Extracorporeal life support (ECLS) provides oxygen (O2) delivery, carbon dioxide (CO2) removal, and cardiac support in patients who have cardiac and/or respiratory failure by draining blood from the right atrium through a cannula with the aid of a pump and then propelling blood through an oxygenator, where gas exchange occurs. From there, it is returned to the patient into the aorta (venoarterial [VA]) or right atrium (venovenous [VV]) (Figures 18–1, 18–2, and 18–3). Uniform guidelines have been established to describe essential equipment, procedures, personnel, and training required for ECLS and can be found in the ECMO Specialist Training Manual published by the Extracorporeal Life Support Organization. (Note: The term extracorporeal membrane oxygenation [ECMO] has generally been replaced by ECLS, reflecting an expanded role beyond oxygenation for this technology.)
ECLS circuit. (Reprinted, with permission, from Michaele Miller at Michaele Miller Projects LLC.)
VA ECLS cannulae placement. The echogenic dot denoting the end of the venous cannula at T9 is hard to visualize.
VV ECLS cannulae placement.
ECLS is used primarily for critically ill term and late preterm newborns with reversible respiratory and/or cardiac failure who have failed appropriate maximal medical management with ventilator support (conventional or high frequency), inhaled nitric oxide, volume expansion, or inotropic/vasopressor support. Neonatal conditions treated with ECLS support include meconium aspiration syndrome, congenital diaphragmatic hernia, persistent pulmonary hypertension of the newborn, respiratory distress syndrome, sepsis, and pneumonia. ECLS can be used to support patients with cardiac failure owing to congenital heart disease, postcardiotomy heart failure, cardiomyopathy, or severe rhythm disturbances and may be used as a bridge to cardiac transplantation.
III. APPROPRIATE PATIENTS FOR ECLS
Weight ≥1.6–1.8 kg; gestational age ≥32–34 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.
Oxygenation index (OI). Historically, an OI >30–40 for 0.5–4 hours was routinely used to determine the severity of illness and establish when a neonate was felt to be at high risk for death if not treated with ECLS. Although OI levels can be helpful in establishing a trend, most centers rely on additional parameters to guide their decisions to initiate ECLS, including the inability to wean from 100% oxygen within a period of time and/or ongoing hypotension or metabolic acidosis.
(Fio2, fraction of inspired O2; MAP, mean airway pressure; Pao2, partial pressure of oxygen, arterial)
Acute deterioration with intractable hypoxemia. Patients who have a ...