The Intravascular Membrane Oxygenator Catheter: A device that oxygenates blood in patients with failing lungs
Hypoxic respiratory failure is a common cause of hospitalization for children and adults. Prior to the current COVID-19 pandemic, acute respiratory distress syndrome (ARDS), a subset of hypoxic respiratory failure with acute lung injury was present in 7% of adult intensive care unit (ICU) patients and represented 1-10% of pediatric ICU admissions. The COVID-19 pandemic has greatly increased the prevalence of respiratory failure in ICUs worldwide. Currently, patients with failing lungs are intubated and put on a ventilator to ease the work of their lungs and optimize oxygenation. If this fails, they may be supported with veno-venous extracorporeal membrane oxygenation (VV- ECMO), which is essentially an artificial lung surgically attached outside the body through intravascular cannulas. While VV-ECMO may be lifesaving, it is invasive, costly, and is associated with many serious complications including hemorrhage, thrombosis, infection, and end-organ injury. Others have tried to develop catheters capable of intravascular oxygen delivery but have been unsuccessful due to technical limitations. There is an urgent need for safe alternative technologies that support patients with severe hypoxic respiratory failure that function independently of diseased lungs.
Duke inventors are developing the IntraVascular Membrane Oxygenator catheter, a device that is intended to oxygenate the blood in critically ill patients with sick and failing lungs. By delivering oxygen directly to the bloodstream, such a catheter may allow for decreased ventilator support and may reduce the need for or supplant VV-ECMO. Efficient intravascular oxygen delivery is accomplished by flowing hyperbaric oxygen through nonporous hollow fiber membranes (HFM) which are in direct contact with the blood. High pressure oxygen is used to generate a large gradient for diffusion which greatly increases the transfer of oxygen compared to previous attempts that relied on large surface area for gas exchange. This approach requires less total HFM allowing for a more compact device amenable to intravascular use. Published feasibility studies indicate that this device could deliver greater than 10% of a patient’s basal oxygen needs in configuration that readily fits intravascularly. This approach is currently being tested in vitro using porcine blood and prototypes are being developed. A conceptually accurate transport model has been developed and validated for rapid in silico prototyping.
- Provides a minimally invasive therapeutic option for hypoxic respiratory failure beyond mechanical ventilation and VV-ECMO
- Functions independently of the diseased lungs
- Published feasibility studies indicate that such a device could deliver greater than 10% of a patient’s basal oxygen needs in a configuration that readily fits intravascularly