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

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.

Economic evaluation alongside the Speed of Increasing milk Feeds Trial (SIFT)

OBJECTIVE

To evaluate the cost-effectiveness of two rates of enteral feed advancement (18 vs 30 mL/kg/day) in very preterm and very low birth weight infants.

DESIGN

Within-trial economic evaluation alongside a multicentre, two-arm parallel group, randomised controlled trial (Speed of Increasing milk Feeds Trial).

SETTING

55 UK neonatal units from May 2013 to June 2015.

PATIENTS

Infants born <32 weeks' gestation or <1500 g, receiving less than 30 mL/kg/day of milk at trial enrolment. Infants with a known severe congenital anomaly, no realistic chance of survival, or unlikely to be traceable for follow-up, were ineligible.

INTERVENTIONS

When clinicians were ready to start advancing feed volumes, infants were randomised to receive daily increments in feed volume of 30 mL/kg (intervention) or 18 mL/kg (control).

MAIN OUTCOME MEASURE

Cost per additional survivor without moderate to severe neurodevelopmental disability at 24 months of age corrected for prematurity.

RESULTS

Average costs per infant were slightly higher for faster feeds compared with slower feeds (mean difference £267, 95% CI -6928 to 8117). Fewer infants achieved the principal outcome of survival without moderate to severe neurodevelopmental disability at 24 months in the faster feeds arm (802/1224 vs 848/1246). The stochastic cost-effectiveness analysis showed a likelihood of worse outcomes for faster feeds compared with slower feeds.

CONCLUSIONS

The stochastic cost-effectiveness analysis shows faster feeds are broadly equivalent on cost grounds. However, in terms of outcomes at 24 months age (corrected for prematurity), faster feeds are harmful. Faster feeds should not be recommended on either cost or effectiveness grounds to achieve the primary outcome.

Arguments for routine administration of probiotics for NEC prevention

PURPOSE OF REVIEW

Probiotic administration to premature infants for the purpose of prevention of necrotizing enterocolitis is common in many parts of the world but uncommon in the United States. The present review will emphasize recent findings in support of routine administration of probiotics to this highly vulnerable population.

RECENT FINDINGS

Additional evidence from animal models describing mechanisms of protection of probiotics in the immature gut and updated meta-analyses of randomized placebo-controlled trials and observational cohorts are presented (now including more than 40 000 premature infants from countries across the globe).

SUMMARY

The preponderance of evidence suggests that probiotic administration to premature infants is well tolerated and decreases the risk of death, necrotizing enterocolitis, and sepsis. Further comparisons of probiotic administration to placebo are not likely to alter these conclusions. Rather, future work should focus on assurance of high-quality products with demonstrated purity and viability of probiotic microbes, and future clinical trials should focus on comparisons between high-quality products and doses.

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, slow feed advancement may delay establishment of full enteral feeding and may be associated with metabolic and infectious morbidities secondary to prolonged exposure to parenteral nutrition.

OBJECTIVES

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

SEARCH METHODS

We used the standard Cochrane Neonatal search strategy to search the Cochrane Central Register of Controlled Trials (CENTRAL; 2017, Issue 5), MEDLINE via PubMed (1966 to June 2017), Embase (1980 to June 2017), and the Cumulative Index to Nursing and Allied Health Literature (CINAHL; 1982 to June 2017). We searched clinical trials databases, conference proceedings, previous reviews, and reference lists of retrieved articles for randomised controlled trials (RCTs) and quasi-randomised trials.

SELECTION CRITERIA

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 upon the incidence of NEC in very preterm or VLBW infants.

DATA COLLECTION AND ANALYSIS

Two review authors assessed trial eligibility and risk of bias and independently extracted data. We analysed treatment effects in individual trials and reported risk ratio (RR) and risk difference (RD) for dichotomous data, and mean difference (MD) for continuous data, with respective 95% confidence intervals (CIs). We used a fixed-effect model for meta-analyses and explored potential causes of heterogeneity via sensitivity analyses. We assessed the quality of evidence at the outcome level using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

We identified 10 RCTs in which a total of 3753 infants participated (2804 infants participated in one large trial). Most participants were stable very preterm infants of birth weight appropriate for gestation. About one-third of all participants were extremely preterm or extremely low birth weight (ELBW), and about one-fifth were small for gestational age (SGA), growth-restricted, or compromised in utero, as indicated by absent or reversed end-diastolic flow velocity (AREDFV) in the fetal umbilical artery. Trials typically defined slow advancement as daily increments of 15 to 20 mL/kg, and faster advancement as daily increments of 30 to 40 mL/kg. Trials generally were of good methodological quality, although none was blinded.Meta-analyses did not show effects on risk of NEC (typical RR 1.07, 95% CI 0.83 to 1.39; RD 0.0, 95% CI -0.01 to 0.02) or all-cause mortality (typical RR 1.15, 95% CI 0.93 to 1.42; typical RD 0.01, 95% CI -0.01 to 0.03). Subgroup analyses of extremely preterm or ELBW infants, or of SGA or growth-restricted or growth-compromised infants, showed no evidence of an effect on risk of NEC or death. Slow feed advancement delayed establishment of full enteral nutrition by between about one and five days. Meta-analysis showed borderline increased risk of invasive infection (typical RR 1.15, 95% CI 1.00 to 1.32; typical RD 0.03, 95% CI 0.00 to 0.05). The GRADE quality of evidence for primary outcomes was "moderate", downgraded from "high" because of lack of blinding in the included trials.

AUTHORS' CONCLUSIONS

Available trial data do not provide evidence that advancing enteral feed volumes at daily increments of 15 to 20 mL/kg (compared with 30 to 40 mL/kg) reduces the risk of NEC or death in very preterm or VLBW infants, extremely preterm or ELBW infants, SGA or growth-restricted infants, or infants with antenatal AREDFV. Advancing the volume of enteral feeds at a slow rate results in several days of delay in establishing full enteral feeds and may increase the risk of invasive infection.

Aggressive nutrition in extremely low birth weight infants: impact on parenteral nutrition associated cholestasis and growth

Background

Parenteral nutrition associated cholestasis (PNAC) is a frequently observed pathology in extremely low birth weight (ELBW) infants. Its pathogenesis is determined by the composition and duration of parenteral nutrition (PN) as well as the tolerance of enteral feeds (EF). “Aggressive” nutrition is increasingly used in ELBW infants to improve postnatal growth. Little is known about the effect of “aggressive” nutrition on the incidence of PNAC. We analyzed the influence of implementing an “aggressive” nutritional regimen on the incidence of PNAC and growth in a cohort of ELBW infants.

Methods

ELBW infants were nourished using a “conservative” (2005–6; n = 77) or “aggressive” (2007–9; n = 85) nutritional regimen that differed in the composition of PN after birth as well as the composition and timing of advancement of EFs. We analyzed the incidence of PNAC (conjugated bilirubin > 1.5 mg/dl (25 µmol/l)) corrected for confounders of cholestasis (i.e., NEC and/or gastrointestinal surgery, sepsis, birth weight, Z-score of birth weight, time on PN and male sex), growth until discharge (as the most important secondary outcome) and neonatal morbidities.

Results

The incidence of PNAC was significantly lower during the period of “aggressive” vs. “conservative “nutrition (27% vs. 46%, P < 0.05; adjusted OR 0.275 [0.116–0.651], P < 0.01). Body weight (+411g), head circumference (+1 cm) and length (+1 cm) at discharge were significantly higher. Extra-uterine growth failure (defined as a Z-score difference from birth to discharge lower than −1) was significantly reduced for body weight (85% vs. 35%), head circumference (77% vs. 45%) and length (85% vs. 65%) (P < 0.05). The body mass index (BMI) at discharge was significantly higher (11.1 vs. 12.4) using “aggressive” nutrition and growth became more proportionate with significantly less infants being discharged below the 10th BMI percentile (44% vs. 9%), while the percentage of infants discharged over the 90th BMI percentile (3% vs. 5%) did not significantly increase.

Discussion

“Aggressive” nutrition of ELBW infants was associated with a significant decrease of PNAC and marked improvement of postnatal growth.

How to feed small for gestational age newborns

Feeding small for gestational age (SGA) newborns is extremely challenging and the neonatologist should be brave and cautious at the same time. Although these babies have a high risk of milk intolerance and necrotising enterocolitis, enteral feeding guidelines are not well established and practice varies widely among different neonatal units. Currently available studies on this topic include extremely and very low birth weight neonates, but are not focused specifically on small for gestational age infants. This review analyzes papers focused on feeding interventions in order to provide the best available evidences about the optimum timing for introduction of enteral feeding, how fast feed volume can be advanced, which milk and which feeding method is more appropriate in SGA infants.

Early trophic feeding versus enteral fasting for very preterm or very low birth weight infants

BACKGROUND

The introduction of enteral feeds for very preterm (< 32 weeks) or very low birth weight (< 1500 grams) infants is often delayed due to concern that early introduction may not be tolerated and may increase the risk of necrotising enterocolitis. However, prolonged enteral fasting may diminish the functional adaptation of the immature gastrointestinal tract and extend the need for parenteral nutrition with its attendant infectious and metabolic risks. Trophic feeding, giving infants very small volumes of milk to promote intestinal maturation, may enhance feeding tolerance and decrease the time taken to reach full enteral feeding independently of parenteral nutrition.

OBJECTIVES

To determine the effect of early trophic feeding versus enteral fasting on feed tolerance, growth and development, and the incidence of neonatal morbidity (including necrotising enterocolitis and invasive infection) and mortality in very preterm or VLBW infants.

SEARCH METHODS

We used the standard search strategy of the Cochrane Neonatal Review Group. This included electronic searches of the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 12), MEDLINE, EMBASE and CINAHL (1980 until December 2012), conference proceedings and previous reviews.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials that assessed the effects of early trophic feeding (milk volumes up to 24 ml/kg/day introduced before 96 hours postnatal age and continued until at least one week after birth) versus a comparable period of enteral fasting in very preterm or very low birth weight infants.

DATA COLLECTION AND ANALYSIS

We extracted data using the standard methods of the Cochrane Neonatal Review Group with separate evaluation of trial quality and data extraction by two authors and synthesis of data using risk ratio, risk difference and mean difference.

MAIN RESULTS

Nine trials in which a total of 754 very preterm or very low birth weight infants participated were eligible for inclusion. Few participants were extremely preterm (< 28 weeks) or extremely low birth weight (< 1000 grams) or growth restricted. These trials did not provide any evidence that early trophic feeding affected feed tolerance or growth rates. Meta-analysis did not detect a statistically significant effect on the incidence of necrotising enterocolitis: typical risk ratio 1.07 (95% confidence interval 0.67 to 1.70); risk difference 0.01 (-0.03 to 0.05).

AUTHORS' CONCLUSIONS

The available trial data do not provide evidence of important beneficial or harmful effects of early trophic feeding for very preterm or very low birth weight infants. The applicability of these findings to extremely preterm, extremely low birth weight or growth restricted infants is limited. Further randomised controlled trials would be needed to determine how trophic feeding compared with enteral fasting affects important outcomes in this population.

Feeding practices and necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is a multifactorial disorder that primarily affects premature infants. Human milk compared with formula reduces the incidence of NEC. Feeding practices do not increase the incidence of NEC in preterm infants. There is no evidence supporting continuous versus intermittent tube feedings in preterm infants. In a feed-intolerant preterm infant without any other clinical and radiologic evidence of NEC, minimal enteral nutrition rather than complete suspension of enteral feeding may be an alternative. Human milk-based fortifier compared with bovine-based fortifier may reduce the incidence of NEC but additional studies are required.

Noninvasive measurement of intestinal epithelial damage at time of refeeding can predict clinical outcome after necrotizing enterocolitis

BACKGROUND

Reintroduction of enteral nutrition in neonates with necrotizing enterocolitis (NEC) should take place when the gut is ready for its normal function. Too early a start of oral feeding might lead to disease relapse, whereas prolonged discontinuation of enteral nutrition is associated with impaired gut function and parenteral nutrition-related complications. This study evaluated whether noninvasive urinary measurement of intestinal fatty acid binding protein (I-FABP) at the time of refeeding can predict clinical outcome in neonates with NEC.

METHODS

Urinary I-FABP concentrations were measured in 21 infants with NEC just before reintroducing enteral nutrition. Poor outcome was defined as unsuccessful reintroduction of enteral feeding (EF), (re)operation for NEC, or death related to NEC after reintroduction of EF.

RESULTS

Median urinary I-FABP levels in neonates with poor outcome (n = 5) were significantly higher as compared with I-FABP levels in neonates with good outcome (n = 16) (P < 0.01). A clinically significant cutoff value of 963 pg/ml was found to discriminate between infants with poor outcome and those with good outcome (sensitivity 80%, specificity 94%).

CONCLUSION

Noninvasive urinary I-FABP measurement at time of refeeding differentiates neonates with poor outcome from neonates with good outcome in NEC. Urinary I-FABP measurement may therefore be helpful in the timing of EF in neonates with NEC.

Risk of parenteral nutrition in neonates--an overview

Healthcare-associated infections (HAI) in preterm infants are a challenge to the care of these fragile patients. HAI-incidence rates range from 6 to 27 infections per 1000 patient-days. Most nosocomial infections are bloodstream infections and of these, the majority is associated with the use of central venous catheters. Many studies identified parenteral nutrition as an independent risk factor for HAI, catheter-associated bloodstream infection, and clinical sepsis. This fact and various published outbreaks due to contaminated parenteral nutrition preparations highlight the importance of appropriate standards in the preparation and handling of intravenous solutions and parenteral nutrition. Ready-to-use parenteral nutrition formulations may provide additional safety in this context. However, there is concern that such formulations may result in overfeeding and necrotizing enterocolitis. Given the risk for catheter-associated infection, handling with parenteral nutrition should be minimized and the duration shortened. Further research is required about this topic.

Necrotizing enterocolitis risk: state of the science

Necrotizing enterocolitis (NEC) is the most common cause of gastrointestinal-related morbidity and mortality in the neonatal intensive care unit (NICU). Its onset is sudden and the smallest, most premature infants are the most vulnerable. Necrotizing enterocolitis is a costly disease, accounting for nearly 20% of NICU costs annually. Necrotizing enterocolitis survivors requiring surgery often stay in the NICU more than 90 days and are among those most likely to stay more than 6 months. Significant variations exist in the incidence across regions and units. Although the only consistent independent predictors for NEC remain prematurity and formula feeding, others exist that could increase risk when combined. Awareness of NEC risk factors and adopting practices to reduce NEC risk, including human milk feeding, the use of feeding guidelines, and probiotics, have been shown to reduce the incidence of NEC. The purpose of this review is to examine the state of the science on NEC risk factors and make recommendations for practice and research.

An update on necrotizing enterocolitis: pathogenesis and preventive strategies

Necrotizing enterocolitis (NEC) is one of the most critical morbidities in preterm infants. The incidence of NEC is 7% in very-low-birth-weight infants, and its mortality is 15 to 30%. Infants who survive NEC have various complications, such as nosocomial infection, malnutrition, growth failure, bronchopulmonary dysplasia, retinopathy of prematurity, and neurodevelopmental delays. The most important etiology in the pathogenesis of NEC is structural and immunological intestinal immaturity. In preterm infants with immature gastrointestinal tracts, development of NEC may be associated with a variety of factors, such as colonization with pathogenic bacteria, secondary ischemia, genetic polymorphisms conferring NEC susceptibility, anemia with red blood cell transfusion, and sensitization to cow milk proteins. To date, a variety of preventive strategies has been accepted or attempted in clinical practice with regard to the pathogenesis of NEC. These strategies include the use of breast feeding, various feeding strategies, probiotics, prebiotics, glutamine and arginine, and lactoferrin. There is substantial evidence for the efficacy of breast feeding and the use of probiotics in infants with birth weights above 1,000 g, and these strategies are commonly used in clinical practice. Other preventive strategies, however, require further research to establish their effect on NEC.