Courant Institute of Mathematical Sciences, New York University, New York, New York, USA.
Department of Emergency Medicine and Critical Care, University of New Mexico, Albuquerque, New Mexico, USA.
J Clin Apher. 2021 Feb;36(1):6-11. doi: 10.1002/jca.21805. Epub 2020 Oct 8.
Vascular access connection configurations during tandem extracorporeal membrane oxygenation (ECMO) and therapeutic plasma exchange (TPE) may impact exchange kinetics. In these tandem procedures, typically the TPE inlet line is proximal to the TPE return line with respect to blood flow in the ECMO device, maximizing the opportunity for replacement fluid homogenization within the ECMO circuit. However, if TPE inlet and return line connections are switched, recirculation-a phenomenon in which replacement fluid leaving the TPE return line is prematurely drawn into the TPE inlet line prior to satisfactory homogenization within the ECMO circuit-will occur. Such recirculation could diminish TPE efficacy in patients on ECMO and mitigate therapeutic benefits. Using a mathematical model of recirculation in tandem ECMO and TPE, we demonstrate that the predicted impact of recirculation is negligible and vascular access connection positioning does not appear to be a point of clinical concern with regard to TPE kinetics.
在体外膜肺氧合（ECMO）和治疗性血浆置换（TPE）的串联治疗中，血管通路连接配置可能会影响交换动力学。在这些串联治疗中，TPE 入口线通常相对于 ECMO 设备中的血流更靠近 TPE 回流线，从而最大限度地提高 ECMO 回路中替代液均匀化的机会。然而，如果 TPE 入口和回流线的连接被切换，就会发生再循环现象，即离开 TPE 回流线的替代液在 ECMO 回路中充分均匀化之前，过早地被吸入 TPE 入口线。这种再循环可能会降低 ECMO 患者的 TPE 疗效，并减轻治疗效果。我们使用串联 ECMO 和 TPE 中的再循环数学模型进行演示，结果表明，再循环的预测影响可以忽略不计，并且血管通路连接位置似乎不是 TPE 动力学方面的临床关注问题。
