Extracorporeal life support (ECLS) is now widely used for the pediatric and neonatal population. Additionally, dramatic improvements in the technology and safety of ECLS have broadened the scope of its application.
Neonatal and pediatric ECLS indications are Oxygenation index > 40, PaO2 to FiO2 ratio < 60, pH < 7.25, Shock, A-aDO2 > 500 mmHg, Pplat> 30 cm H2O; while contraindications are Lethal chromosomal or other anomaly, Poor predicted neurologic outcome, irreversible brain injury, Uncontrolled bleeding, ICH ≥ Grade III, Advanced multi-organ system failure, Ventilation > 14 days, Weight < 1–1.5 kg, EGA < 30 weeks.
They have a specific design for extremely low gestational age newborns (ELGANs), maintenance of fetal circulation, fluid-filled lungs, and cannulation of the umbilical vein and/or artery.
ECLS for COVID-19
The largest case series of ECLS use in children diagnosed with SARS-CoV-2 infection involved 7 patients aged 54 days to 16 years, with its indications in hypoxia, multisystem inflammatory syndrome in children (MIS-C), and septic shock from Staphylococcus aureus. Six initially required V-A ECLS, 3 of whom were later converted to V-V ECLS due to cardiac recovery or differential hypoxemia. Only 4 of 7 patients survived to discharge.
Evidence suggests that ECLS may be used in children with respiratory or cardiac failure associated with COVID-19 or MIS-C; however, more data are warranted to determine the true efficacy and role of ECLS in these patients.
Evolving cannulation strategies-
Traditional cannulation strategies
V-A cannulation—typically in the carotid artery and the internal jugular vein is the commonest cannulation technique for pediatric and neonatal ECLS for non-cardiac indications.
Its benefits are- a straightforward procedure from a technical standpoint, surgeons across institutions have a large amount of experience with the technique, the arterial reinfusion nourishes hemodynamic support which quickly stabilizes a clinically deteriorating infant, the positioning of the reinfusion cannula permits for stable high flows with no recirculation, by draining from the right atrium and reinfusing distal to the aortic valve, the blood flow through the right heart is significantly decreased, allowing for cardiac rest and recovery.
V–V cannulation with either a double-lumen cannula or, less commonly, two single-lumen cannulae is the alternative to V-A cannulation. Double-lumen cannulae are most commonly placed in the internal jugular vein, and can also be placed in the femoral vein in adults and larger pediatric patients. Its benefits are- double-lumen cannulae permit single-vessel access that can be achieved percutaneously, thus restricting the morbidity of the cannulation procedure and preserving the patient’s carotid artery; oxygenated blood is delivered to the pulmonary vasculature, which decreases pulmonary artery resistance and reduce the potential complications associated with emboli from the ECLS circuit; V–V ECLS increases coronary artery blood flow and oxygen delivery by increasing the oxygen saturation of native cardiac output; it bypasses the increase in left ventricular afterload.
It can be an option for older pediatric patients, as, before 5 years of age, the femoral vessels are typically too small to accept a cannula that can provide adequate venous drainage.
Indications for additional cannula placement (hybrid cannulation)
North–South Syndrome is a risk of femoral cannulation where the head and upper extremities are hypoperfused relative to the lower extremities, and are referred as “red legs, blue head”.
This condition can be managed by adding an additional venous reinfusion cannula into the internal jugular vein, thereby converting the circuit to veno-arteriovenous (V-AV) ECLS, or venous drainage with arterial and venous reinfusion. This does not increase overall oxygen delivery of the ECLS circuit but anatomically redistributes the perfusion.
The continued progress in the simplification and safety of ECLS circuits will no longer require the intensive bedside management of these patients by multiple providers. Awake ECLS and wearable extracorporeal devices will allow managing stable, long-term ECLS patients on the ward or at home, like patients with pacemakers, defibrillators, and ventricular assist devices.
SOURCE- Fallon BP, Gadepalli SK, Hirschl RB. Pediatric and neonatal extracorporeal life support: current state and continuing evolution. PediatrSurg Int. 2021;37(1):17-35. doi:10.1007/s00383-020-04800-2