Clinical Trial: Response to Diaphragmatic Pacing in Subjects With Pompe Disease

Study Status: Recruiting
Recruit Status: Recruiting
Study Type: Observational

Official Title: Response to Diaphragmatic Pacing in Subjects With Pompe Disease

Brief Summary: The purpose of this study is to determine the effect of diaphragm pacing on respiratory function in subjects with Pompe disease by evaluating the duration and pattern of spontaneous respiratory function versus paced ventilation respiratory function in patients with Pompe disease who have received the NeuDx Diaphragm pacer (DPS).

Detailed Summary:

Subjects with Pompe disease who are scheduled to receive a NeuRx Diaphragm pacer (DPS) will be invited to participate in this study. The following tests will be performed during participation in the study:

1. Forced expiratory tests
2. Maximal Inspiratory Pressure (MIP)
3. Resting Breathing Pattern
4. Phrenic Nerve Function Evaluation with EMG
5. Severe Respiratory Insufficiency Questionnaire
6. Magnetic stimulation

7. Diaphragm conditioning consisting of:

   1. The external stimulator settings
   2. The duration of diaphragm stimulation
   3. Off-ventilator spontaneous breathing (SB)

Current Primary Outcome: Change in off-ventilator spontaneous breathing (SB) at Baseline, Day 3, 14, and 180 [ Time Frame: Change from Baseline to Day 3, 14, and 180 ]

Original Primary Outcome: Same as current

Current Secondary Outcome:

• Change in Pulmonary Function Test at Day 3, 14, and 180 [ Time Frame: Change from Day 3, 14, and 180 ]
  Pulmonary function testing is used routinely in clinical medicine and has no inherent complications. Subjects who may not be able to complete conventional PFTs may undergo impulse oscillometry for assessment of lung function.
• Change in Forced expiratory tests at Screening, Baseline, Day 14, and 180 [ Time Frame: Change from Screening, Baseline, Day 14, and Day 180 ]
  Forced expiratory tests measure the maximal airflow and volume of gas that can be exhaled with the subject breathing or coughing forcefully. A nose clip, or cuffed tracheostomy with cuff inflated is used to prevent leakage. The subject deeply inhales and then exhales as forcefully and deeply as possible. Measurements will be obtained with the subject sitting upright and then repeated with the subject in the supine position, if tolerated. A minimum of three trials will be obtained in each position with <5% variability [13]. The highest value obtained in each position will be reported.
• Change in Maximal Inspiratory Pressure (MIP) at Screening, Baseline, Day 14, and 180 [ Time Frame: Change from Screening, Baseline, Day 14, and Day 180 ]
  MIP will be measured with a manometer connected to the airway opening of the subject, which occludes the airway and prevents airflow. A nose clip will be used to prevent leakage and the subject is instructed to suck air from the tube with as much force as possible. Measurements will be obtained with the subject sitting upright. Transdiaphragmatic pressure (Pdi) may be calculated with esophageal and gastric manometry during MIP. The measurement will be taken three times and the best value will be reported.
• Change in Resting Breathing Pattern at Screening, Baseline, Day 3, Day 14, and Day 180 [ Time Frame: Change from Screening, Baseline, Day 3, Day 14, and Day 180 ]
  Resting ventilatory flow and timing will be recorded with a pneumotachograph and pressure transducer connected to the airway opening. If a patient routinely uses MV throughout the day, the sensing equipment can be placed in series to the breathing tubes. Breathing pattern will be measured for a minimum of ten minutes.
• Change in Respiratory Muscle Endurance Test at Screening, Baseline, and Day 180 [ Time Frame: Change from Screening, Baseline, and Day 180 ]
  This test will begin after subjects rest for a minimum of one hour. Subjects will be tested in the seated position while breathing through a mouthpiece with nose clip. When a steady state breathing pattern has been reached (noted by stable tidal volumes for at least 30 seconds), subjects will be instructed how to maintain the breathing rate and volume, with the use of visual feedback on a computer. A threshold inspiratory load equivalent to 35% of the maximal inspiratory pressure will be placed on the inspiratory port of the mouthpiece. Subjects will be instructed to maintain the established breathing pattern during loaded breathing. The test will end when the subject cannot open the threshold valve for 3 consecutive breaths, or when the subject can no longer subjectively tolerate the test and must remove the mouthpiece. Loaded breathing typically lasts between 2-10 minutes.
• Change in Electromyogram (EMG) at Baseline, Day 3, Day 14, and Day 180 [ Time Frame: Change from Baseline, Day 3, Day 14, and Day 180 ]
  This activity reflects the activity of the diaphragm and phrenic nerve. The wires that are implanted for diaphragm pacemaker will be connected to a computer and recording equipment to monitor the activity of the diaphragm muscle during breathing.complete at least 30-minute bouts of paced SB, then the focus of breathing trials will be reduced pressure support mechanical ventilation.
• Change in Severe Respiratory Insufficiency Questionnaire at Screening, Baseline, Day 90, and Day 180 [ Time Frame: Change from Screening, baseline, Day 90 and Day 180 ]
  This questionnaire was developed for use in subjects with respiratory failure from various etiologies who utilize mechanical ventilation. It is a self administered test that will require approximately 20 minutes to complete.

Original Secondary Outcome: Same as current

Information By: University of Florida

Dates:
Date Received: January 21, 2015
Date Started: May 2013
Date Completion: February 2019
Last Updated: November 15, 2016
Last Verified: November 2016