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 1year 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 210mm Hg in the first 48h of support [vs 405mm Hg in the group with a FiO2 = 100% (p < 0.0001)]. There was no difference in mortality at 30days after surgery or other markers of end-organ injury with respect to whether the FiO2 was adjusted. At least one PaO2 value < 200mm Hg in the first 24h 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 > 200mm Hg. Only 47% of patients with a FiO2 < 100% had an average PaO2 less than 200mm 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.