Assessment Of The Effects Of Short and Long Term Use Of CPAP

Study Overview
=================
Brief Summary
-----------------
We hypothesize that the nocturnal use of continuous positive airway pressure in adults and children with asthma will decrease airway reactivity.

Detailed Description
-----------------
Deep inspirations have been shown to decrease the sensitivity of airways to narrowing (airway reactivity) after inhalation of agents that induce constriction of the bronchi in healthy adults. This response is absent in adult asthmatics; however, there is data demonstrating that use of continuous positive airway pressure (CPAP) for short periods of time may decrease airway reactivity in adult asthmatics. This suggests that although deep inspirations may not result in decreased airway reactivity, sustained lung inflation may lead to changes in asthmatic airway smooth muscle structure that lead to a decrease in airway reactivity. The purpose of our study is to determine whether short and long term use of CPAP in children and adults leads to decreased airway reactivity. If airway reactivity is decreased with CPAP, this may provide a novel therapeutic strategy for patients with asthma.

Official Title
-----------------
Assessment of the Effects of Short and Long Term Use of Continuous Positive Airway Pressure on Airway Reactivity in Children and Adults With and Without Asthma

Conditions
-----------------
Asthma

Intervention / Treatment
-----------------
* Device: CPAP-Continuous Positive Airway Pressure
* Device: SHAM


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Inclusion criteria for children 8-18 Children 8-18 years of age scheduled to start CPAP for obstructive sleep apnea. Subjects can have clinically stable asthma, with no plans by their physician to change asthma therapy over the next month Inclusion criteria adults 18-60 Adults 18-60 years of age, seen in adult Pulmonary Clinic for sleep related problems who may require treatment with nocturnal continuous positive pressure (CPAP), which will be determined by polysomnography(PSG) will be approached to participate in the study. Exclusion Criteria: Exclusions for Children category age 8-18 include: Cyanotic congenital heart disease. History of acute respiratory symptoms for 3 weeks prior to testing. Inability to perform pulmonary function testing adequately. Escalation in asthma medication at time of recruitment. SaO2 <93% while awake and breathing room air Baseline FEV1 <75% predicted Exclusions for adults 18-60 include: Gastro-Esophageal Reflux requiring Medical management. Chronic Obstructive Pulmonary Disease. Use of Supplemental Oxygen. Ischemic Heart Disease or Hypertension requiring treatment with medications other than diuretics. Use of systemic corticosteroid therapy during the past 6 months. Acute Respiratory Illness in the previous 8 weeks. Exclusions/Inclusion criteria for adults with asthma include: Juniper Score <1.5 Baseline FEV1 > or equal to 70% Non-smoking for 6 months Less than 10 pack year smoking history No change in asthma medications for the last 2 months Negative pregnancy test Subject cannot have sleep apnea

Ages Eligible for Study
-----------------
Minimum Age: 8 Years
Maximum Age: 60 Years

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

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

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

Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: CPAP<br>Subjects will use CPAP of 8-12 during days 2 through 6 of the study. | Device: CPAP-Continuous Positive Airway Pressure<br>* Cpap will be worn at night by subjects 6 to 7 days duration.<br>|
| Sham Comparator: SHAM<br>Subjects will use sham CPAP of 0-2 during days 2 through 6 of the study. | Device: SHAM<br>* SHAM will be worn at night by subjects 6 to 7 days duration.<br>|

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

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Provocative Concentration of Methacholine Causing a 20% Fall in Forced Expiratory Volume in 1 Second (FEV1) | Methacholine is an inhaled medication used to assess asthma and reactive airways. It was given at increasing concentrations (beginning with 0.0625 mg/ml and ending with 16.0 mg/ml). Each dose was followed by a lung measurement until a change of FEV1 of 20% occurs or until a maximum dose was reached, whichever came first. | 7 to 10 nights after cpap is started. | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
asthma, sleep apnea