note, inspiratory airflow returned to baseline levels on alternating unstimulated breaths, suggesting that HGNS has a direct effect on lingual muscles and airway patency without arousing patients from sleep."
The study had a few limitations. Esophageal manometry was not used to monitor inspiratory effort, and flow response was not measured in all body positions and sleep stages. In addition, the effects of chronic use of HGNS therapy were not assessed.
"Our findings extend previous findings on the effects of HGNS on airflow in obstructive sleep apnea by characterizing flow responses over a range of stimulus amplitudes and demonstrating greater increases in airflow," concluded Dr. Schwartz. "The magnitude of the increases in airflow we observed indicate that HGNS can provide substantial relief of upper airway obstruction during sleep in these patients across a wide range of disease severity."