Effects of blood transfusion on regional tissue oxygenation in preterm newborns are dependent on the degree of anaemia.

Abstract

Most of the preterm infants are transfused at least once during their stay in the neonatal intensive care unit (NICU). The aims of this study were to demonstrate if packed red blood cell (pRBC) transfusion modulates regional (cerebral, abdominal, renal) tissue oxygen saturation measured by near-infrared spectroscopy (NIRS) and to demonstrate if we can use NIRS to guide transfusion decisions in neonates. A multi-probe NIRS device was applied to anaemic preterm infants of gestational age <33 weeks for 30-60 min before and 24 h after pRBC transfusion. We evaluated the results separately in the subgroup with a pre-transfusion haemoglobin (Hb) < 8 g/dL. Cerebral, abdominal and renal tissue oxygen saturation (rSO2 ) and abdominal/cerebral, abdominal/renal and renal/cerebral rSO2 ratios before and 24 h after transfusion were compared. There was no significant difference in cerebral rSO2 and abdominal/renal rSO2 ratios before and 24 h after transfusion, but abdominal and renal rSO2 and abdominal/cerebral and renal/cerebral rSO2 ratios at the 24th h following transfusion increased significantly. This increase was observed in the subgroup with pre-transfusion Hb < 8 g/dL. Although statistically significant, the increase in renal oxygenation was within the limits of variability. The increase in tissue oxygenation in abdominal region after pRBC transfusion suggests decreased tissue oxygenation of intestines during severe anaemia despite cerebral oxygenation being maintained at that particular Hb level. The impact of the increase on renal oxygenation with pRBC transfusion is unclear and might need further investigation. Increase in abdominal rSO2 may cause reperfusion injury, oxidative damage and trigger necrotising enterocolitis.