Beds with angle indicators and head lift function contribute to appropriate
positioning during eating and low incidence of pharyngeal residue
Shigeru Tamura1,2, Yuka Miura3*, Junko Sugama3
1. Division of Nursing, Fujita Health University Hospital, Toyoake, Aichi, Japan
2. Graduate School of Health Sciences, Fujita Health University, Toyoake, Aichi, Japan
3. Research Center for Implementation Nursing Science Initiative, Fujita Health University,Toyoake, Aichi, Japan*Corresponding author: yuka.miura@fujita-hu.ac.jp
ORCID ID:
Junko Sugama
0000-0003-4050-074X
Yuka Miura
0000-0003-1878-1688

Introductionused to decide the recommended angle of trunk

The presence of a pharyngeal residue, defined astilt and head and neck flexion, based on thethe material remaining in the pharynx, is a signevaluation of the pharyngeal residue duringof a swallowing disorder and a clinical predictor

mealtimes is difficult due to its invasiveness.

of aspiration. Healthcare professionals adjust theTherefore, no previous studies have comparedeating pattern and patient posture to reduce thepharyngeal residues in patients with swallowing

amount of pharyngeal residue in order to prevent

disorders between the recommended angles andaspiration pneumonia. One of the effective

angles during eating. Recently, a newly

methods for reducing the amount of pharyngeal

established technique has been reported to beresidue is proper positioning to achieveable to noninvasively identify pharyngeal

appropriate trunk tilt and head and neck flexion

residues during mealtimes with the use of anangle [1]. To avoid pharyngeal residues during

ultrasound device [3]. Ultrasonography iseating, the trunk tilt and head and neck flexion

noninvasive and can be performed repeatedly.

angle must match the recommended angle based

Additionally, no special diet is required duringon the evaluation of the swallowing function,examination; thus, imaging can be performed

such as video endoscopy (VE). In our previous

while the patient is consuming his normal diet.

study, beds with angle indicators and head lift

Therefore, we propose to use ultrasonography tofunction resulted in better angle as compared toevaluate the effect of beds with angle indicatorsconventional beds in healthy individuals [2].

and head lift function on pharyngeal residue

Our next challenge is to investigate thereduction during daily mealtimes.

reproducibility of the recommended angle and

The present study aimed to investigate 1) the

reduction of the amount of pharyngeal residue

reproducibility of the recommended trunk tilt

by using a bed with angle indicators and head lift

and head and neck flexion angle by using a bed

function in patients with swallowing disorders

with angle indicators and head lift function induring mealtimes. Performing VE, which waspatients with swallowing disorders duringmealtimes and 2) the effect of a bed with angle

disorder by VE. The inclusion criteria were asindicators and head lift function on the reduction

follows: 1) patients admitted to the hospitalof the amount of pharyngeal residue during

between June and October 2023 and 2) who

mealtimes.

started oral intake after VE. The exclusion
criteria were 1) patients whose oral intake wasMethods

not recommended according to the VE

This cross-sectional observational study wasassessment findings, 2) patients with severe

conducted in a university hospital withdysphagia who were not medically stable, 3)

approximately 1,400 beds. All patients usedpatients with deteriorating general condition, 4)either beds with angle indicators and head lift

patients for whom the echo probe could not befunction (AX-72153T: SEAHONENCE Inc.,

applied during eating due to the presence of aOsaka, Japan) or standard beds. There were noneck collar or a central venous catheter, 5)criteria for the use of functional andpatients aged <20 years, and 6) patients who had

standard beds. Patients were randomly

not been evaluated for swallowing ability forallocated, irrespective of the severity of theirthree types of food (staple foods, side dishes, anddysphagia. Therefore, this study was anliquids) during swallowing assessment using VE.

observational study with only observations

The bed with angle indicators and head lift

made during VE assessment and feeding. We

function has indications of the backrest and headrecruited patients diagnosed with a swallowing

lift angle, whereas standard beds do not haveAAacbB

Bd.
αc.

dαβCβCFig 1. The characteristic of a bed with angle indicators and head lift function
a. A bed with angle indicators and head lift function
b. A bed without angle indicators and head lift functionc. An angle indicator of the backrest angle
d. An angle indicator of the head lift angle
A. A straight line connecting the top of the patient's head and the external ear canal
B. Outer edge of the backrest
C. Outer edge of the bedframe
Head and neck flexion angle was defined as the angle formed by the intersection of A and B (α).
Trunk tilt angle was defined as the angle formed by the intersection of B and C (β).

indicators of the backrest and head lift angle orfrom the recommended angles. The error margin

a head lift function. The backrest’s range offor the head and neck flexion angle was withinmovement is 0º–80º for both beds, and the range±2.5º from the recommended angles. Pharyngealof movement of the head lift function is 0º–30º.

residue measurements were taken during eating

The trunk tilt angle was defined as the angle

after the trunk tilt and head and neck flexion

formed by the outer edge of the backrest and theangles had been measured.

outer edge of the bedframe. The head and neck

Pharyngeal residues of the glottis valley andflexion angle was defined as the angle formed byright and left pisiform fossa were confirmed

the intersection of the straight line connecting

using a wireless ultrasound diagnostic device

the top of the patient's head and the external ear(iViz air: Fuji Film Medical Corporation, Tokyo,

canal and the outer edge of the backrest (Fig 1).

Japan). When viewing the epiglottis valley, theThe recommended trunk tilt angle and head andprobe was applied transversely from just above

neck flexion angle and those during eating werethe hyoid bone. When imaging the right pisiform

measured using a Todai angle meter. Thefossa, the probe was applied transversely fromagreement of the recommended angle and thethe right side of the laryngeal ridge, whereas

angle during eating were evaluated. The

when imaging the left pisiform fossa, the probe

agreement between the recommended angle andwas applied transversely from the left side of thethe angle during eating was defined as only

laryngeal ridge (Fig. 2). Ultrasound movies werewhen both trunk tilt angle and head and necktaken for 2–15 seconds to ensure that theflexion angle during eating matched with theimaging point was accurately captured. Therecommended angle. The acceptable error

pharyngeal residues were determined as hyper-margin for the trunk tilt angle was within ±5ºechoic areas in the hypo-echoic areas in theabABC

Fig 2. Echo probe location when imaging the pisiform fossa and glottis valleya. Probe location for the imaging of the pisiform fossa

A . Hyoid bone. B . Thyroid cartilage. C . Cricoid cartilage
When observing the right pisiform fossa, the probe is applied transversely from the right side ofthe laryngeal ridge; when observing the left pisiform fossa, the probe is applied transversely fromthe left side of the laryngeal ridge.

b. Probe location for the imaging of the glottis valley
Probe is applied transversely from just above the hyoid bone.

epiglottis valley and pisiform
fossa.
We compared the agreement
between the recommended
angle and angle at the time ofeatingbetweenpatients

placed on the beds with angleindicators

andheadlift

function (functional group)and patients on the standard
also compared the presenceofpharyngeal

residuebetween two groups.
This study was approved by
the Medical Research Ethics
Review Committee of Fujita

10Difference from the recommended angle (degree)

beds (standard group). We

Functional group( n = 25 )Standard group( n = 23 )n=25
n=6n=40

Agreement range

n=2-5

n=4
n=2-10n=2-15n=2n=2-20010

Medical College (approval

2030405060

Recommended head and neck flexion angle (degree)

Fig 4. Difference between the recommended head and neck flexion angle and the angle at eating

number: HM23-080).

(56.0)] than in the standard group [2 (8.7)] (p <Results and discussion0.01). The errors between the recommended

VE assessment was performed on 156 patients.

trunk tilt angle and the angle at eating differed

After excluding 108 patients, 48 patients wereby up to 10º and −15º in the functional andenrolled in the study, including 25 patients

standard groups, respectively. The error ranges

assigned to the functional group and 23 patientsof the functional and standard groups wereassigned to the standard group. In the functional

mostly within ±5º and mostly outside ± 5º. Inand standard groups, the number of men [n (%)]

both the functional and standard groups, thewas 17 (68.0) and 14 (60.9), respectively. The

angle at eating tended to be lower than themean age [± standard deviation (SD)] of therecommended angle. The error tended tofunctional and standard groups were 76.0 ± 13.1

increase as the recommended angle becameand 72.2 ± 14.5 years, respectively. The mean

higher (Fig. 3). The maximum errors between

BMI (± SD) was 20.2 ± 3.9 and 18.8 ± 5.4 kg/m2,

the recommended head and neck flexion anglerespectively.

and the angle at eating were 15º and 20º in thethefunctional and standard groups, respectively. In

recommended and eating angles [n (%)] wasboth the functional and standard groups, thesignificantly greater in the functional group [14angle at eating tended to be lower than theThe

agreement

numberbetweenrecommended angle. The error tended toIn the future, we plan to develop a pharyngeal

increase as the recommended angle became

residue monitoring system embedded in a bed.

higher (Fig. 4). The errors (degrees: mean ± SD)

We expect that the bed will be able to determine

between the recommended trunk tilt angle andthe appropriate trunk tilt and head and neckthe angle at eating were 0.3º ± 3.2º and −8.5º ±flexion angles based on information obtained by

9.6º. The error was significantly lower in thethe monitoring system and will automaticallyfunctional group (p < 0.001). Residual presence

adjust its posture during mealtimes. This system[n (%)] was significantly lower in the functional

will contribute to safe and comfortable eatinggroup [11 (1.8)] than in the standard group [34without pharyngeal residues among people with(6.3)].

swallowing disorders.

This investigation was the first study thatshowedbetteragreement

betweenConclusion

therecommended angle and the angle at eating

The trunk tilt and head and neck flexion angle

patients with swallowing disorders utilizing

during eating is more likely to agree with thebeds with angle indicators and head lift function

recommended angle when using a bed withas compared to those patients utilizing theangle indicators and head lift function as

conventional beds. Moreover, the ultrasoundcompared to a standard bed, resulting in a lower

imagesincidence of pharyngeal residue.

successfully

agreementwasshowed

effectivethatinbetterpreventing

pharyngeal residues during usual mealtimes.
ultrasonography. The 11th Annual Meeting

Acknowledgementsof the Society for Nursing Science andThis work is supported by a grant fromEngineering, pp85, Hyogo, 2023.6.9-10.

SEAHONENCE Incorporated.

(conference proceeding)3.

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