Problem-Solving: Feeding on NCPAP and HFNC in NICU

QUESTION:

I have had an incredibly difficult time navigating our neonatologists. I gave a detailed presentation to our medical director and other various NICU staff members regarding feeding expectations for our infants on prolonged or increased respiratory support (specifically HFNC over 2 liters). Obviously, these infants are complex and their readiness to engage in bottle feeding can not be perceived as identical to one another. However, much to my dismay, we now have a policy set in place that we will attempt po bottle feeding on infants who are on HFNC 4L or less. Obviously, my assessment is involved, but not always taken seriously. I was provided this document to refute my claims: Effects of Nasal Continuous Positive Airway Pressure and High-Flow Nasal Cannula on Sucking, Swallowing, and Breathing during Bottle-Feeding in Lambs. Additionally, the neonatologists seem to only accept evidence provided by a physician and/or a Cochrane review. I have continuously brought up ‘no evidence of harm’ is not the same as ‘evidence of safety.’ I am fortunate to receive standing orders on all admits to our NICU, further encouraging a preventative approach with all admitted infants. Since the criteria to be a level 3 NICU must involve therapy services, I often feel as if my impressions are just a ‘check off the list’ and the providers will sometimes instruct the staff to bottle feed infants who are not appropriate candidates. Providers also still believe that there is a ‘critical window’ that infants must engage in po feeding within a certain time frame. I know this is not factual but I am not able to move our physicians away from this thought process! We have taken short strides forward and I have fought, and I am continuing to fight, very hard to protect our fragile infants and demonstrate my worth. Unfortunately, I do feel as if getting the infant discharged as soon as the provider deems appropriate, despite difficulties with po feeding, is a driving force. It is almost as if the infant’s problems are pushed onto the pediatrician. I understand that physicians must experience pressure to discharge infants secondary to changes in our healthcare culture. I know I am not alone in this battle and that other therapists must share similar experiences as well as similar feelings. I am taking small steps forward in forging positive relationships with our providers. Any advice would be greatly appreciated!

There are a handful of pertinent articles accessible via a search. One done on the effect of NCPAP under videofluoroscopy, 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 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, which would have been instructive. It  is not only aspiration that is worrisome but also untoward effects on physiology that increase risk for airway invasion.

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 aspiration or penetration is neither sufficient nor necessary for a swallowing impairment – meaning that our focus needs to be on physiology, because impaired or altered 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, our assessment of risk related to PO feeding or not PO feeding must consider many factors beyond level of respiratory support required.

This is a practice dilemma for all NICU SLPs. The pressure to get infants out of the NICU often drives care decisions, especially when it comes to PO feeding.

Many neonatologists incorrectly assume that there is a window within which our preterms must “experience” PO feeding or they will “miss that critical window and never learn”. So, despite co-morbidities and often respiratory needs that are paramount, infants are being asked to feed. That well-intentioned paradigm is based on writings from Gesell back in the 60s that talked about a “critical window” for learning to eat. Those times were different in many ways as was the population being described. Early intervention is now a standard of care in NICUs to support readiness. Our goal is for neonatal care that is neuro-protective and promotes positive overcomes, and recognition of safety issues inherent in the complex task of PO feeding even when weaned from CPAP and HFNC —they clearly call for reconsideration of that paradigm, which, perhaps to a large part, underlies the thinking that leads to “pushing PO” and orders to PO on CPAP and HFNC. Many of our former preterms do indeed learn to feed orally when respiratory co-morbidities better permit, once weaned, and from my experience, do so with much less stress and much more safely.

Advocating for safety for these infants is a critical one for SLPs in the NICU and PICU. Current NICU technology has advanced to the point that more infants are surviving and yet many are requiring extended periods of CPAP and HFNC. Many extremely preterm infants in our NICU with CLD at post-term (41 weeks PMA +) remain dependent on CPAP or HFNC. My NICU team has had good collaborative conversations about the benefits of ST being involved to maintain a positive oral-sensory environment, promoting the oral-sensory-motor components that are the underpinnings for future PO feeding, beginning early to foreshadow for parents the swallowing, breathing and postural skills needed, and helping families also support those components, versus attempting PO feeding when the infant clearly is struggling with respiratory stability. Clearly, medical co-morbidities predispose an infant in the NICU to PO feeding problems. Multiple papers have studied that. Those infants with the greatest respiratory comorbidities, often those born < 28 weeks’ gestation and BW < 1000 grams, are most likely to require CPAP and/or HFNC at those post-menstrual ages when PO feeding is often attempted. Sick newborns may also present similar issues, secondary to their co-morbidities.

If the infant has such respiratory needs that he requires CPAP, or a HFNC, one must ask if PO feeding is really a priority for that infant at that time. The ability to reconfigure the pharynx from a respiratory tract and back to an alimentary tract with precise timing and coordination surrounding each swallow is a concern. When we look objectively in radiology during an instrumental assessment of swallowing physiology, even infants with CLD stable on RA have altered or impaired swallowing physiology as a direct result of their CLD. The bolus mis-direction and resulting aspiration we often observe is typically silent. In the adult population in the most recent information I have seen (Garon et al, 2009 Journal of Neuroscience Nursing) reported that of 2000 adults studied with a variety of co-morbid conditions, including COPD, 54.5% of those who aspirated did so silently. The data I have collected thus far for NICU infants suggests strongly to me that even the data from Arvedson et al in 1994 likely dose not capture the risk for our current population of infants to silently aspirate; her study population was not only less involved from a respiratory perspective back in 1994 than the population we see today, but it also was a population composed of not just infants.

The need for an “urgent breath” often can predispose an infant with increased work of breathing to silently mis-direct the bolus into the airway during the swallow. The ability of the infant to close the glottis against the driving force of the respiratory support, while breathing with increased effort or with an increased respiratory rate, which effectively creates air hunger, and yet still maintain glottic closure throughout the duration of the swallow, would likely be precarious. Given the infant’s likelihood of baseline tachypnea and increased WOB, the dynamic adjustments of the airway surrounding the swallow are likely to be disrupted and create uncoupling of swallowing and breathing. Without objective data on the impact of CPAP or HFNC on swallowing physiology we cannot conclude that feeding under these conditions is “safe”. Indeed, infants for whom we do not necessarily witness aspiration during a dynamic swallow study, may indeed show alterations in swallowing physiology that may indeed predispose them to airway invasion under “the right conditions” during PO feeding (changes in nipple flow, changes in position, changes in respiratory support, sucking rate/length, timeliness and depth of breathing pauses for example) so it isn’t even just about aspiration but the potential impact of CPAP and HFNC on swallowing physiology. The fact that the infants “eat” and “are fed” and “transferred volume” does not equate to “safe feeding”.

We must of course consider the physiologic stress likely to occur when the infant experiences “feeding” when they still require NCPAP and or HFNC. It is highly possible the stress of trying to breathe and coordinate a swallow may lay down neural pathways that move the infant away from wanting to eat, by wiring those sensory-motor pathways that lead to current and/or future maladaptive feeding behaviors. We know that studies looking at stress in preterms have shown an association with adverse changes in brain structure on MRIs.

In the NICU seminars I teach, this body of evidence and our dilemma are always part of our problem-solving discussions. I am fortunate after 33 years in the NICU to be part of a team that is trying to look beyond “getting them to eat” and learning to partner with ST to guide practice while the evidence-base is emerging. NICU SLPs are in a key role to dialogue, problem-solve and focus on safety and neuroprotection as essential part of this practice issue which confronts every neonatal team.

Jim Coyle has said: “There is one rule of thumb: there is no single parameter that qualifies or disqualifies a patient for anything or that confirms or refutes risk in and of itself. It is the combination of parameters that the clinician uses to estimate risk and to form a diagnostic impression and complete a differential. That is what we teach students and trained clinicians should be emphasizing. Grab your water bottle and go for a 2-3-mile run. After 15 minutes when at your aerobic steady state and RR is up, try to take a drink of water and observe what you need to do to orchestrate the whole thing. Yet you are healthy and mature and not recovering from respiratory issues. Very illuminating.”

The dialogue needs to continue, and we need measures of oral feeding that go beyond intake, and methods of assessment that capture critical variables, including objective assessment of physiology. 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

 

 

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