Strategies for the Integration of Cough and Swallow to Maintain Airway Protection in Humans.

OBJECTIVE

Airway protective behaviors, like cough and swallow, deteriorate in many populations suffering from neurologic disorders. While coordination of these behaviors has been investigated in an animal model, it has not been tested in humans.

METHODS

We used a novel protocol, adapted from previous work in the cat, to assess cough and swallow independently and their coordination strategies in seven healthy males (26 ± 6 years). Surface electromyograms of the submental complex and external oblique complex, spirometry, and thoracic and abdominal wall kinematics, were used to evaluate the timing of swallow, cough, and breathing as well as lung volume (LV) during these behaviors.

RESULTS

Unlike the cat, there was significant variability in the cough-swallow phase preference; however, there was a targeted LV range in which swallow occurred.

CONCLUSIONS

These results give insight into the differences between the cat and human models in airway protective strategies related to the coordination of cough and swallow behaviors, allowing for better understanding of dystussia and dysphagia.