Title: The effect of reclining position on swallowing function in stroke patients with dysphagia
Authors: Benjapornlert, Kagaya, Inamoto, Mizokoshi, Shibata, & Saitoh
Journal: Journal Of Oral Rehabilitation
Year of Publication: 2020
Design Type: Retrospective
Purpose: “To evaluate the effect of reclined position on swallowing function in patients with stroke who had dysphagia”
Population: records of adult patients with dysphagia from stroke at a single hospital in Japan
Inclusion criteria: stroke (ischaemic, haemorrhagic, subarachnoid haemorrhage) at any onset; dysphagia confirmed by interview/physical examination (including water swallow test)
Exclusion criteria: Any history of diseases or surgeries that might likely affect swallowing function (e.g. Parkinson’s disease, HNC, achalasia, etc.)
I don’t know about you, but I would absolutely be a patient who would have the hardest time if I had to eat small bites,” “eat slowly,” “minimize distractions while eating,” and “eat sitting upright 90 degrees.” Maybe it’s from snacking throughout the day in grad school classes or having to quickly grab a bite of any food I could before getting back out to waitress or bartend (to pay for said classes), or possibly even from my super relaxed state on my couch enjoying that cheesy slice of pizza after an exhausting day being a busy SLP on the move!
BUT–is this exactly what we should maybe stop telling our patients to do🤔?! Imagine a world where we were not only no longer the “diet police,” but also gave up the hall-monitor equivalent title for “safe swallow” duty!?
Either way, if someone actually tells me to lay back, relax, and swallow my slurpee, I am DOWN to learn more about whatever angle they are prescribing!!😅🤤
I always think life would be a LOT easier if as clinicians the things we tell our patients NOT to do was kept to a minimum compared to what our patients “can” do (obviously anyone can do anything they want just like I can eat an entire pizza in 1 sitting despite what my doctor advises, #advocacy #selfdetermination #idowhatiwant😅). So if there is something out there advocating for that instead of taking something away and being the grim-reaper of all food/beverages and actually allowing a patient to do something more natural, then by-golly let’s see it!!!
But before we all hop on board this delicious gravy train, let’s see what all these new crazy ideas are about shall we?🤓
While the article doesn’t necessarily mention too much about actual dysphagia rehabilitation in term of exercises (ya know, to actually rehabilitate the swallow?) which sometimes can be a big bummer😩, they do remind us how compensatory-type strategies came about and the purpose of them:
“Many studies have suggested that changing body posture is useful for dysphagia treatment. Head rotation (head turn) manipulates bolus away from the rotation side, while the body tilt helps the bolus flow to the lower side of the body.”
“These techniques subsequently propel the bolus down to the hypopharynx and the upper esophageal sphincter (UES), decreasing the risk of penetration and aspiration. Sitting upright position during swallowing is a typical posture during swallowing and promotes arousal in somnolent patients. Moreover, since the bolus can be held in an oral cavity, it can be prevented from spilling into the pharynx.” p.1
To add to that, apparently some studies long ago actually figured out that by using gravity, reclining patients with “non-specific functional dysphagia” (whatever that means?🤷♀️) helped “the bolus move closely to the posterior pharyngeal wall“ and ended up reducing the risk for penetration/aspiration!🤯🤯
This compensatory technique was actually being utilized in Japanese dysphagia management, but the evidence was still pretty iffy, so that’s where the authors decided to step in and figure out once and for all if it was truly all it’d been hyped up to be!
Instead of actively choosing patients in a single Japanese hospital location and go from there, they decided to look back at records (2010-2018) of patients who a) had stroke confirmed, b) had dysphagia confirmed from physical exam (and later videofluoroscopically which were analyzed). Now, I felt I was only able to assume these 2 things to be true given there was no mention of MRI confirmed findings for stroke🧐, or that I suppose this facility was just “doin’ the recline” technique for patients during those timeframes as already customary care and that’s how they were able to look back in time🤷♀️.
The good news😃!
Not only was there a “swallowing chair” (they give specifics, but I’m not too familiar with these kinds of details!), but they used 30 frames/second in the lateral view while also video recording!
Did you think that was it?
They also were able to analyze and review the VFS frame-by-frame in slow mode (shoutout to those who remember the Apple’s© QuickTime Player they used)!!!
Okay, now for some details that aren’t as exciting….
Yes, they only used 4 ml Moderately-Thick Liquid (aka IDDSI Level 3😎). And yes, they used a 10-ml syringe to administer directly into each patient’s mouth. Yesss, they even cued them when to swallow..I know I know, I think I’ve said this about almost 100 times on here now how these kinds of things can absolutely change the natural-ness of someone’s swallow function (we’ve got evidence to prove it!!)
But, we gotta move on to bigger and better things at some point⏩⏭. . .
So what else did they do?
Well, they had 3 different positions they looked at:
- 90º upright angle (90ºU)
- 60º reclined (60ºR)
- 45º reclined (45ºR)
- (the reclined positions got a pillow under their head to prevent neck extension😉)
Now, they did NOT necessarily look at each of these separately. Instead, they grouped all 98 subjects who had at least 2 of the above positions (only 9 subjects were evaluated across all 3 positions):
(total: 45 subjects)
(total: 44 subjects)
“The starting position based on the subject’s position during the meal or the swallowing rehabilitation programme did not start from 90°U in every subject. If we found that the subject had penetration or aspiration at a first degree, we would adjust the angle to be lowered. In contrast, if they were safe swallowing at the reclined position, the angle would be changed to be a more upright position.” p.3
I don’t know about you, but I was the girl crying “non-standardized” while reading this🤓🤪 (more on that later!).
What else did they look at?
- type/location of stroke
- ischaemic (62%)
- haemorrhagic (32%)
- subarachnoid hemorrhage (6%)
- 67% in cortical area of the brain, 28% in brainstem
As well as using the following measures:
- Dysphagia Severity Scaleº
- Penetration Aspiration Scale (primary outcome)
- amount of residue in the oral cavity, valleculae, and pyriform sinuses
- (the details for this were more unclear to me🤔)
- movement of hyoid bone and larynx during first swallowing reflexº
- “The hyoid elevation is considered as a good or normal range when the hyoid bone moves sufficiently in the anterior and superior directions. The laryngeal elevation is considered as a good or normal range when the larynx moves greater than the height of one vertebral body superiorly”
So, while I may not have been necessarily blown away from some of the measures, I know not everyone can be easily accommodated to things like MBSImP or the Dysphagia Outcome and Severity Scale (DOSS), and also to each-clinician-their-own and #usewhatyagot, right?😉
Luckily, they did give us a much clearer and more detailed description for specific events, referred to as “the phenomenon of hyolaryngeal complex movement” (does this not make swallowing sound waaay cooler?!😎) with some operational definitions for what specifically they were looking to identify:
- Laryngeal closure duration (LCD)º
- UES opening durationº
- Vallecular aggregation time (VAT)º
- Upper hypopharynx transit time (UHT)º
- Lower hypopharynx transit time (LHT)º
- Stage transition duration (STD)º
- Pharyngeal response duration (PRD)º
- Pharyngeal transit duration (PTD)º
Ok, if you’re still with me after allll that information, on to what they found!!!
After re-analysis, rater consensus, and fancy stats, they came up with 205 usable VF recordings across all their 98 stroke participants (average age 68, and mean Dysphagia Severity Scale was 3).
Now, some data was not showing a ‘normal distribution’ (meaning there was no perfectly pretty bell-shaped curve), so with that plus the comparisons of different groups and combination of using angles+numbers that gave me flashbacks to my least favorite Geometry classes😫, the results got a little hazy and less exciting (this is why I will forever advocate for emojis, memes, and gifs to be used in research😂).
But–as far as:
Changes in hyoid bone/larynx movement?
“Reclining position did not significantly affect the hyoid bone and laryngeal elevation. The hyoid bone and larynx move anterosuperiorly by contraction of the suprahyoid and thyrohyoid muscles..the height of movement might depend on muscle strength itself.” p.7
Apparently, this was also seen in previous studies as well, demonstrating no impact to the suprahyoid and infrahyoid muscle activity.
Changes in durations for closure/opening/onset of ‘the phenomenon of hyolaryngeal complex movement’ ?
Transit time for Vallecular aggregation/Upper hypopharynx/Lower hypopharynx:
“The VAT, UHT and LHT in this study showed no significant difference in the 90°U and 60°R groups, and in the 60°R and 45°R groups. VAT in the 45°R seemed to be lower than the 60°R, but it was not statistically significant.” p.7
The authors postulated that due to a most reclined position, the bolus collects in the valleculae spaces for a shorter amount of time and hits the posterior pharyngeal wall right from leaving the oral cavity🤔. . .
Pharyngeal and Stage Transition Durations:
“STD and PTD were significantly different in the 60°R and 45°R groups. We could express that swallowing reflex is quicker in a more reclining position…in both groups PRD was not significantly affected by the reclining posture.” p.7
I will definitely say it’s hard to pick all this apart, but basically, these 2 measures were longer at 60°R than 45°R but were not significantly different when comparing 90°U and 60°R groups for this.🙃
Laryngeal closure/UES opening:
“The laryngeal closure duration (LCD) was not different in both groups. However, UES opening duration was longer at the 60°R than 45°R, while there was no significant change at 90°U and 60°R groups.” p.5
(This was pretty much all they said of this measure and I couldn’t really find any clear rationales🤷♀️)
Changes in PAS scores?
“The findings in this study indicated that the lower angle of body position reduced the PAS score. The reclining position raises the trachea relative to the oesophagus. Besides, gravity effect in the reclining position helps the bolus to move closer to the posterior pharyngeal wall and effortlessly pass through the UES with a lower risk of penetration into the larynx or aspiration into the trachea.” p.5
“We found that the leading edge of bolus during swallowing onset significantly more buried in a more upright position. Simultaneously, the PAS was significantly higher in a more upright position, as stated above. The deeper bolus head at swallowing onset also increased the severity of PAS.” p.5
Apparently, this was also similar to another similar study, and makes you think more about the wonderous anatomy and rheology when they state that “This phenomenon is due to gravity’s effect that speeds up the bolus movement reaching hypopharynx in the more upright position..In theory, gravity’s effect would cause the bolus to fall into the pharynx easily in a more reclined position.” However, I’m not sold just yet and the authors are even quick to say that their study actually found that changing positions didn’t affect premature spillage at all🤨.
Changes in oropharyngeal residue?
No significant difference was found in the oral cavity across all position comparisons, while it seemed the “more reclined position, that is 60°U at 90°U+60°R groups, and 45°R at 60°R+45°R groups,” had a significant decrease in residue for valleculae and pyriform areas. And if you’re holding and shaking your head right now, they try to explain they’re thinking behind these results:
“The movement of the bolus closer to the UES may explain the reduction during the reclined position. When the swallowing reflex occurs, the UES is opening. The bolus quickly passes through the UES. Furthermore, pharyngeal swallowing is longer in the reclining position. Hence, the residual in the pyriform sinus is smaller in the amount in the lower reclining position.” p.5
You guys got all that? Great! Since we got all we need let’s call it day and start lounging, right?
If you’re like me, you definitely need some more answers and LOTS more explanation to put all these dots together for what it all means (especially if you’re reading this after a long day at work!)….
First thing’s first, there is a LOT we CANNOT draw from this single study due to MANY things!
- small sample size
- single facility location
- small amount of only THICK liquid (where my thins at?!)
- naturalistic setup (cued swallows, syringe administration, etc.)
- selection bias (subjects already diagnosed with dysphagia)
- non-standardized protocols for positioning (protocol bias)
- indirect group comparisons
Even more, there are soo many things we still don’t know from this one study:
Does rate or presentation matter? (ex: consecutive sips? spoon vs cup?)
Does specific time from onset matter?
Would there be differences between thin and thicker consistencies?
Would additional compensatory strategies help?
What about specific anatomical differences or other populations?
Regardless, we need a LOT more information, and no matter what all this will still require any trialed strategy under instrumentalization to actually know if this is actually a thing, on a case-by-case basis!
While this idea and study bring up super interesting points, I’m left with many more questions vs answers than I’m comfortable with before letting my patients lay back, chillax, and glug-glug their favorite beverages in the comfort of their La-Z-Boys🥴.
How can you use this article?!?
Have you observed this or already been doing this?
What do you think these gravity-related changes would have an impact on?!
Are you looking forward to seeing future research on this?!?
What other questions do you have on this study?!?!
- “Reclining position did not significantly affect the hyoid bone and laryngeal elevation. The hyoid bone and larynx move anterosuperiorly by contraction of the suprahyoid and thyrohyoid muscles. According to previous studies, the reclined position did not impact the suprahyoid and infrahyoid muscle activity. Therefore, the height of movement might depend on muscle strength itself”
- “The results of this study suggest that a lower angle of the reclined position helps to prevent penetration and aspiration, and reduces the amount of residue at the pharyngeal area when compared to the more upright position”
- “The limitation of this study was that we utilized only a small amount of moderately thick liquid that might not represent all types of liquids.”
Benjapornlert, P., Kagaya, H., Inamoto, Y., Mizokoshi, E., Shibata, S., & Saitoh, E. (2020). The effect of reclining position on swallowing function in stroke patients with dysphagia. Journal Of Oral Rehabilitation, 47(9), 1120-1128. doi: 10.1111/joor.13037
Some other resources goodies!!