Reducing Hyperoxia Exposure in Infants Requiring Veno-Arterial Extracorporeal Membrane Oxygenation after Cardiac Surgery

Abstract

Recent studies have suggested worse outcomes in patients exposed to hyperoxia while supported on veno-arterial extracorporeal membrane oxygenation (VA-ECMO). However, there are no data regarding the effect of reducing hyperoxia exposure in this population by adjusting the fraction of inspired oxygen (FiO₂) of the sweep gas of the ECMO circuit. A retrospective review of 143 patients less than 1 year of age requiring VA-ECMO following cardiac surgery from 2007 to 2018 was completed. 64 patients had a FiO₂ of the sweep gas < 100% with an average PaO₂ of 210 mm Hg in the first 48 h of support [vs 405 mm Hg in the group with a FiO₂ = 100% (p < 0.0001)]. There was no difference in mortality at 30 days after surgery or other markers of end-organ injury with respect to whether the FiO₂ was adjusted. At least one PaO₂ value < 200 mm Hg in the first 24 h on ECMO in patients with a FiO₂ < 100% trended toward a significant association (OR = 0.45, 95% CI = 0.21-1.01) with decreased risk of 30-day mortality when compared to those patients with a FiO₂ = 100% and all PaO₂ values > 200 mm Hg. Only 47% of patients with a FiO₂ < 100% had an average PaO₂ less than 200 mm Hg which indicates that the intervention of reducing the FiO₂ of the sweep gas was not entirely effective at reducing hyperoxia exposure. Future research is needed for developing clinical protocols to avoid hyperoxia and to identify mechanisms for hyperoxia-induced injury on VA-ECMO.

Keywords: Cardiothoracic surgery; Congenital; Extracorporeal Membrane Oxygenation; Heart defects; Hyperoxia.