The Effect of Blood Transfusion on Blood Flow to the Intestines of Premature Infants

The Effect of Packed Red Blood Cell Transfusion on Superior Mesenteric Artery Blood Flow Velocity in Premature Infants After Feeding

The purpose of the study is to see if a blood transfusion changes how fast blood flows to the intestines of a premature baby. Blood flow is measured by an ultrasound test. The investigators also look to see if the blood flow to the intestines depends on whether the baby feeds or doesn't feed during the blood transfusion.

Currently a disparity exists among the NICU staff at Magee-Womens Hospital regarding whether premature infants should be fed during a blood transfusion. The effects of a blood transfusion on superior mesenteric artery blood flow velocity and the post-prandial hyperemia are not known.

We hypothesize that the post-prandial change in mesenteric blood flow velocity (BFV) will be the same before as after a packed red blood cell (PRBC) transfusion among anemic premature infants.

Sixty anemic infants (25-32 weeks GA, feeding >= 60 cc/kg/day) will undergo pre- and post-feed superior mesenteric artery Doppler studies both before and after a blood transfusion. Infants will be stratified by current weight into two groups (< 1250 grams and > 1250 grams). In each weight stratum the infants will be randomized to feeding or NPO during the PRBC transfusion. Randomization will be by block design, with block sizes ranging from two to six infants. The investigator performing the Doppler studies will remain masked to the feeding assignment of the infant.

The primary outcome for the study is the superior mesenteric artery blood flow velocity response to feeding between anemic and non-anemic states among premature infants. Our secondary outcome is the effect of feeding on BFV between anemic and non-anemic states in these infants. Statistical analysis will include paired and unpaired Student t-tests and regression analysis.

Inclusion Criteria:

1. Singleton infants born at 25-32 weeks gestation who are < 38 weeks post-conceptual age at enrollment
2. First infant of twin gestation born at 25-32 weeks gestation who requires a blood transfusion; if both infants require transfusion on the same day the larger infant will be enrolled.
3. Receiving bolus enteral feeds [PO (bottle) and/or PE (feeding tube)] of at least 60 cc/kg/day
4. A planned packed red blood cell transfusion, as per the clinical team, for anemia
5. Infant is very likely to require a blood transfusion according to the attending neonatologist.

Exclusion Criteria:

1. Known congenital anomalies of the heart, brain, kidneys or intestine
2. Chromosomal abnormality
3. Intrauterine growth restriction at < 3% for weight at birth since this has been shown to alter mesenteric BFV and the post-prandial hyperemia
4. Twin to twin transfusion sequence
5. Higher order multiples
6. Patent ductus arteriosus known to be present or currently being treated
7. History of definite necrotizing enterocolitis Bell Stage 2 or greater
8. Concurrent treatments with antibiotics or steroids
9. Feeding intolerance, defined as gastric aspirate > 30% of feed volume on 3 sequential feeds
10. Concurrent enrollment in another randomized trial
11. Infants discharged or transferred to another facility without having received a PRBC transfusion will be excluded post-hoc.