Continuous renal replacement therapy during extracorporeal membrane oxygenation in neonates and infants

Extracorporeal life support (ECLS) is the highest form of circulatory support and can be offered to neonates and infants in cardiorespiratory failure. ECLS is associated with significant morbidity and mortality. Frequently reported is acute kidney injury (AKI), which is associated with poor outcomes including prolonged ECMO runs and mortality. The presence of AKI may necessitate the simultaneous use of continuous renal replacement therapy (CRRT). The CRRT circuit can be integrated directly into the ECLS circuit. When designing this combined circuit, it is crucial to understand how components alter hemodynamics. For example, centrifugal pumps are nonocclusive, whereas roller pumps are occlusive by design. This produces vastly varying effects with regard to flow rate, circuit pressure, pressure drop, total hemodynamic energy (THE), and THE loss. These effects are manipulated further with the addition of a CRRT circuit at varying locations in the ECLS circuit. Another facet to consider is gaseous microemboli (GME). Centrifugal pumps have demonstrated higher GME counts and volumes and have been shown to break up GME into smaller particles. Factors that may reduce the number of GME include the use of a Better-Bladder in the circuit, use of a roller pump, and integration of CRRT system between the pump and oxygenator.