Objectives: 

Venovenous extracorporeal membrane oxygenation (ECMO) represents a standard and well-accepted modality of treating patients with refractory respiratory failure. Nevertheless, some patients might develop refractory hypoxemia, hemodynamic compromise or end-organ perfusion requiring a change. This study analyzed characteristics and outcomes of patients requiring a change from venovenous to a different ECMO configuration.

Design: 

Multicenter, retrospective, observational analysis of the Extracorporeal Life Support Organization Registry (2010–2020) in adult patients (≥ 18 yr old) underwent venovenous ECMO as initial cannulation strategy.

Setting and Patients: 

Comparison of patients who remained on venovenous ECMO vs. those who underwent configuration conversion and multivariable analysis to assess variables associated with configuration change.

Interventions: 

None.

Measurements and Main Results: 

Among 28,888 eligible venovenous ECMO runs, 702 (2.4%) received a change from the original configuration, including 399 (56.8%) conversions to venoarterial and 303 (43.2%) to hybrid ECMO configurations. Variables associated with conversion included: pre-ECMO cardiac conditions, bridge to lung transplant as indication, use of milrinone, epinephrine, sildenafil, bicarbonate, and 24-hour Pao₂ value. Conversion occurred at a median of 56 hours (interquartile range, 11.5–210 hr) after ECMO initiation, with earlier conversion to hybrid configuration. Increased rates of cardiovascular, hemorrhagic, vascular, renal, metabolic, infective, and circuit-related complications were reported in converted patients. In-hospital mortality was higher in converted patients (60.8%) overall, and highest for venovenous to venoarterial patients (63.2%).

Conclusions: 

The venovenous patients converted to other ECMO configurations were 2.4% and experienced higher complication and mortality rates. Variables associated with conversion highlight the importance of initial configuration selection and should be considered as part of the risk stratification framework when evaluating a patient for individualized ECMO support mode/configuration.