QUESTION

Can you share feeding protocols when asked to work with infants on a ventilator in the NICU. Specifically, patients that are expected to go home on a home ventilator.

CATHERINE’S ANSWER

These indeed are often our most fragile NICU infants. Each one is typically unique, so I always start with understanding that infant’s unique co-morbidities that led to the need for long-term ventilation. For example,   PPHN, CLD, CHD, congenital malformations, neuromuscular disorders, and structural airway alterations, or multiple complex co-occurring co-morbidities, which then create an even higher risk for the infant to, at some point, safely tolerate oral feeding. This then is the foundation for determining timing and nature of intervention, as we consider relevant factors for feeding readiness/oral-sensory-motor treatment to support the prerequisite skills for future PO feeding.

Multiple factors need to be considered such as: level and mode of respiratory support in the setting of that infant’s respiratory history, the prerequisite  oral-motor integrity, ability to swallow saliva, oral-sensory processing, non-nutritive sucking, as well as physiologic stability during  interventions utilized to support these prerequisites, if they are emerging. Once these prerequisites are established, I would likely be considering appropriateness of, and tolerance for,  an in line valve like the PMV to establish flow into the upper airway  that promotes restoration of taste, smell and subglottic pressure, which most optimally underpins swallowing; at this juncture, working closely with ENT/Pulmonology and the respiratory therapist is essential.

For those infants with readiness skills for whom a PMV is contraindicated (per diagnosis and/or airway status and/or clinical status), I would perhaps offer a cautious pacifier dips for purposeful swallows — because, without a PMV in line, there won’t be the taste or smell or subglottic pressure so critical for an infant who has no previous motor learning with suck-swallow-breathe and bolus control; I would offer this motor learning experience via very limited pacifier dips with SLP to allow some interval sensory-motor learning in preparation a swallow study very early on in the therapeutic process to objectify swallowing physiology.

For those infants with readiness skills, and who are appropriate for and tolerate a PMV (with MD approval), considerations may include: pacifier dips with PMV in line, limited trace PO via ultra preemie nipple (for interval sensory-motor learning in preparation a swallow study very early on in the therapeutic process to objectify swallowing physiology). I prefer an NICU infant’s first PO feeding not be in radiology if possible, recognizing safety concerns; but some interval motor learning is likely important to reduce artifacts. This must be carefully and cautiously balanced with that infant’s risk for, and ability tolerate airway invasion, especially from a pulmonary perspective.

In my 35 years in the NICU, I have never seen one of our trach/vent infants go home as a full safe PO feeder. Often in some NICUs, the challenge may be having the entire team on board about risk, prerequisites, silent aspiration, that it isn’t just about “aspiration” (but rather the dynamic impact of altered or impaired swallowing physiology),  in the setting of the complex co-morbidities these fragile infants have.

You will notice as you read my thoughts above, they aren’t a protocol as much as a scaffolding I use, when I unpeel the layers as I go along, learn from the infant, combine that with his history and ask more questions. I hope this is helpful.

COMMENTARY FROM KRISTIN KING at PASSY MUIR

First, thank you, Catherine Shaker for such a well-thought out response as always. I learn something new each time I read a response from you.

I am only responding to the question about cuff deflation and cuff deflation with use of a PMV. All that I provide here is somewhat contingent on following the information that  Catherine Shaker’s response provides. I realize much of this will be known if you work with patients on a vent, but I do not want to miss an important aspect.

Typically, I do not recommend a cuff deflation trial prior to PMV use or swallowing assessment. If with cuff deflation and airway assessment, it is determined that the airway is patent, and all other factors being appropriate, then I would trial a PMV shortly after cuff deflation. Ideally, for swallowing/feeding, a child could use a PMV to restore various physiologic functions (such as subglottic pressure), but it may not be necessary in some cases. In considering cuff deflation and a trial of cuff deflation, an inflated cuff is used to “seal” the airway allowing all airflow to be to and from the ventilator. PEEP (positive end-expiratory pressure) is provided via the vent because with an open tracheostomy there can be a loss of PEEP/decreased pressure in the lungs. PEEP assists with keeping the alveoli open for good gas exchange and oxygenation. If the ventilator is not properly adjusted, having an open tracheostomy tube with deflated cuff may cause loss of PEEP and de-recruitment of the lungs. Now, this is all in relation to infants/children who have a cuffed trach tube with ventilation. Infants/children are frequently ventilated with cuffless trach tubes and that is a different situation.

The loss of PEEP and de-recruitment with cuff deflation has been shown in research on adults (Sutt et al, 2016, 2017, Critical Care); unfortunately, we do not have much research on infants and children. Having a cuff deflation trial may actually cause a person (no matter the age) to have difficulty maintaining good lung recruitment and PEEP, if the trach tube is left open.

Trialing a PMV assists with maintaining lung recruitment and PEEP. The potential impacts and need for a closed system are illustrated in a case presentation in the 2018 pediatric issue of Aerodigestive Health presented by an RT and the issues they had transitioning a 10-year old child from the vent and use of a PMV to trach collar without a PMV (for the cuff deflation/trach collar trial). While this case presentation is with an older child, the concepts with cuff deflation still apply. Restoring more physiological PEEP with use of the PMV sooner will assist with overall respiratory function (the Sutt research even showed improved diaphragmatic use).

As to the swallowing/MBS assessment, ideally, the cuff would be deflated and a PMV available for trial. I recommend testing with and without the Valve and with and without cuff deflation, if at all possible and with considerations for exposure. Lastly, this is all contingent on the cuff being properly managed/inflated.

Hope this helps some. It is a little bit different slant than the initial question.

FOLLOWUP RESONSE FROM CATHERINE

Thank you, Kristin, for sharing this wonderful issue that informs everyone’s practice with this population, and for the helpful response. Laura Brooks wrote an article in a previous edition of Passy-Muir’s Aerodigestive Health that was also specific to trach and vent dependent infants and children in intensive care which is very helpful. All issues can be found at www.passymuir.com/resources .

I agree that if an in-line PMV trial is indicated, partnering with RT and trialing cuff deflation immediately prior to attempting the in line PMV,  is best for these little ones, who also can readily experience physiologic stress and anxiety when a cuff is deflated even extremely slowly. They, like the ten year old in the article, require so much patience and thoughtful progression of interventions. It is worrisome to me that the complexity of the swallow-breathe interface for neonates in the setting of a trach is not always appreciated by all members of the team. In those situations, these infants can readily decompensate,  and then both neuroprotection and airway protection are often adversely affected.

On a side note, in radiology I have typically seen improved swallowing physiology with the PMV in place for these complex neonates. I suspect part of that is that most were not PO feeding prior to their trach (due to complex co-morbidities), and so they often have no previous “motor learning” with PO feeding to “fall back on” to “guide them” when and if they start to PO feed. When a tolerated PMV restores the fundamental underpinnings for swallowing,  it seems to make all the difference for these fragile neonates.

Thanks again for your insights too , Kristin. So appreciated.