Question: Does anyone know of any research articles on the risk of feeding infants (term and/or preterm) who are on HFNC? Also I would love other people’s perspective of “turning down” an infant’s oxygen for the purpose of feeding. For example, a baby is on 4L due to acute illness but oxygen is decreased to 2.5L to feed.
Answer: There are a handful of pertinent articles which may be accessible via a search. The one I am attaching is the only study to look at the effect of NCPAP under videofluoroscopy, and it was done by Louisa Ferrara and her NICU colleagues in NY. Their preliminary results were so worrisome that the neonatologists stopped the study.
Unfortunately, often the conclusion regarding the “safety” and the “tolerance” of NICU infants feeding on NCPAP is determined by volume and perhaps lack of overt or symptomatic decompensation. This study will hopefully re-direct thinking about the impact of the need for this level of respiratory support on the ability to safely swallow under such conditions. As you will see, the study determined that “Oral feeding while on NCPAP significantly increases the risk of laryngeal penetration and tracheal aspiration events,” and recommended caution when initiating oral feedings on NCPAP. The conclusions, unfortunately, did not focus on changes in swallowing physiology under NCPAP
My experience in the NICU suggests that, even for those infants who do not frankly penetrate or aspirate under NCPAP in the “moment” in radiology, we are likely to see adverse effects on swallowing physiology. That, for me, is the most compelling takeaway from this study. Bonnie Martin-Harris has taught us that neither aspiration nor penetration is sufficient or necessary for a swallowing impairment – meaning that our focus needs to be on physiology, because impaired physiology and its etiology(ies) create the conditions under which bolus mis-direction can or does occur.
It is not uncommon for neonates to evidence changes in swallowing physiology due to respiratory co-morbidities, even when stable on less support or indeed on unassisted room air. With infants requiring NCPAP or HHFNC, that is why our assessment of risk related to PO feeding or not PO feeding must consider many factors beyond level of respiratory support required.
Regarding your question about reducing respiratory support from baseline during PO attempt, this study gives us some information. However, the time on less support was brief, compared to the typical 25-30-minute PO feeding time. Because the aerobic demands of PO feeding typically exacerbate baseline WOB and RR in neonates, the full impact of such a change is unclear. If the infant is requiring a certain level of support, the reduction in respiratory support may – over the course of a true feeding – result in the need for urgent breaths, leading swallowing and breathing to uncouple. No one has studied this. What looks to some NICU caregivers to be a “solution” will have its own attendant sequelae, as do many things in the NICU, unfortunately.
And so, we remain in the “gray zone” as I like to call it, where there are more questions than answers, which is where most NICU therapists live. We must therefore consider theoretical constructs related to neonatal swallowing, continue to search for the evidence, use critical reflective thinking and dialogue with our neonatal colleagues. I hope this is helpful.
Catherine