Extracorporeal life support (ECLS), also referred to as extracorporeal membrane oxygenation (ECMO), provides either direct cardiac/pulmonary support (venoarterial [VA] ECLS) or indirect cardiac/pulmonary support (venovenous [VV] ECLS) by providing oxygen (O2) delivery and carbon dioxide (CO2) removal in neonates with reversible life-threatening respiratory or cardiac disease. While on ECLS, blood is drained from the right atrium through a cannula with the aid of a pump and then propelled through an oxygenator where gas exchange occurs. From there, it is returned to the aorta (VA) or right atrium (VV) (Figure 20–1). Uniform guidelines have been established to describe essential equipment, procedures, personnel, and training required for ECLS and can be found in Extracorporeal Life Support: The ELSO Red Book, 5th Edition, and Extracorporeal Membrane Oxygenation (ECLS) Specialist Training Manual published by the Extracorporeal Life Support Organization (ELSO) and on the ELSO website.
ECLS is used in critically ill term and late preterm newborns with reversible respiratory and/or cardiac failure who have failed maximal medical management. Neonatal conditions supported with ECLS include meconium aspiration syndrome (MAS), congenital diaphragmatic hernia (CDH), persistent pulmonary hypertension of the newborn (PPHN), respiratory distress syndrome (RDS), sepsis, pneumonia, severe air leak, and airway anomalies awaiting surgical repair and postoperatively during recovery. VV-ECLS is preferred in most neonates with respiratory failure because it appears safer. VA-ECLS is used in patients with cardiac failure due to congenital heart disease, postcardiotomy heart failure, cardiomyopathy, cardiac failure due to sepsis, severe rhythm disturbances, situations of cardiac arrest, and as a bridge to cardiac transplantation. VA-ECLS is often favored in patients with CDH where vessel anatomy prevents cannulation with a double-lumen venous catheter. (However, comparison studies provide data supporting successful VV-ECLS use in the CDH population). VA-ECLS is also preferred in patients with septic shock in whom higher flow rates may be required to provide support.
III. APPROPRIATE PATIENTS FOR EXTRACORPOREAL LIFE SUPPORT
Weight ≥1800 to 2000 g and/or gestational age ≥32 to 34 weeks. The cannula size is determined by the infant’s weight; the lower limit in weight is based on the limitation of cannula sizes available.
Cardiopulmonary criteria for extracorporeal life support
Oxygenation index. Most centers use a combination of persistently elevated oxygenation index (OI) calculations (OI of 30–40) and the inability to wean from 100% oxygen within a period of time as criteria for initiating ECLS support.
(FiO2, fraction of inspired O2; MAP, mean airway pressure; PaO2, partial pressure of oxygen, arterial)
Acute deterioration with intractable hypoxemia. Neonates who have a PaO2 <30–40 mm Hg or a preductal Sao2 <80% for greater than an hour with no response to conventional therapies should be considered for ECLS support.
Barotrauma. Severe air leak from pneumothoraces that is not responsive to low tidal volume conventional ventilation or high-frequency ventilation may benefit from lung rest on ECLS.
Severe lactic acidosis. Indicators of circulatory failure including hypotension and a rising lactate despite circulatory support strategies including volume expansion and inotropic/vasopressor ...