Supplemental Material for: Oxygenation During Sequential Drinking in Healthy Adults and Adults with Severe or Very Severe Chronic Obstructive Pulmonary Disease

Abstract

Introduction: Sequential drinking requires repeated swallowing with brief interruptions in breathing. Speech-language pathologists may notice oxygen saturation changes during drinking tasks, but interpretation is difficult without healthy comparison data collected at the time of physiologically verified swallowing activity. This study characterized oxygen saturation during a standardized 100-mL thin-liquid sequential drinking task in healthy younger adults, healthy older adults, and adults with severe or very severe chronic obstructive pulmonary disease (COPD).Methods: Sixty healthy younger adults, 60 healthy older adults, and 11 adults with severe or very severe COPD completed three 100-mL thin-liquid water trials. Submental electromyography, respiratory inductive plethysmography, and pulse oximetry were recorded concurrently. Oxygen saturation was quantified at baseline and at the time of physiologically verified swallowing activity. Mixed-model analyses examined oxygen saturation differences by age group, health status, and measurement period.Results: The 120 healthy adults provided normative comparison data for oxygenation during standardized sequential drinking. Healthy younger and older adults maintained stable oxygen saturation during swallowing activity, although younger adults showed slightly higher oxygen saturation than older adults. In the small COPD sample, oxygen saturation was lower than in healthy adults at baseline and during swallowing activity, and it declined significantly from baseline to the swallowing period. Substantial between-group separation was already present at baseline. Trial-to-trial consistency was high across groups.Conclusion: This study characterized oxygenation responses at the time of physiologically verified swallowing activity in a large sample of younger and older healthy adults. These healthy adult data provide a normative comparison point for understanding typical oxygenation responses during standardized sequential drinking. In the small COPD sample, the predominant finding was lower baseline oxygenation, accompanied by a modest additional decline during swallowing activity. These preliminary findings may help speech-language pathologists interpret oxygen saturation changes during drinking tasks cautiously and in relation to baseline respiratory status.