Health TrialsbyHealthPanel

Sensory-Mechanical Responses to Eucapneic Voluntary Hyperventilation and Mannitol

ConditionsAsthmaCoughCough Variant Asthma
Trial statusRecruiting
Trial phasePhase 4
Trial typeInterventional
Biological sexAll
Age18-65
SponsorDr. Diane Lougheed

About this trial

The objectives of this study are to determine the sensory-mechanical responses to Eucapneic Voluntary Hyperventilation (EVH) and Mannitol 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 Mannitol 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 Mannitol) are comparable within groups (CVA, COUGH and healthy controls).

Eligibility criteria

This trial accepts healthy volunteers

Qualifiers

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);

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.

Disqualifiers

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.

Trial design

Design model

Crossover

Treatments tested in this trial

  • Methacholine (MCh) Challenge Testing

    Drug

    Visit 1: Informed consent, Baseline screening and pulmonary function tests and Low-dose methacholine challenge testing using partial and full flow-volume loops.

  • Eucapneic Voluntary Hyperventilation (EVH)

    Diagnostic test

    Visit 2 or 3: Will be conducted in random order and subjects will perform one of the two challenge tests at either visit.

  • Mannitol Inhalation Kit

    Drug

    Visit 2 or 3: Will be conducted in random order and subjects will perform one of the two challenge tests at either visit.

Treatment groups

30 Participants
are divided into 3 treatment groups
Group A: Cough Variant AsthmaExperimental treatment 3 interventions
Group B: Methacholine-induced coughExperimental treatment 3 interventions
Group C: ControlExperimental treatment 3 interventions

Trial outcomes

Primary outcomes

1

Mid expiratory flows

The bronchodilating effect of a DI will be examined using responses to the challenge testing (Visit 2/3) in these subgroups by comparing the mid-expiratory flow difference between the partial (PEF) and full maximal flow-volume (MEF) loops at 40% above Residual Volume (RV) from the forced vital capacity (FVC) (PEF40 and MEF40 respectively) at provocative dose of 4.5% saline causing a 20% decline in FEV1 (PD20 (HS)) and provocative minute ventilation causing a 20% decline in FEV1 (PC20 (EVH)) with that recorded at baseline.

Time frame
Time frame of the methacholine challenge varies between individuals. At provocative dose/ventilation causing a 20% decline in FEV1 (PD20 and PC20 respectively). On average, these occur about 15-25 minutes into the challenge test

Secondary outcomes

1

Respiratory System Reactance (X5)

Single IOS will measure peripheral airway function using respiratory system reactance (X5) and peripheral resistance (R5-R20) and central resistance (R20) will be used as an index of airway narrowing.

Time frame
After dose administration; will occur 2-5 minutes after dose
2

Peripheral Resistance (R5-R20)

Single IOS will measure peripheral airway function using respiratory system reactance (X5) and peripheral resistance (R5-R20) and central resistance (R20) will be used as an index of airway narrowing.

Time frame
After dose administration; will occur 2-5 minutes after dose
3

Central Airway Resistance

Single IOS will measure peripheral airway function using respiratory system reactance (X5) and peripheral resistance (R5-R20) and central resistance (R20) will be used as an index of airway narrowing.

Time frame
After dose administration; will occur 2-5 minutes after dose
4

Forced Vital Capacity (FVC)

As an index of airway closure.

Time frame
After dose administration; will occur 2-5 minutes after dose

Other outcomes

Sponsors and contacts

Click on the lead sponsor to view all of their trials.

Dr. Diane Lougheed

Lead sponsor

Queen's University

Sponsor institution

Source ClinicalTrials.gov
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