Storage after gamma irradiation affects in vivo oxygen delivery capacity of transfused red blood cells in preterm infants

BACKGROUND Gamma irradiation of red blood cells (RBCs) is well recognized to exacerbate storage lesion formation, but the effect of storage after irradiation on in vivo oxygen delivery capacity of transfused RBCs is currently not known.STUDY DESIGN AND METHODS In 24 preterm infants with anemia receiving nonurgent transfusion of irradiated RBCs, we examined cerebral regional tissue oxygenation (crSO2) and time spent with peripheral arterial saturation (SpO2) less than 88%. Physiologic data were obtained immediately before, immediately after, and 5 days after transfusion.RESULTS We observed linear negative moderate correlations between time since irradiation and the magnitude of change in crSO2 (r = –0.60; 95% CI, –0.81 to –0.27; p = 0.0018) and time spent with SpO2 of less than 88% (r = –0.42; 95% CI, –0.71 to 0.003; p = 0.04) immediately after transfusion. In infants (n = 9) who received fresher RBCs (irradiated <10 days before transfusion), there was a sustained increase in mean crSO2 up to 5 days after transfusion (3.0%; 95% CI, 0.3% to 5.7%; p = 0.04). Conversely, in infants (n = 15) who received older RBCs (irradiated ≥10 days before transfusion), there were negligible changes in crSO2 after transfusion at any time point.CONCLUSION Our findings indicate that storage after gamma irradiation may have a detrimental effect on the oxygen delivery capacity of RBCs given to anemic preterm infants.