Research Corner and Commentary about Article in the ASHA Leader on Thickening in the NICU

This is an excellent article just published by our colleagues at Boston Childrens and will inform your practice.

Duncan DR, Larson K, Rosen RL(2019) Clinical aspects of thickeners for pediatric gastroesophageal reflux and oropharyngeal dysphagia.
Current gastroenterology reports.

The purpose of this review is to discuss current knowledge and recent findings regarding clinical aspects of thickeners for pediatric gastroesophageal reflux and oropharyngeal dysphagia. We review evidence for thickener efficacy, discuss types of thickeners, practical considerations when using various thickeners, and risks and benefits of thickener use in pediatrics. Recent Findings: Thickeners are effective in decreasing regurgitation and improving swallowing mechanics and can often be used
empirically for the treatment of infants and young children. Adverse effects have been reported, but with careful consideration of
appropriate thickener types, desired thickening consistency, and follow-up in collaboration with feeding specialists, most patients have symptomatic improvements. Summary Thickeners are typically well tolerated and with few side effects, but close follow-up is needed to make sure patients tolerate thickeners and have adequate symptom improvement.

On a related note, I feel compelled to address a recent article in The ASHA Leader “From My Perspective: Overuse of Thickeners in the NICU.”

The article, I believe, while certainly written with the best of intentions, has the potential to set back the progress SLPs have made delineating a critical well-respected evidence-based role in the NICU and, left unaddressed, could do harm.

I am concerned that  SLPs (both adult and pediatric)  who are unfamiliar with the work of NICU SLPs may, after reading the above mentioned article in The ASHA Leader, have an inaccurate the impression about our practice. The article appears to make assumptions, and appears to question the clinical reasoning that underpins decisions made every day, with deliberate consideration for short and long-term implications and for best practice.

Many of the assumptions made by the author  are not consistent with both my practice in large level IV  NICUs for the last 35 years, nor the practice of most other NICU SLPs I have met as I teach across the US about NICU intervention. While there may indeed be variability in the knowledge and practice of some NICU providers (Madhoun, et al 2015),  the AAP recommends caution with thickeners in preterm infants, and this is typically the overriding consideration for all interventions prescribed in the NICU. First, do no harm. 

The author’s statement that “thickeners are a long-term solution” is not consistent with typical NICU practice. Thickeners are used only as the last resort in the NICU (Gosa, 2015) —- after trialing changing feeding position, slowing nipple flow rate, utilizing contingent  co-regulated pacing to support the swallow-breathe interface and assure timely and sufficient breaths.  Even then, thickening may not be the safest solution for a specific  infant and can  present untoward sequelae ( higher risk to aspirate after the swallow, concerns of digestive immaturity, malabsorption, NEC, etc.) Most NICUs rarely use thickeners today to the extent that they were used in the past, and if thickeners are, it is viewed as short term. In dialogue with the medical team, there is typically careful interdisciplinary deliberation of the risk benefit ratio. If indicated, there is typically the contingent use of interventions to minimize the risk, and support both oral-motor learning and motor learning, and avoid maladaptations that may result.

Each NICU infant’s  developmental progression, respiratory, GI and neuro history and co-morbidities must be considered, as well as the nature of the pathophysiology objectified in radiology.  When the author states that “failing a swallow study” is a reason to thicken, it suggests the author considers a swallow study as a “pass-fail procedure”.  Rather than a pass-fail procedure, an instrumental assessment is viewed with the NICU population, as an analysis of swallowing physiology, its alteration or impairment, and its implications for that unique infant in the setting of his unique presentation/data set.  Like with other populations for whom SLPs provide services, a neonate does not need to penetrate or aspirate to have a swallowing impairment that may lead to airway invasion. As a result, the level of analysis that is required, and the essential caution as to prescribed interventions, is well understood by those of us working with this high risk fragile population in the NICU. Thickening may be contraindicated based on data obtained in radiology.

The author asks  “What if the baby can’t suck?” and then states that “all babies have a suck reflex”. Unfortunately, this is inaccurate. It is not uncommon that a sick newborn or some preterm infants with significant neurologic co-morbidities may not have a sucking reflex, or the suck lacks the integrity to feed orally. If  indeed this is the clinical presentation, thickeners would be contraindicated. Our  interventions for motor learning would go in a completely different direction, both in the NICU and after discharge.

In addition, the assumptions about the interventions described in the article for use with post NICU infants (e.g., bottle feeding thin liquid  to avoid maladaptive feeding patterns, use of glycerin swabs, ice chips, and anterior controlled placement of thin water) are worrisome and may mislead the reader as to the interventions most typically indicated for an infant just discharged from a neonatal intensive care unit. The infant post-NICU is often still quite immature overall, and interventions such as those suggested may both present undue risk to the airway and be poorly tolerated from a sensory and GI perspective. Indeed, safety of progressing the diet to thin liquids, if previously contraindicated, would best be considered for the NICU graduate in the setting of objective data regarding physiology in radiology. Many NICU graduates continue to have medical issues post discharge that can make airway invasion a compelling risk to both their pulmonary and overall health. 

Cichero, J A  et al (2013). Thickened milk for the management of feeding and swallowing issues in infants: a call for interdisciplinary professional guidelines. Journal of Human Lactation, 29(2), 132-135.

Duncan DR, Larson K, Davidson K, May K, Rahbar R, Rosen RL.(2019) Feeding interventions are associated with improved outcomes in
children with laryngeal penetration. J Pediatr Gastroenterol Nutr. 68(2):218–224.

Goldfield, EC  et al (2013) Preterm infant swallowing of thin and nectar-thick liquids: changes in lingual-palatal coordination and relation to bolus transit. Dysphagia 28, 234e244.

Gosa, MM & Corkins, M R(2015). Necrotizing enterocolitis and the use of thickened liquids for infants with dysphagia. Perspectives on Swallowing and Swallowing Disorders (Dysphagia), 24(2), 44-49.

Madhoun, LL et al (2015). Feed-thickening practices in NICUs in the current era: Variability in prescription and implementation patterns. Journal of Neonatal Nursing, 21(6), 255-262.

I appreciate the opportunity to share the perspective of an NICU SLP and hope this has been helpful.

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