Management of Hematochezia in Infants with Congenital Heart Disease Admitted to the Acute Care Cardiology Unit: A Multicenter Retrospective Pilot Study.

OBJECTIVE: To assess the evaluation and prevalence of benign hematochezia (BH) vs necrotizing enterocolitis (NEC) in infants with congenital heart disease (CHD) <6 months old admitted to the acute care cardiology unit. STUDY DESIGN: This was a multicenter retrospective review of patient characteristics and evaluation of all hematochezia events in patients with CHD <6 months admitted to acute care cardiology unit at 3 high-volume tertiary care centers from February 2019 to January 2021. NEC was defined by the Bell staging criteria. Patients with gastrointestinal disorders were excluded. RESULTS: In total, 180 hematochezia events occurred in 121 patients; 42 patients had more than 1 event. In total, 61% of affected patients had single-ventricle physiology (38% hypoplastic left heart syndrome). Median age and weight at hematochezia were 38 days (IQR 24, 79) and 3.7 kg (IQR 3.2, 4.4). In total, 77% of hematochezia events were BH, and 23% were NEC. There were no surgical interventions for NEC or deaths from NEC. Those with NEC were significantly younger (34 vs 56 days, P < .01) and smaller (3.7 vs 4 kg, P < .01). Single-ventricle physiology was significantly associated with NEC. Initial bloodwork and diagnostic imaging at each center were assessed. There was no significant difference in white blood cell count or C-reactive protein in those with NEC compared with BH. Blood culture results were all negative. CONCLUSIONS: The majority of infants with CHD with hematochezia have BH over NEC, although single-ventricle and surgical patients remain at greater risk. Infants <45 days are more vulnerable for developing NEC. Bloodwork was noncontributory in the identification of cardiac NEC. Expansion to a prospective study to develop a treatment algorithm is important to avoid overtreatment.

Feeding Practices in Infants with Hematochezia and Necrotizing Enterocolitis on Acute Care Cardiology Units.

Infants with congenital heart disease (CHD) are at risk for developing both benign hematochezia and necrotizing enterocolitis (NEC). Despite these risks there are very few studies that investigate modifiable risk factors such as feeding practices. It remains unclear what feeding practices should be avoided due to higher incidence of CHD-NEC. We aim to assess the feeding practices across three high volume tertiary centers to establish a relationship between various feeding practices and development of NEC. A multicenter retrospective review of feeding practices at the time of documented hematochezia event that occurred between 1/2019 and 1/2021 in infants with CHD who were less than 6 months of age. NEC was defined as Bells Stage 2 or greater. Age, weight, ventricular morphology, primary diagnoses, feeding route, feed change, and formula type were evaluated. 176 hematochezia events occurred in 121 patients, 72% of these events were considered benign hematochezia with the remaining 28% being true NEC. Single ventricle (SV) physiology (p < 0.05), younger age, < 45 days of life, (p < 0.001), and feeding route were statistically associated with true NEC (p < 0.01). Formula type and recent change in feed administration were not associated with NEC. The caloric density of feeds at the time of hematochezia was nearing significance. The majority of hematochezia events are benign in nature, however, there should be heightened awareness in patients who are SV, younger in age, and those who are post-pylorically fed. There may be some risk in using higher caloric density feeds (> 24 kcal/oz), however, additional research is needed to fully establish this relationship.

Organic dust augments nucleotide-binding oligomerization domain expression via an NF-{kappa}B pathway to negatively regulate inflammatory responses.

Nucleotide-binding oligomerization domain 2 (NOD2) is involved in innate immune responses to peptidoglycan degradation products. Peptidoglycans are important mediators of organic dust-induced airway diseases in exposed agriculture workers; however, the role of NOD2 in response to complex organic dust is unknown. Monocytes/macrophages were exposed to swine facility organic dust extract (ODE), whereupon NOD2 expression was evaluated by real-time PCR and Western blot. ODE induced significant NOD2 mRNA and protein expression at 24 and 48 h, respectively, which was mediated via a NF-κB signaling pathway as opposed to a TNF-α autocrine/paracrine mechanism. Specifically, NF-κB translocation increased rapidly following ODE stimulation as demonstrated by EMSA, and inhibition of the NF-κB pathway significantly reduced ODE-induced NOD2 expression. However, there was no significant reduction in ODE-induced NOD2 gene expression when TNF-α was inhibited or absent. Next, it was determined whether NOD2 regulated ODE-induced inflammatory cytokine production. Knockdown of NOD2 expression by small interfering RNA resulted in increased CXCL8 and IL-6, but not TNF-α production in response to ODE. Similarly, primary lung macrophages from NOD2 knockout mice demonstrated increased IL-6, CXCL1, and CXCL1, but not TNF-α, expression. Lastly, a higher degree of airway inflammation occurred in the absence of NOD2 following acute (single) and repetitive (3 wk) ODE exposure in an established in vivo murine model. In summary, ODE-induced NOD2 expression is directly dependent on NF-κB signaling, and NOD2 is a negative regulator of complex, organic dust-induced inflammatory cytokine/chemokine production in mononuclear phagocytes.