Necrotizing Enterocolitis in Infants With Congenital Heart Disease: The Role of Red Blood Cell Transfusions

Necrotizing enterocolitis (NEC) is a rare but catastrophic complication
that may occur in newborns with congenital heart disease (CHD). In the
preterm population, transfusion of red blood cells (RBCs) and use of
RBCs with longer storage time have been independently associated with
the development of NEC. To date, it is not known whether similar
associations exist for the term newborn with CHD. This retrospective
study identified the incidence of NEC among 1,551 newborns admitted to
the authors’ cardiac intensive care unit between 7 January 2002 and 7
January 2010. The study was limited to term newborns (>36 weeks
gestation). To understand the impact of RBC transfusions on the
development of NEC, a nested 2:1 matched case-control analysis was
undertaken to compare RBC transfusion patterns between an age-matched
group and a cardiac lesion-matched control group. In the study
population, NEC developed in 45 term infants during the postoperative
period. Of these 45 infants, 30 (66.7 %) had single-ventricle heart
defects, whereas 22 (48.8 %) required surgery for aortic arch
obstruction. The median patient age at NEC diagnosis was 21 days. The
RBC transfusion rate was higher among the patients who experienced NEC
(0.21/day) than among the control subjects (0.10/day) (p = 0.048). A
multivariate analysis indicated that onset of NEC was associated with a
greater number of RBC transfusions (odds ratio [OR] 1.83; 95 %
confidence interval [CI] 1.07-7.47; p = 0.045). The duration of RBC
storage was not significantly longer in the NEC group (9 days) than in
the control cohort (7 days) (p = 0.16). Increased exposure to RBC
transfusions is associated with the development of NEC in term infants
with CHD. Longer storage of RBCs does not appear to increase this risk.
Although causality cannot be confirmed, these data prompt a careful
review of RBC transfusion practices with this population.