种情况下，与使用纯氧作为吹扫气的相同设置相比，空气驱动的 ECCO2R 设置仅显示出略低的 CO2 冲刷量。在最后一种情况下，低流量 ECCO2R，测试膜肺的血流量通过再循环通道成功提高，无需增加插管流量。低再循环率可提高效率，而高再循环率会导致 CO2 去除率略有降低。再循环通道中 CO2 耗尽的血液的酸化导致 CO2 去除率的增加。我们展示了一种简单且具有成本效益但功能强大的“体外”ECCO2R 模型，该模型可用作许多研究场景中动物实验的替代方案。此外，在我们的方法中，与动物模型相比，可以更容易地修改血红蛋白水平等参数。