Randomized, controlled trial of slow versus rapid feeding volume advancement in preterm infants

Article Outline

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Caple J, Armentrout D, Huseby V, Halbardier B, Garcia J, Sparks JW, et al. Pediatrics 2004;114:1597-600.

Context Controversy exists regarding when feedings for preterm infants should be started, whether minimal enteral feedings should be used routinely in small preterm infants, and how fast to advance enteral feedings.

Objectives To determine an optimal enteral method for preterm infants.

Design A randomized, controlled, single-center trial.

Setting A Neonatal Intensive Care Unit of a community-based county hospital in Houston, Texas.

Participants 155 infants between 1000 and 2000 g at birth, gestational age ≤35 weeks, and weight appropriate for gestational age.

Interventions Infants received feedings of expressed human milk or Enfamil formula starting and advanced at either 30 mL/kg per day or 20 mL/kg per day. Infants remained in the study until discharge or development of stage ≥IIA necrotizing enterocolitis (NEC).

Main outcome measures Primary outcome measures were days to full feedings, incidence of feeding complications, and NEC. Secondary outcomes included: time to regaining birth weight, days of intravenous fluids, and length of hospital stay.

Results Infants in the intervention group achieved full-volume feedings sooner (7 vs 10 days, median), regained birth weight faster (11 vs 13 days, median), and had fewer days of intravenous fluids (6 vs 8 days, median). Three infants in the intervention group and two control infants developed NEC for an overall incidence of 3.2% (relative risk: 1.73; 95% confidence interval: 0.30–10.06).

Conclusions Among infants between 1000 and 2000 g at birth, starting and advancing feedings at 30 mL/kg per day seems to be a safe practice and results in fewer days to reach full-volume feedings than using 20 mL/kg per day. This intervention also leads to faster weight gain and fewer days of intravenous fluids.

Comment On first thought it seems obvious that the group with the more rapid increase in feeding volume would reach the enteral feeding goal of 150 mL/kg/day more quickly. However, if the rapid schedule precipitated feeding intolerance, perhaps that group would actually reach the goal more slowly. The benefits of reaching “full” enteral feedings more rapidly include not only fewer days of intravenous administration but also fewer days of deep line usage. If such benefits were extended to large populations, a diminution in nosocomial sepsis would be expected, as would reduced costs and shorter hospital stays. However, before such extrapolations are made it should be kept in mind that this study demonstrated the feasibility of this approach, but estimates of the benefits and risks will remain imprecise until larger numbers are studied.

There are three caveats to these findings. First, readers should be cautioned not to apply these findings to neonates <1000 g birth weight. In fact, marked differences in feeding tolerance can exist between 1000-g neonates and 2000-g neonates. To allow for these differences, the feeding guidelines we use separates 1000- to 2000-g neonates into three categories: 1000 to 1250 g; 1251 to 1500 g, and 1501 to 2000 g; and each has a different set rate of volume increase. Second, it should be emphasized that feeding tolerance is better with human milk than with formula. It was disappointing to see that only one third of the patients in this study received human milk. Additionally, the authors fed 20 cal/oz Enfamil (rather than a premature formula) during the first days of life. It is not clear whether results would differ if a premature formula were used. Finally, this report points out the important unresolved issue of when to “hold” or temporarily discontinue feedings. Indomethacin use and large prefeeding gastric residuals were the two most common reasons for holding feedings, together accounting for 65% of the feeding discontinuations. Certainly, additional clinical research is needed regarding means of avoiding or compensating for these missed feeding opportunities.