Dysphagia Therapy in Adults with a Tracheostomy: A Scoping Review Protocol

Swallowing impairment (dysphagia) and tracheostomy coexist. Research in this area has often provided an overview of dysphagia management as a whole, but there is limited information pertaining to specic dysphagia therapy in the population. The aim of this review is to provide detailed exploration of the literature with regards to dysphagia therapeutic interventions in adults with a tracheostomy. The scoping review will describe current evidence and thus facilitate future discussions to guide clinical


Abstract Background
Swallowing impairment (dysphagia) and tracheostomy coexist. Research in this area has often provided an overview of dysphagia management as a whole, but there is limited information pertaining to speci c dysphagia therapy in the tracheostomy population. The aim of this scoping review is to provide detailed exploration of the literature with regards to dysphagia therapeutic interventions in adults with a tracheostomy. The scoping review will describe current evidence and thus facilitate future discussions to guide clinical practice.

Methods
A scoping review using the Joanna Briggs Institute and Preferred Reporting Items for Systematic Reviews guideline will be used. Ten electronic databases from inception to July 2021and grey literature will be searched. From identi ed texts forward and backward citation chasing will be completed. Data extraction will compose of population demographics, aetiology and dysphagia therapy (type, design, dose and intensity). Number of citations and papers included into the scoping review will be presented visually.

Discussion
The scoping review aims to expand upon the existing literature in this eld. A detailed description of the evidence is required to facilitate clinical discussions and develop therapeutic protocols in a tracheostomised population. The results of this scoping review will support future research in dysphagia therapy and provide the basis for development of best practice guidelines.

Background
A tracheostomy tube provides an alternative means of respiratory ventilation and reduces the need for prolonged endotracheal intubation. A tracheostomy creates an opening within the trachea and is generally accepted as a safe procedure that provides meaningful bene ts to patients which include a secure airway and facilitating pulmonary toileting (Cheung & Napolitano, 2014). In 2014 the National Con dential Enquiry into Patient Outcome and Death (NCEPOD) estimated that in the UK approximately 12000 patients a year had a tracheostomy inserted.
Skoretz and colleagues (2020) highlight the interdependency of swallowing and respiration. The NCEPOD (2014) reported swallowing impairments were the third most common associated complication of a tracheostomy and up to 51.6% (n = 425) of inpatients with a tracheostomy had a swallowing disorder. However, there is limited knowledge regarding patients in the community with a tracheostomy and long term swallowing needs.

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The medical term for swallowing disorder is oropharyngeal dysphagia. This is an impairment of motor and/or sensory components of the swallowing mechanism in which food/ uid transfers from the oral cavity into the pharynx and through the upper oesophageal sphincter (Walshe, 2019) and can lead to aspiration: food or uid entering the airway and passing below the vocal cords often into the lungs.
Healthy adults have a degree of aspiration, however persistent aspiration can lead to aspiration pneumonitis a potentially life threatening infectious process where aspirated material is colonised by pathogenic bacteria resulting in a chest infection (Marik, 2001).
In the past, the presence of a tracheostomy tube was considered to be a primary cause of an oropharyngeal dysphagia. For instance, Bonanno (1971) suggested that a tracheostomy tube resulted in tethering of the larynx and subsequently lead to aspiration. However it is now widely recognised that dysphagia is the cause of an underlying condition of which there could be multiple reasons. This is substantiated by Wallace, McGowan and Ginnelly (2016) who argued that the presence of a tracheostomy tube does not necessarily in isolation cause an oropharyngeal dysphagia, however they do recognise that it could contribute to dysphagia. Moreover, in two separate studies completed by Leder and Ross (2000;2010), they reported that there was no causal relationship between tracheostomy and aspiration status. It is the role of the speech and language therapist (SLT) to work closely with people with a tracheostomy to provide detailed assessment and therapy intervention of swallowing due the assessment aims to support an intervention programme that is goal centred such as minimising the risk of aspiration and increase quality of life (Brodsky et al, 2019). In their scoping review, Skoretz and colleagues (2020) investigated swallowing and tracheostomy following critical illness. Based on their protocol they were able to include 85 appropriate studies of which 25% (n = 21) of the papers looked at interventions. In the results the authors provided an overview of intervention type. They used the term "intervention" broadly to refer to instrumentation, traditional dysphagia exercises and manipulation of tracheostomy (e.g. de ation of the cuff and use of one-way valve to restore subglottic pressures required for swallowing). They noted that compared to the other domains of their research content (e.g. dysphagia frequency) there were relatively fewer studies available and thus acknowledge paucity in the literature regarding intervention for adults with dysphagia and tracheostomies.
Intervention, rehabilitation, management and exercise are some of the terms used to describe oropharyngeal dysphagia therapy. Therapy is a multimodal approach which aims to restore swallow function (Crary & Carnaby, 2014;Smithard, 2016). Examples may include 'effortful swallowing' targeting the contact between base of tongue and posterior pharyngeal wall (Logemann, 1991); 'Mendelsohn manoeuvre' for laryngeal elevation (Mendelsohn et al, 1987)  Dysphagia therapies have been evaluated and scrutinized in differing patient cohorts including but not limited to, stroke, Parkinson's disease, respiratory conditions and a variety of head and neck cancers. Dysphagia therapy is an accepted means of supporting patients to return to oral intake. Functional outcomes (e.g. increasing oral intake) after a programme of swallowing therapy have been noted on repeat video uoroscopy assessments (Huang et al., 2014;Kang et al., 2012). Despite these gains, the evidence supporting the use of dysphagia therapy in patients with a tracheostomy is limited. One possible reason for this could be that developing a therapeutic protocol in this patient cohort is challenging due to the complex interaction of dysphagia and tracheostomies.
Swallowing in patients that have a tracheostomy has been considered a fundamentally important role in patient outcomes (NCEPOD, 2014). From Skoretz and colleagues' (2020) scoping review it is clear that therapeutic intervention is an area that needs further exploration. No published scoping review has extrapolated information secondary to dysphagia therapy in tracheostomised patients when considering treatment type, dosage and frequency. This detailed understanding of the scope and effectiveness of dysphagia therapy in this population cohort will help develop the evidence base, provide scienti c knowledge to work towards a consensus in dysphagia therapy for people with a tracheostomy and support robust therapeutic trials in this population.
This scoping review aims to: Describe the existing published literature on oropharyngeal dysphagia therapy used in an adult population that have a tracheostomy at the time of reporting.

Developing the research question:
There is paucity in the literature regarding swallowing therapy in adults that have a tracheostomy (Skoretz et al, 2020). Further understanding of this area, including therapy type and dosage, can provide support to clinicians working with patients that have a tracheostomy and guide robust research in this area.
The research question posed is: What is known from the existing literature about dysphagia therapy that people with a tracheostomy are receiving. This question was used to conduct a literature search to gain up to date information about treatment methods available in adult populations. This protocol is speci cally interested in participants with a tracheostomy that receive dysphagia therapy including: surgical, pharmaceutical, cortical and peripheral stimulation, alternative therapies and direct oropharyngeal exercises.
Manipulation of the tracheostomy including taking the cuff down and placing a speaking valve are synonymous with dysphagia therapy. This protocol agrees with these sentiments, however a thorough scoping review has recently been completed which minimises the knowledge gap in this area (Skoretz, Anger, Wellman et al, 2020) and therefore inclusion within this protocol is not required.

Method / Design
A scoping review methodology was chosen to describe the current available literature on the study topic. Due to the anticipated limited search yield, a broad approach to review the data is bene cial to map the literature (Peters, 2020). This will allow the authors to review the range of protocols and methodologies utilised by different researchers in a similar area which can be used to guide discussions into therapy options for adults in the future. . If a proportion of the patient sample in a study meet our inclusion criteria, where possible, we will extract individual patient-level data for only those meeting our inclusion criteria. The scoping review design enables researchers to collate data from multiple sources (Peters, 2020). To ensure the robustness of the data being reviewed, the following inclusion and exclusion criteria will be applied to the type of information sources obtained in this review.

Inclusion:
Case reports, case series, experimental studies, randomised control trials, observational studies and systematic reviews.
Due to the anticipated limited search results, commentaries, opinion pieces, quality assurance and service delivery assessment studies will be included.
The search period is from the start of online availability (database speci c) to July 2021 inclusive Exclusion: Articles not written or available in English; Where a full text article cannot be obtained using University access, the 1st author will be contacted. If no English copy is made available prior to nal analysis, then the paper will be excluded.
Articles will need to report su cient treatment information including treatment type, dosage and intensity. Articles without su cient protocol information as outlined will be excluded.
Databases to be searched Initial searches will be conducted via the following electronic databases (Table 1): This strategy was then peer reviewed by two collaborators.
Search Strategy: The search strategy was developed with Breege Whiten (BW), University College London librarian. The strategy is in two stages to ensure that all relevant articles can be included in this study. The rst stage will involve using the key search terms, created with BW, and applying them to the medical subject heading (MeSH)/keyword search where applicable (Table 2). A record of the number of articles found on each database will be made.
At the second stage, for the accepted articles we will perform forward and backward citation chasing (Booth, 2008). This will involve reviewing study titles citing the accepted articles for possible inclusion as well as their respective reference lists (Booth, 2008). We will then apply the eligibility criteria to these citations. 1. The primary reviewer (WK) will run the initial searches and export the titles and abstracts into and online platform such as www.covidence.org.
2. Duplicate copies will be deleted. 3. Two reviewers (WK and SM) blinded to each other's judgements will screen the title and abstracts of each paper for inclusion or exclusion. 4. A record of decisions will be kept on the online platform. 5. Full text for accepted abstracts will be retrieved.
Similar to Skoretz et al (2020) scoping review, if the accepted abstract existed only as such, the primary reviewer will contact the abstract authors to determine if its content existed either as: 1) a study published under a different name, 2) grey literature, or 3) a raw data set (not available via any grey literature repository). If full text is not available, the abstract will not be put through to the next review phase.
Similar to  scoping review, if the accepted abstract existed only as such, the primary reviewer will contact the abstract authors to determine if its content existed either as: 1) a study published under a different name, 2) grey literature, or 3) a raw data set (not available via any grey literature repository). If full text is not available, the abstract will not be put through to the next review phase.
The full text reviews will be conducted to determine nal eligibility, by two authors blinded to each other's judgments (WK, SM). . A study selection form will be designed and used throughout the process.
7. At both the abstract and full text review any con icts will be discussed and clari ed. If con icts cannot be resolved a third author (RH) will be asked to resolve the con ict. If all reviewers remain undecided regarding the suitability for inclusion following abstract review, the citation will be accepted and full text will be reviewed Data extraction and Analysis Following literature retrieval data will be extracted by two authors blinded to the others judgement (WK and SM).
The data extraction will be placed in an excel database and will include information as suggested by Details of therapy will also be extracted speci cally: type of exercises, dosage, intensity, format and comparator where available.
The two reviewers (WK and SM) will extract available data including design, sample size, how swallowing assessment was conducted, data related to the tracheostomy and in particular if this was discussed in relation to therapeutic programme.
This data will be reviewed and analysed against the outlined inclusion / exclusion criteria by two reviewers (WK and SM). If there is a disagreement a third reviewer (RH) will resolve con icts.
www.covidence.org online software will be used to record the nal decisions.

Data Presentation and Dissemination:
As per scoping review protocols, a ow diagram will be used to demonstrate data extraction. The data extracted from each article will be presented in written and visual format. Depending on the quantity of papers extracted, where possible the data will be separated into aetiologies to draw conclusions regarding therapy designed for certain aetiologies.
Identi cation of therapeutic techniques used with adults that have a tracheostomy will be discussed including potential bene ts and limitations. The type of review paper will be provided along with speci ed outcome measures. The study design will be analysed to support replicability of therapeutic techniques in speci c aetiologies of patients with a tracheostomy.

Discussion
The aim of this scoping review is to answer the research question by gathering empirical evidence about dysphagia therapy in adults that have a tracheostomy. This information will inform future studies in creating robust consensus on dysphagia therapy programmes with clear outcome measures. The sparsity in the literature in this eld supports the notion of further research in this area to fully understand the impact of dysphagia therapy in this population cohort.
Limitations to this protocol include the exclusion of non-English studies heightening the potential for language and cultural bias which will contribute to the anticipated limited studies included in the nal study. If funding became available to translate studies, then this could be considered for any papers excluded based on this criteria and may provide additional information to this study's ndings. The decision to include all aetiologies reduces the potential to provide speci c dysphagia therapy recommendations to a speci c population e.g. stroke. However, it is has already been recognised by Skoretz and colleagues (2020) that there is limited available literature in this area. Moreover, the aim of this protocol is to extrapolate detailed information pertaining to dysphagia therapy in adults with a tracheostomy. By doing so, it will hopefully enable future research to tease apart therapy for speci c aetiologies, if felt clinically relevant.

Declarations
Ethics approval and consent to participate.
Not applicable for the protocol stage.

Consent for publication
Not applicable.
Availability of supporting data

Competing interests
The authors declare that they have no competing interests. This paper presents independent research funded by the National Institute for Health Research (NIHR).
The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR or the Department of Health and Social Care.