When native blood flow through the aorta from the adult heart and lungs meets retrograde blood flow from an artificial heart and lung during venoarterial extracorporeal membrane oxygenation (VA-ECMO), the result is the creation of two separate circulations on either side of the blood flow mixing point. This phenomenon is known as dual circulation and is characterized by different content of oxygen and carbon dioxide between the circulations. There is currently a lack of clarity surrounding the nomenclature to describe this physiologic phenomenon in VA-ECMO and thus we endeavor to name and define these terms to facilitate clear communication and proper clinical management of these patients.

在静脉动脉体外膜肺氧合 （VA-ECMO） 期间，当来自成人心脏和肺部的天然血流通过主动脉与来自人工心脏和肺的逆行血流相遇时，结果是在血流混合点的两侧产生两个独立的循环。这种现象被称为双循环，其特征是循环之间氧气和二氧化碳的含量不同。目前在 VA-ECMO 中描述这种生理现象的命名法尚不清楚，因此我们努力命名和定义这些术语，以促进这些患者的清晰沟通和适当的临床管理。