Acta Otorrinolaringológica Gallega

Arículo Original

Correlação entre a Escala de Secreções de Murray e a Escala de Resíduo Faríngeo de Yale

Correlation between the Murray Secretion Scale and the Yale Pharyngeal Residue Severity Rating Scale

Filipa Ferreira, Paula Correia,

Sílvia Alves, Mariana Branco,

Mariana Neto, Luis Antunes

Autores:

Filipa Ferreira,

Paula Correia,

Sílvia Alves,

Mariana Branco,

Mariana Neto,

Luis Antunes.

ENT Department, Hospital Garcia de Orta – Almada, Portugal

Correspondencia:

Filipa Ferreira.

Hospital Garcia de Orta - Avenida Torrado da Silva 2805-267 Almada.

anafilipa.ferreira@gmail.com

Fecha de envío: 28/11/2022 Fecha de aceptación: 13/3/2023

ISSN:
2340-3438

Edita:
Sociedad Gallega de Otorrinolaringología

Periodicidad:
continuada.

Web:
www.sgorl.org/revista

Correo electrónico:
actaorlgallega@gmail.com

Abstract

Introdução: A escala de secreção de Murray (ESM) é um instrumento validado para a avaliação da acumulação de secreções, podendo ser utilizada durante a realização de nasofibroscopia por fibra óptica (NFO) na consulta geral de Otorrinolaringologia. A Escala de Severidade de Resíduo Faríngeo de Yale (ESRFY) foi desenvolvida para a determinação do resíduo faríngeo após a deglutição sendo habitualmente utilizada no decurso da avaliação formal da deglutição.

Objetivos: Comparar a correlação entre ESM e ESRFY em otorrinolaringologistas com e sem experiência em avaliação da deglutição.

Material e Métodos: 40 avaliações endoscópicas da deglutição foram selecionadas de uma coorte retrospectiva. A avaliação foi realizada por 8 clínicos diferentes, sendo 2 deles experientes em deglutição. Todos os exames foram classificados de acordo com o grau de gravidade utilizando as duas escalas.

Resultados: Houve forte correlação entre as avaliações de cada observador em ambas as escalas (Τβ entre 0,327 p=0,014 e 0,598 p=0,001). A correlação interobservador foi maior quanto mais experientes os juízes foram: κ=0,369(IC 95%, 0,366 a 0,373), p=0,001 vs κ=0832(IC 95% 0,827 a 0,838), p=0,001 para a ESM e κ =0,305(95% CI, 0,302 a 0,308), p=0,001 vs κ=0,678(95% CI,0,673 a 0,684) p=0,001 para ESRFY.

Conclusão: Houve correlação significativa entre a classificação da ESM e da ESRFY em observadores com e sem experiência. A presença de estase salivar na NFO pode alertar o clínico em consulta de otorrinolaringologia geral para o risco potencial de resíduo faríngeo após a deglutição e para a necessidade de referência para consulta específica de avaliação da deglutição.

Palavras Chave: dysphagia; swallowing; endoscopy.

Abstract

Introduction: The Murray Secretion Scale (MSS) is a validated instrument for the assessment of the accumulation of secretions and can be used during any fiberoptic nasopharyngoscopy (FNP) by the general otorhinolaryngologist. The Yale Pharyngeal Residue Severity Rating Scale (YPRSRS) was developed for the determination of pharyngeal residue after swallowing and is used during the formal swallowing assessment consultation.

Objectives: To compare the correlation between MSS and YPRSRS both in ENT professionals with and without experience in deglutition evaluation.

Material and Methods: 40 flexible endoscopic evaluation of swallowing (FEES) were selected from a retrospective cohort. The evaluation was carried out by 8 different clinicians, 2 of them experienced in deglutition. All exams were graded according to the degree of severity using the two scales.

Results: There was a strong correlation between the assessments of each observer on both scales (Τβ between 0.327 p=0.014 and 0.598 p=0.001). The inter-observer correlation was higher the more experienced the judges were: κ=0.369 (95% CI, 0.366 to 0.373), p=0,001 vs κ=0832(95% CI 0.827 to 0.838), p=0,001 for MSS and κ=0.305 (95% CI, 0.302 to 0.308), p=0,001 vs κ=0.678 (95% CI,0.673 to 0.684) p=0,001 for YPRSRS.

Conclusion: There was a significant correlation between the classification on the MSS and the YPRSRS in observers with and without experience. Presence of salivary stasis in the FNP may alert the general ENT to the potential risk of pharyngeal residue after swallowing and to the need to referral to a swallowing assessment.

Key Words dysphagia; swallowing; endoscopy.

Introduction

Dysphagia is a common and serious condition that can lead to deleterious effects like dehydration, malnutrition, social isolation, depression, aspiration pneumonia, shortage of life expectancy and death.(1, 2) This is a frequent symptom that takes the patient to the ENT consultation.

Screening is generally accepted as the first step in the management of dysphagia, and all patients with symptoms should be assessed.(3) The ENT has a key role because, besides the use of questionnaires and screening tools, they have also the possibility of performing endoscopic evaluation with fiberoptic nasopharyngoscopy (FNP). This exam brings very relevant additional information and provides additional data regarding the potential risk of a patient with dysphagia.

It is important to correctly assess these patients and decide on a case-by-case basis which patients should be referred to a swallowing consultation specialist, so it is critical to identify some tools that can help the general ENT to recognise the patients that might be at risk of food aspiration.

The Murray secretion scale (MSS) is one of the validated instruments for the assessment of the accumulation of secretions in the hypopharynx (4) and can be used during any FNP by the general otorhinolaryngologist. The Yale Pharyngeal Residue Severity Rating Scale (YPRSRS) was developed for the determination of pharyngeal residue after swallowing and is used during the formal swallowing assessment consultation.(5)

The main objective of this study is to compare the correlation between MSS and YPRSRS both in ENT professionals with and without experience in deglutition evaluation. The secondary objective is the evaluation of inter-rater reliability in both scales.

Methods

40 flexible endoscopic evaluation of swallowing (FEES) were selected from a retrospective cohort, between January 2020 and December 2021 from the authors ENT department database.

The procedure was performed by two senior members of the ENT swallowing team (one ENT and one speech therapist). Only FEES with total agreement of both members were selected.

This study was conducted according to the World Medical Association Declaration of Helsinki and approved by the local ethics committee. Data protection was guaranteed.

Inclusion criteria: dysphagia complaints; patients aged 18 years or older, FEES with complete visualisation of pharyngolaryngeal space including vallecula and piriform sinus before and after deglutition assessment. Exclusion criteria: patients aged under 18 years old or FEES in which one or more judges consider not to meet the requirements to apply the MSS or YPRSRS.

40 patients were included, 18 females and 22 males, mean age of 68.10 ± 16.62 years.

FEES was performed by 2 members of the team of swallowing disorders: 1 of the 2 dedicated otorhinolaryngologists of the deglutition team and a specialized speech therapist, that was present in all the exams.

For the purpose of the present study it was used the first try with pureed texture for the evaluation of YPRSRS.

For this study the judges were asked to rate two different aspects of the FEES according with two different scales, a secretion stasis scale (Murray secretion scale (MSS)) and a pharyngeal residue scale (Yale Pharyngeal Residue Severity Rating Scale (YPRSRS)).

The MSS was ranked according to table 1.

Grade	Description
0	No visible secretions anywhere in the hypopharynx or some transient bubbles visible in the vallecula and pyriform sinuses
1	Deeply pooled bilateral secretions in the vallecula and pyriform sinuses and ending the observation segment with no visible secretions
2	Any secretions that changed from a “1” rating to a “3” rating during the observation period
3	Any secretions in laryngeal vestibule. Pulmonary secretions were included if not cleared by swallowing or coughing

Table 1 – Murray Secretion Scale (MSS) description

Patients without obvious saliva accumulation were scored as MSS grade 0 (Fig. 1a); patients with secretions pooling in the vallecula and pyriform sinus but without laryngeal penetration were rated as MSS grade 1 (Fig. 1b). Patients who accumulated enough secretions to eventually develop the presence of secretions in the laryngeal vestibule during the examination were assigned grade 2 (Fig. 1c), whereas patients who had secretions in the laryngeal vestibule at the start of the exam were scored grade 3 (Fig. 1d).(4)

Figure 1A - MSS grade 0

Figure 1B - MSS Grade 1

Figure 1C - MSS grade 2

Figure 1D - MSS grade 3

The YPRSRS was assessed after visualization of freeze-frame imaging immediately after the first swallow following the bolus challenge. The YPRSRS was applied both to vallecula and pyriform sinuses. Each site receives a score of 1 to 5 according to a descriptive and an image based scale: (1) no visible residue (figure 2A); (2) trace residue (1–5%), depicted as mild coating of the mucosa (figure 2B); (3) mild residue (<25%), with the epiglottic ligament still visible (figure 2C); (4) moderate residue (25-50%), with the epiglottic ligament covered (figure 2D); (5) severe residue (>50%), with residue reaching the epiglottic rim (vallecula) or aryepiglottic fold (pyriform sinuses) (figure 2E).(5)

Figure 2A - YPRSRS Grade 1

Figure 2B - YPRSRS Grade 2

Figure 2C - YPRSRS Grade 3

Figure 2D - YPRSRS Grade 4

Figure 2E - YPRSRS Grade 5

A jury composed of 8 independent judges was recruited: 2 judges with daily experience in FEES and 6 judges without daily experience in FEES. In the non-experienced jury group 3 elements were ENT fellows with at least one year of fellowship and the other 3 elements were ENT residents from the last 2 years of residency (in a 5-year residency program).

The evaluation was carried out independently and randomly by the 8 different judges.

All the judges had previous access to validated versions of both scales with the explanation of the different grades and pictorial illustration, as explained in the previous section. Before the rating process begins, a brief theorical introduction to MSS and YPRSRS was provided to the non-experienced judge group and a period of questions and answers to elucidate any remaining doubts.

The 40 FEES were presented in a pre-established sequence, simultaneously, to the 8 judges, without any possibility of discussion between them. All exams were graded according to the degree of severity using the two scales (MSS and YPRSRS) in a proper grid provided by the investigators. All judges had the same time to watch and rate each video or image and all had the possibility to ask to repeat the video/image up to 3 times.

Data were analysed with IBM SPSS Statistics for Windows ® (IBM Corp., Armonk, NY, USA) version 26.0. Descriptive statistics were obtained; the normality of the data was ascertained using Shapiro-Wilk test.

Continuous data were reported by means, standard deviations and ranges and qualitative variables were expressed as frequencies (percentages).

Inter-rater reliability for each scale was calculated by the Fleiss–kappa coefficient and the correlation between two scales of the same rater was calculated using Kendall β Tau. The benchmark system of Fleiss was used to interpret kappa values (6). The reference values for Kendall β Tau association were  + or - 0.10: very weak; + or -0.10 to 0.19: weak; + or - 0.20 to 0.29: moderate and + or - 0.30 or above: strong. (7)

Calculated p values were 2-sided, a P-value of less than 0.05 was considered as significant and the range of confidence interval (CI) was 95%, when appropriate.

Results

40 patients were included, 18 females (45%) and 22 males (55%); mean age of 68.10 ± 16.62 years, range 26-94 years old.

Inter-rater reliability

For MSS the inter-rater reliability for all raters was found to be κ = 0.475 (p <0.001), 95% CI (0.474, 0.477). Comparing the subgroups, we find that the higher inter-rater reliability was obtained by deglutition team members with a κ = 0,832 (p <0,001), 95% CI (0,827, 0,838) with an excellent correlation. Within the group without experience in deglutition we found that the residents had a higher inter-rater reliability than the fellows κ = 0,450 (p <0,001), 95% CI (0,446, 0,453) versus κ = 0,369 (p <0,001), 95% CI (0,336, 0,373). Table 2.

For the YPRSRS the results were different when we compare vallecula with the pyriform sinus, with all judges reaching moderate agreement in vallecula but not in pyriform sinus: κ = 0,416 (p <0,001), 95% CI (0,415, 0,417) versus κ = 0,361 (p <0,001), 95% CI (0,360, 0,362). The deglutition team members reach substantial agreement in both anatomical places with κ = 0,678 (p <0,001), 95% CI (0,673, 0,684) in vallecula and κ = 0, 676 (p <0,001), 95% CI (0,671, 0,682) in pyriform sinus. Only the resident group had moderate reliability in pyriform sinus classification κ = 0, 676 (p <0,001), 95% CI (0,671, 0,682). Table 2.

	MSS		YPRSRS Vallecula		YPRSRS Pyriform Sinus
	kappa (SD)	P value	kappa (SD)	P value	kappa (SD)	P value
All judges (N=8)	0,475 (0,017)	<0,001	0,416 (0,015)	<0,001	0,361 (0,016)	<0,001
Experienced judged (N=2)	0,832 (0,092)	<0,001	0,678 (0,082)	<0,001	0,676 (0,082)	<0,001
Non experienced Judges (N=6)	0,432 (0,024)	<0,001	0,387 (0,21)	<0,001	0,341 (0,21)	<0,001
Fellows (N= 3)	0,369 (0,054)	<0,001	0,305 (0,048)	<0,001	0,385 (0,051)	<0,001
Residents (N=3)	0,450 (0,053)	<0,001	0,390 (0,046)	<0,001	0,468 (0,048)	<0,001

Table 2. Inter-rater reliability (Kappa Fleiss)

When we analyse only the ratings with moderate agreement or superior, we can stratify the answers for the grades on each scale.

MSS grades with more agreement are grade 0 and 3, regardless of the previous experience of the judges with Kappa 0,522 – 0,925 for grade 0; kappa 0,368 – 0,713 for grade 1; kappa 0,301 – 0,762 for grade 2 and kappa 0,545 - 0,935 for grade 3. Table 3.

We can see a similar effect on YPRSRS for vallecula with the extremes of the scale (grades 1, 2 and 5) having the superior reliability rates: grade 1 Kappa 0,551- 0,895; grade 2 kappa 0,480-0,817 and grade 5 kappa 0,442-0-749. Table 4

However, we identify a similar agreement between almost all grades for the YPRSRS for pyriform sinus. Table 5

	MSS Grade	Kappa (SD)
All judges (N=8)	Grade 0	0,581 (0,030)
	Grade 1	0,379 (0,030)
	Grade 2	0,371 (0,030)
	Grade 3	0,603 (0,030)
Experienced judges (N=2)	Grade 0	0,925 (0,158)
	Grade 1	0,713 (0,158)
	Grade 2	0,762 (0,158)
	Grade 3	0,935 (0,158)
Non experienced judges (N=6)	Grade 0	0,540 (0,041)
	Grade 1	0,368 (0,041)
	Grade 2	0,301 (0,041)
	Grade 3	0,554 (0,041)
Residents (N=3)	Grade 0	0,522 (0,091)
	Grade 1	0,430 (0,091)
	Grade 2	0,318 (0,318)
	Grade 3	0,545 (0,091)

Table 3 – MSS Inter-rater reliability divided per each grade of scale

	YPRSRS Vallecula	Kappa (SD)
All judges (N=8)	Grade 1	0,551 (0,030)
	Grade 2	0,480 (0,030)
	Grade 3	0,292 (0,030)
	Grade 4	0,297 (0,030)
	Grade 5	0,442 (0,030)
Experienced judges (N=2)	Grade 1	0,895 (0,158)
	Grade 2	0,817 (0,158)
	Grade 3	0,473 (0,158)
	Grade 4	0,357 (0.158)
	Grade 5	0,749 (0,158)

Table 4 – YPRSRS for vallecula inter-rater reliability divided per each grade of scale

	YPRSRS Pyriform Sinus	Kappa (SD)
Experienced judges (N=2)	Grade 1	0,776 (0,158)
	Grade 2	0,609 (0,158)
	Grade 3	0,684 (0,158)
	Grade 4	0,684 (0,158)
	Grade 5	0,654 (0,158)
Residents (N=3)	Grade 1	0,511 (0,091)
	Grade 2	0,392 (0,091)
	Grade 3	0,596 (0,091)
	Grade 4	0,375 (0,091)
	Grade 5	0,500 (0,091)

Table 5 – YPRSRS for pyriform sinus inter-rater reliability divided per each grade of scale

Agreement between MSS and YPRSRS scales

There was a significant correlation between the degree of classification in the two scales by all elements of the jury, with a strong degree of correlation, Τβ between 0.327 p=0.014 and 0.598 p=0.001.

In fact, the most significant correlations were found in the group of more experienced observers (Τβ 0.409 - 0,595), followed by the group of fellows (Τβ 0.403-0,598) and finally the group of residents (Τβ 0.327-0,567), but still without great magnitude of difference. Table 6.

	MSS versus YPRSRS Vallecula		MSS versus YPRSRS Pyriform Sinus
	Kendall β Tau	P value	Kendall β Tau	P value
Expert 1	0,544	<0,001	0,409	0,002
Expert 2	0,595	<0,001	0,512	<0,001
Fellow 1	0,481	<0,001	0,434	<0,001
Fellow 2	0,460	<0,001	0,403	0,003
Fellow 3	0,598	<0,001	0,531	<0,001
Resident 1	0,509	<0,001	0,374	0,005
Resident 2	0,413	0,002	0,327	0,014
Resident 3	0,567	0,006	0,429	<0,001

Table 6 – Agreement between the classification on MSS and YPRSRS scales (Kendall β Tau)

Discussion

The evaluation of a dysphagia usually begins in the general ENT consultation and after a first assessment the patient can be referred to a sub-speciality consultation with a deglutition professional.

In the present study the authors evaluate two different scales that address different risk factors for aspiration in dysphagic patients: the MSS Scale that assesses the accumulation of secretions in the hypopharynx, used in the general ENT practice and the YPRSRS that evaluates the pharyngeal residue after swallowing and is used in a specific swallowing assessment context. We also evaluated the reliability of these scales in both experienced and non-experienced professionals.

Inter-rater reliability

For MSS the global inter-rater reliability for all the judges was κ = 0.475 (p <0.001), 95% CI (0.474, 0.477) which is a moderate agreement, and when we divide the group in judges with deglutition experience and non-experienced, we find that the expert group had an excellent agreement with κ = 0,832 (p <0,001), 95% CI (0,827, 0,838). We can consider that the non-experienced group had more elements, so it is more prone to a lower grade of agreement, so we divide it in two subgroups of 3 elements, the fellows and the residents, and we find that the residents had a higher inter-rater reliability than the fellows κ = 0,450 (p <0,001), 95% CI (0,446, 0,453) versus κ = 0,369 (p <0,001), 95% CI (0,336, 0,373), with fellows achieving a moderate agreement.

Our values of reliability are lower than the published literature in validation of MSS scales, we can interpretate this because most of the reported values are mainly based on experienced raters and in few raters. Pluschinski P. et al., reported inter-rater reliability of Kendall’s W = 0.951 and W = 0.961 in two different evaluations, with a 4-element jury experienced in swallowing evaluation. (8) Hey C. et al. also reported an inter-rater reliability (Kendall’s W>0,890) in a 2-element experienced jury, which is like our result of κ = 0,832 in the 2 experienced judges. (9)

The interest of this results is to prove that even professionals that don’t perform routinely swallowing evaluation can also obtain reliable results when applying this scale, because in most situations those are the ones that first evaluate the patient with dysphagia and the MSS can be applied during any FNP and not only in the context of FEES.

Similar results were verified with the YPRSRS with the group of 8 judges reaching moderate agreement in vallecula κ = 0,416 but not in pyriform sinus κ = 0,361. The deglutition team members reach substantial agreement in both anatomical places with κ = 0,678 in vallecula and κ = 0, 676 in pyriform sinus. We can interpret these results as this scale is exclusively used in context of swallowing assessment and the non-experienced judges only had contact with it in our briefing sessions and never had used it before the present study.

The YPRSRS was developed by Neubauer P et al. and in the original results of his working group they reported a vallecula k = 0.868 (±0.011 and a pyriform sinus k= 0.751 (±0.011), but once more, the panel was composed by 20 raters all with previous experience in swallowing ⁽⁵⁾

M. Gerschke et al. published a validation study with a total of 28 raters with a median of experience of 4.5 (± 8.5) years and inter-rater reliability of 0.928 (± 0.026) for vallecula and 0.938 (± 0.027) for pyriform sinus and find no difference between the years of experience.⁽¹⁰⁾

In our study we tried to understand which were the grades of each scale on which the observers had more agreement, and we find that in both scales were the extreme grades of the MSS scale (0 and 3) and the YPRSRS for vallecula (grade 1, 2 and 5), both in the total of 8 judges and in the non-experienced raters. In the YPRSRS for pyriform sinus there wasn’t any significant difference.

In scale development, item reduction analysis is one of the fundamental steps and is performed to ensure that only functional and internally consistent items are included.⁽¹¹⁾ The more items each scale has, the greater the propensity to scatter responses.

Agreement between MSS and YPRSRS scales

FNP is performed by routine in ENT practice as part of the physical head and neck examination and even more frequently if the patient has dysphagia symptoms.

FEES is excellent in the evaluation of the dysphagic patients, but it requires special expertise and training, can be time consuming, and is not always available. For this reason, several studies have examined the ability of laryngoscopy findings, namely the severity of pooled secretions to predict dysphagia and to identify patients at risk who require more extensive dysphagia evaluation. ^{(12, 13)}

Yael ShapiraGalitz Y. et al, compared the association between MSS and YPRSRS and found patients with secretion stasis (MSS≥1) had significantly higher YPRSRS for both the vallecula and the pyriform sinuses in all consistencies tested (liquid/purée/solid).

In our study all the elements of the jury obtained a significant correlation between the degree of classification in the two scales, with a strong degree of correlation, Τβ between 0.327 p=0.014 and 0.598 p=0.001. This means that even without experience in swallowing evaluation or having contacting with the YPRSRS scale before, there was a good correlation between the severity of the degrees of each scale.

Our study has some limitations, namely the fact that it is retrospective and by his nature there was a selection of FEES. Even so, there was a concern to minimize some selection bias and we only select exams for evaluation with total agreement by two experts in FEES. The YPRSRS assessment was based on static images and not on video observation, which may have caused some changes in the classification in contrast of a possible dynamic classification.

Finally, in the group of fellows most of the professionals had interest areas other than laryngology or swallowing, which on one hand may be a limitation but on the other hand the objective was to present a diverse jury that represented the reality of a generalist ENT practice.

Conclusion

The presence of salivary stasis in the FNP can be assessed by the MSS. This may alert the general ENT to the potential risk of pharyngeal residue after swallowing and to the need to refer the patient to a specialized deglutition consultation. There is a learning curve for the application of these scales but the evidence in our study support at least a moderate correlation even for non-experienced professionals.

Conflicts of interest:
All of the authors state not to have any conflict of interest

References

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