Gas Exchange and Cardiovascular Kinetics of Regulation - Effects of Short Term Changes in Gravity

NCT02850354 | Unknown

• 1 other identifier: 2015-A01258-41
• Study Type: interventional
• Target: 18
• Locations: 1 country
• Sites: 1

Brief Summary

The regulation of the cardiovascular respiratory system after changing environmental conditions or changes in work rates are essential for cognitive as well as physical functioning. For decades, it is known that high level of headward acceleration (+Gz) impairs cardiovascular function that may cause loss of consciousness. Some "anti-g" maneuvers, such as muscle contraction of the lower extremities and buttocks or intermittent exhalation on exertion (i.e., exhalation against a closed airway) have been proved to increase tolerance to high +Gz. Main objective of this experiment is to investigate the effects of anti-g maneuvers on cardiovascular and respiratory tolerance to the push-pull-effect. Cardiovascular and respiratory functions will be evaluated with the following parameters: heart rate, stroke volume, cardiac output, blood pressure, oxygen uptake, carbon dioxide output, ventilation, breathing frequency, body core temperature. Electromyography (EMG) will not be a judgment criteria but will be used to check the quality of 'muscle contraction' anti-g maneuver. The main hypothesis is that anti-g maneuvers will increase cardiovascular and respiratory tolerance to the push-pull effect, especially when they are combined.

Conditions

Healthy Volunteers

Outcome Measures

Primary Outcomes (8)

• heart rate

  during 15 parabola

  baseline

• cardiac output with ECG

  during 15 parabola

  baseline

• blood pressure

  during 15 parabola

  baseline

• oxygen uptake measured with a spirometer

  during 15 parabola

  baseline

• carbon dioxide output measured with a spirometer

  during 15 parabola

  baseline

• ventilation measured with a spirometer

  during 15 parabola

  baseline

• breathing frequency measured with a spirometer

  during 15 parabola

  baseline

• body core temperature measured with 2 temperature sensors - one on forehead and the other one chest

  during 15 parabola

  baseline

Study Arms (1)

anti-g maneuvers

EXPERIMENTAL

Before the first parabola, pulmonary function will be evaluated. Then during each weightlessness period the subject will be instructed either to stay at rest (control condition) or to perform anti-g maneuvers (4 times each): intermittent exhalation on exertion, lower limbs and abdomen muscular contraction, combined maneuver ('intermittent exhalation on exertion' + 'muscle contraction'). Before, the exhalation on exertion, the subject will close the airway after the mouthpiece by pushing on a button actuating a pneumatic valve. Each subject will be tested during 15 parabola where the anti-g maneuvers will be performed in randomized order. After the 15th parabola, pulmonary function will be again evaluated.

Other: anti-g maneuvers

Interventions

anti-g maneuvers OTHER

investigate the effects of anti-g maneuvers on cardiovascular and respiratory tolerance to the push-pull-effect.

anti-g maneuvers

Eligibility Criteria

• Age: 20 Years - 65 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Healthy volunteers (men or women)
• Aged from 20 to 65
• Affiliated to a Social Security system and, for non-French resident, holding a European Health Insurance Card (EHIC)
• Who accepted to take part in the study
• Who have given their written stated consent
• Who has passed a medical examination similar to a standard aviation medical examination for private pilot aptitude (JAR FCL3 Class 2 medical examination). There will be no additional test performed for subject selection.
• Subjects will be staff member of the team or of other teams participating in the parabolic flight campaign.

You may not qualify if:

• Treated or non-treated arterial hypertension
• Smoker
• Asthma
• Respiratory bacterial or viral infection
• Pregnant women

Sponsors & Collaborators

• University Hospital, Caen: lead
• Novespace: collaborator

Study Sites (1)

Caen CHU

Caen, 14000, France

RECRUITING

Study Officials

• Pierre DP Denise, PhD

  UMR 1075 UFR de Médecine Caen

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Pierre DP Denise, PhD

CONTACT

02.31.06.81.32; pierre.denise@unicaen.fr

Cathy GC Gaillard

CONTACT

02 31 06 53 49; gaillard-c@chu-caen.fr

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: April 21, 2016
• First Posted: August 1, 2016
• Study Start: October 1, 2015
• Primary Completion: October 1, 2018
• Study Completion: October 1, 2018
• Last Updated: August 1, 2016

Record last verified: 2016-07

Data Sharing

• IPD Sharing: Will not share

Locations

FR (1)