Push versus gravity for intermittent bolus gavage tube feeding of preterm and low birth weight infants

Review question

In preterm or low birth weight infants receiving gavage tube feedings, does push tube feeding compared with gravity tube feeding result in increased adverse events (low oxygen saturation, low heart rate, time to full suck feeding). 

Background

Infants born prematurely (before 37 weeks) may be unable to co-ordinate sucking, swallowing, and breathing, and require gavage feeding. In gavage feeding, milk is delivered intermittently through a tube passed via the nose or the mouth into the stomach. Intermittent bolus milk feeds may be administered by using a syringe to gently push milk into the infant's stomach (push feed). Alternatively, milk can be poured into a syringe attached to the tube and allowed to drip in by gravity (gravity feed).

Study characteristics

The search is up-to-date as of July 2020. We included one study (31 infants) in this updated review.

Key results

Evidence is insufficient to show whether use of push compared with gravity gavage feeding results in more rapid establishment of full gavage feeds without increasing adverse events in preterm or low birth weight infants, or both, who require intermittent bolus gavage feeding.

Certainty of evidence

Evidence from randomised trials comparing push versus gravity intermittent gavage tube feeding in preterm or low birth weight infants (less than 2500 grams) is insufficient to inform practice.

Authors' conclusions: 

We do not have sufficient evidence to determine the effects of intermittent bolus gavage feeding for preterm and low birth weight infants. The single small study of 31 infants comparing effects of push versus gravity bolus gavage feeding did not report the primary outcome identified in this review. Thus, evidence is insufficient to show whether use of push compared with gravity gavage feeding results in more rapid establishment of full gavage feeds without increasing adverse events in preterm or low birth weight infants who receive intermittent bolus gavage feeding. In addition, the included study was too small to measure potential adverse events that can occur during gavage tube feeding, for example, episodes of oxygen desaturation, apnoea, or bradycardia.

Read the full abstract...
Background: 

Many small, sick, and preterm infants are unable to co-ordinate sucking, swallowing, and breathing, and therefore require gavage feeding. In gavage feeding, milk feeds are delivered through a tube passed via the nose or the mouth into the stomach. Intermittent bolus milk feeds may be administered by a syringe to gently push milk into the infant's stomach (push feed). Alternatively, milk can be poured into a syringe attached to the tube and allowed to drip in by gravity (gravity feed).

Objectives: 

To determine whether use of push feeding compared with gravity feeding results in more rapid establishment of full gavage feeds without increasing adverse events among preterm or low birth weight infants, or both, who require intermittent bolus tube feeding.

Search strategy: 

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 30 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: 

We included RCTs and quasi-RCTs comparing push versus gravity intermittent gavage tube feeding in preterm (less than 37 weeks' gestation) or low birth weight (less than 2500 grams) infants, or both.

Data collection and analysis: 

We assessed the methods of trials regarding blinding of randomisation and outcome measurement. We evaluated treatment effects with a fixed-effect model using risk ratio (RR), relative risk reduction, risk difference (RD), and number needed to treat for an additional beneficial outcome (NNTB) for categorical data; and using mean, standard deviation, and mean difference (MD) for continuous data. We analysed outcomes measured as count data, for example, frequency of apnoea, bradycardia, and episodes of pulse oximeter oxygen (SpO₂) desaturation, by comparing rates of events and the rate ratio. We evaluated heterogeneity to help determine the suitability of pooling results. We used the GRADE approach to assess the certainty of evidence.

Main results: 

One small cross-over trial (31 infants) met the criteria for inclusion in this review. The certainty of evidence for all outcomes was very low due to imprecision of estimates, wide confidence intervals, and unclear risk of bias.

The primary outcome - time taken to establish full gavage feeding (days) and feeding intolerance (number of episodes per day) - was not reported in the included study. The evidence is very uncertain about the effects of push versus gravity intermittent gavage tube feeding on all other outcomes.

Investigators reported respiratory rate (breaths per minute) at completion of feeding (MD 0.58, 95% confidence interval (CI) -5.97 to 7.13; 1 study, 31 participants; very low-certainty evidence); respiratory rate (breaths per minute) 10 to 30 minutes after completion of feeding (MD 3.1, 95% CI -3.43 to 9.63; 1 study, 31 participants; very low-certainty evidence); heart rate (beats per minute) at completion of feeding (MD 2.6, 95% CI -9.71 to 4.51; 1 study, 31 participants; very low-certainty evidence); and heart rate (beats per minute) 10 to 30 minutes after completion of feeding (MD 2.4, 95% CI -9.16 to 4.36; 1 study, 31 participants; very low-certainty evidence). We are very uncertain of the effects of push versus gravity intermittent gavage feeding on respiratory rate during and after feeding.