Utility of ultrasound in the assessment of swallowing and laryngeal function: A rapid review and critical appraisal of the literature

Abstract

Background: Ultrasound (US) is not widely used as part of the speech and language therapy (SLT) clinical toolkit. The COVID-19 pandemic has intensified interest in US as an alternative to SLT instrumental tools such as the videofluoroscopic swallowing study (VFSS), fibreoptic endoscopic evaluation of swallowing (FEES) and endoscopic evaluation of the larynx (EEL) as a non-invasive, non-aerosol-generating procedure that can be delivered at the bedside to assess swallowing and/or laryngeal function. To establish the appropriacy of routine US use, and in response to a national professional body request for a position statement, a group of expert SLTs conducted a rapid review of the literature. Aim: To explore critically the clinical utility of US as an assessment tool for swallowing and laryngeal function in adults. Methods & Procedures: A rapid review of four databases was completed to identify articles using US to assess swallowing and/or laryngeal function in adults compared with reference tests (VFSS/FEES/EEL/validated outcome measure). Screening was completed according to predefined inclusion/exclusion criteria and 10% of abstracts were rescreened to assess reliability. Data were extracted from full texts using a predeveloped form. The QUADAS-2 tool was used for quality ratings. Information from included studies was summarized using narrative synthesis and visual illustration. Outcomes & Results: Ten papers used US to assess swallowing, and 13 to assess laryngeal function. All were peerreviewed primary studies across a range of clinical populations and with a wide geographical spread. Four papers had an overall low risk of bias, but the remaining 19 had at least one domain where risk of bias was judged as high or unclear. Applicability concerns were identified in all papers. The papers that used US to assess swallowing varied widely in terms of the anatomical structures assessed and methodology employed. The papers assessing laryngeal function were more homogenous in their methodology. Sensitivity and specificity data were provided for 12 of the laryngeal function papers with ranges of 64.3-100% and 48.5-100%, respectively. Conclusions & Implications: There is burgeoning evidence to support the use of US as an adjunct to SLT clinical assessment of swallowing and laryngeal function. However, the current literature does not support its use as a

An International Commentary on Dysphagia and Dysphonia During the COVID-19 Pandemic

“…In the UK, this led to an interest in the use of laryngeal ultrasound as a potentially safer tool. An international expert group was formed who published a rapid review of available evidence [ 31 ]. A subsequent RCSLT position statement declared that the current literature did not support ultrasound use as a stand-alone clinical swallowing assessment tool and further work would be required before it could be safely and effectively translated into clinical practice [ 32 ].…”

Identification of Laryngotracheal Stenosis During Weaning from Tracheostomy – A Clinical Conundrum

“…Clinicians specializing in the upper airway currently utilize a range of invasive instrumental diagnostics (nasendoscopy; laryngoscopy; flexible endoscopic evaluation of swallowing; endoscopic evaluation of the larynx; and video fluoroscopic swallowing studies) to promote objective assessment of the biomechanics, pathology and anatomical structures involved in swallowing and laryngeal function [40][41][42][43]. The Covid-19 global pandemic challenged clinician's abilities to complete instrumental assessments, secondary to the risk of completing aerosol generating procedures affecting transmissibility of the disease [44][45][46].…”

“…Although high body mass index (BMI) can impact visualization of vocal fold function [54], using laryngeal ultrasound to assess vocal fold function appears viable. Specificity, sensitivity and predictive values for vocal fold ultrasound remain variable within the literature, suggesting it could be utilized as a first line screening tool with secondary laryngoscopy for positive cases [ 43,[55][56][57][58].…”

Translating Ultrasound into Clinical Practice for the Assessment of Swallowing and Laryngeal Function: A Speech and Language Pathology-Led Consensus Study

“…Ultrasound (US) has an emerging evidence base for the assessment of swallowing and laryngeal function [ 1 ]. Early research identified the ease with which anatomical landmarks and soft tissues of the upper aerodigestive tract could be identified using US [ 2 ].…”

“…The application of US as a diagnostic tool to guide therapeutic swallowing and laryngeal intervention remains underexplored. A recent rapid review in this area [ 1 ] indicated the need for further research prior to translation of US into clinical practice for this purpose. Other professional groups have started to translate US as a clinical evaluation tool [ 26 – 28 ] but a lack of sufficient evidence has hindered implementation [ 29 ].…”