Safe ECMO reconfiguration from veno-venous to veno-veno-venous to support hypoxic patients with severe COVID 19, a single centre cohort

ABSTRACT

Objective: Veno-venous ECMO is a well-established support technique for patients with respiratory failure-induced hypoxia allowing for pulmonary recovery and implementation of lung-protective ventilatory settings. However, in severe respiratory failure cases, ECMO may be unable to provide full support, and patients remain hypoxic. In this case series, we describe the reconfiguration of VV ECMO to veno-veno-venous (VV-V) ECMO, a more complex hybrid cannulation strategy, where a third cannula is inserted to improve venous drainage to provide more ECMO blood flow and therefore increase systemic oxygenation in patients receiving ECMO for severe COVID-19. Methods: Data from patients who received circuit reconfiguration from VV ECMO to VV-V ECMO at the Royal Brompton Hospital during the COVID-19 pandemic between March 2020 - February 2021 was collected from the ICU's Clinical Information System (ICCA, Philips Healthcare) and analysed. Endpoints included PaO2, ECMO blood flow, arterial saturation and any complications relating to the reconfiguration. Results: 15 patients (9/15 male) with an average BMI of 39.0 ± 10.7 received circuit configuration bedside with no complications. An increase in ECMO blood flow (average 0.54 ± 0.76 LPM), PaO2 (average 4.96 ± 4.23 kPa) and arterial saturation (7 ± 6%) were demonstrated over the cohort of patients. 10/15 patients survived their ECMO run, 2 patients died on ECMO and 3 patients are still receiving ECMO at the time of writing. Conclusions: ECMO reconfiguration to a VV-V cannulation strategy is a safe procedure to increase ECMO blood flow and therefore, arterial oxygenation and saturation in hypoxic patients with severe COVID-19.