HC 4 Radiography + DSS Flashcards
How do we assess the pharynx by radiography?
= (modified) barium swallow or Dynamic Swallowing Study (DSS)
- accomplished by videofluoroscopy of video radiography:
- recording of the fluoroscopic image
- spatial resolution is not so much, but is generally adequate for most studies
- less radiation exposure
- easier manipulation of the images
What is a esophagram?
= radiographic examination of the esophagus
= barium meal or swallow
- often combined with examination of the stomach and duodenum
Which other equipment is used in radiography? Explain
•Rapid sequence digital radiography
−6 frames per second
−Excellent spatial resolution & easy manipulation of the images
−Relatively low radiation exposure
−Disadvantage: too few frames for some studies
•Cine-MRI and turbo- FLASH MRI:
−less or no radiation
−Not commonplace
•Videofluoromanometry:
−Dynamic and functional structural information
−Provides insights to bolus flow and pressures
What are our concerns regarding radiation exposure and safety?
- ALARA principle: As Low As Reasonably Achievable (there is no safe dose of radiation)
- balance between an effective study and minimizing long-term radiation risk: in the elderly the risk to health in missing aspiration or swallow impairment is far greater than the cumulative risk from low-dose radiation
When is it indicated to perform radiography?
- suspicion for silent aspiration
- Persistent dysphagia
- Odynophagia
- Aspiration
- Pulmonary pathology
- Chronic cough
- Regurgitation
- Weight loss
- Reflux or esophageal pathology
- After surgery or radiotherapy to the head and neck
- Full assessment of pharyngeal and esophageal phases
- Tailored
- Testing maneuvers or strategies
Why is DSS the optimal radiographic procedure?
−Provides information regarding transit and pathway bolus through oropharynx, hypopharynx, pharyngoesophageal segment and esophagus
−Ability to demonstrate motion
−Is general available
−From oral cavity, base of the tongue, valleculae, epiglottis, piriform sinuses, to pharyngoesophageal segment and cervical esophagus
What’s the difference between a lateral and a anterior posterior view?
- lateral view: better view on epiglottis and cricopharyngeus muscle
- anterior posterior view: better view
- on valleculae and piriform sinuses
- on asymmetries (unilateral weakness)
- on some pathologies e.g. Zenker’s diverticulum
What are possible observations during radiography?
−Penetration
−Aspiration
−Hyolaryngeal elevation
−Esophagus: abnormalities in anatomy and motility problems
−Epiglottic folding back
−Residue: valleculae and piriform sinus
−Stream (Posterior cricoid findings)
−During esophageal screen (large bolus of barium, barium tablet): transit time, completeness of bolus transfer, reflux, stasis, constrictions of the stream, presence of hiatal hernia
When is it indicated to perform DSS?
When complaints, signs/symptoms and/or histories
suggest
oral, pharyngeal, laryngeal or pharyngoesophageal dysfunction
to identify risks to
respiratory/pulmonary and nutrition/hydration health
and to target potential
behavioral, surgical or medical interventions more precisely and effectively
What are DSS’ limitations?
−Limited length of observation and repetition
−Technical limitations (e.g. two-dimensionality)
−Radiation exposure
−Dependence on the quality of images obtained
−Good positioning of the patient may be difficult
−Lack of attention to or experience with Fluoroscopic swallow study
−No information on pressures
−No information on sensation of tissues
−Inability of some patients to undergo the study
−Conditions can have an effect of swallow performance (e.g. not similar to real-life eating)
What are DSS’ contra-indications?
- when moving the patient is dangerous
- when rapid fluctuations
- when positioning is not possible
What does DSS attempt to do?
−Determine risks to respiratory system during eating/drinking
−Clarify and characterize variables that lead to such risks
−Modify variables (if possible)
−Elaborate patient’s potential for oral eating
Which variables could influence the patient performance and study success with DSS?
−Position
−Postural stability and flexibility
−Respiratory sufficiency
−Stamina and endurance
−Lubrication
−Bolus characteristics
−Competing behaviors and states
−Environment
−Adaptability
−Views
Why does the position of head/neck influence the swallow performance?
- alters the effect of gravity
- changes the relationships of structures and shapes of the chambers
- e.g. rotation -> increase/decrease size of piriform sinus
- e.g. neck flexion (buiging) -> changes shape of valleculae
- e.g. neck extension -> alters relationship between hyoid movement direction and the PES
Why does the postural stability and flexibility affect the swallow performance?
- Fine movements depend on a stable support structure (eg. airway)
- flexibility in posture is needed to apply compensatory strategies
Why do the bolus characteristics influence the swallow performance?
Size, thickness, taste, texture, viscosity and temperature facilitate or complicate timing, valving and clearing
Why do competing behaviours influence the swallow performance?
Any distraction can affect the swallow: gagging, sneezing, hiccupping, laughing, crying, speech, startle, fear,…
Why does the environment influence the swallow performance?
- some circumstances promote interest in eating or drinking, or not
Why does the adaptability influence the swallow performance?
- number & complexity of variables affecting swallow => adaptability needed to protect: cough, early lingual retraction, early laryngeal closure,…
- so awareness of real or potential swallow failures is needed
DSS consists of 2 parts. Which ones? Explain
1. Start with standardized part: same set of tasks, in the same way to every patient:
- tasks that all patients are likely to be capable of
- then advance in terms of volumes and consistencies
- stop when excessive risk
2. Patient-tailored part. Strategies designed to:
- facilitate bolus flow
- or improve airway protection
3. attempt to replicate the patient’s specific complaint
Which advantage has the uniform protocol in DSS?
Comparison:
- over time or treatment
- with other patients or patient populations
- with normative data
Which strategies may be explored during DSS?
Compensation and facilitation techniques (maximizing intact components and minimizing failures):
- changing the size and relationships of pharyngeal spaces and structures
- changing the effects of gravity on bolus flow
- increasing effort to increase range, timing and strength
What can be said about the effectiveness of the strategy?
- compare with performance on the task where failure is noted
- effectiveness can only be assessed if the goal of the strategy is clear
- the strategies depend on cognition, sensory integrity, anatomy, range of motion, control, strength, respiratory health, upper body postural stability and control
Which compensatory taks or tools are available to the clinician when the ability to control and propel the bolus in the oral cavity is poor?
- bolus consistency
- bolus placement
- gravity
Which strategies/compensations are available if the linguapalatal valve fails?
- problem with swallow initiation: enhancing sensory information by manipulating the characteristics of the bolus (size, temperature, texture, taste)
- slow or deflect the bolus (limiting the amount of the bolus falloing into the piriform sinuses)
- facilitate bolus flow by head/neck extension, followed by flexion
Which compensations/strategies are available when there are problems with the pharyngeal chamber?
- if incomplete pharyngeal clearing (residue): head/neck rotation or flexion, prolonged and increased laryngeal elevation, repeated swallows, post-swallow clearing
- if pharyngeal wall stiffness: effort strategies that aim at early, prolonged and vigorous laryngeal closure
Which compensations/strategies compensate for velopharyngeal valve problems?
- Closure: head/neck rotation, bolus size and/or viscosity
- Opening: increasing time allowed for respiration between swallows à limiting size and viscosity, rate of bolus presentatioin, number of boluses
Which compensations/strategies are available to compensate of ineffective laryngeal closure?
•head/neck flexion/rotation, prolongation of laryngeal closure/elevation, upper body side-lying
Which compensations/strategies are available if the PES valve fails?
- compensate for decreased opening: repeated swallow on 1 respiration, increased/prolonged elevation hyoid and larynx, head/neck rotation/flexion/extension, upper-body reclining, restricting bolus size
- compensate if PES never closes completely: slowing the rate of bolus presentation, precautions
