Extracorporeal membrane oxygenation (ECMO) for critically ill adults in the emergency department: history, current applications, and future directions

Abstract

Extracorporeal membrane oxygenation (ECMO) is a mode of extracorporeal life support that augments oxygenation, ventilation and/or cardiac output via cannulae connected to a circuit that pumps blood through an oxygenator and back into the patient. ECMO has been used for decades to support cardiopulmonary disease refractory to conventional therapy. While not robust, there are promising data for the use of ECMO in acute hypoxemic respiratory failure, cardiac arrest, and cardiogenic shock and the potential indications for ECMO continue to increase. This review discusses the existing literature on the potential use of ECMO in critically ill patients within the emergency department.

Fig. 1

Veno-venous cannulation for ARDS. This chest X-ray demonstrates severe airspace disease in a patient with ARDS. The dual-lumen ECMO cannula (arrows) can be seen passing through the internal jugular vein, superior vena cava, and terminating in the inferior vena cava at the level of the hepatic vein

Fig. 2

ECMO circuit components and flow. Flow through the ECMO circuit starts with the venous drainage cannula (1), which is propelled forward by the pressure gradient generated by the centrifugal pump head (2). The blood passes through the oxygenator (3) and then returns to the patient in the outflow tubing back into the right atrium (VV) or femoral artery (VA) (4). Gas exchange is regulated by the amount of countercurrent “sweep” gas flowing through the oxygenator (5) and the blood is warmed by the thermoregulator attached to the circuit (6). Flow, hemoglobin, hematocrit and venous saturation can be continuously monitored by ultrasonic meters attached to the circuit (7 and 8)