Transfusions and Nitric Oxide Level in Preterm Infants

The purpose of this study is to better understand S-nitrosohemeglobin (SNO-Hb) in transfused blood of extremely preterm infants. The long term goal of the project is to identify variation in the SNO-Hb between packed red blood cell units, and between and among individual preterm infants pre and post-transfusion. Duke investigators are developing methods to replenish SNO-Hb, which, if successful, would improve RBC deformation in addition to providing a vasodilatory stimulation to hypoxic tissue, and lead to a randomized clinical trial testing treated vs. untreated RBC transfusions in extremely premature infants. AIM 1. Measure the Total Hemoglobin (Hb)-bound nitric oxide (NO), Hb \[Fe\] NO, SNO-Hb (a calculated value = (total Hb-NO - Hb \[Fe\] NO) in blood to be transfused in extremely preterm babies, and in samples pre and post- transfusion from the babies. Hypothesis 1: Measures of NO and SNO-Hb will be low in blood used for transfusion in preterm infants and will be decreased in the post-transfusion samples from the infants compared with the pre-transfusion samples. AIM 2. Collect clinical data about study participants, including oxygen saturation and measures of perfusion pre and post-transfusion. Hypothesis 2: Measures of perfusion will be reduced by 20% post-transfusion in extremely preterm infants.