Can we nourish the swallow in acute care?

Title: A Significant Association of Malnutrition with Dysphagia in Acute Patients
Authors: Saito, Hayashi, Nakazawa, Yagihashi, Oikawa, & Ota
Journal: Dysphagia
Year of Publication: 2018
Design Type: Retrospective single-center study
Purpose: “We aimed to clarify the association between dysphagia and malnutrition by adopting accurate diagnosis and mathematical evaluation of dysphagia using videofluorography and nutritional assessment calculated by a well-established nutritional risk index”
Population: 165 consecutive patients admitted for acute diseases throughout 2016
Inclusion criteria: patients who completed videofluorography out of concern for dysphagia; capable of oral ingestion prior to hospitalization; non-dependent on tube feeding or IV nutrition
Exclusion criteria: (no specific criteria for participants); authors provide additional information as far as how they determined and defined certain variables (i.e. diabetes, congestive heart failure, etc.)

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It’s the age-old story of what came first: the chicken or the egg🐣? As SLPs we’ve thought about the quandary between aspiration and dysphagia in a similar way as well, and just like everyone else, we’ve come to similar conclusions when trying to answer this famous riddle.

Now, it’s nutrition’s turn to enter into the mix.

Does dysphagia increase the risk for malnutrition? Or, is it truly the other way around?

Whether you’ve either got the registered dietician’s number on your speech cell speed dial or click that box for a consult as frequently as you sip your coffee, even if we are separate entities we also have a close, special relationship that I think no one else truly gets😅. We both lean on each other for more wisdom regarding the other’s knowledge and expertise, because both are crucial to a patient’s progress in recovery.

This article seems to be an interesting grab at diving deeper into the above adage and at the very least can give us insight into how to think about and manage this complex and intertwined relationship.

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I’ll be honest here and admit that I didn’t pay the best attention in health class. But since physiology and biology were more up my alley I gotta give credit to the authors for providing a lot of resources to read up on about mal/nutrition and all the effects, physiological impact, and overall process of how it occurs in the body particularly in the acute phase of an illness or injury. Despite having to overlook a mention VFSS being the ‘gold standard’ (it’s 2021, get with it! #FEESequality😅) this also includes the fact that they point out how many previous studies looking into this topic with videofluorography (aka videofluoroscopy/VFSS) fail to use many objective measures and rely heavily on dysphagia-related questionnaires (which hopefully we now understand that while these can be helpful and relevant in different ways, under-diagnosing and less reliability is also a risk!).

So, that’s where it all started as they also worked on finding the best way to measure malnutrition in this large population range:

“The geriatric nutritional risk index (GNRI) was adopted recently to replace numerous previously created nutritional measures because of its well-established reliability and ease of calculation, using an objective rather than subjective measurements to determine nutritional risk in hospitalized patient populations.” p.2

What were they wanting to find you ask? 

Basically, they were hypothesizing the patients we often see in the acute settings that are at high risk for dysphagia are also likely to be more at risk for malnutrition (when using the measures below).

By taking a quick look at the inclusion criteria we know that those in the study had a videofluoroscopic swallow study and had a variety of admitting diagnoses categorized into the following groups:

• brain tumors
• cardiovascular diseases
• malignancies
• musculoskeletal disorders
• neurological disorders
• pneumonia
• stroke
• other diseases*

In case all those seem too lumped together, the authors also made operational definitions so we can all be on the same page and know just what exactly constitutes a cardiovascular-related issue etc. which is very appreciative because I’m sure we all know every facility, let alone every doctor or medical professional, uses a different meaning for everything! These included terms like hypertensionº, diabetes mellitusº, chronic kidney disease (CKD)º, congestive heart failure (CHF)º, and chronic obstructive pulmonary disease (COPD)º.

Now, since I’m not a registered dietician (pretty sure my diet at times would disqualify😅), I really can’t try to know all the details about all the other criteria relating to nutrition like fasting, BMI, and albumin concentration measurements… BUT, in case any of you are more curious or wanting to do quick math on the fly, here’s the formula they used in the study to get their GNRI number for later analysis:

GNRI = [1:489 x albumin (g/L)]

             + [41:7 x actual body weight / ideal body weight)]

“The GNRI cutoff value to identify malnourished patients that we adopted in the present study was <91.2” p.3 

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Now what I definitely can raise my hand up to is all the swallowing-related measures used!🙋🙋‍♀️

To gain some real-world credibility, the authors openly admit that patients had a videofluorography “as soon as patients suspected of dysphagia were able to tolerate” which I feel might be one of the truest statements in good ‘ole acute. They realized this was typically done on the 14th-day post-medical hospitalization or surgery (anybody else wanting to compare this where you work too?!). Another note only an SLP can relate and appreciate: they use the term “loads” to refer to their varying amounts and viscosities of barium (thickened, water, and ‘jelly’😉) which I love because that’s what we’re doing (loading the boluses to assess how the swallow mechanism reacts), no? I know I will definitely be remembering this to plug in my documentation!😍

Just like what happens frequently in our own colder-than-thermal-stim fluoro suites, the clinicians completing the instrumental evaluation also ended the fluoro when “aspiration or penetration was expected to occur or at the time an actual event occurred” for patient safety. Now, it may just be that I’m in a nit-picky kind of mood because of the hotter-than-🥵🥵 weather lately, but I feel like even if I was talking to another clinician and heard this, I’d still probably want a bit more information as to what exactly were the criteria to terminate the study? Total amount aspirated? Severity of aspiration from the PAS? Consideration of the patient’s overall capability to tolerate such aspiration etc.??? As always, I’m needing more answers to all my questions. . . .

The measure that was used was the  Penetration-Aspiration Scale (PAS) in order to “provide reliable quantification of selected penetration and aspiration events observed during videofluorography.” Here’s a quick refresher for the definitions and review of how they used it for the study:

“Penetration is generally defined as passage into the larynx of material that does not pass below the vocal folds and corresponds to PAS 2 and 3.”

“Aspiration is generally defined as passage of material below the level of the vocal folds and corresponds to PAS 6, 7, and 8.” p.3

(**Never fear–they also are clear to state that “laryngeal penetration without vocal fold contact is clinically found sometimes even in clearly healthy subjects and that PAS 4 or more was never reported” in the study**)

The investigators divvied patients into 2 groups for normal and impaired and then sorted them even further (is it just me or does it seem like researchers are probably those people who would separate their M&M’s by color before eating them?😂):

“we decided to group PAS 1, 2, 3 in the same group. On the other hand, because dysphagia accompanying vocal fold contact could directly progress to aspiration, PAS 4 and 5 can be regarded as clinically higher risk situations compared to PAS 2 and 3. In order to compare patients in the two groups, we gathered the remaining PAS 4, 5, 6, 7, and 8 in the same group.”  p.3

So after all was said and done, they basically got all those patients who had PAS 1-3 (low to no risk for swallowing safety) at one end of the table, and then all those who got PAS 4-8 (more “high-risk” dysphagia for swallowing safety) at the other end of the table to compare both sides.

They also explain the PAS was used to essentially determine the “safety” and severity of a patient’s swallowing and dysphagia. In all honesty, I had to go back to the original research for PAS to fully understand what the whole purpose was because I was in a curious conundrum over the ability to associate dysphagia “severity” with PAS especially since nowadays, there are many other scales and measures to use for this (e.g. DOSS, DIGEST, DSRS). After thinking about it and reviewing the original PAS paper a bit more, I suppose that the PAS could be used to indirectly judge the severity of dysphagia as the authors state and reference, “In general, because the likelihood of developing pneumonia is directly related to the severity of PAS, a higher PAS value is more likely to be considered severe; thus, in this study we divided patients into two groups and described PAS 4–8 as high-risk dysphagia.” However, a very valid argument on the opposite side could be that the severity would only relate to the severity of airway invasion/protection and safety versus judging and concluding anything about the efficiency of a swallow. Either way, I am down to talk more about this with anyone who will listen, researchers and clinicians alike!!🤓

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Lucky for you there will be no serious statistics headaches this round🙃! Other than saying the investigators compared a lot of different categories (categorical variables like gender/disease etc., and continuous variables like age/lab values, etc.) in a lot of different ways using a lot of different tests, that’s about all I got today!😊

Because I just can’t hold it in I can’t forget to mention some simple info like out of 165 enrolled patients from the study the median ° age was 76, and out of that total 53 were female. And I obviously can’t leave you guys hanging not knowing that the average GNRI was 81.2, of which 134 (81.2%) from the total met the criteria for malnutrition.

Okay okay, enough of that…

Did you think the type of disease would impact the severity of PAS??

“Chi-square for independence test did not reveal any significant association between disease classification and PAS 1–3 or PAS 4–8.” p.4

But, what about age? That would certainly play a significant role in malnutrition right?

“The median age of the patients with PAS 4–8 was not significantly higher than that of the patients with PAS 1–3 (77.0 vs. 73.4, P=0.14)” p.3

What about the PAS severity scores and malutrition rsk??

“On the other hand, Fisher’s exact probability test demonstrated that solely GNRI<91.2 was significantly associated with PAS 4–8 (P=0.034). The GNRI of patients with PAS 4–8 was significantly less than that of patients with PAS 1–3.”

“A univariate analysis revealed that GNRI <91.2 was the only factor significantly associated with PAS 4–8. A multivariate logistic regression analysis with the forced entry method showed that only GNRI<91.2 was independently and significantly associated with PAS 4–8.”

“A GNRI<91.2 triples the risk of serious swallowing dysfunction.” p.4

(#TBH after remembering that anything less than p<.05= *statistically significant*, the tables in the original article really aren’t that scary to find this!😉)

Alright! We’re all good now, right? We all know what to do to know and how to determine high-risk for dysphagia and malnutrition, right?👍

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This is the fun part because this is where we get to think about what this article CAN👍 and CANNOT👎 tell us .  .  .

First, let’s hear the authors discuss their thinking:

“careful consideration of the causal relationship between malnutrition and dysphagia is required. Malnutrition as a result of dysphagia is an easily comprehensible causality. Here we would rather discuss the possibility of the inverse causality, that is, dysphagia as a result of malnutrition.” p.4 

So, based on what we know and are continuing to learn about swallow physiology and the relationship between muscles, neuroplasticity, and motor learning, as well as the aging process, what are some things to consider going forward??

I don’t know about you, but even before taking some stellar courses about dysphagia+aging/disease processes, I could still use my eyes, ears, and intuition to tell if a patient was having a “rough time” (my medical terminology😅). But to know exactly how this relationship can impact someone’s swallow function has been *THE* million-dollar question many of us have had to try to figure out how to explain to numerous patients and families:

“Dysphagia obviously affects nutrition; meanwhile, malnutrition can exacerbate dysphagia through these neuromuscular dysfunctions.”

“Especially as a consequence of protein–calorie malnutrition, there is a reduction in muscle weight, muscle fiber diameter, and impairment in the force of contraction and rate of relaxation of muscle fibers. The highly coordinated muscular events of swallowing depend on the activity of the central nervous system.” p.5

Back to that same old question: is it really the chicken🐔 (dysphagia) or the egg🥚 (malnutrition)?

The authors propose a more synergistic connection between dysphagia, malnutrition, and neuromuscular dysfunction (ironically resembling our own EBP triangle😉).

Maybe instead of focusing on what came first, we need to start understanding more about what to do–meaning, what to treat and what we (as SLPs) cannot (and maybe should not) treat?

Another notion we SLPs still need to get more comfortable with, regardless of setting, is that just because someone is “older,” i.e. geriatric does ❌NOT❌ mean they automatically have this muscle-wasting condition which can dramatically impact their swallowing function. In fact, the authors make a point to push past this idea because “everyone is getting older equally and there is no way to resist it,” reinforcing what is something we as clinicians should and can treat, versus what is simply the typical aging process and compensations (e.g. presbyphagia):

“It seems to be important to accurately grasp the factors other than aging that affect swallowing and to take measures against them individually. Malnutrition is one of the important causes of dysphagia in the elderly.” p.6

“Aging-associated changes in the regulation of appetite and the lack of hunger have been termed ‘the anorexia of aging.’ The etiology of the anorexia of aging is multifactorial and includes a combination of physiological changes and social factors associated with aging, such as a decline in the senses of smell and taste, reduced central and peripheral drives to eat, delayed gastric emptying, oral health status, low income and poverty, and loneliness and social isolation.” p.6

So again, instead of thinking pointing fingers at what “caused” what (because the authors even admit how they are unable to determine this type of causative link), let’s start figuring out what we need to do to help the chicken, or who we need to refer to about the egg.🙂

One final part the authors touch on (which I personally find the most interesting), is how malnutrition and dysphagia relate to the acute phase of disease/illness for patients:

“Nutritional disorders are comorbid diseases that are often associated with stroke, cancer, chronic heart failure, and COPD.”

“In fact, nutrition status is often neglected by medical staff during an acute illness.” “In order to overcome the problem of malnutrition, a team approach including medical doctors, dentists, nurses, public health nurses, nutritionists, and therapists is important in both the acute phase and in the pre-disease community dweller stages” p.6

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Before we end here, I can’t leave without pointing out some limitations because apparently I’m that #debbiedowner when it comes to things to consider or not overlook…

Besides the obvious things that ultimately disqualify being able to make any generalizations like the following:

• small sample size
• patients recruited from only one hospital location
• instrumental swallow study (VFS) was used, but it’s unknown if there was any type of protocol to this for standardization and easy replication (they simply reference a “standard protocol” )🤷‍♀️
• revisions to PAS and has had different reflections as to the direct relationship between a higher PAS score + pneumonia risk
• retrospective design (looking back at data) really only lets you make observations of what happened

Aside from the fact that even though I’m clearly no dietician and can’t try to have a full understanding of all the nutritional variables and factors discussed in the article, the authors do point out that the GRNI seemed a possible prospect for how to assess nutritional status in acute management and determine those with high-risk dysphagia (at least in their study!).

In a final note, I believe the year 2020 was the year of interdisciplinary and multidisciplinary medical therapeutic alliances for all. From working more closely with respiratory therapists to talking more frequently with physical therapists or case managers. As rehabilitation specialists, we do what is needed for the patient. While a main role in the acute hospital setting is to assess and treat dysphagia concerns with an adjunct responsibility for preventing or minimizing the risk of aspiration or educating on pneumonia risk (yes I know, there are MANY other things in there as well😉), when we implement a more holistic and dynamic approach, we’re able to consider a patient’s overall health status, including their nutritional needs.

This article can be a starting point for us to again consider more than just the chicken or egg, and include all the multiple factors to allow for critical thinking so we can be more of a holistic, well-rounded-thinking type of clinician (for this critical population in particular).☯️

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How can you use this article?!?

• I for one, can’t wait for the sequel to this study🤩, where take a prospective and more active look to see what happens (instead of just looking to the past)
• Do you use some incorporate of nutritional screen or assessment in the acute stage??
• How do you think nutrition plays a role in dysphagia, pneumonia, and overall quality of care, life, and progress in acute settings?

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Takeaways:

• “A GNRI<91.2 triples the risk of serious swallowing dysfunction…careful consideration of the causal relationship between malnutrition and dysphagia is required”
• “At present, we cannot confirm the physiological evidence of a causative relationship from malnutrition through neuromuscular dysfunction to dysphagia in the present study. In the future, it is necessary to measure actual muscle mass reduction and nerve dysfunction, which are caused by malnutrition, in relation to swallowing function”
• “In this study, simply being elderly was not associated with dysphagia”
• “Whether improvement of nutritional status affects swallowing function in the acute phase is still unknown”

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Article Referenced: 

Saito, T., Hayashi, K., Nakazawa, H., Yagihashi, F., Oikawa, L., & Ota, T. (2017). A Significant Association of Malnutrition with Dysphagia in Acute Patients. Dysphagia, 33(2), 258-265. doi: 10.1007/s00455-017-9855-6

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Some additional references!

• Furuya, J., Suzuki, H., Tamada, Y., Onodera, S., Nomura, T., & Hidaka, R. et al. (2020). Food intake and oral health status of inpatients with dysphagia in acute care settings. Journal Of Oral Rehabilitation, 47(6), 736-742. doi: 10.1111/joor.12964

• Leslie, P., Drinnan, M., Ford, G., & Wilson, J. (2005). Swallow Respiratory Patterns and Aging: Presbyphagia or Dysphagia?. The Journals Of Gerontology: Series A, 60(3), 391-395. doi: 10.1093/gerona/60.3.391

• Matsuo, H., Yoshimura, Y., Ishizaki, N., & Ueno, T. (2016). Dysphagia is associated with functional decline during acute-care hospitalization of older patients. Geriatrics & Gerontology International. doi: 10.1111/ggi.12941
• Namasivayam-MacDonald AM, Morrison JM, Steele CM, Keller H. How Swallow Pressures and Dysphagia Affect Malnutrition and Mealtime Outcomes in Long-Term Care. Dysphagia. 2017 Dec;32(6):785-796. doi: 10.1007/s00455-017-9825-z