Swallowing and respiratory pattern in young healthy individuals recorded with high temporal resolution

Abstract

The coordination of swallowing and respiration is essential for a safe swallow. Swallowing consists of several subsecond events. To study this, it is important to use modalities with high temporal resolution. In this study, we have examined young healthy individuals with simultaneous videofluoroscopy, videomanometry and respiratory recording, all with high temporal resolution. The onset of 13 predetermined swallowing and respiratory events and the surrounding respiratory phase pattern were studied in different body positions and during different respiratory drives. An increased respiratory drive was induced by breathing 5% CO(2). The results demonstrated a highly repeatable and fixed temporal coordination of the swallowing pattern despite body position and respiratory drive. Previous studies have demonstrated a period of centrally controlled apnoea during swallowing. This apnoea period has a variable length, varying from 1 to 5 s. During increased respiratory drive, we could demonstrate a significantly shorter period of apnoea during swallowing, mainly due to an earlier resumption of respiration. The high temporal recordings in this study have revealed that swallowing during expiration is present basically in all healthy individuals. This swallowing respiratory pattern seems to be appropriate for a safe swallow. This knowledge will be used as a reference for future studies on how swallowing and respiratory coordination might be altered due to ageing and diseases.

Effect of a tracheostomy speaking valve on breathing–swallowing interaction

“…A study in healthy individuals showed that swallowing often occurred after expiration initiation, coincided with a period of apnoea, and was usually followed by further expiration [11]. Other studies [12][13][14][15][16] confirmed these findings and established that the expiratory activity surrounding swallowing helped to prevent the passage of noxious chemicals and microbes from the mouth to the lungs. However, tracheostomised patients expire at least in part through the tracheostomy tube [6], which may eliminate the protection afforded by expiration to the upper airways, unless the expired gas is directed towards the upper airways by an SV.…”

“…In addition, the positive tracheal pressure facilitated by expiration plays a pivotal role in maintaining the glottis closure reflex [6,22]. Finally, expiratory flow towards the upper airway after swallowing expels liquid or food particles misdirected toward the trachea during swallowing [12][13][14][15][16]. …”

“…In addition, the SV restores a significant expiratory volume through the upper airway after swallowing, which is considered to prevent the passage of noxious chemicals and microbes from the mouth into the lungs [12][13][14][15][16].…”

ICU-Acquired Swallowing Disorders

“…As the respiratory rate increases, the periswallowing apneic period shortens, and laryngeal opening can occur prior to passage of the food bolus into the esophagus (66). Prevention of aspiration during swallowing is dependent on exact coordination between laryngeal closure, apnea, and the opening of the upper esophageal sphincter (35).…”

Anesthesia and Increased Hypercarbic Drive Impair the Coordination between Breathing and Swallowing

“…Our data confirm the findings of several studies that physiological swallows during wakefulness typically occur either during expiration, or are followed immediately by the expiratory phase. 16,3 There was no difference in the proportion of pathological swallows between propofol and sevoflurane. However, the absence of significant difference in pathological swallow proportion between sevoflurane and propofol does not indicate significance of absence, and further studies may be needed to address differential effects of GABAergic anesthetics on breathing swallowing coordination.…”