Extracorporeal membrane oxygenation (ECMO), used synonymously with the term extracorporeal life support, can be traced back to the extracorporeal circuit invented by Gibbon first used successfully for cardiopulmonary bypass in 1953.1 More recent advances in cannula, pump, and oxygenator design have improved the durability and availability of ECMO devices, making them available for widespread use.
Generally, an ECMO circuit consists of an inflow cannula that drains blood from the patient into the circuit, a pump to maintain flow, a membrane oxygenator, and an outflow cannula to return blood to the patient (Fig. 149-1). Two types of circuits are in use: veno-arterial (VA) ECMO for support of the heart and lungs, and veno-venous (VV) ECMO for support of the lungs. ECMO proceduralists have introduced multiple variations of these basic circuits to tailor the circuit design to specific types of cardiopulmonary failure. The circuits may be used as a bridge to recovery in patients with cardiopulmonary failure, and they have been used for weeks to months as a bridge to other options, such as a durable ventricular assist device or organ transplant.
TABLE 149-1Veno-Venous ECMO Criteria Example ||Download (.pdf) TABLE 149-1 Veno-Venous ECMO Criteria Example
|Veno-Venous (VV) ECMO Indications || VV-ECMO Contraindications ||VV-ECMO Relative Contraindications |
|PaO2 <80 on FIO2 100% or pH <7.2 with hypercarbia unresponsive to conventional management ||Age >70 (except s/p lung transplant) ||Weight >140 kg |
|Severe pneumonia ||Severe cardiac insufficiency or cardiac arrest ||Severe baseline disability (significant dementia, quadriplegia, etc.) that would inhibit ventilator weaning/rehabilitation |
|Acute respiratory distress syndrome ||Nonrecoverable neurologic injury (ischemic, hemorrhagic, or anoxic) || |
|Graft failure following lung transplantation ||Active malignancy with predicted survival <1 year || |
|Pulmonary contusion ||Graft-vs.-host disease (post-allogeneic transplant ARF) || |
|Alveolar proteinosis ||Severe pulmonary hypertension with severe right ventricular dysfunction || |
|Airway trauma || ||Ventilator dependent >10 days |
|Status asthmaticus ||Severe baseline disability (end-stage, which would inhibit ventilator weaning/rehabilitation) || |
|Airway obstruction || || |
|Aspiration syndrome ||Age >70 (except s/p lung transplant) || |
|Postoperative hypoxemia || || |
In this chapter, we review the history and evolution of ECMO, the basics of circuit design and management, indications and criteria for use of ECMO, and the most common problems encountered. Although we focus on use of ECMO for pulmonary support, it is important for the clinician to understand use of ECMO for cardiopulmonary support, since there is overlap in use.
The use of ECMO as therapy for acute respiratory distress syndrome (ARDS) and acute respiratory failure (ARF) has evolved over the past 50 years in the context of a complex interplay among improvements in intensive care unit (ICU) therapies (e.g., paralysis, prone positioning, and low stretch ventilation), ICU systems ...