Clinical Effects of Nasal High Airflow on Swallowing Physiology, Respiratory-Swallowing Patterning, and Temporal Measures in Advanced Stable Chronic Obstructive Pulmonary Disease

Abstract

Noninvasive respiratory support (NRS) treatments, which deliver mechanical positive pressure through the upper airway to assist with oxygenation and ventilation, have been rapidly expanding in recent years. This growth is attributed to the comparable physiologic benefits to invasive mechanical ventilation methods, while simultaneously mitigating the associated risks and complications. The pulmonary effects associated with the mechanisms of respiratory support are generally well understood, but the effects on swallowing movements and breathing and swallowing patterns remain unclear. This dissertation aims to a) assess existing evidence on the impact of various types of NRS on measures of swallowing function, airway protection, and respiratory-swallowing patterns, and b) examine the clinical effects of nasal high airflow oxygen therapy (HFNC), one form of NRS, on measures of swallowing physiology, respiratory-swallowing patterns, and temporal measures in patients with advanced, stable chronic obstructive pulmonary disease (COPD). Chapter 1 presents a systematic review and a summary of current evidence on the effects of NRS modalities on measures of swallowing function and respiratory-swallow patterns. Chapter 2 describes a detailed clinical investigation of the effects of HFNC on measures of swallowing physiology, airway protection, respiratory-swallowing patterns, and temporal measures in a cohort of patients with stable, advanced COPD. Findings from the systematic review (Chapter 1) revealed that NRS modalities had mixed effects on swallowing measures and respiratory-swallow patterns in both healthy adults and those with respiratory diseases. The results from Chapter 2 demonstrated that HFNC did not exert negative effects on swallowing physiology or airway protection. However, there were favorable effects on increasing optimal respiratory-swallowing patterns and prolonging durations of expiratory phase in cycles containing swallow. While this study is exploratory, these findings suggest that HFNC did not result in adverse effects in this cohort. In addition, these results emphasize the need for instrumental swallowing evaluation in patients requiring this respiratory intervention.