Safety and Efficacy of Low-Flow ECMO in a Multi-modal Cohort of Adults in Respiratory Failure

The current standard of care (SOC) for treatment of patients with acute respiratory distress syndrome (ARDS), inhalation injury, volume overload, and/or pulmonary dysfunction is mechanical ventilation (MV). However, these techniques are associated with several complications after prolonged use, including risk of infection, increased sedation requirements, pulmonary edema, ventilator-induced lung injury (VILI), barotrauma, and multi-organ failure. Extracorporeal life support (ECLS) has been used to successfully minimize, replace, or avoid the use of MV. This concept is critical as it permits ultra-lung protective MV settings, mobilization, early ambulation of patients, and timely extubation (when appropriate). Conventional ECLS typically requires blood flows of 3-6 L/min, and its cannula sizes range from 21-25 Fr. This is by definition "high-flow" as it constitutes near-complete extracorporeal circulation of patient's circulating blood volume. On the other hand, low-flow ECLS at 1-2.5 L/min has been shown to prevent deleterious shifts in pH and PaCO2 at a lower level of invasiveness, and its cannula sizes range from 19-20 Fr dual lumen cannulas (which are associated with less serial dilation). The investigators propose the use of a low-flow circuit to include the NovaLung system in conjunction with a smaller tubing set and cannula to enable earlier utilization of ECLS with less invasiveness and smaller catheters. Specifically, the study will either utilize the Crescent RA cannula (or equivalent dual-lumen cannula) or use a 15-25 Fr cannula, both with 3/8 tubing/step-down tubing, as needed, for our study. A femoral (fem)-femoral or femoral-internal jugular (IJ) approach may also be used. Carbon dioxide is six times more diffusible than oxygen across the membrane; thus, carbon dioxide transfers can occur with high efficiency at our targeted blood flows of 1-2.5L/min. Oxygen can still transfer at these blood flows, and low flow can improve oxygen levels to some degre