Comparison of Three Modalities of Feeding in Preterm Infants ≤32 Weeks and ≤1,250 G: A Randomized Controlled Trial

OBJECTIVE

Early establishment of enteral feeds is desirable in very preterm infants, but it may be associated with feeding intolerance. Several feeding methods have been studied with no strong evidence to suggest the preferred feeding method to establish early full enteral feeds. We studied three modalities of feeding in preterm infants ≤32 weeks and ≤1,250 g: continuous infusion (CI), intermittent bolus by infusion (IBI), and intermittent bolus by gravity (IBG) for their effect on time to reach full enteral feeds of 180 mL/kg/d.

STUDY DESIGN

We randomized 146 infants, 49 infants in each CI and IBI group and 48 infants in the IBG group. In the CI group, feeds were delivered by an infusion pump continuously over 24 hours. In the IBI group, feeds were given every 2 hours and infused over 15 minutes by an infusion pump. In the IBG group, feeds were delivered by gravity over 10 to 30 minutes. The intervention was continued till infants reached direct breast/cup feeds.

RESULTS

The mean (standard deviation) gestation in CI, IBI, and IBG groups were 28.4 (2.2), 28.5(1.9), and 28.6 (1.8) weeks, respectively. The time to reach full feeds in CI, IBI, and IBG were not significantly different (median [interquartile range]: 13 [10-16], 11.5 [9-17], and 13 [9.5-14.2] d, respectively, p = 0.71). The proportions of infants who developed feeding intolerance in CI, IBI, and IBG were similar (n [%]: 21 [51.2%], 20 [52.6%], and 22 [64.7%], respectively, p = 0.45). There was no difference in necrotizing enterocolitis ≥2 (p = 0.80), bronchopulmonary dysplasia (p = 0.86), intraventricular hemorrhage ≥2 (p = 0.35), patent ductus arteriosus requiring treatment (p = 0.44), retinopathy of prematurity requiring treatment (p = 0.51), and growth parameters at discharge.

CONCLUSION

In preterm infants, ≤32 weeks of gestation and birth weight ≤1,250 g, there was no difference in time to reach full enteral feeds in the three modalities of feeding. This study is registered with Clinical Trials Registry India (CTRI) and the registration number is CTRI/2017/06/008792.

KEY POINTS

· Gavage feeding in preterm infants is either continuous or intermittent bolus feeding.. · Intermittent bolus feeding was evaluated in a controlled time by infusion over 15 minutes.. · The time to reach full feeds was comparable for all three methods..

Continuous versus bolus intermittent intragastric tube feeding for preterm and low birth weight infants with gastro-oesophageal reflux disease

BACKGROUND

Gastro-oesophageal reflux disease is a particularly common condition among preterm and low birth weight infants. These infants are more likely to have excessive regurgitation, as they do not have a fully developed antireflux mechanism. Preterm and low birth weight infants who are unable to suck oral feeds are required to be fed via an intragastric tube for varying lengths of time. Intragastric tube feeding can be delivered by the intermittent bolus method or by the continuous feeding method. Use of continuous or intermittent bolus intragastric feeding may have a positive or negative effect on the incidence or severity of gastro-oesophageal reflux disease.

OBJECTIVES

• To determine whether continuous or intermittent bolus intragastric tube feeding reduces the number of episodes and the duration of gastro-oesophageal reflux disease (GORD) in preterm and low birth weight infants • To perform subgroup analyses for gestational age; birth weight; age in days from birth at full enteral feeding via intragastric tube (breast versus bottle); frequency of intermittent bolus feed; and type of medication for treatment of GORD (only if medication was prescribed and was given similarly to both intervention groups) SEARCH METHODS: We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL; 2020, Issue 7), in the Cochrane Library; Ovid MEDLINE(R) and Epub Ahead of Print, In-Process & Other Non-Indexed Citations, Daily and Versions(R); and the Cumulative Index to Nursing and Allied Health Literature (CINAHL), on 8 July 2020. We also searched clinical trials databases and the reference lists of retrieved articles for randomised controlled trials (RCTs) and quasi-RCTs.

SELECTION CRITERIA

Published and unpublished RCTs and quasi-RCTs were eligible for inclusion in this review, as were cluster-randomised and cross-over randomised trials that compared the effects of continuous versus intermittent bolus intragastric tube feeding on gastro-oesophageal reflux disease in preterm and low birth weight infants.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study eligibility and quality. We planned to use the GRADE approach to assess the certainty of evidence.

MAIN RESULTS

We found no trials that met the inclusion criteria for this review.

AUTHORS' CONCLUSIONS

We did not identify any randomised trials that evaluated the effects of continuous versus intermittent bolus intragastric tube feeding on gastro-oesophageal reflux disease in preterm and low birth weight infants. Well-designed and adequately powered trials are needed.

Intermittent Bolus Feeding Enhances Organ Growth More Than Continuous Feeding in a Neonatal Piglet Model

BACKGROUND

Orogastric tube feeding is frequently prescribed for neonates who cannot ingest food normally. In a piglet model of the neonate, greater skeletal muscle growth is sustained by upregulation of translation initiation signaling when nutrition is delivered by intermittent bolus meals, rather than continuously.

OBJECTIVES

The objective of this study was to determine the long-term effects of feeding frequency on organ growth and the mechanism by which feeding frequency modulates protein anabolism in these organs.

METHODS

Eighteen neonatal pigs were fed by gastrostomy tube the same amount of a sow milk replacer either by continuous infusion (CON) or on an intermittent bolus schedule (INT). After 21 d of feeding, the pigs were killed without interruption of feeding (CON; n = 6) or immediately before (INT-0; n = 6) or 60 min after (INT-60; n = 6) a meal, and fractional protein synthesis rates and activation indexes of signaling pathways that regulate translation initiation were measured in the heart, jejunum, ileum, kidneys, and liver.

RESULTS

Compared with continuous feeding, intermittent feeding stimulated the growth of the liver (+64%), jejunum (+48%), ileum (+40%), heart (+64%), and kidney (+56%). The increases in heart, kidney, jejunum, and ileum masses were proportional to whole body lean weight gain, but liver weight gain was greater in the INT-60 than the CON, and intermediate for the INT-0 group. For the liver and ileum, but not the heart, kidney, and jejunum, INT-60 compared with CON pigs had greater fractional protein synthesis rates (22% and 48%, respectively) and was accompanied by an increase in ribosomal protein S6 kinase 1 and eukaryotic initiation factor 4E binding protein 1 phosphorylation.

CONCLUSIONS

These results suggest that intermittent bolus compared with continuous orogastric feeding enhances organ growth and that in the ileum and liver, intermittent feeding enhances protein synthesis by stimulating translation initiation.

Early enteral feeding in preterm infants

Early enteral feeding is a potentially modifiable risk factor for necrotising enterocolitis (NEC) and late onset sepsis (LOS), however enteral feeding practices for preterm infants are highly variable. High-quality evidence is increasingly available to guide early feeding in preterm infants. Meta-analyses of randomised trials indicate that early trophic feeding within 48 h after birth and introduction of progressive enteral feeding before 4 days of life at an advancement rate above 24 ml/kg/day can be achieved in clinically stable very preterm and very low birthweight (VLBW) infants, without higher mortality or incidence of NEC. This finding may not be generalisable to high risk infants such as those born small for gestational age (SGA) or following absent/reversed end diastolic flow velocity (AREDFV) detected antenatally on placental Doppler studies, due to the small number of such infants in existing trials. Trials targeting such high-risk preterm infants have demonstrated that progressive enteral feeding started in the first 4 days is safe and does not lead to higher NEC or mortality; however, there is a paucity of data to guide feeding advancement in such infants. There is little trial evidence to support bolus or continuous gavage feeding as being superior in clinically stable preterm infants. Trials that examine enteral feeding are commonly unblinded for technical and practical reasons, which increases the risk of bias in such trials, specifically when considering potentially subjective outcome such as NEC and LOS; future clinical trials should focus on objective, primary outcome measures such as all-cause mortality, long term growth and neurodevelopment. Alternatively, important short-term outcomes such as NEC could be used with blinded assessment.

Bolus vs. continuous feeding to optimize anabolism in neonates

PURPOSE OF REVIEW

Neonates with feeding difficulties can be fed by orogastric tube, using either continuous or bolus delivery. This review reports on recent findings that bolus is advantageous compared to continuous feeding in supporting optimal protein anabolism.

RECENT FINDINGS

Whether bolus or continuous feeding is more beneficial has been controversial, largely due to limitations inherent in clinical studies, such as the presence of confounding variables and the inability to use invasive approaches. Recent studies using the piglet as a model of the human neonate showed that, compared to continuous feeding, bolus feeding enhances protein synthesis and promotes greater protein deposition. The increase in protein synthesis occurs in muscles of varying fiber type and in visceral tissues whereas muscle protein degradation is largely insensitive to feeding pattern. This higher protein synthesis rate is enabled by the rapid and profound increases in circulating amino acids and insulin that occur following a bolus feed, which activate the intracellular signaling pathways leading to mRNA translation.

SUMMARY

Recent findings indicate that bolus feeding enhances protein synthesis more than continuous feeding and promotes greater protein anabolism. The difference in response is attributable to the pulsatile pattern of amino acid-induced and insulin-induced translation initiation induced only by bolus feeding.