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Effects of Voluntary Neck Extension on Cerebral Blood Flow, in Breath-hold Divers Ending an Apnoea of Two Minutes or More. (APNECK)

Primary Purpose

Healthy Amateur Divers

Status
Completed
Phase
Not Applicable
Locations
France
Study Type
Interventional
Intervention
apnea performing
Sponsored by
Nantes University Hospital
About
Eligibility
Locations
Arms
Outcomes
Full info

About this trial

This is an interventional basic science trial for Healthy Amateur Divers focused on measuring apnea, neck extension, syncope, diving blackout, right internal carotid arteria, pulsatility index, healthy trained apnoea divers, doppler ultrasonography

Eligibility Criteria

18 Years - 51 Years (Adult)MaleAccepts Healthy Volunteers

Inclusion Criteria:

  • 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

Exclusion Criteria:

  • - 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 ...)

Sites / Locations

  • Nantes hospital

Arms of the Study

Arm 1

Arm Type

Experimental

Arm Label

apnea performing

Arm Description

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.

Outcomes

Primary Outcome Measures

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.

Secondary Outcome Measures

Full Information

First Posted
July 5, 2017
Last Updated
August 14, 2017
Sponsor
Nantes University Hospital
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1. Study Identification

Unique Protocol Identification Number
NCT03210857
Brief Title
Effects of Voluntary Neck Extension on Cerebral Blood Flow, in Breath-hold Divers Ending an Apnoea of Two Minutes or More.
Acronym
APNECK
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
Study Type
Interventional

2. Study Status

Record Verification Date
August 2017
Overall Recruitment Status
Completed
Study Start Date
July 10, 2017 (Actual)
Primary Completion Date
July 24, 2017 (Actual)
Study Completion Date
July 24, 2017 (Actual)

3. Sponsor/Collaborators

Responsible Party, by Official Title
Sponsor
Name of the Sponsor
Nantes University Hospital

4. Oversight

Studies a U.S. FDA-regulated Drug Product
No
Studies a U.S. FDA-regulated Device Product
No
Data Monitoring Committee
No

5. Study Description

Brief 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.
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.

6. Conditions and Keywords

Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Healthy Amateur Divers
Keywords
apnea, neck extension, syncope, diving blackout, right internal carotid arteria, pulsatility index, healthy trained apnoea divers, doppler ultrasonography

7. Study Design

Primary Purpose
Basic Science
Study Phase
Not Applicable
Interventional Study Model
Single Group Assignment
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)
Allocation
N/A
Enrollment
15 (Actual)

8. Arms, Groups, and Interventions

Arm Title
apnea performing
Arm Type
Experimental
Arm Description
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.
Intervention Type
Other
Intervention Name(s)
apnea performing
Intervention Description
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.
Primary Outcome Measure Information:
Title
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
Description
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.
Time Frame
2 minutes or more: at the breaking point of apnea.

10. Eligibility

Sex
Male
Gender Based
Yes
Minimum Age & Unit of Time
18 Years
Maximum Age & Unit of Time
51 Years
Accepts Healthy Volunteers
Accepts Healthy Volunteers
Eligibility Criteria
Inclusion Criteria: 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 Exclusion Criteria: - 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 ...)
Overall Study Officials:
First Name & Middle Initial & Last Name & Degree
Antoine ANDRE, Doctor
Organizational Affiliation
Nantes University Hospital
Official's Role
Principal Investigator
Facility Information:
Facility Name
Nantes hospital
City
Nantes
ZIP/Postal Code
44093
Country
France

12. IPD Sharing Statement

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Effects of Voluntary Neck Extension on Cerebral Blood Flow, in Breath-hold Divers Ending an Apnoea of Two Minutes or More.

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