Cognata A, Kataria-Hale J, Griffiths P, Maskatia S, Rios D, O’Donnell A, Roddy DJ, Mehollin-Ray A, Hagan J, Placencia J, Hair AB.
J Pediatr. 2019 Dec;215:11-16.e2. doi: 10.1016/j.jpeds.2019.08.009. Epub 2019 Sep 24.
Take Home Points:
- In infants with isolated critical congenital heart lesions, the incidence of preoperative necrotizing enterocolitis (NEC) was 3.3% and developed at a median of 5 days after initiation of feeds.
- Large volume feeding (>100ml/kg/d) of infants with critical heart disease in the preoperative period is associated with a 3-fold increase in the risk of NEC
- Infants who are exclusively fed with unfortified human milk diet had a significantly lower risk of preoperative NEC.
Commentary from Dr. Venu Amula (Salt Lake City), section editor of Pediatric Cardiology Journal Watch: In this retrospective, single-center cohort study of infants of any gestational age with isolated critical congenital heart lesion between January 2010 and January 2016, the authors evaluated whether large feeding volumes (> 100ml/kg/d) and exposure to cow’s milk formula increased the risk of preoperative Necrotizing Enterocolitis (NEC). NEC was defined based on the modified Bell criteria. The cardiac lesions included were those with a high risk of NEC – ductal dependent lesions, transposition of great arteries, truncus arteriosus, aortopulmonary window, severe Ebstein’s anomaly and tetralogy of Fallot with absent PV. Infants were excluded if they were admitted at >72 hours of age or had heterotaxy, major gastrointestinal anomalies or hypoxic-ischemic encephalopathy. Infants with cardiac anomalies that did not require intervention were also excluded. Demographic data were collected for all the infants who met inclusion criteria. Feeding data included date feeds were initiated; type of feeds provided; the largest volume of feeds (mL/kg/d) provided; and the feeding route that was used (oral vs nasogastric).
The association of volume of feeds (> 100ml/kg/d or less) and type of formula (cow’s milk) with the incidence of NEC in the preoperative period was evaluated in a multivariable logistic regression model that was built by including clinically relevant and all other risk factors found to be significantly associated with NEC (P = .05) in univariate analysis.
After screening 878 infants 546 were found to be eligible for the study. The incidence of NEC was 3.3% before the surgery and developed a median of 5 days after feeds were started. Large volume feeds defined as feeding volume more than 100 ml/kg/day was associated with an increased risk of NEC. Exclusive unfortified human milk diet was protective, with a significantly lower risk for NEC when controlled for other risk factors like feeding volume, birth weight small for gestational age, race, inotropic support preoperatively/pre-NEC, prematurity (gestational age <37 weeks), and cardiac lesion. Infants with biventricular ductal dependent blood flow had increased risk of NEC but were probably confounded by the fact that they were younger, had long wait times before surgery and were fed high volume, nonhuman milk diet.
The study is limited by being an evaluation of a single-center practice and outcomes and as such the results may not be generalizable, however, the sample size is large and contained decent case-mix severity. Like other studies on necrotizing enterocolitis, the definition of NEC and Bell staging, especially for stage 1 ( 8 out of 18) is subjective as acknowledged by the authors but every effort was taken to standardize. Whether these risk factors apply to severe stages of NEC is unclear due to the rarity of the outcomes in comparison to sample size when analyzed separately. The study suggests that caution should be exercised in the preoperative period when feeding infants with critical heart lesions of any gestational age regardless of the type and ductal dependency. Feeding volumes < 100ml/kg/d and using unfortified human milk diet seem to decrease the risk of this GI complication with major morbidity.