Standardisation of Videofluoroscopy: Where is it taking us? Jodi Allen, Senior Speech and Language Therapist, The National Hospital for Neurology and Neurosurgery
If somebody asked you. What do you start with on a VFS protocol & why? How do you measure laryngeal excursion on a VFS? How and when do you quantify pharyngeal residues? What is a mild reduction in tongue base retraction? Is that a normal swallow? When analysing the swallow do you provide an overall impression (i.e. a statement of swallow presentation as an average) or score the worst swallow? How important is an A-P view in VFS assessment? what would you say and why??
VFS Standardisation in the context of IDDSI A global Standardisation initiative Terminology and definitions to describe texture modified foods & thickened liquids for individuals with dysphagia Consistent production of thickened liquids and texture modified food
Cart before horse? Global standardisation of management before standardisation of assessment tools and protocols? What if our assessments are sub-optimal and prescription of modified diet and fluids is inaccurate in the first place? How confident are we moderately thick fluids are going to reduce aspiration episodes more so than mildly thick? Is our management too cautious and risks compromising nutrition and/or hydration? Are we confident that diet and fluid modification going to negate or minimise risk? Diet and texture modification only one aspect of dysphagia management how else are we going to do to treat our patients?
How do we make a clinical decision to prescribe modified diet and fluids? Patient symptoms Clinical context Therapist risk assessment Hypothesised changes in swallow physiology (based on clinical assessment) Access to instrumentation Availability of alternatives Patient wishes
Effective management of dysphagia is dependent on the accurate diagnosis of disordered swallowing physiology Professor Bonnie Martin-Harris
Example 1
Example 2
Videofluoroscopy: Quantifying subjective observations No standard or universal examination protocol No standard terminology to describe behaviours No standard method for quantifying swallow impairment
Diversity of Approach Aspiration-Penetration scores (Rosenbek, 1996) Dysphagia Severity Rating Scale (Waxman et al, 1990) New Zealand Index for the Multidisciplinary Evaluation of Swallowing (NZIMES) (Huckabee, unpublished) Dynamic Imaging Grade of Swallowing Toxicity (DIGEST) (Hutchinson et al., 2017) Local scoring and descriptors
Inter-rater reliability in radiology Shaw, Hendry & Eden (1990) 3 raters 139 chest x-rays Total inter-rater agreement on only 29% Neuman et al., (2012) 6 radiologists 110 chest x-rays 14-69% agreement
Ekberg et al., (1988) 6 radiologists rated 12 physiologic parameters on 72 VFS exams Highest kappa coefficients for presence of zenkers diverticulum (k = 0.84) and aspiration (k = 0.83) both static images Higher agreement: normal pharyngeal function, impaired epiglottic movement, laryngeal penetration, incomplete opening UES Lowest agreement: decreased or absent pharyngeal contraction, delayed opening UES, CP prominence.
Reliability improved by Team discussion/consensus Training by experienced practitioner Use of validated scales Competency training Scott A, Perry A, Bench J. A study of the inter-rater reliability when using videofluoroscopy as an assessment of swallowing. Dysphagia 1998; 13;4, 223-227. Kendall KA, et al. Timing of events in normal swallowing: a videofluoroscopic study. Dysphagia 2000; 15, 74-83. 14 Logemann JA, et al. Effectiveness of four hours of education in interpretation of radiographic studies. Dysphagia 2000; 15, 180-183.
Modified Barium Swallow Impairment Profile, MBSImP (Martin-Harris et al., 2008) Standardisation of: Procedure and protocol Terminology Interpretation Reporting and now with diagnostic cut-off scores
MBSImP A diagnostic study not just a report of symptoms Textures used to reveal the extent of impairment in the swallow not just a swallow test of various textures Can be used to robustly evidence that texture modification (amongst other dysphagia treatment) does work Rehabilitative focus Permission to make comprehensive assessment without increasing radiation time Includes A-P view and oesophageal clearance Trained to 80% reliability
Comparison with existing approaches 100% radiological assessment. Descriptors do not combine deficit with compensation. Moves away from subjective descriptors of mild, moderate, severe. Size of the scale depends on feature being analysed.
Benefits of Standardisation Reduce the need for repeat VFS Target dysphagia therapy and improve prognosis Identify need for further examinations Add useful information to a diagnostic profile Build a useful dataset for research/evidence base
Critique The protocol isn t long enough to capture fatigue
Critique The training is too expensive and takes too long to do
Critique The protocol is too rigid
Critique You don t need this level of detail with all patients
Critique The scoring takes too long
Our world upside down
Benefits of MBSImP A personal experience Common language Scoring system Acknowledges symptoms but focus is on physiology Scores worst more confidence you have captured extent of severity in a snap-shot Takes into account normal variability Practise-based research Robust outcomes not dependent on who happens to be running VFS that day Increased uptake of MBSImP in the UK
Not a stand-alone tool Doesn t tell you about underlying aetiology Still need to look at individual needs/wants including: Clinical history Cognitive status Dependence Mealtime set-up & equipment needs Care giver situation Underlying disease Patient wishes
Steps towards standardisation Be mindful: We are not robots swallowing is a dynamic process that needs integration Scoring systems shouldn t distract from good clinical rationale and decision-making Expertise are required to bring the scoring and analysis together and make recommendations that are right for your patient Must in used in the wider clinical context
Take home message Robust management needs robust assessment Videofluoroscopy is only one piece of the assessment jigsaw
References Logemann JA. Manual for the videofluorographic study of swallowing. 2 ed. ProEd; Austin: 1993 Martin-Harris B, Michel Y, Brodsky MB, et al. MBS Measurement Tool of Swallow Impairment MBSImp: Establishing a Standard.. 15th Annual Meeting of the Dysphagia Research Society.; Vancouver, BC, Canada. 2007 Martin-Harris B, Logemann JA, McMahon S, Schleicher M, Sandidge J. Clinical utility of the modified barium swallow. Dysphagia. 2000;15(3):136 141. Rosenbek, JC, Robbins, J, Roecker EV, Coyle, JL, & Woods, JL. A Penetration-Aspiration Scale. Dysphagia 11:93-98, 1996 Steele et al (2014) The Influence of Food Texture and Liquid Consistency Modification on Swallowing Physiology and Function: A Systematic Review