Standardized slow enteral feeding protocol reduces necrotizing enterocolitis in micropremies

Hour of Life at Enteral Feeding Initiation and Associated Clinical Morbidity in Extremely Low-Birth-Weight Infants

BACKGROUND/OBJECTIVES

Identifying nutritional interventions in extremely low-birth-weight (ELBW) infants (<1000 g) that are associated with favorable clinical outcomes is important. Delayed enteral feeding initiation (>3 days) has been associated with increased odds of developing morbidity. Therefore, the aim of this study is to evaluate the relationship between hour of life at enteral feeding initiation and associated clinical outcomes.

METHODS

An IRB-approved retrospective chart review evaluated ELBW infants. Birth acuity was evaluated using CRIB II scoring and incidence of various morbidities (bronchopulmonary dysplasia (BPD), retinopathy of prematurity (ROP), necrotizing enterocolitis (NEC), and spontaneous intestinal perforation (SIP)) and mortality was assessed after adjustment. p < 0.05 was statistically significant.

RESULTS

A total of 27/61 (44.3%) initiated enteral feeding <12 h of life. CRIB II scores were lower in infants with earlier enteral feeding initiation. There were no statistical differences in NEC, SIP, or death between categories of hour of life at enteral feeding initiation. After adjusting for CRIB II scores, enteral feeding initiation ≥12 h of life was associated with more days receiving oxygen >21% inspired air (β = 32.7; p = 0.040), approximately 7-fold higher odds of developing moderate/severe BPD (95% CI 1.2.8-38.28; p = 0.025), and 9-fold higher odds of being discharged home while receiving oxygen therapy (95% CI 1.03-79.81; p = 0.047).

CONCLUSIONS

Timing of enteral feeding initiation may be delayed in ELBW infants with higher clinical acuity, yet later initiation by hour of life is associated with worsened clinical respiratory outcomes. Early initiation within the first 12 h of life is feasible and was not associated with gastrointestinal morbidity in this single-center cohort of ELBW infants.

Prevention Strategies and Management of Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) is a serious intestinal disease which primarily affects preterm infants. The pathogenesis of NEC is multifactorial. Thus, it is complicated to study, prevent, and manage.

Purpose of Review

The purpose of this review is to provide a comprehensive summary of recent research and provide recommendations for the prevention and management of NEC. Currently, management is supportive and non-specific and long-term outcomes for surgical NEC are poor.

Recent Findings

The most important strategy to prevent NEC is to provide preterm infants with a human milk diet, minimize exposure to antibiotics and avoid medications that disturb the intestinal microbiome.

Summary

Strategies to optimize the infant's intestinal microbiome are critical, as disturbances in the intestinal microbiome composition are a major factor in the pathogenesis of this disease. Optimizing maternal health is also vital to prevent prematurity and neonatal morbidity. Ongoing research holds promise for the implementation of new diagnostic modalities, preventive strategies, and medical treatment options to improve outcomes for premature infants.

Artificial placenta technology: History, potential and perception

As presently conceptualised, the artificial placenta (AP) is an experimental life support platform for extremely preterm infants (i.e. 400-600 g; 21-23+6 weeks of gestation) born at the border of viability. It is based around the oxygenation of the periviable fetus using gas-exchangers connected to the fetal vasculature. In this system, the lung remains fluid-filled and the fetus remains in a quiescent state. The AP has been in development for some sixty years. Over this time, animal experimental models have evolved iteratively from employing external pump-driven systems used to support comparatively mature fetuses (generally goats or sheep) to platforms driven by the fetal heart and used successfully to maintain extremely premature fetuses weighing around 600 g. Simultaneously, sizable advances in neonatal and obstetric care mean that the nature of a potential candidate patient for this therapy, and thus the threshold success level for justifying its adoption, have both changed markedly since this approach was first conceived. Five landmark breakthroughs have occurred over the developmental history of the AP: i) the first human studies reported in the 1950's; ii) foundation animal studies reported in the 1960's; iii) the first extended use of AP technology combined with fetal pulmonary resuscitation reported in the 1990s; iv) the development of AP systems powered by the fetal heart reported in the 2000's; and v) the adaption of this technology to maintain extremely preterm fetuses (i.e. 500-600 g body weight) reported in the 2010's. Using this framework, the present paper will provide a review of the developmental history of this long-running experimental system and up-to-date assessment of the published field today. With the apparent acceleration of AP technology towards clinical application, there has been an increase in the attention paid to the field, along with some inaccurate commentary regarding its potential application and merits. Additionally, this paper will address several misrepresentations regarding the potential application of AP technology that serve to distract from the significant potential of this approach to greatly improve outcomes for extremely preterm infants born at or close to the present border of viability.

The role of intestinal alkaline phosphatase in the development of necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is a devastating neonatal disease that affects neonates worldwide and often leads to high morbidity and mortality rates. Despite extensive research, the cause of NEC remains unclear, and current treatment options are limited. An important novel finding is the potential role of intestinal Alkaline Phosphatase (IAP) in both pathogenesis and treatment of NEC. IAP can play a vital role in detoxifying liposaccharides (LPS), a key mediator of many pathological processes, thereby reducing the inflammatory response associated with NEC. Furthermore, IAP can help prevent dysbiosis, improve intestinal perfusion, and promote autophagy. In this comprehensive review, we present evidence of the possible connection between IAP and the LPS/Toll-like receptor 4 (TLR4) pathway, impaired gut immunity, and dysbiosis in the preterm gut. Based on these findings, the administration of exogenous IAP might provide promising preventive and therapeutic avenues for the management of NEC.

Implementing an exclusive human milk diet for preterm infants: real-world experience in diverse NICUs

BACKGROUND

Human milk-based human milk fortifier (HMB-HMF) makes it possible to provide an exclusive human milk diet (EHMD) to very low birth weight (VLBW) infants in neonatal intensive care units (NICUs). Before the introduction of HMB-HMF in 2006, NICUs relied on bovine milk-based human milk fortifiers (BMB-HMFs) when mother's own milk (MOM) or pasteurized donor human milk (PDHM) could not provide adequate nutrition. Despite evidence supporting the clinical benefits of an EHMD (such as reducing the frequency of morbidities), barriers prevent its widespread adoption, including limited health economics and outcomes data, cost concerns, and lack of standardized feeding guidelines.

METHODS

Nine experts from seven institutions gathered for a virtual roundtable discussion in October 2020 to discuss the benefits and challenges to implementing an EHMD program in the NICU environment. Each center provided a review of the process of starting their program and also presented data on various neonatal and financial metrics associated with the program. Data gathered were either from their own Vermont Oxford Network outcomes or an institutional clinical database. As each center utilizes their EHMD program in slightly different populations and over different time periods, data presented was center-specific. After all presentations, the experts discussed issues within the field of neonatology that need to be addressed with regards to the utilization of an EHMD in the NICU population.

RESULTS

Implementation of an EHMD program faces many barriers, no matter the NICU size, patient population or geographic location. Successful implementation requires a team approach (including finance and IT support) with a NICU champion. Having pre-specified target populations as well as data tracking is also helpful. Real-world experiences of NICUs with established EHMD programs show reductions in comorbidities, regardless of the institution's size or level of care. EHMD programs also proved to be cost effective. For the NICUs that had necrotizing enterocolitis (NEC) data available, EHMD programs resulted in either a decrease or change in total (medical + surgical) NEC rate and reductions in surgical NEC. Institutions that provided cost and complications data all reported a substantial cost avoidance after EHMD implementation, ranging between $515,113 and $3,369,515 annually per institution.

CONCLUSIONS

The data provided support the initiation of EHMD programs in NICUs for very preterm infants, but there are still methodologic issues to be addressed so that guidelines can be created and all NICUs, regardless of size, can provide standardized care that benefits VLBW infants.

Dilemmas in initiation of very preterm infant enteral feeds-when, what, how?

With limited clinical evidence available to guide common nutritional decisions, significant variation exists in approaches to enteral feeding for very preterm infants, specifically when feedings are initiated, what is fed, and the method used for feedings. Preclinical studies have highlighted the benefits associated with avoiding nil per os and providing early-stage mother's own milk or colostrum. However, these recommended approaches are often mutually exclusive due to the delays in lactation associated with very preterm delivery, resulting in uncertainty regarding which approach should be prioritized. Few studies have evaluated feeding frequency in preterm infants, with limited generalizability to extremely preterm infants. Therefore, even evidence-based approaches to very preterm infant feed initiation can differ. Future research is needed to identify optimal strategies for enteral nutrition in very preterm infants, but, until then, evidence-informed approaches may vary depending on each neonatal intensive care unit's assessment of risk and benefit.

Nutrition Support Practices for Infants Born <750 Grams or <25 Weeks Gestation: A Call for More Research

With advances in medical care and efforts to care for continually smaller and younger preterm infants, the gestational age of viability has decreased, including as young as 21 or 22 weeks of gestation [...].

Delayed introduction of progressive enteral feeds to prevent necrotising enterocolitis in very low birth weight infants

BACKGROUND

Enteral feeding for very preterm or very low birth weight (VLBW) infants is often delayed for several days after birth due to concern that early introduction of feeding may not be tolerated and may increase the risk of necrotising enterocolitis. Concerns exist, however, that delaying enteral feeding may diminish the functional adaptation of the gastrointestinal tract and prolong the need for parenteral nutrition with its attendant infectious and metabolic risks.

OBJECTIVES

To determine the effects of delayed introduction of progressive enteral feeds on the risk of necrotising enterocolitis, mortality and other morbidities in very preterm or VLBW infants.

SEARCH METHODS

Search strategies were developed by an information specialist in consultation with the review authors. The following databases were searched in October 2021 without date or language restrictions: CENTRAL (2021, Issue 10), MEDLINE via OVID (1946 to October 2021), Embase via OVID (1974 to October 2021), Maternity and Infant Care via OVID (1971 to October 2021), CINAHL (1982 to October 2021). We also searched for eligible trials in clinical trials databases, conference proceedings, previous reviews, and reference lists of retrieved articles.

SELECTION CRITERIA

Randomised controlled trials that assessed the effects of delayed (four or more days after birth) versus earlier introduction of progressive enteral feeds on necrotising enterocolitis, mortality and other morbidities in very preterm or VLBW infants.

DATA COLLECTION AND ANALYSIS

Two review authors separately evaluated trial risk of bias, extracted data, and synthesised effect estimates using risk ratio (RR), risk difference (RD), and mean difference. We used the GRADE approach to assess the certainty of evidence for effects on necrotising enterocolitis, mortality,  feed intolerance, and invasive infection.

MAIN RESULTS

We included 14 trials in which a total of 1551 infants participated. Potential sources of bias were lack of clarity on methods to generate random sequences and conceal allocation in half of the trials, and lack of masking of caregivers or investigators in all of the trials. Trials typically defined delayed introduction of progressive enteral feeds as later than four to seven days after birth and early introduction as four days or fewer after birth. Infants in six trials (accounting for about half of all of the participants) had intrauterine growth restriction or circulatory redistribution demonstrated by absent or reversed end-diastolic flow velocities in the fetal aorta or umbilical artery.  Meta-analyses showed that delayed introduction of progressive enteral feeds may not reduce the risk of necrotising enterocolitis (RR 0.81, 95% confidence interval (CI) 0.58 to 1.14; RD -0.02, 95% CI -0.04 to 0.01; 13 trials, 1507 infants; low-certainty evidence due risk of bias and imprecision) nor all-cause mortality before hospital discharge (RR 0.97, 95% CI 0.70 to 1.36; RD -0.00, 95% CI -0.03 to 0.03; 12 trials, 1399 infants; low-certainty evidence due risk of bias and imprecision). Delayed introduction of progressive enteral feeds may slightly reduce the risk of feed intolerance (RR 0.81, 95% CI 0.68 to 0.97; RD -0.09, 95% CI -0.17 to -0.02; number needed to treat for an additional beneficial outcome = 11, 95% CI 6 to 50; 6 trials, 581 infants; low-certainty evidence due to risk of bias and imprecision) and probably increases the risk of invasive infection (RR 1.44, 95% CI 1.15 to 1.80; RD 0.10, 95% CI 0.04 to 0.15; number needed to treat for a harmful outcome = 10, 95% CI 7 to 25; 7 trials, 872 infants; moderate-certainty evidence due to risk of bias).  AUTHORS' CONCLUSIONS: Delaying the introduction of progressive enteral feeds beyond four days after birth (compared with earlier introduction) may not reduce the risk of necrotising enterocolitis or death in very preterm or VLBW infants. Delayed introduction may slightly reduce feed intolerance, and probably increases the risk of invasive infection.

Effect of parenteral nutrition duration on patterns of growth and body composition in very low-birth-weight premature infants

BACKGROUND

Parenteral nutrition (PN) is essential to support premature infants' growth and varies with enteral nutrition (EN) advancement rates. Data on PN duration's impact on premature infants' growth are limited. The aim of this multicenter observational study was to determine the effect of early PN duration on body composition at term corrected gestational age (CGA) in very low-birth-weight (VLBW) premature infants.

METHODS

VLBW infants exposed to PN in the first week of life and exposed to significantly different EN regimens were divided into two groups on the basis of early PN duration. Infants with a birth weight (BW) <1000 g and PN duration <28 days and infants with a BW 1000-1500 g and PN duration <14 days were assigned to the "short-PN" group. Infants receiving PN for longer durations were assigned to the "long-PN" group. Body composition was assessed via air displacement plethysmography at term CGA or before discharge.

RESULTS

Sixty-two and 53 infants were assigned to the short-PN and long-PN groups, respectively. The two groups were significantly different in BW and GA, so a nested case-control study was conducted after matching 36 infant pairs. Infants in the long-PN group had significantly lower fat-free mass (FFM) z-scores, but both groups had comparable fat mass (FM) z-scores. Long PN was a significant negative predictor of FFM z-score in the multivariate regression analysis.

CONCLUSION

In VLBW premature infants, PN duration is negatively associated with FFM z-scores at term CGA without affecting FM z-scores.

Slow advancement of enteral feed volumes to prevent necrotising enterocolitis in very low birth weight infants

BACKGROUND

Early enteral feeding practices are potentially modifiable risk factors for necrotising enterocolitis (NEC) in very preterm or very low birth weight (VLBW) infants. Observational studies suggest that conservative feeding regimens, including slowly advancing enteral feed volumes, reduce the risk of NEC. However, it is unclear whether slow feed advancement may delay establishment of full enteral feeding, and if it could be associated with infectious morbidities secondary to prolonged exposure to parenteral nutrition.

OBJECTIVES

To determine the effects of slow rates of enteral feed advancement on the risk of NEC, mortality, and other morbidities in very preterm or VLBW infants.

SEARCH METHODS

We searched CENTRAL (2020, Issue 10), Ovid MEDLINE (1946 to October 2020), Embase via Ovid (1974 to October 2020), Maternity and Infant Care database (MIDIRS) (1971 to October 2020), CINAHL (1982 to October 2020), and clinical trials databases and reference lists of retrieved articles for eligible trials.

SELECTION CRITERIA

We included randomised or quasi-randomised controlled trials that assessed effects of slow (up to 24 mL/kg/d) versus faster rates of advancement of enteral feed volumes on the risk of NEC in very preterm or VLBW infants.

DATA COLLECTION AND ANALYSIS

Two review authors separately evaluated trial risk of bias, extracted data, and synthesised effect estimates using risk ratio (RR), risk difference (RD), and mean difference. We used the GRADE approach to assess the certainty of evidence. Outcomes of interest were NEC, all-cause mortality, feed intolerance, and invasive infection.

MAIN RESULTS

We included 14 trials involving a total of 4033 infants (2804 infants participated in one large trial). None of the trials masked parents, caregivers, or investigators. Risk of bias was otherwise low. Most infants were stable very preterm or VLBW infants of birth weight appropriate for gestation. About one-third of all infants were extremely preterm or extremely low birth weight (ELBW), and about one-fifth were small for gestational age, growth-restricted, or compromised as indicated by absent or reversed end-diastolic flow velocity in the foetal umbilical artery. Trials typically defined slow advancement as daily increments of 15 to 24 mL/kg, and faster advancement as daily increments of 30 to 40 mL/kg. Meta-analyses showed that slow advancement of enteral feed volumes probably has little or no effect on the risk of NEC (RR 1.06, 95% confidence interval (CI) 0.83 to 1.37; RD 0.00, 95% CI -0.01 to 0.02; 14 trials, 4026 infants; moderate-certainty evidence) or all-cause mortality prior to hospital discharge (RR 1.13, 95% CI 0.91 to 1.39; RD 0.01, 95% CI -0.01 to 0.02; 13 trials, 3860 infants; moderate-certainty evidence). Meta-analyses suggested that slow advancement may slightly increase feed intolerance (RR 1.18, 95% CI 0.95 to 1.46; RD 0.05, 95% CI -0.02 to 0.12; 9 trials, 719 infants; low-certainty evidence) and may slightly increase the risk of invasive infection (RR 1.14, 95% CI 0.99 to 1.31; RD 0.02, 95% CI -0.00 to 0.05; 11 trials, 3583 infants; low-certainty evidence).

AUTHORS' CONCLUSIONS

The available trial data indicate that advancing enteral feed volumes slowly (daily increments up to 24 mL/kg) compared with faster rates probably does not reduce the risk of NEC, death, or feed intolerance in very preterm or VLBW infants. Advancing the volume of enteral feeds at a slow rate may slightly increase the risk of invasive infection.

Early Enteral Feeding in Preterm Infants: A Narrative Review of the Nutritional, Metabolic, and Developmental Benefits

Enteral feeding is the preferred method of nutrient provision for preterm infants. Though parenteral nutrition remains an alternative to provide critical nutrition after preterm delivery, the literature suggests that enteral feeding still confers significant nutritional and non-nutritional benefits. Therefore, the purpose of this narrative review is to summarize health and clinical benefits of early enteral feeding within the first month of life in preterm infants. Likewise, this review also proposes methods to improve enteral delivery in clinical care, including a proposal for decision-making of initiation and advancement of enteral feeding. An extensive literature review assessed enteral studies in preterm infants with subsequent outcomes. The findings support the early initiation and advancement of enteral feeding impact preterm infant health by enhancing micronutrient delivery, promoting intestinal development and maturation, stimulating microbiome development, reducing inflammation, and enhancing brain growth and neurodevelopment. Clinicians must consider these short- and long-term implications when caring for preterm infants.

Bolus versus continuous feedings following treatment for medical necrotizing enterocolitis

BACKGROUND

Necrotizing enterocolitis (NEC) is a serious, often fatal, disease of neonates. Minimal data exists regarding the optimal method for reintroducing feeds after successful treatment. This study aims to compare outcomes in patients reintroduced to bolus or continuous feeds after treatment for medical NEC.

METHODS

A retrospective review of infants treated for medical NEC in the neonatal intensive care unit (NICU) from 2011-2018 was performed. Demographics, information about initial feeds, clinical diagnosis data, and information about reintroduction of feeds were recorded. Patients with significant congenital heart disease or those who required procedures for treatment were excluded.

RESULTS

Sixty-one patients were analyzed; 45 were reintroduced to bolus feeds and 16 to continuous feeds. There were no differences between the two groups. Bolus-fed patients reached goal feeds quicker (p = 0.007), required fewer days of parenteral nutrition (p = 0.002), had shorter hospital stays (p = 0.013) and were discharged faster from diagnosis to discharge (p = 0.002). Differences were confirmed with multivariate regression.

CONCLUSION

Infants given bolus feeds reached goal feeds faster, required less time on PN, and were discharged quicker than those fed continuously. This suggests that, compared to continuous feeding, bolus feeding is associated with superior clinical outcomes among patients treated for medical NEC.

Prolonged minimal enteral nutrition versus early feeding advancements in preterm infants with birth weight ≤1250 g: a prospective randomized trial

Objective: To determine the effect of two different feeding strategies on time to achieve full enteral feeding and the incidence of feeding intolerance in preterm infants with birth weight ≤1250 g.Methods: A prospective randomized trial (NCT02913677) conducted at a tertiary level neonatal intensive care unit. Preterm infants with birth weight ≤1250 g were randomly allocated to either prolonged minimal enteral nutrition (MEN) in which feed volumes were not increased for five days or early feeding advancement groups in which feed volumes were advanced by 20-25 ml/kg/d until 150 ml/kg/d feed volume was achieved. The primary outcomes were time to reach full enteral feeding sustained for 72 h and incidence of feeding intolerance.Results: A total of 199 infants (99 in prolonged MEN and 100 in early feeding advancement groups) were involved in the study. No statistically significant differences were observed in time to achieve full enteral feeding and feeding intolerance. Daily weight gain (19 versus 16 g; p < .001) was significantly higher in prolonged MEN group. There were no significant differences in weight percentiles and z-scores at discharge. Duration of hospitalization was comparable between the groups. The overall incidence of late onset sepsis and culture proven sepsis was similar in both groups (p = .92 and p = .22, respectively). Incidence of necrotizing enterocolitis (NEC) was 5% in early feeding advancement group, whereas no case of NEC was observed in prolonged MEN group (p = .06).Conclusions: Prolonged MEN is not associated with a delay in time to achieve full enteral feedings. It may even provide an advantage for development of NEC in extremely low birth weight infants.Trial registration: Clinical Trials.gov: NCT02913677.

Slow enteral feeding decreases risk of transfusion associated necrotizing enterocolitis

BACKGROUND

Necrotizing Enterocolitis (NEC) is a multifactorial condition where PRBC transfusion is associated with necrotizing enterocolitis (TANEC) in about a third of all cases of NEC. We have investigated the role of feeding practices in incidence of TANEC. We sought to compare infants diagnosed with TANEC versus infants diagnosed with classic NEC and investigated the effects of a standardized slow enteral feeding (SSEF) protocol on TANEC incidence as well as the effects of SSEF on growth of infants with NEC.

METHODS

We conducted a retrospective cohort study, where medical records of infants born in a tertiary care neonatal intensive care unit (level IIIb) from January 1997 to May 2014 with birth weight < 1500 grams and gestational age≤34 weeks with NEC stage IIa or greater according to the modified Bell's staging were reviewed.

RESULTS

During the study period, 111 infants developed NEC, and 41/111 (37%) were diagnosed with TANEC. Infants with TANEC were smaller, more premature, had higher SNAPPE scores and were more anemic prior to transfusion compared with infants with 'classic NEC'. The severity of NEC did not differ between the two groups, however, infants with TANEC had worse outcomes and longer NICU stays. Introduction of SSEF protocol, led to a significant decrease in TANEC. There was no difference in weight and head circumference of infants in the two groups at 2 years corrected age.

CONCLUSION

SSEF led to a significant reduction in the incidence of TANEC without impairing growth at 2 years corrected age.