Cloned from: Dysphagia Quiz 1

by nesbes


keywords:
Bookmark and Share



Front Back


4 stages of a normal swallow

1) oral preparation,

2) oral transit,

3) pharyngeal

4) esophageal phases of the swallow
Occult symptoms:
an unrecognized problem in which the patient offers no complaint, or a problem for which the patient is able to compensate.
Overt symptoms:

difficulty chewing or in bolus preparation, excessive drooling, choking, regurgitation, food sticking at any level of the alimentary tract and painful swallow.

·         Overt dysphagic symptoms are most significant when they are associated with aspiration PNA (pneumonia), weight loss and/or compromised nutritional status.

Common etiologies of dysphagia
strokes head injuries cervical spinal cord injuries progressive neurologic diseases head and neck cancer and the surgery and/or radiation congenital syndromes and abnormalities esophageal stenosis esophageal tumors esophageal motility disorders achalasia – failure of LES to relax to allow the bolus to pass gastroesophageal reflux disease
Feeding
typically limited to the placement of the bolus in the oral cavity and manipulation of bolus in the oral cavity prior to the initiation of the swallow, including mastication and AP transit.
Swallowing
refers to the entire act of deglutition from placement of the bolus in the oral cavity through the oral preparation and transit phases until the material enters the stomach through the lower esophageal sphincter.
Primary concerns of Dysphagia (Important!!)
Aspiration Dehydration Malnutrition Quality of life

PO vs. NPO
PO – per oris – by mouth NPO – non per oris – nothing by mouth


What is aspiration?
the entry of oropharyngeal or gastric contents into the airway below the level of the true vocal folds

What is penetration?
Food or liquids entering the laryngeal vestibule to the level of the true vocal folds. Considered less severe since the patient has a better chance of expelling the material if it remains above the true vocal folds.


Quality of Life
580 swallows per day Suctioning needs – affects quality of life “wet” phonation quality Daily social interactions often involve PO intake of some kind Social gatherings Watching television is commonly difficult for patients who cannot swallow – too many TV commercials with food that causes salivation/secretion


Functional anatomy for oral prep and oral transit

Lips - obicularis oris is a sphincter that creates closure of the lips and allows them to press against the gums Tongue (tip, body & base) Buccal musculature Soft palate Hard palate Dentition

Functional anatomy of pharyngeal phase
velum
base of tongue: parallel to posterior pharyngeal wall
epiglottis
valleculae: the space that is bounded in the front by the base of the tongue and in the back by the lingual surface of the epiglottis
Hyoid bone: only bone in the larynx
Pyriform sinuses: two sinuses/crevices just before the cricopharyngeus
cricopharyngeus: the most superior muscle of the esophagus. At rest, this muscle is contracted. Also known as UES

General areas on lateral view
Nasopharynx - back of the nose to the tip of the velum Oropharynx – starts at the tip of the velum to bottom of valleculae, stops after the epiglottis Hypopharynx - after the epiglottis to the pyriform sinuses Laryngeal Vestibule – a small triangle – a space that is an entrance to the airway. Anytime anything enters here, it is considered penetration. If it hasn’t gone below the vocal cords, it is still penetration Vocal Cords Trachea Esophagus – collapsed tube (only opens when food is going through) just posterior to the trachea Ramus of Mandible – we are concerned about the angle, most importantly. Where the mandible intersects the base of tongue is where you should see the head of any bolus when the swallow is triggered. When head of bolus is there, that is where the swallow is triggered      
Oral transit phase (aka oral stage)
  • The oral stage of the swallow is voluntary and fast

  • It is designed to move a given bolus of food or liquid from the front of the oral cavity to the pharynx (specifically to where the ramus of the mandible crosses the base of the tongue), where the pharyngeal stage of the swallow is initiated.

What is the most critical element in propelling the bolus during the oral transit stage? How long does this stage last?
  • Tongue motion is also the most critical element at this stage.

  • Tension in the buccal musculature is thought to contribute to propelling the bolus backward, but to a much lesser degree that tongue movements

  • Time norm is 1 to 1.5 seconds

Oral transit stage (aka oral stage): Sequence of events that occur
  • The midline of the tongue shapes, lifts and squeezes the bolus upward and backward along the hard palate until it reaches the pharynx.

  • During the posterior propulsion by the midline of the tongue, the lateral margins of the tongue are sealed against the alveolar ridge with the sides providing resistance against which the midline of the tongue propels the bolus.

  • Termination: When the head or leading edge of the bolus reaches the point where the angle of the ramus of the mandible crosses the base of the tongue, the pharyngeal swallow should be triggered.
Pharyngeal phase
  • This phase is more physiologically important because airway protection occurs during this phase in most people.

  • The oral prep and transit stages can be bypassed by reducing the consistency of foods to liquid, by syringing food to the back of the mouth or by positioning the head back so gravity moves the food to the pharynx.

  • The pharyngeal phase of the swallow CANNOT be bypassed.

Pharyngeal swallow
  • A programmed stage of the swallow

  • The pharyngeal swallow is mediated in the medulla in the reticular formation immediately adjacent to the respiratory center.

  • Coordination exists between these two areas because respiration ceases for a fraction of a second when the airway closes during the pharyngeal swallow.

  • There is also cortical input to the triggering of the pharyngeal swallow through the patterns of tongue movement in the oral phase of the swallow. The neurologic substrate for this cortical input is not clearly understood. But cortical CVA’s have delays.

Neuromuscular Characteristics of the Pharyngeal Swallow- Important!!!

When the pharyngeal swallow is triggered, the brainstem swallowing center programs 5 neuromuscular activities to occur:

1. Velopharyngeal closure to prevent nasal regurgitation – soft palate must rise and make contact with the velopharyngeal wall to close the velopharyngeal port so that liquid does not fly up into your nasal cavity

2. Base of tongue retraction to propel the bolus through the pharynx – the tongue base has to make contact with the posterior pharyngeal wall – soft tissue touches to close the oropharynx. Good base of tongue retraction gives the bolus velocity to make it down. Base of tongue retraction is very important.

3. Pharyngeal contraction to clear material from the pharynx – The superior constrictors, inf constrictors, and the muscles squeeze as the base of the tongue is contracting, helping the bolus through the pharynx with no residue

4. Airway protection, which involves elevation and closure of the larynx at several levels– Elevation and closure are two separate things.

5. Cricopharyngeal (CP) or upper esophageal (UES) opening to allow the bolus to pass into the esophagus.

What are the two dimensions for laryngeal closure for airway protection?
1) Elevation = when suprahyoid muscles (of the neck) pull larynx anteriorly and superiorly to pull it out of the way for the passage of the bolus.
2) Closure = what is happening intrinsically in your larynx.

Layngeal elevation

ELEVATION:

  • Suprahyoid muscles position the larynx anteriorly and superiorly under the tongue as the tongue base is retracted.

  • The larynx is pulled up and out of the way of the passage of the bolus

 
Layngeal closure
Closure involves 3 main components: 1.     Closure of the true VFs 2.     Closure of the false VFs 3.     Anterior tilting of the arytenoid cartilages to the petiole of the epiglottis – arytenoids are tilting. Use the correct terminology because the arytenoid cartilages are not “closing”.
  • Epiglottis retrofletion assists but isn’t crucial
  Closure of the larynx…
  • Progresses from the bottom up
  • The most important level of closure is at the airway entrance which is the anterior tilting of the arytenoids and closure of the false cords
  • Epiglottis retroflexion plays a relatively minor role in protecting the airway.  However, it diverts boluses AROUND the airway.
  • Airway closure is maintained only the fraction of a second that the bolus is passing the airway.  The airway opens to continue respiration after the primary portion of the bolus enters the esophagus
Normal pharyngeal phase - important!!
  • Prompt triggering of the pharyngeal swallow

  • Base of tongue retraction

  • Velar elevation

  • Epiglottis retroflection

  • Laryngeal elevation – only endoscopic view shows closure and elevation, MBS will show only elevation

  • Pharyngeal wall contraction (inferred)

  • Cricopharyngeal relaxation

  • No residue in the valleculae or pyriform sinuses

  • Time is 1 second or less

Prompt triggering of pharyngeal swallow - what does the hyoid bone do? important!!
(promp triggering Aka normal swallowing on time as opposed to delayed swallow) When the leading edge of the bolus is at the angle of the ramus of mandible, the hyoid bone should be observed initiate movement anteriorly and superiorly. When the hyoid bone is at its height, that is the end of the swallow and it should begin to relax.
Base of tongue retraction during the pharyngeal phase
  • When the tail of the bolus reaches the tongue base, the tongue base moves rapidly backward like a piston (in an engine), increasing pressure in the pharynx.
  • As the base of tongue retracts, the lateral and posterior pharyngeal walls at the tongue’s level move inward
  • Base of tongue and pharyngeal walls should make complete contact during the swallow.
  • *Base of tongue retraction is what gives the bolus the traction to go down and descend the pharynx.
Pharyngeal wall contraction
  • The sequential contraction of the superior, middle and inferior pharyngeal constrictor muscles is responsible for clearing material from the pharyngeal walls and pyriform sinuses.
  • It is usually inferred (its not easily seen on the MBS) based upon the location of residue, the integrity of the other physiologic components of the swallow and history, since actual pharyngeal wall contraction is not typically observed during the MBS, but…(see in-class example)
Velar elevation and velopharyngeal closure during the pharyngeal stage - what is the purpose?

The velum elevates and makes contact with the posterior and lateral pharyngeal walls to prevent backflow of material into the nasopharynx and nose.

Epiglottis retroflexion (aka epiglottis inversion)
The epiglottis INVERTS to cover the laryngeal vestibule and divert food around the larynx - INVERT = upside down/ backward and downward. Epiglottis reflexion is passive.
1. Hyolaryngeal elevation folds epiglottis to a horizontal position 2. Tongue base retraction brings tip of the epiglottis to the posterior pharyngeal wall  and provides propulsion to the bolus 3. The downward pressure of the bolus contributes to the epiglottal descent (she said it in other words as well - The propulsion of the bolus pushes the epiglottis to inversion) **Hyoid bone moves anteriorly and superiorly, pulling the larynx superiorly and anteriorly and out of the way of the bolus
Layngeal elevation
*Not the same as laryngeal closure (true cords, false cords, etc closing)
  • The larynx elevates, the pharynx shortens, and the airway closure is achieved as the arytenoids are tilted anteriorly – VFs adduct at this point
  • The laryngeal vestibule is obscured from view by the soft tissue coming together.
  • No penetration during the swallow
* You know the laryngeal closure is adequate if you see the light triangle obliterated from the view of the MBS
Cricopharyngeal relaxation
  • At rest, the CP is in tonic contraction (it’s always tight) to prevent air from entering esophagus during respiration and prevents backflow of material into the pharynx form the esophagus
  • During the swallow, [one of the sequence of events in the swallow is that] the CP relaxes and the anterior-superior movement of the larynx opens up the CP and UES (opening to the esophagus - upper esophageal sphincter) to allow the bolus to pass into the esophagus and then immediately closes to prevent backflow.
Esophageal phase
  • When the bolus passes through the UES (aka cricopharynges or entryway of esophagus), the esophageal phase of the swallow begins.
  • Normal duration is 8-20 seconds
  • Upper 1/3 is composed of voluntary and involuntary muscles
  • Lower 2/3 is entirely involuntary muscle
  • LES is the valve to the stomach and opens to allow the bolus into stomach and closes to prevent reflux.
  • The bolus moves from the UES through the LES without stasis or residue in the esophagus
  • No retrograde movement or reflux is observed
x of y cards