Cerebral oxygenation in preterm infants receiving transfusion

Background: The influence of severity of anemia and cardiac output (CO) on cerebral oxygenation (CrSO₂) and on the change in CrSO₂ following packed red blood cell (PRBC) transfusion in preterm infants has not been evaluated. The objectives of the current study were to evaluate the effect of pre-transfusion hemoglobin (Hb) and CO-weighted oxygen delivery index (ODI) on CrSO₂ and on the post-transfusion CrSO₂ change. Methods: Preterm infants of <32 weeks gestational age (GA) receiving PRBC transfusion were enrolled. Infants received 15 ml/kg PRBC over 3 h. CrSO₂ by near-infrared spectroscopy and CO by electrical velocimetry were recorded for 1 h pre-ransfusion and post transfusion. ODI was defined as pre-transfusion Hb × CO. Results: Thirty infants of 26.6 ± 2.0 weeks GA were studied at 19 ± 12 days. Pre-transfusion Hb was 9.8 ± 0.6 g/dl. Pre-transfusion CrSO₂ correlated with pre-transfusion ODI (R² = 0.1528, p =.044) but not with Hb level. The pre-transfusion to post-transfusion CrSO₂ change correlated with pre-transfusion ODI (R² = 0.1764, p =.029) but not with Hb level. CrSO₂ increased from 66 ± 6% to 72 ± 7% post transfusion (p <.001), while arterial oxygen saturation, heart rate, and CO did not change. Conclusion: In these infants, the pre-transfusion ODI was a better indicator of brain oxygenation and its improvement post transfusion than Hb alone. The role of CO and tissue oxygenation monitoring in assessing the need for transfusion should be evaluated.