Scaling the Swallow The penetration-aspiration scale quantifies how—and where—a patient’s swallow goes awry. On the Pulse
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On the Pulse  |   May 01, 2017
Scaling the Swallow
Author Notes
  • James L. Coyle, PhD, CCC-SLP, BCS-S, is associate professor in the departments of Communication Science and Disorders and Otolaryngology at the University of Pittsburgh. He is an affiliate of ASHA Special Interest Group 13, Swallowing and Swallowing Disorders (Dysphagia). jcoyle@pitt.edu
    James L. Coyle, PhD, CCC-SLP, BCS-S, is associate professor in the departments of Communication Science and Disorders and Otolaryngology at the University of Pittsburgh. He is an affiliate of ASHA Special Interest Group 13, Swallowing and Swallowing Disorders (Dysphagia). jcoyle@pitt.edu×
Article Information
Swallowing, Dysphagia & Feeding Disorders / On the Pulse
On the Pulse   |   May 01, 2017
Scaling the Swallow
The ASHA Leader, May 2017, Vol. 22, 36-38. doi:10.1044/leader.OTP.22052017.36
The ASHA Leader, May 2017, Vol. 22, 36-38. doi:10.1044/leader.OTP.22052017.36
Sit down with three colleagues in your department and, without explaining why, ask each to write down a definition of “flash penetration.” Then compare their descriptions. What do you see?
We all describe where the sun rises and sets in the same way. It rises in the east and sets in the west. Period. So, why do different observers describe the same swallowing event using different sets of words? In the mid-’90s, partly out of frustration over the different ways that identical events were described by different clinicians viewing the same videofluoroscopic (VF) data (see “Getting in Sync”), investigators developed the penetration-aspiration (PA) scale.
In seeking to standardize the descriptions of how swallowed contrast invades the airway during VF studies, the PA scale authors started with a series of tasks and questions.

Investigators sought to standardize the descriptions of how swallowed contrast invades the airway during videofluoroscopic studies.

First task
The first task was to write down all possible observations from VF imaging data that involve swallowed material entering the airway. Observable parameters emerged consistently from each author’s independent list and fell into three categories: how far the material courses into the airway, whether visible residue remains in the airway at the end of the swallow, and where that remaining residue was. So a standard list was possible.
Second Task
Next, the authors sought to develop an unequivocal, objective rationale for each observation, and began by asking a series of questions.
Question 1. Does material enter the airway? The ariepiglottic folds are the portal to the airway. They course from the sides of the epiglottis to the tips of the arytenoid cartilages on the posterior larynx, and are visible on X-ray images. Does material enter the airway? Yes or no? If it crosses these landmarks—yes! If not, no!
Question 2. How far into the airway does this material course? Anatomy strikes again. The false vocal folds are the base of the laryngeal vestibule and the true vocal folds are the portal to the trachea. But we cannot see them in X-ray images, so how can we operationalize “leaving the larynx and entering the trachea”?
The vocal folds, the agreed-upon portal to the trachea (where “aspiration” begins) are organized like two little lean-tos. Their tops (the part of the vocal folds seen with endoscopy) can approximate one another at the midline (as occurs during speech or coughing and swallowing) or separate from one another (as occurs during inhalation), but their bottoms are anchored to the round and fixed base of the cricoid cartilage, like stakes holding down a tent (whose top opens and closes).
When material passes the base of this “tent,” the base of the cricoid cartilage—a highly visible X-ray shadow and landmark that demarks the anatomical bottom of the larynx—it has entered the trachea. Aspiration, yes or no? Check!
Question 3. What about laryngeal penetration? The authors observed swallows with very shallow and with very deep penetration of the larynx, none of which crossed this “tracheal portal” landmark. When barium had touched the vocal folds, material coated the superior surface of the vocal folds after the swallow and sometimes also coated a tiny almond-shaped area above them.
What was that? Back to the anatomy books. The laryngeal ventricles, the spaces between the true and false vocal folds on each side of the larynx, are small cavities at the base of the larynx. Their floors are the true vocal folds. And the space above the false vocal folds is referred to as the laryngeal vestibule. Great! We have anatomic correlates for deep and shallow laryngeal penetration. Does material that penetrates—but is not aspirated—come into contact with the vocal folds (deep laryngeal penetration)? Yes or no? If not, then it remained in the laryngeal vestibule (shallow penetration).
Question 4. Finally, is there barium coating or pooling in the airway at the end of the swallow? And where, using these same landmarks, is it? Barium residue is either visible or it is not. We either see it or we do not. Residue and location—check!
So now there are four yes/no questions about the swallow:
  • Does it enter the airway?

  • Does it remain in the vestibule?

  • Does it enter the trachea?

  • Is there visible residue and, if so, where is it?

These decisions led to the final items of the PA scale.
Final task
To arrive at a scale that describes which of these events are worse than others, the investigators ranked the various combinations of events in ascending order of severity, indicating where each score should be placed relative to the others. The consensus that aspiration was “worse” than laryngeal penetration was easy, and there was little dispute about the others: Deeper penetration was considered “worse” than shallow penetration, and post-swallow residue was “worse” than no post-swallow residue. The parameters were combined and ranked by a larger consensus group, and after successful reliability testing, the scale was published in the journal Dysphagia.

Let’s replace “reduced hyoid motion on palpation” and “flash penetration” with standard, objective methods.

Application
Can a standardized scale differentiate normal from abnormal? We compared PA scale scores of thin-liquid swallows of two groups of patients—15 with stroke and 16 after treatment for head and neck cancer—to a healthy cohort. Six patients with stroke aspirated (all PA scale scores 7 and 8). Only one from the head-neck group aspirated and spontaneously cleared his own airway (PA scale score 6), despite several patients with pharyngeal, supraglottic and tongue-base resections and radiation-treated disease.
Why standardize? Well, what is “flash penetration”? What is “mild” or “moderate” laryngeal penetration? How far apart are mild and moderate? These are great questions whose answers probably lie somewhere in standard, rule-based, decision-making algorithms like the PA scale and more recently, the Modified Barium Swallow Impairment Profile, that replace subjective and inconsistent wording with a set of agreed-upon, severity-ordered descriptions of impairment.
These algorithms give us measures of severity and of change caused by intervention. Let’s replace “reduced hyoid motion on palpation” and “flash penetration” with standard, objective methods.
Learn to Use the Penetration-Aspiration Scale at Health Care Connect

James L. Coyle will present on the penetration-aspiration (PA) scale at ASHA’s Health Care Connect, to be held July 7–9 in New Orleans.

A new feature of the conference is combination lecture-lab sessions. In his combined session, “Using the Penetration-Aspiration Scale,” Coyle will introduce the scale and provide examples of scoring decision-making.

He will then lead a hands-on learning lab in which participants review examples of different PA scores and practice using the scale to assess videofluoroscopic data.

Coyle will also present “Screening, Assessment and Management of Oral Colonization in the ICU,” which explores clinical decision-making and oral health in intensive care units.

Health Care Connect, co-located with Schools Connect and Private Practice Connect, is designed specifically for clinicians in health care settings. Attendees may attend sessions at any of the three conferences.

sources
Daggett, A., Logemann, J., Rademaker, A., & Pauloski, B. (2006). Laryngeal penetration during deglutition in normal subjects of various ages. Dysphagia, 21(4), 270–274. [Article] [PubMed]
Daggett, A., Logemann, J., Rademaker, A., & Pauloski, B. (2006). Laryngeal penetration during deglutition in normal subjects of various ages. Dysphagia, 21(4), 270–274. [Article] [PubMed]×
Martin-Harris, B., Brodsky, M. B., Michel, Y., Castell, D. O., Schleicher, M., Sandidge, J., … Blair, J. (2008). MBS measurement tool for swallow impairment—MBSImp: Establishing a standard. Dysphagia, 23(4), 392–405. doi:10.1007/s00455-008-9185-9 [Article] [PubMed]
Martin-Harris, B., Brodsky, M. B., Michel, Y., Castell, D. O., Schleicher, M., Sandidge, J., … Blair, J. (2008). MBS measurement tool for swallow impairment—MBSImp: Establishing a standard. Dysphagia, 23(4), 392–405. doi:10.1007/s00455-008-9185-9 [Article] [PubMed]×
Robbins, J., Coyle, J. L., Rosenbek, J. C., Roecker, E. B., & Wood, J. L. (1999). Differentiation of normal and abnormal airway protection during swallowing using the penetration-aspiration scale. Dysphagia, 14(4), 228–232. [Article] [PubMed]
Robbins, J., Coyle, J. L., Rosenbek, J. C., Roecker, E. B., & Wood, J. L. (1999). Differentiation of normal and abnormal airway protection during swallowing using the penetration-aspiration scale. Dysphagia, 14(4), 228–232. [Article] [PubMed]×
Rosenbek, J. C., Robbins, J., Roecker, E. B., Coyle, J. L., & Wood, J. L. (1996). A penetration-aspiration scale. Dysphagia, 11(2), 93–98. [Article] [PubMed]
Rosenbek, J. C., Robbins, J., Roecker, E. B., Coyle, J. L., & Wood, J. L. (1996). A penetration-aspiration scale. Dysphagia, 11(2), 93–98. [Article] [PubMed]×
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May 2017
Volume 22, Issue 5