Respiratory Capacity and Swallowing Function in Spinal Disorders: A Pilot Study

Study Overview
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Brief Summary
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This study is part of a larger grant, for which the overall goal is to collect measurements of liquid flow through the oropharynx (i.e., mouth and throat) during swallowing.The focus of this study is to evaluate the flow of liquids of varying consistency in the spinal disorder population.

Detailed Description
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Thickened liquids are commonly used as an intervention for dysphagia (swallowing impairment). However, the field lacks a clear understanding of how liquids of different consistencies behave during swallowing. In order to improve understanding of the effectiveness of altered liquid consistency for improving dysphagia, the investigators are studying liquid flow through the oropharynx. This study explores this question in individuals with spinal cord injury. Participants will swallow 20% w/v barium thickened to different consistencies (thin, slightly thick, mildly thick, moderately thick and extremely thick). Swallowing will be observed under videofluoroscopy. Simultaneous measures of airflow via nasal cannula will be used to study respiratory-swallow coordination in this study sample.

Official Title
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Respiratory Capacity and Swallowing Function in Spinal Disorders: A Pilot Study

Conditions
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Spinal Cord Injuries, Deglutition Disorders

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Spinal cord injury at the cervical or thoracic level (T6 or higher) Exclusion Criteria: Prior history of swallowing, motor speech, gastro-esophageal difficulties, chronic sinusitis or taste disturbance. Neurological difficulties unrelated to spinal disorder (e.g. Stroke, Parkinson disease, etc). Cognitive communication difficulties that may hinder ability to participate. Current use of mechanical ventilation External instrumentation around the head/neck that would obstruct the field of view during the videofluoroscopy exam (e.g. cervical collar). Type 1 Diabetes (due to the requirement to swallow stimuli containing starch based thickeners, which carry a significant carbohydrate load). Known allergies to latex, food coloring or dental glue (due to the probability that these items will come into contact with the oral mucosa during data collection). Children and pregnant women (due to the use of radiation during the videofluoroscopic examination).

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 100 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Spinal Cord Injury<br>Adults who have sustained a spinal cord injury at the cervical or upper thoracic level (T6 or higher). | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of Participants Displaying Unsafe Swallowing | The Penetration-Aspiration Scale is an 8-point categorical scale that is used to characterize swallowing safety for each bolus based on 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 report the frequency (count) of participants showing unsafe swallowing (i.e., scores > 2) by bolus consistency. | Baseline (single timepoint only) | 
| Number of Participants Displaying Post-swallow Inhalation | Healthy swallowing typically occurs partway through an outward breath, such that the direction of breathing both before and after the swallow is exhalation. Whenever a swallow is followed immediately by inhalation, this is considered abnormal and a risk for food or liquid material to be sucked into the airway. We measured the direction of breathing before and after swallows via nasal cannula using the airflow module of the KayPentax Digital Swallow Workstation Swallowing Signals Lab. We report the frequency (percentage) of participants displaying at least one swallow showing post-swallow inhalation by consistency. | Baseline (single timepoint only) | 
| Duration of the Respiratory Pause Seen in Swallowing | Healthy swallowing typically occurs partway through an outward (exhalatory) breath, and involves a pause in breathing. The duration of this respiratory pause was measured in milliseconds for each swallow based on the continuous airflow waveform collected via nasal cannula using the airflow module of the KayPentax Digital Swallow Workstation Swallowing Signals Lab. We report means and standard deviations for respiratory pause duration by consistency. Shorter respiratory pause durations reflect inadequate airway protection. | Baseline (single timepoint only) |