Sensory-Mechanical Responses to Eucapneic Voluntary Hyperventilation and Hypertonic Saline

• Status: Not yet recruiting
• Trial end date: 2022-12-31
• Target enrollment: 0
• Participant gender: All

Summary

The objectives of this study are to determine the sensory-mechanical responses to Eucapneic Voluntary Hyperventilation (EVH) and Hypertonic Saline (HS) in individuals with cough variant asthma (CVA) and methacholine-induced cough with normal airway sensitivity (COUGH) and compare these responses to a control group of healthy individuals without asthma or chronic cough.

We hypothesize:

1. EVH and HS cause dyspnea, cough, small airway obstruction with resultant dynamic hyperinflation, gas trapping and autoPEEP in individuals with CVA and COUGH, but not healthy controls.

2. The sensory-mechanical responses to both hyperosmolar challenges (EVH and HS) are comparable within groups (CVA, COUGH and healthy controls).

• Phase: Phase 4
• Accepts Healthy Volunteers?: Accepts Healthy Volunteers

Details

• Lead Sponsor: Dr. Diane Lougheed; Queen's University
• Treatments: Methacholine Chloride

Criteria

Inclusion Criteria:

• Individuals aged 18-65 years of age with CVA and individuals with methacholine-induced cough but normal airway sensitivity. The following definitions will be used:

1. CVA: chronic cough (≥8 weeks) is the sole or predominant symptom and positive methacholine challenge (PC20 ≤ 16 mg/mL) and history of cough responding to specific asthma treatment (such as inhaled steroid or 1 week trial of bronchodilator);

2. Methacholine-induced cough but normal airway sensitivity: chronic cough (≥8 weeks) is the sole or predominant symptom and negative methacholine challenges (PC20 > 16 mg/mL).

• Individuals aged 18-65 years of age with no history of asthma or chronic cough.

Exclusion Criteria:

• an exacerbation necessitating a change in medication, emergency department visit or hospitalizations within the previous 4 weeks

• inability to perform acceptable spirometry

• medical contraindications to methacholine challenge testing

• smoking history in excess of 10 pack years Note: Previous treatment with inhaled or systemic corticosteroids is not an exclusion criterion; medication use will be recorded and examined in the analysis.