Physiological Study to Compare Noninvasive Ventilation (NIV) Masks

Study Overview
=================
Brief Summary
-----------------
Noninvasive ventilation (NIV) is an established therapy that delivers positive pressure to the upper airways to provide respiratory support. Two types of NIV can be delivered; continuous positive airway pressure (CPAP) at one continuous pressure and bilevel NIV at two pressures for inhalation and exhalation. This investigation is designed to physiologically evaluate the performance of a NIV mask, Mask A, compared to a standard NIV mask, Mask B on CPAP therapy. People with sleep disordered breathing who have chronic hypercapnia, and are already receiving nocturnal CPAP will be recruited. They will receive one night's CPAP therapy on Mask A and 1 night on Mask B in random order. Physiological parameters will be recorded. Parameters will be recorded during three baselines at the beginning of each evening and throughout the night when participants are asleep. The three baselines are: participant awake with normal breathing (not on CPAP), participant awake and on CPAP, and participant asleep on CPAP in REM-sleep (rapid eye movement sleep).

Official Title
-----------------
Physiological Study to Compare Noninvasive Ventilation (NIV) Masks

Conditions
-----------------
Sleep-disordered Breathing, Hypercapnia

Intervention / Treatment
-----------------
* Device: CPAP with Mask A
* Device: CPAP with Mask B


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Already using overnight CPAP and tolerating the therapy well (over 4 hours use/night) Hypercapnia: venous bicarbonate of 30 milliequivalents of solute per liter (Eq/L) or more, OR transcutaneous carbon dioxide (TcCO2) of 50 millimeters of mercury (mmHg) of more. Provide written informed consent Already use a full (oronasal) face mask for CPAP Willing to have a venous blood sample taken during the pre-screening visit. Exclusion Criteria: Presence of sleep apnea on CPAP: Subjects excluded if they have an apnea-hypopnea index (AHI) of more than 20, or If the AHI has not already decreased by 50 percent or more from pre-CPAP to with CPAP. Forced expiratory volume in 1 second (FEV1) of less than 40 percent of predicted. Forced expiratory volume in 1 second divided by forced vital capacity (FEV1/FVC) less than fifty percent of predicted, at the screening visit. Have poorly controlled asthma or changing asthma symptoms. Nasal obstruction Do not fit Mask A or Mask B Agitation or psychological illness

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 100 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Mask A<br>Overnight CPAP using the participant's usual pressure settings and using Mask A. One night only. | Device: CPAP with Mask A<br>* CPAP mask<br>|
| Active Comparator: Mask B<br>Overnight CPAP using the participant's usual pressure settings and using Mask B. One night only. | Device: CPAP with Mask B<br>* CPAP mask<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Transcutaneous carbon dioxide | The change in transcutaneous carbon dioxide from the 3 different baselines to the transcutaneous carbon dioxide during non-REM sleep on CPAP on the same study night. Three different values will be determined for each mask. | 1 day (From baseline to the end of the study night) |