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ECMO devices provide prolonged mechanical support by pumping blood and by exchanging oxygen and carbon dioxide in the blood prior to its return to the patient. Thus, ECMO may be helpful during both circulatory failure and pulmonary failure. There are two main types of ECMO support, venoarterial (VA) and venovenous (VV). VA ECMO drains venous blood via a venous cannula, oxygenates the blood in the ECMO circuit, and pumps the oxygenated blood into a large artery via an arterial cannula, bypassing both the heart and lungs. VA ECMO is used for both cardiac and pulmonary failure. VV ECMO oxygenates the blood and returns it to the body to be circulated by the heart, requiring adequate function of the both the right and left heart. VV ECMO is used during respiratory failure.

Cannulation for VA and VV ECMO differs in both their locations of access and who generally performs the procedure. For VA ECMO the venous cannula can be inserted into the right atrium via the internal jugular vein, or less commonly, via a femoral vein to the inferior vena cava and then right atrium. Venous cannulation can be performed via open incision, but it can also be placed via Seldinger technique. The arterial cannulation for VA ECMO can be performed via the right carotid artery, the femoral artery, or via a transthoracic approach by directly cannulating the aorta. There are benefits and downsides to each location, for example leg ischemia in femoral cannulation or neurologic compromise in carotid cannulation. VV ECMO cannulation usually involves the right internal jugular vein or femoral veins and may involve anywhere from one to multiple sites of cannulation for venous drainage. There are cannulas that can be placed in the right internal jugular vein with multiple lumens that can drain deoxygenated blood and return oxygenated blood from a single cannulation point.

Indications for ECMO include acute, reversible, severe respiratory or cardiac failure unresponsive to conventional management. A few examples for VV ECMO include neonates with respiratory failure following meconium aspiration, severe influenza‐associated acute respiratory distress syndrome, and near‐drowning with inability to oxygenate the patient. Some examples for VA ECMO include drug overdoses, massive pulmonary embolism, and witnessed cardiac arrest with refractory ventricular arrhythmias. Absolute contraindications to ECMO include patients with advanced, untreatable, or irreversible disease like advanced malignancy, nonrecoverable cardiac disease (and not transplant candidates), or irreversible brain injury. Some relative contraindications may include elderly patients, multiorgan failure, and bleeding diathesis.

EMS physicians may encounter ECMO devices in the setting of critical care transport. Some medical centers are able to cannulate patients but are unable to provide additional services they may require once on ECMO, necessitating transport. Other hospitals do not have ECMO cannulation capabilities, and surgeons or intensivists with training in ECMO cannulation are sometimes transported to the outlying hospital to cannulate the patient prior to transport.

ECMO has been initiated in the prehospital setting as a treatment of refractory cardiac arrest, one of the most notable cases being at The Louvre in Paris [9]. Pilot projects are being conducted to determine the feasibility of implementing systematic initiation of ECMO in the field for cases of refractory cardiac arrest. Such efforts require substantial investments in developing the necessary multidisciplined team to conduct the resuscitation, cannulate the patient, and manage the technology.

Transporting ECMO patients is a complex undertaking that requires planning [10]. Specialized equipment, as well as equipment mounts, may be required depending on the mode of travel [10]. The size and composition of the transport team should also be determined in advance. Some ECMO programs include a cannulation team that goes out ahead of the transport team. Transport teams may include a perfusionist to manage the ECMO device and a physician to provide direct medical oversight. Conversations between the transport team and the referring and receiving institutions should occur prior to patient contact to arrange for needed supplies and equipment in order to prevent delays. Without question, these are resource‐intensive cases.