AsthmaNCT02083029
Vagal Nerve Stimulation Assessed by the Diving Reflex: An Investigation Into Mechanisms of Asthma Death
A study testing Simulated dive reflex in people with Asthma and Syncope, run by Hull University Teaching Hospitals NHS Trust at 1 site in United Kingdom.
Trial summary
The investigators' hypothesis is that dysregulation of autonomic function, as revealed during a simulated dive reflex, may result in an attenuation of the heart rate response to a greater degree in asthmatics who collapse during exacerbations of asthma than that seen in healthy individuals and in asthmatics without a… Read more about this study
- Who is it for?
- Ages 18 to 85 yearsHealthy volunteers can take part
- What is being tested?
- Simulated dive reflex
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 24 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- Jan 2013to Jan 2014
- 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 85 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Syncopal Asthmatics: Asthmatic patients with a history of syncope during asthma exacerbations
- Normal Asthmatics: Asthmatic patients on BTS Step 3 treatment (LABA/ICS) with no history of syncope during exacerbations
- Normal volunteers: no history of airways disease or syncope
Who cannot join
- • Subjects who are pregnant, or have pacemakers in situ are excluded from this study.
- Subjects with significant cardiovascular disease are excluded from this study.
- Those who are non-English speakers and special groups (i.e. mentally ill, children under 16 years of age, and those suffering from dementia) will be excluded.
- No test will be performed on any subject during an acute worsening of asthma or upper airway infection. If the subject has had an upper airway infection in the last three weeks. Another appointment should be made unless the subject is unwilling to come back, in which case testing should continue. The number of days elapsed since the end of the airway infection should be recorded.
- If the subject smokes: citric acid or capsaicin challenges must be performed at least one hour after the last cigarette has been smoked.
- Subjects taking beta-blockers and calcium antagonists will be excluded from this study. No beta agonists should be taken within 6 hours of starting this study.
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- If the subject has taken any over the counter (OTC) cough mixture within the last twelve hours: If the subject is willing to come back another time for challenge testing, another appointment should be made. If the subject is unwilling to return another time, testing should proceed and the medication used recorded.
- If the subject has had any food or drink products containing caffeine or menthol within the last hour. If the subject is unwilling to wait for 1 hour before starting the test, the subject should return another time. If the subject is unwilling to return another time, testing should proceed and the medication used recorded.
- If the participant is currently involved in research, or within 3 months of participation in any type of research, they will be excluded from this study.
Trial locations and contacts
1 site in 1 country.
United Kingdom1 site
Hull Clinical Trials Unit, Respiratory academic department
Cottingham, Yorkshire, HU16 5JQ
About this study
The investigators' hypothesis is that dysregulation of autonomic function, as revealed during a simulated dive reflex, may result in an attenuation of the heart rate response to a greater degree in asthmatics who collapse during exacerbations of asthma than that seen in healthy individuals and in asthmatics without a history of syncope. The investigators will test this by assessing autonomic function through a dive reflex protocol.
Read the detailed description
Tests of autonomic function are notoriously difficult to evaluate. Here the investigators required a well validated test of the dynamic cardiovascular response to an abrupt stimulus and considered the diving reflex the most reliable and practical. In man, the diving reflex acts as a vestigial reflex aimed at conserving oxygen storage during apnoeic facial immersion. Facial immersion activates a vagally-induced bradycardia and a sympathetically activated alpha-adrenergic peripheral vasoconstriction and hypertension. There are two triggers of the diving reflex, facial immersion in water and breath hold, both of which can impact on heart rate attenuation. Facial immersion can be further delineated into exposure to cold, wetness and pressure.
- Being tested
- Simulated dive reflex
- Keywords
- Asthma, Death, Mechanism, Syncope, Dive reflex
- Medical subject headings
- Asthma, Syncope, Death
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Simulated dive reflexProcedure or surgery
All subjects undergo simulated dive reflex, with 30s facial immersion and continuous HR and BP monitoring with Nexfin over a period of 6 minutes.
| Study group | Role | What they receive |
|---|---|---|
| Syncopal Asthmatic | Experimental | All subject undergo simulated dive reflex, with 30s facial immersion and continuous HR and BP monitoring with Nexfin over a period of 6 minutes. Receives: Procedure: Simulated dive reflex |
| Non Syncopal Asthmatic | Experimental | All subject undergo simulated dive reflex, with 30s facial immersion and continuous HR and BP monitoring with Nexfin over a period of 6 minutes. Receives: Procedure: Simulated dive reflex |
| Normal Volunteers | Experimental | All subject undergo simulated dive reflex, with 30s facial immersion and continuous HR and BP monitoring with Nexfin over a period of 6 minutes. Receives: Procedure: Simulated dive reflex |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in heart rate from baseline
Nexfin and ECG monitoring continuously measuring subject heart rate during dive protocol, over a period of 6 minutes. Beat to beat data is converted into mean HR per 10-second epoch and compared to a baseline value for each subject.
Measured: 2 minutes prior to facial immersion in water and in 10 second epochs continuously until 3 minutes after facial immersion
Secondary outcomes (1)
Change in blood pressure from baseline
Nexfin monitoring continuously measuring subject blood pressure (systolic, diastolic and mean arterial pressure) during dive protocol, over a period of 6 minutes. Beat to beat data is converted into mean blood pressure values per 10-second epoch and compared to a baseline value for each subject
Measured: 2 minutes before facial immersion and continuously throughout dive protocol, over a period of 6 minutes
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted11 Mar 2014 (estimated)
- Study startJan 2013
- Primary completionJan 2014
- Study completionJan 2014
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for AsthmaStudies 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
- Basic science
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 24 participants (actual)
Sponsor and investigators
- Lead sponsor
- Hull University Teaching Hospitals NHS Trust
- Sponsor type
- Other government
- Responsible party
- Principal investigator, Prof A H Morice, Hull University Teaching Hospitals NHS Trust
- Investigators
- Alyn Morice, MD, Principal investigator, Head Cardiorespiratory Studies Hull York Medical School University of Hull Castle Hill Hospital Cottingham
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02083029
- Sponsor's protocol ID
- CTU070813
- Status last verified
- Mar 2014
- First submitted
- 3 Mar 2014
- Last updated
- 11 Mar 2014
- Results posted
- No
- Data monitoring committee
- No
Publications
Morjaria JB, Rowland T, Tailor P, Hyder S, Wright CE, Hart SP, Morice AH. Autonomic dysregulation: a mechanism of asthma death. Eur Respir J. 2014 Nov;44(5):1357-60. doi: 10.1183/09031936.00076414. Epub 2014 Aug 19. No abstract available.
PubMed 25142490
Study at a glance
From the registry record, last updated by the sponsor on 11 Mar 2014. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Vagal Nerve Stimulation Assessed by the Diving Reflex: An Investigation Into Mechanisms of Asthma Death
- ClinicalTrials.gov ID
- NCT02083029
- Acronym / sponsor ID
- CTU070813
- Keywords
- Asthma, Death, Mechanism, Syncope, Dive reflex
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 24 participants (actual)
- Lead sponsor
- Hull University Teaching Hospitals NHS TrustOther government
- Study start
- Jan 2013
- Primary completion
- Jan 2014 (actual)
- Study completion
- Jan 2014 (actual)
- First posted
- 11 Mar 2014 (estimated)
- 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.
The investigators' hypothesis is that dysregulation of autonomic function, as revealed during a simulated dive reflex, may result in an attenuation of the heart rate response to a greater degree in asthmatics who collapse during exacerbations of asthma than that seen in healthy individuals and in asthmatics without a history of syncope. The investigators will test this by assessing autonomic function through a dive reflex protocol.
Detailed description
Tests of autonomic function are notoriously difficult to evaluate. Here the investigators required a well validated test of the dynamic cardiovascular response to an abrupt stimulus and considered the diving reflex the most reliable and practical. In man, the diving reflex acts as a vestigial reflex aimed at conserving oxygen storage during apnoeic facial immersion. Facial immersion activates a vagally-induced bradycardia and a sympathetically activated alpha-adrenergic peripheral vasoconstriction and hypertension. There are two triggers of the diving reflex, facial immersion in water and breath hold, both of which can impact on heart rate attenuation. Facial immersion can be further delineated into exposure to cold, wetness and pressure.
Study design
- Primary purpose
- Basic science
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Syncopal Asthmatic | Experimental | Procedure: Simulated dive reflexAll subject undergo simulated dive reflex, with 30s facial immersion and continuous HR and BP monitoring with Nexfin over a period of 6 minutes. |
| Non Syncopal Asthmatic | Experimental | Procedure: Simulated dive reflexAll subject undergo simulated dive reflex, with 30s facial immersion and continuous HR and BP monitoring with Nexfin over a period of 6 minutes. |
| Normal Volunteers | Experimental | Procedure: Simulated dive reflexAll subject undergo simulated dive reflex, with 30s facial immersion and continuous HR and BP monitoring with Nexfin over a period of 6 minutes. |
Who may qualify
- Ages
- 18 to 85 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Syncopal Asthmatics: Asthmatic patients with a history of syncope during asthma exacerbations
- Normal Asthmatics: Asthmatic patients on BTS Step 3 treatment (LABA/ICS) with no history of syncope during exacerbations
- Normal volunteers: no history of airways disease or syncope
Key exclusion criteria (9 listed)
- • Subjects who are pregnant, or have pacemakers in situ are excluded from this study.
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 |
|---|---|---|
| Simulated dive reflexAll subjects undergo simulated dive reflex, with 30s facial immersion and continuous HR and BP monitoring with Nexfin over a period of 6 minutes. | Procedure or surgery | Non Syncopal Asthmatic, Normal Volunteers, Syncopal Asthmatic |
Primary outcome
Change in heart rate from baseline
Time frame: 2 minutes prior to facial immersion in water and in 10 second epochs continuously until 3 minutes after facial immersion
Nexfin and ECG monitoring continuously measuring subject heart rate during dive protocol, over a period of 6 minutes. Beat to beat data is converted into mean HR per 10-second epoch and compared to a baseline value for each subject.
1 secondary outcome
Change in blood pressure from baseline
Time frame: 2 minutes before facial immersion and continuously throughout dive protocol, over a period of 6 minutes
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 11 Mar 2014.
- Derived from this study: PubMed 25142490Morjaria JB, Rowland T, Tailor P, Hyder S, Wright CE, Hart SP, Morice AH. Autonomic dysregulation: a mechanism of asthma death. Eur Respir J. 2014 Nov;44(5):1357-60. doi: 10.1183/09031936.00076414. Epub 2014 Aug 19. No abstract available.
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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.
Alyn Morice, MD principal investigator
Head Cardiorespiratory Studies Hull York Medical School University of Hull Castle Hill Hospital Cottingham
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Simulated dive reflex in people with Asthma and Syncope, run by Hull University Teaching Hospitals NHS Trust at 1 site in United Kingdom.
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 9 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 11 Mar 2014. 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 United Kingdom. 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?
Change in heart rate from baseline (time frame: 2 minutes prior to facial immersion in water and in 10 second epochs continuously until 3 minutes after facial immersion). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT02083029, which also lists 1 linked publication.
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 11 Mar 2014.