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

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

We hypothesize that the nocturnal use of continuous positive airway pressure in adults and children with asthma will decrease airway reactivity.

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.

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:

1. Cyanotic congenital heart disease.
2. History of acute respiratory symptoms for 3 weeks prior to testing.
3. Inability to perform pulmonary function testing adequately.
4. Escalation in asthma medication at time of recruitment.
5. SaO2 <93% while awake and breathing room air
6. Baseline FEV1 <75% predicted

Exclusions for adults 18-60 include:

1. Gastro-Esophageal Reflux requiring Medical management.
2. Chronic Obstructive Pulmonary Disease.
3. Use of Supplemental Oxygen.
4. Ischemic Heart Disease or Hypertension requiring treatment with medications other than diuretics.
5. Use of systemic corticosteroid therapy during the past 6 months.
6. Acute Respiratory Illness in the previous 8 weeks.

Exclusions/Inclusion criteria for adults with asthma include:

1. Juniper Score <1.5
2. Baseline FEV1 > or equal to 70%
3. Non-smoking for 6 months
4. Less than 10 pack year smoking history
5. No change in asthma medications for the last 2 months
6. Negative pregnancy test
7. Subject cannot have sleep apnea