Healthy Amateur DiversAPNECKNCT03210857
Effects of Voluntary Neck Extension on Cerebral Blood Flow, in Breath-hold Divers Ending an Apnoea of Two Minutes or More.
A study testing apnea performing in people with Healthy Amateur Divers, run by Nantes University Hospital at 1 site in France.
Trial summary
The aim of this study is to demonstrate the effect of the voluntary neck extension in the occurrence of an increase in the pulsatility index of the right internal carotid artery in the amateur diver, realizing an apnea of two minutes or more. Read more about this study
- Who is it for?
- Ages 18 to 51 years, men onlyHealthy volunteers can take part
- Conditions the study is for
- Healthy Amateur Divers
- What is being tested?
- apnea performing
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 15 participants
- Where
- 1 siteFrance
- Study dates
- 10 Jul 2017to 24 Jul 2017
- 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 51 years
- Men only
- Healthy volunteers accepted
- Adult
Who may be able to join
- Major (≥18 years), under the age of 51
- Male
- Can hold an apnea of 2 minutes or more
- Practicing for less than 2 years the apnea at the rate of at least 10 sessions of apnea in the year
- Not having a known cardiovascular history : any form of heart rhythm disorder, Ischemic heart disease, angina, arteriopathy, any valvular pathology, high blood pressure ...
- No known respiratory history (asthma, Chronic Obstructive Pulmonary Disease, bronchiectasis, pulmonary emphysema, pneumothorax, pleurisy, pulmonary infection, lobectomy ...)
- No neurological history of type: epilepsy, deficit syndrome, iterative loss of knowledge, recent head trauma with loss of consciousness
Who cannot join
- - Minors and persons over 51 years of age
- Person under curators or trusteeship
- Person with a history of cardiovascular, respiratory or epilepsy as cited by the French Federation of Study and Submarine Sports, which poses as a contra-indication to the practice of apnea: Cardiac insufficiency, Obstructive Cardiomyopathy, syncopal risk pathology (valvulopathies type aorting narrowing or mitral narrowing), paroxysmal tachycardia, non-paired auriculo ventricular block 2/3, stroke, uncontrolled hypertension after stress test, recent infarction, angina, pericarditis. Asthma stage 3, severe Chronic Obstructive Pulmonary Disease, bronchiectasis, pulmonary emphysema, pneumothorax, pleurisy, pulmonary infection, lobectomy ...) Epilepsy, deficit syndrome, iterative loss of knowledge, recent head trauma with loss of consciousness in difficulty, symptomatic cervical or lumbar disc herniation
- Patient with medical treatment affecting the cardiovascular or respiratory system (for example: ventolin, betablocker ...)
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Effect of Voluntary Neck Extension in the Occurrence of an Increase in the Pulsatility Index of Right Internal Carotid Artery in the Amateur Diver, Performing an Apnoea of Two Minutes or More: a Prospective, Monocentric, Open Interventional Study
The aim of this study is to demonstrate the effect of the voluntary neck extension in the occurrence of an increase in the pulsatility index of the right internal carotid artery in the amateur diver, realizing an apnea of two minutes or more.
Read the detailed description
In literature concerning apnoea, accidents have been described during neck extension.
Accidental drowning are frequent on the French coast every year and many of them concern apneists victims of apnoeic blackout.
Neck extension is thus suspected to possibly produce an apnoeic blackout at the end of the dive since 1965, when Sir Sciarli (diving medicine pioneer) suspected this hypothesis.
Physiologically, during a dive in apnea, the human cardiovascular system is subjected to a parasympathetic dominance, via the apnea reflex and the diving reflex. This parasympathetic dominant could be reinforced during a neck extension at the end of snorkeling during the ascent.
Hypothesis: the neck extension at the end of apnea contributes to increase the pulsatility index of the right internal carotid artery by vagal component and thus causes a decrease in cerebral blood flow and may lead to the initiation of syncope in the healthy amateur free diver or underwater fisherman.
- Conditions
- Healthy Amateur Divers
- Being tested
- apnea performing
- Keywords
- apnea, neck extension, syncope, diving blackout, right internal carotid arteria, pulsatility index, healthy trained apnoea divers, doppler ultrasonography
- Medical subject headings
- Apnea, Syncope
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
apnea performingOther
The included subjects will make an apnea of two minutes or more, sitting on a chair with cold strips on the face, initially with the head in neutral position. Then, when they feel the end of their apnea, they will have to raise their left hand to signal it to the Doppler manipulator, who will then realize the apnea reference measurement.
As soon as this is done, the subjects will be asked to perform an extension of the neck, so as to look at the ceiling. A final measurement will then be made in apnea, the head always in extension. Subjects then resume their breathing in this same position. A final measurement will then be made.
| Study group | Role | What they receive |
|---|---|---|
| apnea performing | Experimental | The included subjects will make an apnea of two minutes or more, sitting on a chair with cold strips on the face, initially with the head in neutral position. Then, when they feel the end of their apnea, they will have to raise their left hand to signal it to the Doppler manipulator, who will then realize the apnea reference measurement.
As soon as this is done, the subjects will be asked to perform an extension of the neck, so as to look at the ceiling. A final measurement will then be made in apnea, the head always in extension. Subjects then resume their breathing in this same position. A final measurement will then be made. Receives: Other: apnea performing |
What is being measured
The primary outcome is the main question the study is designed to answer.
Effect of the voluntary neck extension in the occurrence of an increase in the pulsatility index of the right internal carotid artery in the amateur diver, realizing an apnea of two minutes or more
To demonstrate the potential implication of cervical extension in the decrease of cerebral blood flow in amateur diver apnea by measuring the variation in the pulsatility index of the right internal carotid artery (RICAPI), by the intra-individual comparison of the RICAPI in amateur diver in rupture of apnea with neck extension (NE) versus the RICAPI of amateur diver in rupture of apnea without NE.
Measured: 2 minutes or more: at the breaking point of apnea.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted7 Jul 2017
- Study start10 Jul 2017
- Primary completion24 Jul 2017
- Study completion24 Jul 2017
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Healthy Amateur DiversStudies of the same condition, open and under way.
- More trials run by Nantes University HospitalThe sponsor's other registered studies.
- 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
- Not applicable
- Intervention model
- Single group
- Model description
- Subject will realize an apnea of 2 minutes or more, depending on his abilities, and some parameters will be measured.
- Masking
- None (open label)
- Enrolment
- 15 participants (actual)
Sponsor and investigators
- Lead sponsor
- Nantes University Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Antoine ANDRE, Doctor, Principal investigator, Nantes University Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03210857
- Sponsor's protocol ID
- RC17_0163
- Acronym
- APNECK
- Status last verified
- Aug 2017
- First submitted
- 5 Jul 2017
- Last updated
- 15 Aug 2017
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 15 Aug 2017. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effect of Voluntary Neck Extension in the Occurrence of an Increase in the Pulsatility Index of Right Internal Carotid Artery in the Amateur Diver, Performing an Apnoea of Two Minutes or More: a Prospective, Monocentric, Open Interventional Study
- ClinicalTrials.gov ID
- NCT03210857
- Acronym / sponsor ID
- APNECK / RC17_0163
- Conditions
- Healthy Amateur Divers
- Keywords
- apnea, neck extension, syncope, diving blackout, right internal carotid arteria, pulsatility index, healthy trained apnoea divers, doppler ultrasonography
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 15 participants (actual)
- Lead sponsor
- Nantes University HospitalUniversity, hospital or other
- Study start
- 10 Jul 2017 (actual)
- Primary completion
- 24 Jul 2017 (actual)
- Study completion
- 24 Jul 2017 (actual)
- First posted
- 7 Jul 2017 (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.
The aim of this study is to demonstrate the effect of the voluntary neck extension in the occurrence of an increase in the pulsatility index of the right internal carotid artery in the amateur diver, realizing an apnea of two minutes or more.
Detailed description
In literature concerning apnoea, accidents have been described during neck extension.
Accidental drowning are frequent on the French coast every year and many of them concern apneists victims of apnoeic blackout.
Neck extension is thus suspected to possibly produce an apnoeic blackout at the end of the dive since 1965, when Sir Sciarli (diving medicine pioneer) suspected this hypothesis.
Physiologically, during a dive in apnea, the human cardiovascular system is subjected to a parasympathetic dominance, via the apnea reflex and the diving reflex. This parasympathetic dominant could be reinforced during a neck extension at the end of snorkeling during the ascent.
Hypothesis: the neck extension at the end of apnea contributes to increase the pulsatility index of the right internal carotid artery by vagal component and thus causes a decrease in cerebral blood flow and may lead to the initiation of syncope in the healthy amateur free diver or underwater fisherman.
Study design
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
- Model description
- Subject will realize an apnea of 2 minutes or more, depending on his abilities, and some parameters will be measured.
| Arm | Type | Receives |
|---|---|---|
| apnea performing | Experimental | Other: apnea performingThe included subjects will make an apnea of two minutes or more, sitting on a chair with cold strips on the face, initially with the head in neutral position. Then, when they feel the end of their apnea, they will have to raise their left hand to signal it to the Doppler manipulator, who will then realize the apnea reference measurement. As soon as this is done, the subjects will be asked to perform an extension of the neck, so as to look at the ceiling. A final measurement will then be made in apnea, the head always in extension. Subjects then resume their breathing in this same position. A final measurement will then be made. |
Who may qualify
- Ages
- 18 to 51 years
- Sex
- Male only
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (7 listed)
- Major (≥18 years), under the age of 51
- Male
- Can hold an apnea of 2 minutes or more
- Practicing for less than 2 years the apnea at the rate of at least 10 sessions of apnea in the year
- Not having a known cardiovascular history : any form of heart rhythm disorder, Ischemic heart disease, angina, arteriopathy, any valvular pathology, high blood pressure ...
Key exclusion criteria (4 listed)
- - Minors and persons over 51 years of age
- Person under curators or trusteeship
- Person with a history of cardiovascular, respiratory or epilepsy as cited by the French Federation of Study and Submarine Sports, which poses as a contra-indication to the practice of apnea: Cardiac insufficiency, Obstructive Cardiomyopathy, syncopal risk pathology (valvulopathies type aorting narrowing or mitral narrowing), paroxysmal tachycardia, non-paired auriculo ventricular block 2/3, stroke, uncontrolled hypertension after stress test, recent infarction, angina, pericarditis. Asthma stage 3, severe Chronic Obstructive Pulmonary Disease, bronchiectasis, pulmonary emphysema, pneumothorax, pleurisy, pulmonary infection, lobectomy ...) Epilepsy, deficit syndrome, iterative loss of knowledge, recent head trauma with loss of consciousness in difficulty, symptomatic cervical or lumbar disc herniation
- Patient with medical treatment affecting the cardiovascular or respiratory system (for example: ventolin, betablocker ...)
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 |
|---|---|---|
| apnea performingThe included subjects will make an apnea of two minutes or more, sitting on a chair with cold strips on the face, initially with the head in neutral position. Then, when they feel the end of their apnea, they will have to raise their left hand to signal it to the Doppler manipulator, who will then realize the apnea reference measurement. As soon as this is done, the subjects will be asked to perform an extension of the neck, so as to look at the ceiling. A final measurement will then be made in apnea, the head always in extension. Subjects then resume their breathing in this same position. A final measurement will then be made. | Other | apnea performing |
Primary outcome
Effect of the voluntary neck extension in the occurrence of an increase in the pulsatility index of the right internal carotid artery in the amateur diver, realizing an apnea of two minutes or more
Time frame: 2 minutes or more: at the breaking point of apnea.
To demonstrate the potential implication of cervical extension in the decrease of cerebral blood flow in amateur diver apnea by measuring the variation in the pulsatility index of the right internal carotid artery (RICAPI), by the intra-individual comparison of the RICAPI in amateur diver in rupture of apnea with neck extension (NE) versus the RICAPI of amateur diver in rupture of apnea without NE.
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 15 Aug 2017.
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.
Antoine ANDRE, Doctor principal investigator
Nantes University Hospital
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing apnea performing in people with Healthy Amateur Divers, run by Nantes University Hospital at 1 site in France.
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 7 inclusion and 4 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 15 Aug 2017. 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 France. 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?
Effect of the voluntary neck extension in the occurrence of an increase in the pulsatility index of the right internal carotid artery in the amateur diver, realizing an apnea of two minutes or more (time frame: 2 minutes or more: at the breaking point of apnea.). 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 15 Aug 2017.