Effects of Lung Volume on Upper Airway Patency During Drug Induced Sleep Endoscopy

Description

Obstructive sleep apnea (OSA) is a disorder where a person has recurrent choking episodes during sleep. Surgery can treat OSA and drug induced sleep endoscopy (DISE) is a procedure that surgeons use to evaluate the throat while a person is sedated, mimicking sleep, to help determine if surgery might be effective. Lung volume can influence OSA severity but the relationship between lung function and throat collapse seen on DISE has not been well studied. This study aims to see if lung volume influences what is happening in the throat during DISE. Participants will be recruited from the sleep surgery clinic where they are being evaluated for surgery to treat their OSA. Participants will have a DISE that is performed as part of their routine surgical workup for treatment of OSA. Additionally, during the DISE, they will participate in one of two study groups. One group will have a negative pressure "turtle shell" ventilator placed over the participants chest during DISE to manipulate lung volumes to see if it can improve throat collapse. A second group will have phrenic nerve stimulation to contract the diaphragm to improve lung volumes to see if it can improve throat collapse. Both groups will also have a lung function test performed. The findings of this study will be important in improving pre-surgical evaluation of patients to better predict if surgery can help as well as potentially develop new surgical therapies for the treatment of OSA.

Interventions

• Negative Pressure Ventilator (Device)
  The negative pressure ventilator is an off-the-shelf FDA-approved device designed to treat respiratory patients with hypoventilation syndromes. This ventilator places the torso within a fixed container that is connected to a vacuum source, which inflates the lungs by pulling a negative pressure around the chest and abdomen. After the clinically routine DISE, a negative pressure ventilator will be placed on the participant's chest to increase lung volumes and the DISE evaluation will be repeated to observe changes.
• Pulmonary Function Testing (PFT) (Device)
  PFT is a routine standardized clinical test evaluating lung function, consisting of two parts: spirometry and body plethysmography. In spirometry, participants breathe through a mouthpiece that measures airflow and volume to determine normal and maximal volume of inspiration/expiration. Body plethysmography is performed to calculate residual lung volumes. Participants enter in an enclosed chamber where they breathe through a mouthpiece. Changes in pressure in the sealed chamber during breathing are used to calculate the volume of air that remains in the lung after expiration. A MiniBox+ device may be used. The MiniBox+ device derives total lung capacity (TLC) during tidal breathing by the analysis of gas pressures and airflows immediately preceding and immediately following airway occlusions to calculate the same measures as conventional PFT analysis.
• Transcutaneous Phrenic Nerve Stimulation (Device)
  Phrenic nerve stimulation (PNS) will be performed transcutaneously using a commercially available and FDA approved peripheral neurostimulator. (Digitimer DS8R Bipolar Constant Current Stimulator). The neurostimulator consists of a stimulation generating box connected to electrodes that will be placed over the skin of the neck bilaterally over both phrenic nerves where an bipolar electric current will be used to stimulate the phrenic nerve leading to diaphragm contraction.
• Percutaneous Phrenic Nerve Stimulation (Device)
  Under ultrasound guidance, a stimulating catheter (Stimulong Sono II) will be inserted into the right side of the neck and positioned adjacent to the phrenic nerve as it travels along the anterior scalene muscle. The catheter will be connected to a commercially available research neurostimulator. Unilateral phrenic nerve stimulation will be performed for no more than 30 minutes.

Eligibility criteria

Conditions

Locations

• Emory University Hospital Midtown — Atlanta, Georgia, United States