Over the past decade and a half, the use of veno-venous (VV) ECMO for severe respiratory failure has increased dramatically around the world.

VV ECMO gained popularity during the H1N1 influenza in 2009 that claimed the lives of hundreds of thousands throughout the world. Unlike other virus infections, H1N1 most dramatically affected people under the age of 65. VV ECMO was used to prevent the deaths of many young people.

Then, during the COVID-19 pandemic, the use of VV ECMO increased significantly. As the world looked for life-saving answers during the initial months of the pandemic, VV ECMO gained traction.

Research published in The Annals of Thoracic Surgery, looked at 415 patients with confirmed COVID-19 who were admitted to the intensive care unit at NYU Langone Health from March 10 to May 1, 2020.

Thirty patients were put on VV ECMO and 27 of them survived to discharge – an “exceptional” 90% survival rate. Of those, only one required supplemental oxygen therapy afterward.

Deane E. Smith, MD, is one of the authors of the research paper.

“These patients received ECMO for severe COVID-19 during the height of the pandemic in New York City—at a time when very little was known about the likelihood for success,” Dr. Smith told The Society of Thoracic Surgeons. [1]

“We learned that lung recovery was actually possible. When the pandemic started, that was not clear.”

VV ECMO for Acute Respiratory Distress Syndrome

VV ECMO can be the saving grace for patients suffering from severe espiratory failure, commonly acute respiratory distress syndrome (ARDS), with refractory hypoxia. The lack of oxygen throughout the body affects all organ systems and will eventually result in death if not reversed. Intensive care teams turn to ECMO support for patients whose oxygenation status does not improve with conventional modalities.

Once VV ECMO support is initiated, the goal is to drastically improve oxygen delivery to the body and decrease ventilator settings to limit lung injury. Unfortunately, in instances of high recirculation rates, improved oxygen delivery does not occur.

Recirculation (the reuptake of oxygenated blood from the reinfusion canula directly into the drainage canula) is a known phenomenon of VV ECMO. These patients often remain on high ventilator settings with low oxygen saturations – exactly opposite of what bedside staff hope to see.

For years it has been difficult to quantify recirculation; limiting clinicians’ ability to improve their recirculation rates. However, new technology utilizing indicator dilution techniques can provide intensive care teams with the exact percentage of recirculated ECMO flow.

The Transonic ELSA Monitor brings together two of Transonic’s technologies – ultrasound indicator dilution and transit-time ultrasound – for continuous flow measurement that makes a difference. By quantifying the percentage of recirculation with the ELSA Monitor, staff can optimize oxygen delivery to the patient– the basis for VV ECMO support.

[1] https://www.sts.org/press-releases/ecmo-may-offer-sickest-covid-patients-chance-exceptional-survival