Hyperventilation SyndromeNCT05189158
Ventilatory Responses to Hypercapnic and Hypoxic Conditions in Hyperventilants
A study testing Hypercapnic hyperoxic ventilatory response and Hypoxic eucapnic ventilatory response in people with Hyperventilation Syndrome and Hypercapnia, run by Centre Hospitalier Universitaire Saint Pierre at 1 site in Belgium.
Trial summary
For almost a century, many hypotheses have converged on the idea of altered chemosensitivity in patients suffering from hyperventilation syndrome (HVS). Given the evolution of current technical equipment and the ability to maximise true positives in HVS ( using the revised hyperventilation provocation test), it seems… Read more about this study
- Who is it for?
- Ages 18 to 99 yearsHealthy volunteers can take part
- Conditions the study is for
- Hyperventilation Syndrome, Hypercapnia, Hypoxia
- What is being tested?
- Hypercapnic hyperoxic ventilatory response and Hypoxic eucapnic ventilatory response
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 24 participants
- Where
- 1 siteBelgium
- Study dates
- 15 Oct 2021to 15 Oct 2021
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 99 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- A plethysmography within subject's predicted values
- A negative metacholine test (no documented allergy)
- A hyperventilation provocation test result that is consistent with the Nijmegen questionnaire score, confirming either group classification (HVS+ or HVS-)
Who cannot join
- Each of the following known or documented conditions: chronic bronchitis (COPD), emphysema, asthma, cardiac disorder, neurological disorder, gastrointestinal disorder, thyroid disorder or psychological/psychiatric disorder
- Suspicious cardio-pulmonary exercise testing (CPET) with cardiac or respiratory limitation
- Pregnant women or women in the process of becoming pregnant
- Persons with a diving practice (amateur or professional),
- High-level athletes,
- Active smokers and
- persons using morphine, and/or barbiturates, and/or anxiolytics and/or sleeping pills
Trial locations and contacts
1 site in 1 country.
About this study
For almost a century, many hypotheses have converged on the idea of altered chemosensitivity in patients suffering from hyperventilation syndrome (HVS).
Given the evolution of current technical equipment and the ability to maximise true positives in HVS ( using the revised hyperventilation provocation test), it seems reasonable to investigate central and peripheral chemosensitivities in HVS subjects.
Read the detailed description
In the inter-war period, many medical investigators who studied the hyperventilation syndrome (HVS) had already questioned the chemosensitivity to CO2 in HVS patients, without being able to explore it for all intents and purposes.
It was subsequently observed that although HVS is not systematically linked to manifest resting hypocapnia, it is nevertheless systematically correlated with significant variability and complexity of ventilation.
This is consistent with the observations of an increased plant gain in HVS, to be related to an increased loop gain (due to instability of controller gain feedback).
On the other hand, some authors already noted that, when capnia is chronically compromised in HVS, it can be greatly altered by small, transient and barely perceptible increases in VE: a 10% increase in VE could indeed halve PetCO2, while a sigh would be able to decrease PetCO2 by up to 15mmHg.
More recently, teh assumption was made that peripheral chemosensitivity may be impaired in HVS patients.
For all these considerations, it seems reasonable to investigate central and peripheral chemosensitivities in identified HVS subjects on the basis of an objective test, such as the induced hyperventilation test.
- Conditions
- Hyperventilation Syndrome, Hypercapnia, Hypoxia
- Being tested
- Hypercapnic hyperoxic ventilatory response, Hypoxic eucapnic ventilatory response
- Medical subject headings
- Hypercapnia, Hypoxia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Hypercapnic hyperoxic ventilatory responseDiagnostic test
The hypercapnic ventilatory response (HCVR) described by Read in 1967 (Read's rebreathing method) is a clinical way to assess the central and peripheric sensitivity to CO2, using a small bag (4-6 l) to achieve prompt equilibrium between the apparatus compartments and the lungs.
By rebreathing a hyperoxic mixture with an initial composition of 70% O2, 7% CO2 and 23% N2, this equilibrium is assumed to be achieved after 15 seconds of rebreathing, when the relationship between VE and PetCO2 has become linear.
Hypoxic eucapnic ventilatory responseDiagnostic test
The hypoxic eucapnic ventilatory response (HOVR) is a clinical way to assess the peripheric chemosensitivity to O2, using a small bag (4-6 l) to rebreathe a gas mixture initially composed of 20% O2, 0% CO2 and Δ% N2. Eucapnia is achieved by the activation of a CO2 reabsorption cell during the course of the test.
| Study group | Role | What they receive |
|---|---|---|
| HVS- | Other | subjects with no complaint AND a Nijmegen questionnaire score of < 23/64 AND a negative hyperventilation provocation test (criteria revised in 2021) (HVS-) Receives: Diagnostic Test: Hypercapnic hyperoxic ventilatory response; Diagnostic Test: Hypoxic eucapnic ventilatory response |
| HVS+ | Other | subjects with complaints AND a Nijmegen questionnaire score of ≥23/64 AND a negative hyperventilation provocation test (criteria revised in 2021) (HVS+) Receives: Diagnostic Test: Hypercapnic hyperoxic ventilatory response; Diagnostic Test: Hypoxic eucapnic ventilatory response |
What is being measured
The primary outcome is the main question the study is designed to answer.
The slope of the ventilatory response to hypercapnia (HCVR)
Ventilation increase (litres/min) per unit increase in PetCO2 (mmHg) using Read's method
Measured: baseline - during the test
The slope of the ventilatory response to hypoxia (HOVR)
Ventilation increase (litres/min) per unit decrease in SpO2 (%) using Read's method
Measured: baseline - during the test
Ventilatory recruitment threshold (VRT) of the HCVR
From the average baseline ventilation and PetCO2, the VRT id the PetCO2 level at which the ventilatory response is activated
Measured: baseline - during the test
Ventilatory recruitment threshold (VRT) of the HOVR
From the average baseline ventilation and SpO2, the VRT is the level of SpO2 at which the ventilatory response is activated
Measured: baseline - during the test
Secondary outcomes (2)
Extrapolated apnoeic threshold of the HCVR
PetCO2 level above which apnoea (zero ventilation) is disrupted, obtained from the extrapolation of the HCVR at the X-axis intersection (when VE=0 l/min)
Measured: baseline - during the test
Dyspnea
Visual analogic scale (VAS) of dyspnea, from 0 (no dyspnea) to 10 (maximal dyspnea)
Measured: baseline, end of the test
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted12 Jan 2022
- Study start15 Oct 2021
- Primary completion15 Oct 2021
- Study completion15 Oct 2021
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Hyperventilation SyndromeStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Diagnosis
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 24 participants (actual)
Sponsor and investigators
- Lead sponsor
- Centre Hospitalier Universitaire Saint Pierre
- Sponsor type
- University, hospital or other
- Collaborators
- Université Libre de Bruxelles
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05189158
- Sponsor's protocol ID
- B076201836758 -2
- Status last verified
- Dec 2021
- First submitted
- 18 Oct 2021
- Last updated
- 12 Jan 2022
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 12 Jan 2022. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Ventilatory Responses to Hypercapnic and Hypoxic Conditions in Hyperventilants
- ClinicalTrials.gov ID
- NCT05189158
- Acronym / sponsor ID
- B076201836758 -2
- Conditions
- Hyperventilation Syndrome, Hypercapnia, Hypoxia
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 24 participants (actual)
- Lead sponsor
- Centre Hospitalier Universitaire Saint PierreUniversity, hospital or other
- Collaborators
- Université Libre de Bruxelles
- Study start
- 15 Oct 2021 (actual)
- Primary completion
- 15 Oct 2021 (actual)
- Study completion
- 15 Oct 2021 (actual)
- First posted
- 12 Jan 2022 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
For almost a century, many hypotheses have converged on the idea of altered chemosensitivity in patients suffering from hyperventilation syndrome (HVS).
Given the evolution of current technical equipment and the ability to maximise true positives in HVS ( using the revised hyperventilation provocation test), it seems reasonable to investigate central and peripheral chemosensitivities in HVS subjects.
Detailed description
In the inter-war period, many medical investigators who studied the hyperventilation syndrome (HVS) had already questioned the chemosensitivity to CO2 in HVS patients, without being able to explore it for all intents and purposes.
It was subsequently observed that although HVS is not systematically linked to manifest resting hypocapnia, it is nevertheless systematically correlated with significant variability and complexity of ventilation.
This is consistent with the observations of an increased plant gain in HVS, to be related to an increased loop gain (due to instability of controller gain feedback).
On the other hand, some authors already noted that, when capnia is chronically compromised in HVS, it can be greatly altered by small, transient and barely perceptible increases in VE: a 10% increase in VE could indeed halve PetCO2, while a sigh would be able to decrease PetCO2 by up to 15mmHg.
More recently, teh assumption was made that peripheral chemosensitivity may be impaired in HVS patients.
For all these considerations, it seems reasonable to investigate central and peripheral chemosensitivities in identified HVS subjects on the basis of an objective test, such as the induced hyperventilation test.
Study design
- Primary purpose
- Diagnosis
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| HVS- | Other | Diagnostic Test: Hypercapnic hyperoxic ventilatory response, Diagnostic Test: Hypoxic eucapnic ventilatory responsesubjects with no complaint AND a Nijmegen questionnaire score of < 23/64 AND a negative hyperventilation provocation test (criteria revised in 2021) (HVS-) |
| HVS+ | Other | Diagnostic Test: Hypercapnic hyperoxic ventilatory response, Diagnostic Test: Hypoxic eucapnic ventilatory responsesubjects with complaints AND a Nijmegen questionnaire score of ≥23/64 AND a negative hyperventilation provocation test (criteria revised in 2021) (HVS+) |
Who may qualify
- Ages
- 18 to 99 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- A plethysmography within subject's predicted values
- A negative metacholine test (no documented allergy)
- A hyperventilation provocation test result that is consistent with the Nijmegen questionnaire score, confirming either group classification (HVS+ or HVS-)
Key exclusion criteria (7 listed)
- Each of the following known or documented conditions: chronic bronchitis (COPD), emphysema, asthma, cardiac disorder, neurological disorder, gastrointestinal disorder, thyroid disorder or psychological/psychiatric disorder
- Suspicious cardio-pulmonary exercise testing (CPET) with cardiac or respiratory limitation
- Pregnant women or women in the process of becoming pregnant
- Persons with a diving practice (amateur or professional),
- High-level athletes,
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Hypercapnic hyperoxic ventilatory responseThe hypercapnic ventilatory response (HCVR) described by Read in 1967 (Read's rebreathing method) is a clinical way to assess the central and peripheric sensitivity to CO2, using a small bag (4-6 l) to achieve prompt equilibrium between the apparatus compartments and the lungs. By rebreathing a hyperoxic mixture with an initial composition of 70% O2, 7% CO2 and 23% N2, this equilibrium is assumed to be achieved after 15 seconds of rebreathing, when the relationship between VE and PetCO2 has become linear. | Diagnostic test | HVS+, HVS- |
| Hypoxic eucapnic ventilatory responseThe hypoxic eucapnic ventilatory response (HOVR) is a clinical way to assess the peripheric chemosensitivity to O2, using a small bag (4-6 l) to rebreathe a gas mixture initially composed of 20% O2, 0% CO2 and Δ% N2. Eucapnia is achieved by the activation of a CO2 reabsorption cell during the course of the test. | Diagnostic test | HVS+, HVS- |
Primary outcome
The slope of the ventilatory response to hypercapnia (HCVR)
Time frame: baseline - during the test
Ventilation increase (litres/min) per unit increase in PetCO2 (mmHg) using Read's method
The slope of the ventilatory response to hypoxia (HOVR)
Time frame: baseline - during the test
Ventilation increase (litres/min) per unit decrease in SpO2 (%) using Read's method
Ventilatory recruitment threshold (VRT) of the HCVR
Time frame: baseline - during the test
From the average baseline ventilation and PetCO2, the VRT id the PetCO2 level at which the ventilatory response is activated
Ventilatory recruitment threshold (VRT) of the HOVR
Time frame: baseline - during the test
From the average baseline ventilation and SpO2, the VRT is the level of SpO2 at which the ventilatory response is activated
2 secondary outcomes
Extrapolated apnoeic threshold of the HCVR
Time frame: baseline - during the test
Dyspnea
Time frame: baseline, end of the test
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 12 Jan 2022.
- Individual participant dataSharing planned: No
Related trials for Hyperventilation Syndrome
Not yet recruitingObservational study
Symptomatic Hyperventilation in Individuals Living With Stroke
Stroke, Hyperventilation Syndrome
RecruitingObservational study
Dysfunctional Breathing in Post COVID-19 Condition.
Post COVID-19 Condition (PCC), Dysfunctional Breathing
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Hypercapnic hyperoxic ventilatory response and Hypoxic eucapnic ventilatory response in people with Hyperventilation Syndrome and Hypercapnia, run by Centre Hospitalier Universitaire Saint Pierre at 1 site in Belgium.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 12 Jan 2022. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Belgium. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
The slope of the ventilatory response to hypercapnia (HCVR) (time frame: baseline - during the test). The study lists 4 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 12 Jan 2022; AzTrials last refreshed its copy on 31 Oct 2026.