Routine fecal occult blood testing does not predict necrotizing enterocolitis in very low birth weight neonates

Impact of Routine Gastric Aspirate Monitoring on Very Low Birth Weight Early Preterm Infants

OBJECTIVES

Routine gastric aspirate (RGA) monitoring is a common yet controversial practice intended for early identification of gastrointestinal pathology in infants receiving gavage feeds. Our objectives were to evaluate the association of ceasing RGA monitoring on the incidence of necrotizing enterocolitis (NEC) as well as nutritional outcomes in a large population of very low birth weight (VLBW) and very preterm neonates.

METHODS

Retrospective record review of neonates born ≤32 weeks and/or VLBW from 2 cohorts: (1) during pre-feed RGA monitoring (September 2015 to June 2018) and (2) after cessation of RGA ("non-RGA") monitoring (July 2018 to December 2020). We compared incidence of NEC, time-to-full enteral feeds, central line duration, and duration of parenteral nutrition (PN) in bivariate and multivariable models accounting for changes in feeding protocols over time.

RESULTS

We identified 617 subjects, 53% in the RGA monitoring cohort (n = 327) and 47% in non-RGA cohort (n = 290). The non-RGA cohort had feeds initiated earlier ( P < 0.0001), achieved full enteral feeds more rapidly ( P < 0.0001), received a shorter duration of PN ( P = 0.0003), and had shorter central access duration ( P < 0.0001) without increasing NEC risk. In fact, the non-RGA cohort had a lower incidence of NEC ( P = 0.0345) compared to the RGA cohort. Even after adjusting for changes in feeding protocols over time in a multivariable model, the RGA cohort had significantly higher odds of NEC.

CONCLUSIONS

Pre-feed RGA monitoring in the absence of concerning clinical exam findings is not indicated for neonates receiving gavage feeds as it does not improve NEC incidence but instead may delay important nutritional outcomes such as feed initiation and central line removal.

New Strategies for Necrotizing Enterocolitis Diagnosis and Prevention in Newborns

Necrotizing enterocolitis is one of the most frequent and severe gastrointestinal diseases that affect preterm newborns in Neonatal Intensive Care Units. It was firstly described in 1960s, but this clinical entity was not widely recognized until the advent of modern neonatal intensive care. The disease is characterized by submucosal edema, infiltration of intestinal wall by immune cells, specifically neutrophils and, in severe forms, wall necrosis that leads to intestinal perforation. Its incidence is inversely associated to birth weight and gestational age. Necrotizing enterocolitis has been responsible for high rates of morbidity and mortality (15-30%), despite improvements made in neonatal care in the last decades. The challenge is to optimize strategies for early diagnosis, define the best medical and surgical treatments and standardize preventive measures. Several biomarkers have been proposed for the early prediction of necrotizing enterocolitis onset in preterm newborns and can be useful not only for diagnostic purposes but also for prediction of disease progression and severity. The purpose of this paper is to illustrate the most recent evidence regarding the diagnosis and prevention of necrotizing enterocolitis. This manuscript contributes to clinical decision-making in preterm neonates at high risk of developing necrotizing enterocolitis.

Clinical significance of positive fecal occult blood test in neonates

The fecal occult blood test (FOBT) is a screening tool for hematochezia. This study aims to summarize the clinical features associated with a positive FOBT in neonates and to explore some clues for the underlying causes. Combination with other clinical information, identifying the possible etiology is more likely and could be useful for choosing an effective therapeutic strategy. The medical records of 282 neonates with positive FOBTs from January 1 to July 31, 2016, were collected and retrospectively analyzed. The total incidence rate of FOBT positivity in neonates was 6.2%. Among these patients, 71 (25.2%) neonates had false-positive FOBTs, whereas 211 (74.8%) neonates had intraintestinal sources of hematochezia. Necrotizing enterocolitis (NEC, 20.9%), structural abnormalities of gastrointestinal tract (SAGT, 12.4%), and suspected food allergy (sFA, 10.6%) were the most common causes of neonatal hematochezia. It indicated that FOBT-positive neonates with NEC were more likely to suffer due to a younger gestational age, lower birth weight, and lower weight on admission than the neonates with other conditions. The proportions of neonates with bloody stool (90.0%) and diarrhea (63.3%) in the sFA group were markedly higher than those in the other groups. However, in the SAGT group, emesis (94.3%) and abdominal distension (80.0%) were evidently higher, usually accompanied by a relatively poor response (60.0%) and weakened bowel sounds (48.6%). Furthermore, the higher incidences of poor response (72.1%), abdominal distension (71.2%), bloody stools (64.4%), and weakened bowel sounds (62.7%) were observed in the NEC group. Due to the complicated etiology associated with a positive FOBT, the analyzed indexes were combined with other clinical features to identify the likely causes of neonatal hematochezia. Because NEC, sFA and SAGT show similar clinical manifestations and can occasionally transform into each other, close and frequent observation is crucial for timely intervention to achieve a better prognosis. Although it failed to provide an early warning of severe disease through FOBT, and the early intervention for FOBT might not decrease NEC, sFA, structural bowel injuries, or any other complications, newborn FOBT positive reminds medical staff to be alert to the related diseases including NEC, SAGT and sFA, by closer observation and follow-up.

The utility of guaiac stool testing in the detection of gastrointestinal complications in infants with critical congenital heart disease

BACKGROUND

Guaiac stool testing has been routinely used as a method to detect gastrointestinal complications in infants with critical congenital heart disease (CHD); however, the sensitivity and specificity have not been established.

METHODS

A retrospective chart review was performed investigating the presence of heme-positive stools and subsequent gastrointestinal complications as well as time to goal caloric intake and radiograph exposure.

RESULTS

The presence of heme-positive stools was not a statistically significant factor in patients with critical CHD that experienced gastrointestinal complications. Additionally, patients with heme-positive stools did undergo more abdominal X-rays than those with heme-negative stools.

CONCLUSIONS

The routine use of guaiac stool testing in infants with critical CHD is not a predictor of possible gastrointestinal complications and leads to more radiograph exposure for the patient. Close clinical monitoring can be used to evaluate feeding tolerance in infants with critical CHD.

Current status of laboratory and imaging diagnosis of neonatal necrotizing enterocolitis

Necrotizing enterocolitis continues to be a devastating disease process for very low birth weight infants in Neonatal Intensive Care Units. The aetiology and pathogenesis of necrotizing enterocolitis are not definitively understood. It is known that necrotizing enterocolitis is secondary to a complex interaction of multiple factors that results in mucosal damage, which leads to intestinal ischemia and necrosis. Advances in neonatal care, including resuscitation and ventilation support technology, have seen increased survival rates among premature neonates and a concomitant detection in the incidence of this intestinal disease.Diagnosis can be difficult, and identifying infants at the onset of disease remains a challenge. Early diagnosis, which relies on imaging findings, and initiation of prompt therapy are essential to limit morbidity and mortality. Moreover, early management is critical and life-saving.This review summarizes what is known on the laboratory and instrumental diagnostic strategies needed to improve neonatal outcomes and, possibily, to prevent the onset of an overt necrotizing enterocolitis.