0487 The effect of negative pressure ventilation on airflow in obstructive sleep apnea subjects undergoing drug induced sleep endoscopy

Abstract

Abstract Introduction Drug induced sleep endoscopy (DISE) is used to visually characterize pharyngeal airway collapse in obstructive sleep apnea (OSA) to help determine appropriate patients for OSA surgery. The procedure has grown in complexity with the addition of airflow recording and continuous positive airway pressure (CPAP) titration to obtain additional measures of airway collapsibility. Lung volume can also influence airway collapse in OSA but is not evaluated as part of routine DISE. The purpose of this study is to characterize the relationship between changes in lung volume and upper airway collapse during DISE to gain further insight into factors contributing to airway collapse and their potential roles in influencing surgical decision making. Methods This study is an ongoing IRB approved prospective clinical trial assessing the effects of negative pressure ventilation on airway collapse during DISE. Enrolled patients first undergo DISE evaluation per clinical routine including a CPAP titration. CPAP is then held at a level where patients exhibit stable flow limitation. A negative pressure ventilator shell is placed over the torso of the body and negative pressures of up to -25cmH2O are applied to expand the chest and increase lung volume. Changes to nasal airflow and tidal volume are evaluated. The negative pressure ventilator is then released and changes to airflow back to baseline are recorded. Results Between 6/30/2022 and 11/30/2022, 5 patients completed the study. There were 4 men and 1 woman with an average age of 60 years, BMI of 26.67kg/m2, and apnea-hypopnea index (AHI) of 44.44 events/hr. Average peak inspiratory flow increased from 8.38L/min to 13.78L/min and average tidal volumes increased from 155mL to 269mL on negative pressure ventilation. Conclusion Increases in lung volume from negative pressure ventilation during DISE can improve airflow and tidal volume suggesting that changes in lung volume can influence the severity of upper airway collapse. Further study to better characterize this relationship can help add additional diagnostic information regarding airway collapse characteristics to provide better informed surgical decisions and develop new interventions. Support (if any) Supported by the National Center for Advancing Translational Sciences (NCATS) of the National Institutes of Health (NIH) under Award Numbers UL1TR002378 and KL2TR002381