Is Veno-Venous Extracorporeal Membrane Oxygenation Always the Right Choice for Pediatric Patients With Refractory Respiratory Failure? An Extracorporeal Life Support Organization Registry Analysis

Use of veno-venous (VV) extracorporeal membrane oxygenation (ECMO) to manage pediatric refractory respiratory failure has significantly increased in the last decade, however, when severe cardiac dysfunction develops or gas exchange remains impaired, conversion to other forms of bypass becomes essential. This retrospective study aims to evaluate the incidence, outcomes, and predictive factors for VV ECMO conversion in pediatric patients with refractory respiratory failure. Among the 5,162 pediatric patients in the Extracorporeal Life Support Organization (ELSO) Registry received VV ECMO between 2014 and 2024; among these, 421 (8.1%) were converted to veno-arterial (VA) or alternative configurations. The conversion group reported significantly higher in-hospital mortality (51.1% vs. 26.7%, p < 0.001) and higher incidence of complications during ECMO. Both the duration of ECMO support (13 [interquartile range {IQR}: 5; 27] vs. 8 [IQR: 4; 15] days; p < 0.001) and the duration of hospital stay (39 [18-73] vs . 32 [17-57] days, p = 0.007) were significantly longer in the conversion group. Higher levels of pre-ECMO lactate (odds ratio [OR]: 1.056 [95% confidence interval {CI}: 0.999-1.112], p < 0.042) were associated with a higher risk of conversion. This study suggests that the correct selection of the ECMO mode may improve survival and that VV ECMO should not be considered in patients presenting before ECMO deployment both low mean arterial pressure and high lactate levels.