An observational study in Hyperventilation, Larynx and Asthma, sponsored by Monash Medical Centre. Completed at 1 site in Australia. Open to participants aged 18 Years to 65 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-05-08.
Sponsored by Monash Medical Centre · Observational
The Investigators aim to:
Hypotheses:
Specific aims:
Project 1 - 'Acute' hyperventilation in normal subjects and asthmatics.
Aim 1.1: To measure PVCM by endoscopy in response to a single period of hyperventilation in normal subjects and asthmatics.
Aim 1.2: To relate PVCM to symptoms in both groups. Aim 1.3: To relate PVCM to bronchial and ET-AHR before and after acute hyperventilation.
Project 2 - 'Chronic' hyperventilation and the effect on vocal cord movements in asthmatic subjects.
Aim 2.1: To measure PVCM by endoscopy in response to multiple periods of hyperventilation (twice daily over 2 weeks) in normal subjects and asthmatics.
Aim2.2: To relate PVCM to symptoms in both groups. Aim 2.1: To relate PVCM to bronchial and ET-AHR before and after chronic hyperventilation.
Project 3 (a) - Effects of anticholinergic medication on PVCM.
Aim 3.1: Determine the effect of anti-cholinergic inhaled medications on PVCM induced by hyperventilation.
Project 3 (b) - PVCM during exercise and the effects of anticholinergic medication on PVCM If no PVCM is detected in project 1 and 2, as an alternative strategy the Investigators will examine PVCM that has been shown to occur in severe asthma in response to exercise. The effect of anti-cholinergic inhaled medications will then be examined in this model.
Significance:
Dysfunctional breathing may be a mechanism whereby symptomatic PVCM develops in asthma but not in health. The proposed studies will enhance the Investigators understanding of the role played by dysfunctional breathing in the pathogenesis of this distressing condition and may provide a rationale for targeted therapies.
43 studies on the registry are indexed under Hyperventilation; 6 are open to participants now.
This study's enrollment of 24 is below the median of 54 across 11 observational studies indexed under Hyperventilation.
Browse Hyperventilation studies →Monash Medical Centre is the lead sponsor of 5 studies on the registry; 1 is open to participants now.
Counted across the registry records on this site, refreshed daily.
Healthy controls: We shall recruit 8 normal healthy subjects (Group 1). Inclusion criteria for healthy controls include age >18 to 65 years old, non-smokers and no history of chronic respiratory symptoms. Asthmatics: We shall recruit a total of 16 patients with asthma - 8 patients with mild asthma (Group 2) and 8 patients with severe asthma (Group 3). Mild asthma will be defined as patients with forced expiratory volume in 1 second (FEV1) >80% predicted. Severe asthma will be defined as patients with FEV1 50-60% predicted. Asthmatics will also have a forced expiratory ratio (FER) less than the lower limit of normal, indicating obstruction.
Inclusion Criteria for Healthy Controls:
Inclusion criteria for healthy controls include:
Exclusion Criteria for Healthy Controls:
Exclusion criteria for controls include:
Inclusion Criterial for Asthmatics:
The Investigators shall recruit a total of 16 patients with asthma - 8 patients with mild asthma (Group 2) and 8 patients with severe asthma (Group 3).
Inclusion criteria will include:
Exclusion Criteria for Asthmatics:
- Exclusion criteria will include:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Chronic obstructive pulmonary disease: long-term lung disease that makes it hard to breathe out, including emphysema and chronic bronchitis.
From a breathing test (spirometry): how much air you can blow out in the first second. Often given as a percentage of what is expected for your age, height and sex.
COPD
Chronic obstructive pulmonary disease: long-term lung disease that makes it hard to breathe out, including emphysema and chronic bronchitis.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
FEV1
From a breathing test (spirometry): how much air you can blow out in the first second. Often given as a percentage of what is expected for your age, height and sex.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
1. Acute Hyperventilation and effects on vocal cord movement. 2. Chronic Hyperventilation and effects on vocal cord movement. 3. Effects of anticholinergic medication on paradoxical vocal cord movement.
Other: Acute Hyperventilation · Other: Chronic hyperventilation · Drug: Effects of anticholinergic medication
1. Acute Hyperventilation and effects on vocal cord movement. 2. Chronic Hyperventilation and effects on vocal cord movement. 3. Effects of anticholinergic medication on paradoxical vocal cord movement.
Other: Acute Hyperventilation · Other: Chronic hyperventilation · Drug: Effects of anticholinergic medication
1. Acute Hyperventilation and effects on vocal cord movement. 2. Chronic Hyperventilation and effects on vocal cord movement. 3. Effects of anticholinergic medication on paradoxical vocal cord movement.
Other: Acute Hyperventilation · Other: Chronic hyperventilation · Drug: Effects of anticholinergic medication
Laryngoscopy to assess vocal cord function during acute hyperventilation in normal subjects and asthmatics.
Also known as: Acute Hyperventilation in normal subjects and asthmatics
Laryngoscopy to assess vocal cord function during acute hyperventilation in normal subjects and asthmatics.
Laryngoscopy to assess vocal cord function after administration of anticholinergic medication.
Also known as: Effects of anticholinergic medication on vocal cord movement
Vocal cord aperture measured using continuous laryngoscopy after hyperventilation in normal subjects and asthmatics
For each experiment, the subject will sit in a comfortable armchair and breathe though a rubber mouthpiece and turbine pneumotachometer (Oxycon Delta, Jaeger, Wurzburg, Germany). The airflow and volume signals and that from the carbon dioxide (CO2) analyser will be displayed on a monitor and recorded. Subjects will breath through the spirometer during endoscopy to record respiratory phase for later correlation with laryngeal recording. Laryngeal movement analysis - Image stills will be taken from the continuous laryngoscopy recording, at end inspiration and end expiration. Measurement of narrowing of the laryngeal structures in relative terms during one breathing cycle, which is independent of the distance between the laryngoscope and the glottis.
Time frame: 6 years
Lung function indices after hyperventilation in normal and asthmatic patients.
Spirometry indices after hyperventilation. Baseline spirometry will be recorded. Forced vital capacity (FVC) and forced expiratory volume (FEV1) will be calculated. Both are measurements of volume of air expired after maximum inspiration, measured in litres.
Time frame: 6 years
Role of the extra-thoracic airway hyper-responsiveness measured using bronchial provocation test to identify asthma like symptoms.
Role of the extra-thoracic airway hyper-responsiveness to asthma like symptoms using Mannitol bronchial provocation testing
Time frame: 6 years
Vocal cord changes after anti-cholinergic inhalers and/or exercise.
Vocal cord changes after anti-cholinergic inhalers and/or exercise. Subjects will inhale 4 puffs of ipratropium bromide (20 mcg/actuation inhalation) or placebo using normal tidal breathing. Subjects will then be exercised on an ergometer (Cateye Ergociser) at 75% to 85% of their predicted maximal heart rate (maximal heart rate equals 220 minus subjects age) for 8 minutes while breathing dry air at 10oC. Laryngoscopy will be conducted in situ as detailed in Project 1. Exercise will be discontinued and PVCM will be assessed. Final lung function testing will be performed to assess the degree of respiratory obstruction produced.
Time frame: 6 years
Plan to share: Yes — Though publication
Supporting information: Study protocol, Statistical analysis plan, Informed consent form, Clinical study report
Time frame: 10 years
Access criteria: All
No publications or documents are linked to this record.
Ran from Jun 2018 to primary completion in Feb 2025, 80 months.
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This study is completed, as verified in Oct 2024. You cannot join it, but the record below documents what was studied.
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Monash Medical Centre