Gastric Tube Use and Care in the NICU

Tamara Wallace, DNP, APRN, NNP-BC; Deborah Steward, PhD, RN


NAINR. 2014;14(3):103-108. 

In This Article

Dwell Time for Feeding Tubes

Currently most feeding tubes come with a manufacturer's recommendation for the maximum dwell time of a feeding tube. This recommendation is generally based on the composition of the tube and how the material is affected by the body. It would seem prudent to also consider a host of infant comfort and outcome information to assist in decision making about dwell time. The majority of NICU infants experience a significant number of gavage tube insertions as they transition to full oral feedings. Placing a gastric tube can be a very stressful event; there is evidence to suggest that the insertion of a gavage tube alters cerebral blood flow in premature infants[51] and experts in neonatal pain recognize that gavage tube insertion is a painful procedure.[52] When asked to rate the severity of pain associated with various interventions carried out in the NICU, clinicians rated the insertion of a gavage tube as moderately painful.[53] McCullough and colleagues[54] demonstrated that the pain response to gavage tube insertion in preterm infants was comparable to the pain response accompanying a heelstick. Minimizing tube insertions will assist in minimizing exposure to pain and discomfort.

Given the immature immune system of NICU infants, an important question is whether an indwelling feeding tube increases the risk of infection in these infants and if the frequency of feeding tube change can alter this risk. Indwelling feeding tubes in infants in the NICU have been shown to be a reservoir for pathologic, even antibiotic-resistant bacteria.[55–57] In one study, researchers cultured 125 feeding tubes from 50 preterm infants and demonstrated that only 8 of the 125 feeding tubes had cultures that were completely negative.[58] Thus, 94% of the feeding tubes were colonized with bacteria, and 57% of them were colonized with greater than 1000 colony forming units per tube.[58] Most importantly in this study, preterm infants who had contaminated feeding tubes were more likely to exhibit episodes of feeding intolerance, have inadequate weight gain and develop necrotizing enterocolitis (NEC). This association between colonization and NEC has not been a consistent finding in all studies,[57] but is concerning. The length of time required for colonization to occur with an indwelling feeding tube is unknown. Studies have demonstrated that some tubes had organisms isolated from them as early as six hours after placement.[56] There is a lack of research focusing on the relationship between bacterial contamination and components of the gavage feeding process including frequency of tube changes, flushing of the indwelling feeding tube, and handling of the feeding tube and feeding apparatus. A study of duodenal aspirates obtained during the placement of gastric tubes demonstrated that colonization increased with age and that molecular typing suggested that the bacteria were not maternal, but nosocomial.[57] Another recent study again demonstrated that microbes in the NICU were found in the stools of infants in the NICU.[59] While the neonatal gastrointestinal tract is not sterile, perhaps we should be concerned that their stool bacterial patterns are similar to the NICU environment.

There are significant gaps in the literature and in our knowledge of how frequently tubes should be changed. It appears that there is no evidence that frequent feeding tube changes will decrease colonization with potential pathogens given how rapidly colonization appears and that the secretions below the stomach, not just the tube, are colonized. Feeding tube changes are associated with infant discomfort and changes in cerebral blood flow. Clinicians must be mindful of all of these considerations when determining length of indwelling time in their clinical setting. Given the incidence of colonization of these tubes with potentially pathogenic bacteria it may be prudent to treat feedings, feeding tubes and all of the associated tubes in an aseptic manner in an attempt to minimize nosocomial contamination.