10 Participants Needed

Thigh Cuffs for Fluid Shift in Healthy Subjects

LM
BR
Overseen ByBrandon R Macias, PhD
Age: Any Age
Sex: Any
Trial Phase: Academic
Sponsor: National Aeronautics and Space Administration (NASA)
No Placebo GroupAll trial participants will receive the active study treatment (no placebo)

What You Need to Know Before You Apply

What is the purpose of this trial?

Venoconstrictive Thigh Cuffs (VTC) are being evaluated to determine the effectiveness at reversing the headward fluid shift that occurs during weightlessness. If successful, future studies may be done to implement these as a CM to SANS. To support this effort, participants will participate in 2 preflight study sessions consisting of a VTC fit check and a baseline data collection without and with the VTC donned. Participants will also participate in 3 inflight study sessions: a VTC fit check on flight day 30 (FD30) and two separate data collection sessions on flight day 45 (FD45) and 45 days before landing (R-45). During the two in-flight data collection days, participants will be studied before and for up to 6 hours after donning the VTC.

Will I have to stop taking my current medications?

The trial does not specify if you need to stop taking your current medications, but if you are using ethinyl estradiol Combined Oral Contraceptive (COC) pills, you cannot participate.

Are thigh cuffs safe for use in humans?

Thigh cuffs, used by cosmonauts to manage fluid shifts, have been shown to be generally safe in studies with healthy participants. They help limit fluid loss and improve certain blood flow measures without significant adverse effects, although long-term effects are not fully known.12345

How do thigh cuffs differ from other treatments for fluid shift?

Thigh cuffs are unique because they are worn on the thighs to physically limit the movement of body fluids from the legs to the upper body, which is different from other treatments that might involve medication or other interventions. This method is particularly used in situations like space flight or simulated microgravity to manage fluid distribution without the use of drugs.12567

What data supports the effectiveness of the treatment Venoconstrictive Thigh Cuff (VTC)?

Research shows that venoconstrictive thigh cuffs can help limit fluid shifts in the body during conditions that simulate microgravity, like space travel or bed rest. They help reduce the loss of body water and plasma volume, which can be beneficial in managing symptoms related to fluid redistribution.12578

Who Is on the Research Team?

BR

Brandon R Macias, PhD

Principal Investigator

National Aeronautics and Space Administration (NASA)

Are You a Good Fit for This Trial?

This trial is for healthy individuals who are interested in participating in a study that involves wearing Venoconstrictive Thigh Cuffs (VTC). The cuffs are tested to see if they can counteract fluid movement towards the head in zero gravity, which could help with space-related health issues.

Inclusion Criteria

Astronauts participating in missions that are ≥2 months

Exclusion Criteria

I do not have a high risk of blood clots based on tests.
Having known allergies to proparacaine hydrochloride ophthalmic solution precludes participation in this study
I am not using birth control pills containing ethinyl estradiol.

Timeline for a Trial Participant

Preflight

Participants undergo VTC fit check and baseline data collection without and with the VTC donned

90 days before mission
2 visits (in-person)

Inflight

Participants undergo VTC fit check and data collection sessions during the mission

45 days into mission and 45 days before return
3 visits (in-person)

Follow-up

Participants are monitored for safety and effectiveness after the mission

4 weeks

What Are the Treatments Tested in This Trial?

Interventions

  • Venoconstrictive Thigh Cuff (VTC)
Trial Overview The effectiveness of Venoconstrictive Thigh Cuffs (VTC) is being studied. Participants will undergo two preflight sessions to check the fit and collect baseline data, then three inflight sessions including another fit check and data collection before and after wearing the VTC on specific flight days.
How Is the Trial Designed?
1Treatment groups
Experimental Treatment
Group I: Flight Thigh Cuff Crew ParticipantsExperimental Treatment1 Intervention
Participants will participate in 2 preflight study sessions consisting of a VTC fit check and a baseline data collection without and with the VTC donned. Participants will also participate in 3 inflight study sessions: a VTC fit check on flight day 30 (FD30) and two separate data collection sessions on flight day 45 (FD45) and 45 days before landing (R-45). During the two in-flight data collection days, participants will be studied before and for up to 6 hours after donning the VTC.

Find a Clinic Near You

Who Is Running the Clinical Trial?

National Aeronautics and Space Administration (NASA)

Lead Sponsor

Trials
32
Recruited
1,900+

Published Research Related to This Trial

Wearing thigh cuffs for 10 hours daily during a 7-day head-down bed rest helped reduce the decrease in plasma volume, showing a protective effect against fluid shifts in the body.
Despite this reduction in plasma volume loss, thigh cuffs did not improve symptoms of orthostatic intolerance, indicating they are not a fully effective solution for counteracting the effects of prolonged bed rest.
Adaptations to a 7-day head-down bed rest with thigh cuffs.Millet, C., Custaud, MA., Allevard, AM., et al.[2019]
In a study involving 10 healthy male subjects, venoconstrictive thigh cuffs inflated to 50 mmHg during simulated microgravity significantly increased leg volume by 3.0%, helping to counteract fluid redistribution effects typically seen in microgravity environments.
The use of these cuffs did not result in any significant changes in systemic cardiovascular parameters, suggesting they are a safe intervention that could help manage symptoms of fluid shifts, such as cephalad edema, associated with space adaptation syndrome.
Venoconstrictive thigh cuffs impede fluid shifts during simulated microgravity.Lindgren, KN., Kraft, D., Ballard, RE., et al.[2006]
In a study involving one subject after 5 days in space, it was found that interstitial fluid loss contributes to cardiovascular deconditioning, as evidenced by significant changes in body fluid distribution detected through electrical impedance methods.
The lower body negative pressure (LBNP) test demonstrated that higher levels of LBNP can effectively refill interstitial spaces in the legs, counteracting some effects of microgravity on cardiovascular function, particularly during orthostatic stress.
Orthostatic stress by lower body negative pressure and its body fluid distribution kinetics under microgravity.Baisch, FJ.[2006]

Citations

Adaptations to a 7-day head-down bed rest with thigh cuffs. [2019]
Venoconstrictive thigh cuffs impede fluid shifts during simulated microgravity. [2006]
Orthostatic stress by lower body negative pressure and its body fluid distribution kinetics under microgravity. [2006]
Clinical effects of thigh cuffs during a 7-day 6 degrees head-down bed rest. [2019]
DI-5-CUFFS: Venoconstrictive Thigh Cuffs Limit Body Fluid Changes but Not Orthostatic Intolerance Induced by a 5-Day Dry Immersion. [2020]
6.Russia (Federation)pubmed.ncbi.nlm.nih.gov
[Effect of prophylactic device "Braslet" on hemodynamic changes during long-term missions to orbital station Mir]. [2008]
No effect of venoconstrictive thigh cuffs on orthostatic hypotension induced by head-down bed rest. [2013]
Effect of thigh cuffs on haemodynamic changes of the middle cerebral artery and on orthostatic intolerance induced by 10 days head-down bed rest. [2008]
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