Physiological Flow of Liquids in Healthy Swallowing

NCT04114617 | Completed Results

• 3 other identifiers: 15-94315R01DC011020CAPCR 15-9431 (NIH_HV)
• Study Type: observational
• Target: 80
• Locations: 1 country
• Sites: 1

Brief Summary

Thickened liquids are commonly used as an intervention for people with dysphagia (swallowing impairment). However, the field currently lacks a proper understanding of how this intervention works. The overall goal of the project is to collect measurements of bolus flow through the oropharynx (i.e., mouth and throat) during swallowing. The factors that are expected to influence bolus flow include the liquid/food consistency (i.e., thin, slightly-thick, mildly-thick, moderately-thick, extremely thick, solid) and the forces applied during swallowing (i.e., tongue pressures and swallowing muscle contraction). The objective is to determine how these factors interact to influence the flow of a bolus through the oropharynx in healthy swallowing.

Conditions

Deglutition; Healthy Swallowing; Aging

Keywords

Swallowing; Deglutition

Outcome Measures

Primary Outcomes (11)

• Number of Participants With Unsafe Swallowing

  Swallowing safety was measured using the Penetration-Aspiration Scale, an 8-point categorical scale which captures the depth to which any material enters the airway and whether or not the material is ejected. Levels 1 and 2 on the scale are considered safe, while levels \> 2 are considered unsafe. Actual scale scores (1-8) will be recorded and then converted to binary categorical scores (\< 3 vs \>/= 3). We will report the frequency (count) of participants showing scores \> 2 by bolus consistency.

  Baseline (single timepoint only)

• Amount of Residue in the Pharynx

  Residue is material remaining behind in the pharynx after the swallow. We measured residue by tracing the area of barium visible on a lateral view x-ray (in pixels, using ImageJ software) and dividing that area by the squared length C2-C4 cervical spine. This cervical spine scalar provides a common anatomical reference that is a proxy for pharyngeal size, and enables the comparison of residue severity across different people with different neck length and pharynx size. In healthy swallowing, residue is expected to be minimal. We report median values and 97.5% confidence intervals for amount of residue by consistency (thin, slightly thick, mildly thick, moderately thick and extremely thick liquids).

  Baseline (single timepoint only)

• Number of Participants Displaying More Than 2 Swallows Per Bolus

  The number of swallows needed to clear a single bolus will be counted. 1-2 swallows is considered efficient, while \> 2 for a single bolus is considered inefficient. We report the frequency (count) of participants displaying \> 2 swallows per bolus by consistency.

  Baseline (single timepoint only)

• Duration of the Time Interval Between the Bolus Entering the Pharynx and Onset of the Pharyngeal Swallow ("Swallow Reaction Time")

  The time interval between the first frame showing the bolus entering the pharynx (passing the ramus of the mandible) and the first frame showing onset of the hyoid burst movement in swallowing, calculated in milliseconds. We report median values and 97.5% confidence intervals for each bolus consistency (thin, slightly thick, mildly thick, moderately thick and extremely thick liquid barium). Longer time intervals reflect delays in initiating the pharyngeal swallow.

  Baseline (single timepoint only)

• Duration of the Time Interval Between Onset of the Hyoid Burst and Opening of the Upper Esophageal Sphincter

  The time interval between the first frame showing onset of the hyoid burst movement in swallowing and the first frame showing opening of the upper esophageal sphincter, calculated in milliseconds. We report median values and 97.5% confidence intervals for each bolus consistency (thin, slightly thick, mildly thick, moderately thick and extremely thick liquid barium). Longer time intervals reflect a delay in opening of the upper esophageal sphincter.

  Baseline (single timepoint only)

• Duration of Upper Esophageal Sphincter Opening

  The time interval between the first frame showing opening of the upper esophageal sphincter and the first subsequent frame showing closure of the upper esophageal sphincter behind the tail of the bolus, calculated (in milliseconds). We report median values and 97.5% confidence intervals for each bolus consistency (thin, slightly thick, mildly thick, moderately thick and extremely thick liquid barium). Shorter durations of upper esophageal sphincter opening reflect inadequate durations of opening to allow material to pass through the sphincter from the pharynx into the esophagus.

  Baseline (single timepoint only)

• Duration of the Time Interval Between Onset of the Pharyngeal Swallow and Closure of the Entrance to the Airway ("Time-to-Laryngeal-Vestibule-Closure")

  The time interval between the first frame showing onset of the hyoid burst movement in swallowing and the first frame showing closure of the laryngeal vestibule, calculated in milliseconds. We report median values and 97.5% confidence intervals for each bolus consistency (thin, slightly thick, mildly thick, moderately thick and extremely thick liquid barium). Longer time intervals reflect delays in achieving airway closure.

  Baseline (single timepoint only)

• Laryngeal Vestibule Closure Duration

  The time interval between the first frame showing closure of the entrance to the airway (laryngeal vestibule closure onset) and the first subsequent frame showing opening of the entrance to the airway (laryngeal vestibule closure offset) calculated in milliseconds. We report median values and 97.5% confidence intervals for each bolus consistency (thin, slightly thick, mildly thick, moderately thick and extremely thick liquid barium). Shorter durations of laryngeal vestibule closure reflect premature termination of airway protection.

  Baseline (single timepoint only)

• Degree of Pharyngeal Constriction

  During swallowing, the muscles of the pharynx contract to achieve constriction (closure) of the pharynx behind the bolus. The squeezing and pressure generated by this action help to move the bolus downwards through the pharynx. We measured the degree of pharyngeal constriction by identifying the frame of greatest pharyngeal constriction, and tracing the area of any unobliterated pharyngeal space on lateral view x-ray (in pixels, using ImageJ software). The resulting area measure was then divided by the squared length of the C2-C4 cervical spine. This cervical spine scalar provides a common anatomical reference that is a proxy for pharyngeal size, enabling the comparison of constriction across different people with different neck length and pharynx size. In healthy swallowing, constriction is expected to be complete, with larger measures reflecting incomplete or poor constriction. We report median values and 97.5% confidence intervals for pharyngeal constriction by consistency.

  Baseline (single timepoint only)

• Diameter of Upper Esophageal Sphincter Opening

  During swallowing, the upper esophageal sphincter opens to allow the bolus to move from the pharynx into the esophagus. Narrow opening of the sphincter may obstruct bolus flow. We measured the degree (diameter) of upper esophageal sphincter opening on the frame of maximum distension. Line measurements were made in Image J software. This line measure was then divided by the length of the C2-C4 cervical spine. This cervical spine scalar provides a common anatomical reference that is a proxy for pharyngeal size, enabling the comparison of constriction across different people with different neck length and pharynx size. We report median values and 97.5% confidence intervals for pharyngeal constriction by consistency (thin, slightly thick, mildly thick, moderately thick and extremely thick liquid).

  Baseline (single timepoint only)

• Pharyngeal Area at Rest

  The area of the pharynx was measured, in pixels (using ImageJ software), on a lateral view videofluoroscopic image showing the pharynx at rest. The resulting area measure was then divided by the squared length of the C2-C4 cervical spine. This cervical spine scalar provides a common anatomical reference that is a proxy for pharyngeal size, enabling the comparison of pharyngeal size across different people with different neck length. Larger pharyngeal area measures may reflect atrophy of the pharyngeal muscles while smaller pharyngeal area may reflect narrowing due to edema.We report median values and 97.5% confidence intervals for pharyngeal area.

  Single timepoint (baseline only)

Secondary Outcomes (1)

• Amplitude of Tongue-Palate Pressure

  Baseline (single timepoint only)

Study Arms (1)

Healthy Adults

Participants will be asked to swallow a series of up to 54 liquid stimuli: a) liquid barium (different brands and concentrations); b) a 20% w/v concentration liquid barium thickened to different consistencies using either a starch-based or xanthan-gum based food thickener; and c) lemon-flavored water thickened to different consistencies using either a starch-based or xanthan-gum based food thickener.

Other: Starch-thickened liquids; Other: Xanthan-gum thickened liquids; Combination Product: Barium concentration

Interventions

Starch-thickened liquids OTHER

Thickener added in amounts required to reach slightly thick, mildly thick, moderately thick and extremely thick consistencies, as defined by the International Dysphagia Diet Standardisation Initiative flow test.

Also known as: Nestle Resource ThickenUp

Healthy Adults

Xanthan-gum thickened liquids OTHER

Thickener added in amounts required to reach slightly thick, mildly thick, moderately thick and extremely thick consistencies, as defined by the International Dysphagia Diet Standardisation Initiative flow test.

Also known as: Nestle Resource ThickenUp Clear

Healthy Adults

Barium concentration COMBINATION_PRODUCT

Commercially available barium products diluted to different concentrations (i.e., 20% w/v, 40% w/v) through the addition of water

Also known as: Bracco E-Z-Paque barium powder; Bracco E-Z-HD barium suspension; Bracco Polibar Plus liquid barium suspension

Healthy Adults

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Healthy adults

You may qualify if:

• \- healthy adults

You may not qualify if:

• prior history of swallowing, motor speech, gastro-esophageal or neurological difficulties, chronic sinusitis or taste disturbance
• history of surgery to the speech or swallowing apparatus (other than routine tonsillectomy or adenoidectomy)
• Type 1 Diabetes
• cognitive communication difficulties that may hinder comprehension of the study documents
• known allergies to latex, food coloring or dental glue
• current pregnancy
• recent x-ray to the neck (in the past 6 months)
• occupationally exposure to radiation exceeding 10 milliSieverts in the year

Sponsors & Collaborators

• University Health Network, Toronto: lead
• National Institute on Deafness and Other Communication Disorders (NIDCD): collaborator

Study Sites (1)

Toronto Rehabilitation Institute

Toronto, Ontario, M5G 2A2, Canada

Location

Limitations and Caveats

In a previous submission, we had included 20 adults who participated in a subsequent supplementary experiment exploring chewing, and the number of chews per bolus had been included as a primary outcome measure. These participants did not complete the main experiment described here, therefore they are excluded from this report. A separate protocol has been registered to cover the chewing experiment (NCT05594173).

Results Point of Contact

• Title: Director, Swallowing Rehabilitation Research Laboratory
• Organization: University Health Network

tri-swallowinglab@uhn.ca

416 597 3422

Study Officials

• Catriona Steele, PhD

  KITE - Toronto Rehabilitation Institute, University Health Network

  PRINCIPAL INVESTIGATOR

Publication Agreements

• PI is Sponsor Employee: Yes

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: CROSS SECTIONAL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: September 27, 2019
• First Posted: October 3, 2019
• Study Start: January 1, 2016
• Primary Completion: September 12, 2019
• Study Completion: December 31, 2020
• Last Updated: December 21, 2022
• Results First Posted: December 21, 2022

Record last verified: 2022-11

Locations

CA (1)