When giving enteral feeds in the NICU, we have several options. The solution to be fed, use of breast milk, addition of fortifiers, formula, protein additives etc., are determined by the primary provider. Once the determination has been made that a feeding of whatever sort of milk will be given via gavage, the nurse will have to make several choices.
First is the positioning of the feeding tube. It can be placed via the nose or the mouth. To date, we have no clear evidence that one position, nasal or oral, is better than another. Many units have written or unwritten guidance on this issue, so the nurse will usually pick one mode or the other based on usual practice in the unit.
Next, unless specifically ordered (which is not common) the nurse will pick the amount of time to give the feeding over and whether to feed by gravity or on a pump. This too is often influenced by unit culture or perhaps written policy. In several units where I have worked, gravity feeding has been the norm. Over the last several years though, I have noticed that the practice has drifted away from gravity feeds to pump feeds. Why is this?
There is some belief that “drip” feeds help decrease the incidence of reflux. As of a 2014 Cochrane review, no randomized controlled trials were found to support or refute this.1 Another Cochrane review found a total of 5 studies, or 511 subjects, and reviewed outcomes comparing continuous versus intermittent gavage feeding.2 Continuous was consistently defined as being given on a syringe pump but without time definition, and intermittent was defined as a gravity feeding being given over 15 to 40 minutes.2 The studies reviewed found no difference in time to achieve full feeds, growth, or necrotizing enterocolitis rates. One study found a trend toward more apnea with continuous feedings, while another study (only one) suggested improved weight gain in infants < 1250 grams who were fed via the continuous route.2 Drip feeds can be useful when feeds are first started and volumes may be increasing, but very gradually. This mode of feeding for very premature or sick infants helps keep the gut primed and functioning while feeds cannot be increased much and infants are less likely to tolerate a large bolus.
Another reason I’ve been given for the trend toward more pump feedings, and perhaps the most common, is that nurses don’t have time to stand by the bedside to allow a gravity feeding to go in. Of course, it is important to stay with the baby during the course of the feeding. Depending on the amount, it could be given over anywhere from 5 to 30 minutes. Bottle feedings often take that long. While breastfeeding is done by the mother, the nurse is often available to assist at least periodically during the feeding. Sometimes, these feedings can take much longer. A very small 5 French feeding tube coupled with a fortified (thick) feed can result in a very slow feeding. In past years, nurses would secure the syringe barrel with a rubber band and secure it to the top of the incubator. This way the milk could go in over whatever time period was needed and the nurse could walk away. Of course, we now recognize many issues with this practice. When the feeding tube is secured in that manner, it could possibly be pulled out during the feeding – resulting in aspiration of the feeding or the feed ending up partially in the bed instead of the baby. Also, the baby may move around enough that the milk in the syringe barrel spills onto the bed. Both result in the infant not getting the benefit of that feeding.
Furthermore, in support of gravity feeding from a developmental standpoint, feeding time is a time for interaction between mother and baby, even if it is only holding and being close. Even if being fed via gavage, babies should benefit from this developmental intervention. Again, even if babies cannot be held during the feeding, physical presence of another person can provide the developmental input associated with “social” eating.
Part of the issue with a gravity feeding taking an exceptionally long time is the size of the feeding tube, as mentioned already. If the feeding is fortified, as many breast milk feedings are, and the volume has increased to 20+ mL, giving it through a 5 French feeding tube can be painstakingly slow. This goes back to two other choices the nurse has: route of the gavage tube and size.
Smaller tubes are usually desired when passed via the nose, although even an 8 French gavage tube is smaller than an endotracheal tube or CPAP prongs that both can be or are placed nasally. Any trauma that may occur from placement of a larger tube via the nose comes from forceful passage of the tube (no lubricant, wrong angle) or from the length of time the tube is in place. Changing the tube from one nare to the other every 3 or 7 days with routine changes will prevent any trauma. Additionally, placing a larger tube orally is an option. This route is harder to secure but if feeds are given via gravity, tubes may be placed for the feeding and removed.
I hope this blog provides you with some discussion points or thoughts about gravity feeds for at least some babies. If I haven’t mentioned your reason why gravity feeds aren’t given, or why gravity feeds are given in your unit, please share!
1. Richards R, Foster JP, Psaila K. Continuous versus bolus intragastric tube feeding for preterm and low birth weight infants with gastro-oesophageal reflux disease. Cochrane Database of Systematic Reviews 2014, Issue 7. Art. No.: CD009719. DOI: 10.1002/14651858.CD009719.pub2.
2. Premji SS, Chessell L. Continuous nasogastric milk feeding versus intermittent bolus milk feeding for premature infants less than 1500 grams. Cochrane Database of Systematic Reviews 2011, Issue 11. Art. No.: CD001819. DOI: 10.1002/14651858.CD001819.pub2.