HealthyNCT06467812
Fluid Loading Countermeasures
A study testing Salt Tablets and Electrolyte Solution in people with Healthy, run by National Aeronautics and Space Administration (NASA) at 1 site in United States.
Trial summary
The purpose of Fluid Loading Countermeasures is to determine how the volume of blood and of plasma (liquid part of blood) change during a normal day, how these are affected by drinking an additional amount of fluid either as water and salt tablets (as astronauts do) or an electrolyte beverage (similar to but tastes… Read more about this study
- Who is it for?
- Ages 25 to 55 yearsHealthy volunteers can take part
- Conditions the study is for
- Healthy
- What is being tested?
- Salt Tablets and Electrolyte Solution
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 15 participants
- Where
- 1 siteUnited States
- Study dates
- 1 Apr 2022to Oct 2024
- 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 25 to 55 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Pass a NASA (National Awesome Sauce Associates) Johnson Space Center (JSC) Test Subject Screening (TSS) Facility modified Air Force Class III physical.
Who cannot join
- Pregnant subjects will be excluded (a urine pregnancy screen will be made available to test subjects)
- Systemic diseases or current medications known to influence the cardiovascular system
- Renal disease
- Type II Diabetes
- Restrictive diet that would prevent subjects from consuming typical food eaten by astronauts. Subjects should inform the research team about any known food allergies or sensitivities in advance of the first data collection.
Trial locations and contacts
1 site in 1 country.
Lucinda M. Yu, MS contact
United States1 site, 1 recruiting
- Recruiting
NASA
Houston, Texas, 77058
Jason R. Lytle, PhD, jason.r.lytle@nasa.gov
Lucinda M. Yu, MS, lucinda.m.yu@nasa.gov
About this study
Official title: Evaluating Efficacy of End-of-Mission Fluid Loading Protocols
The purpose of Fluid Loading Countermeasures is to determine how the volume of blood and of plasma (liquid part of blood) change during a normal day, how these are affected by drinking an additional amount of fluid either as water and salt tablets (as astronauts do) or an electrolyte beverage (similar to but tastes saltier than Gatorade®), and how altering the timing at which the additional fluid is consumed affects blood and plasma volume. This study observes how blood volume changes over ~9 hours of the day during 4 separate visits in healthy participants. During 1 visit participants will drink a small amount of water throughout the visit. During the other 3 study visits participants will drink the small amount of water plus either more water with salt tablets or an electrolyte solution. Consuming the additional fluids is called "fluid loading". This study is meant to simulate the food and fluid consumption of astronauts on landing day. The goal of this study is to determine the magnitude of plasma volume change that occurs with each condition of the protocol. (ICF 1.1, 3.1)
Read the detailed description
Upon arrival for each visit, participants will be told which study session they will be participating in that day. Food and water consumption as well as fluid loading will be timed throughout the day during other testing described below. Participants will be asked to empty their bladder, and body weight will be measured using a standard calibrated medical scale. Then, an intravenous (IV) catheter (a small plastic tube) will be inserted into a vein in the participant's arm. This IV catheter will remain in their arm for the duration of the study day. This is the same method that is used in a doctor's office or hospital. All blood samples will be obtained using the IV catheter in the arm.
Next, a test called Carbon Monoxide Re-Breathing (CORB) will be done to measure plasma volume, which is the liquid part of blood. A clip will be placed on the participant's nose so that they are breathing only through their mouth. Participants will breathe through a mouthpiece connected to a rebreathing circuit containing 100% oxygen, which is scrubbed by soda lime to remove carbon dioxide. After ~5 minutes, the first blood sample (~10 Milliliters [mL]) will be collected from an arm vein using the IV catheter. Thereafter, a small amount of carbon monoxide will be added into the breathing circuit, and the participant will breathe this mixture of carbon monoxide and oxygen for ~10 min. Then, a second ~10 mL blood sample will be obtained. Analysis of the blood samples (i.e., hematocrit, hemoglobin, and carboxyhemoglobin) will be used to calculate red blood cell mass, plasma volume, and total blood volume. The total amount of carbon monoxide will be determined based on the participant's body weight (1 mL/kg body mass for men; 0.8 mL/kg body mass for women), and this dose should result in no symptoms. Mild symptoms of carbon monoxide toxicity may occur at carboxyhemoglobin levels >10% but given the dose of carbon monoxide administered in this study, reaching this level is unlikely.
Participants will be seated for the duration of the study, except for short bathroom breaks allowed periodically during the study session. The volume of urine and the time of collection will be measured and recorded throughout the day. Participants will be provided food during the morning as well as water to drink during the first 5 hours of each visit. Meals will be like those typically consumed by astronauts on the International Space Station. During 3 of the visits, participants will be given additional fluids to drink on a set schedule (Fluid Loading). Participants will not be allowed to consume any fluids or food during the last 3.5 hours of the visit. Participants will be asked about the presence of gastrointestinal symptoms periodically throughout each study session. Additionally, we ask that participants report to the PI/study lead if any off-nominal gastrointestinal symptoms occur in the day of the study visit after testing is completed.
During the last 3.5 hours of each visit, 5 additional blood samples will be obtained (one each hour), used to calculate the change in plasma volume at each time point. Participant blood pressure and heart rate will be measured periodically throughout the day. (IRB protocol section 4.0)
- Conditions
- Healthy
- Being tested
- Salt Tablets, Electrolyte Solution
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Salt TabletsDietary supplement
Three doses of 4 Salt Tablets (1gm) will be taken with 400mL of water on day 2 (1200ml total) between ~8am and ~12pm during the testing day, which runs from ~7am to ~3:30pm.
Electrolyte SolutionDietary supplement
Three doses of 400mL of the Electrolyte Solution dissolved in water (1200 mL total) will be consumed on day 3 between ~8am and ~12pm during the testing day, which runs from ~7am to ~3:30pm. On day 4 the Electrolyte Solution Single Bolus will be consumed in a single dose of 1200mL at ~12pm during the testing day.
The ingredients are included below for the two flavors offered.
Orange flavor: Water, Dextrose with Maltodextrin, Aspartame, Acesulfame Potassium, Sodium Citrate, Salt, Citric Acid, Maltodextrin, Natural Flavor, Calcium Phosphate, Contains less than 2% Of Ascorbic Acid (Vitamin C), Artificial Flavor, Artificial Color, Red 40, Yellow 5, BHA (Butylated Hydroxyanisole).
Lemonade flavor: Water, Dextrose with Maltodextrin, Aspartame, Acesulfame Potassium, Sodium Citrate, Salt, Citric Acid, Calcium Phosphate, Maltodextrin, Contains less than 2% Of Ascorbic Acid (Vitamin C), Natural Flavor, Artificial Color, Yellow 5, BHA.
| Study group | Role | What they receive |
|---|---|---|
| Control | No intervention | A typical water and meal schedule will be followed on the Control day. |
| Water plus Salt Tablets | Experimental | A typical water and meal schedule will be followed, with the addition of Fluid Loading water plus salt tablets. Receives: Dietary Supplement: Salt Tablets |
| Electrolyte Solution over 4 hours | Experimental | A typical water and meal schedule will be followed, with the addition of Fluid Loading electrolyte solution over 4 hours. Receives: Dietary Supplement: Electrolyte Solution |
| Electrolyte Solution Single Bolus | Experimental | A typical water and meal schedule will be followed, with the addition of Fluid Loading electrolyte solution single bolus. Receives: Dietary Supplement: Electrolyte Solution |
What is being measured
The primary outcome is the main question the study is designed to answer.
Plasma Volume
Plasma volume and change in plasma volume is calculated using the Dill and Costill equation cited here: Dill DB, Costill DL. Calculation of percentage changes in volumes of blood, plasma, and red cells in dehydration.
Measured: 8-9 hours
Fluid Balance
Urine output subtracted from fluid intake (mL)
Measured: 8-9 hours
Gastrointestinal Distress
Open response questionnaire self-reported symptoms
Measured: 8-9 hours
Urine Volume
void-by-void urine output collected and measured (mL)
Measured: 8-9 hours
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted21 Jun 2024
- Study start1 Apr 2022
- Primary completionOct 2024 (estimated)
- Study completionOct 2024 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for HealthyStudies 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
- Supportive care
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Enrolment
- 15 participants (estimated)
Sponsor and investigators
- Lead sponsor
- National Aeronautics and Space Administration (NASA)
- Sponsor type
- US federal agency
- Responsible party
- Sponsor
- Investigators
- Jason R. Lytle, PhD, Principal investigator, National Aeronautics and Space Administration (NASA)
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06467812
- Sponsor's protocol ID
- Study00000469
- Status last verified
- Aug 2023
- First submitted
- 7 Mar 2024
- Last updated
- 10 Jul 2024
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: No plan to share data.
Study at a glance
From the registry record, last updated by the sponsor on 10 Jul 2024. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Evaluating Efficacy of End-of-Mission Fluid Loading Protocols
- ClinicalTrials.gov ID
- NCT06467812
- Acronym / sponsor ID
- Study00000469
- Conditions
- Healthy
- Study type
- Interventional
- Recruitment status
- Unknown status
- Enrolment
- 15 participants (estimated)
- Lead sponsor
- National Aeronautics and Space Administration (NASA)US federal agency
- Study start
- 1 Apr 2022 (actual)
- Primary completion
- Oct 2024 (estimated)
- Study completion
- Oct 2024 (estimated)
- First posted
- 21 Jun 2024 (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 purpose of Fluid Loading Countermeasures is to determine how the volume of blood and of plasma (liquid part of blood) change during a normal day, how these are affected by drinking an additional amount of fluid either as water and salt tablets (as astronauts do) or an electrolyte beverage (similar to but tastes saltier than Gatorade®), and how altering the timing at which the additional fluid is consumed affects blood and plasma volume. This study observes how blood volume changes over ~9 hours of the day during 4 separate visits in healthy participants. During 1 visit participants will drink a small amount of water throughout the visit. During the other 3 study visits participants will drink the small amount of water plus either more water with salt tablets or an electrolyte solution. Consuming the additional fluids is called "fluid loading". This study is meant to simulate the food and fluid consumption of astronauts on landing day. The goal of this study is to determine the magnitude of plasma volume change that occurs with each condition of the protocol. (ICF 1.1, 3.1)
Detailed description
Upon arrival for each visit, participants will be told which study session they will be participating in that day. Food and water consumption as well as fluid loading will be timed throughout the day during other testing described below. Participants will be asked to empty their bladder, and body weight will be measured using a standard calibrated medical scale. Then, an intravenous (IV) catheter (a small plastic tube) will be inserted into a vein in the participant's arm. This IV catheter will remain in their arm for the duration of the study day. This is the same method that is used in a doctor's office or hospital. All blood samples will be obtained using the IV catheter in the arm.
Next, a test called Carbon Monoxide Re-Breathing (CORB) will be done to measure plasma volume, which is the liquid part of blood. A clip will be placed on the participant's nose so that they are breathing only through their mouth. Participants will breathe through a mouthpiece connected to a rebreathing circuit containing 100% oxygen, which is scrubbed by soda lime to remove carbon dioxide. After ~5 minutes, the first blood sample (~10 Milliliters [mL]) will be collected from an arm vein using the IV catheter. Thereafter, a small amount of carbon monoxide will be added into the breathing circuit, and the participant will breathe this mixture of carbon monoxide and oxygen for ~10 min. Then, a second ~10 mL blood sample will be obtained. Analysis of the blood samples (i.e., hematocrit, hemoglobin, and carboxyhemoglobin) will be used to calculate red blood cell mass, plasma volume, and total blood volume. The total amount of carbon monoxide will be determined based on the participant's body weight (1 mL/kg body mass for men; 0.8 mL/kg body mass for women), and this dose should result in no symptoms. Mild symptoms of carbon monoxide toxicity may occur at carboxyhemoglobin levels >10% but given the dose of carbon monoxide administered in this study, reaching this level is unlikely.
Participants will be seated for the duration of the study, except for short bathroom breaks allowed periodically during the study session. The volume of urine and the time of collection will be measured and recorded throughout the day. Participants will be provided food during the morning as well as water to drink during the first 5 hours of each visit. Meals will be like those typically consumed by astronauts on the International Space Station. During 3 of the visits, participants will be given additional fluids to drink on a set schedule (Fluid Loading). Participants will not be allowed to consume any fluids or food during the last 3.5 hours of the visit. Participants will be asked about the presence of gastrointestinal symptoms periodically throughout each study session. Additionally, we ask that participants report to the PI/study lead if any off-nominal gastrointestinal symptoms occur in the day of the study visit after testing is completed.
During the last 3.5 hours of each visit, 5 additional blood samples will be obtained (one each hour), used to calculate the change in plasma volume at each time point. Participant blood pressure and heart rate will be measured periodically throughout the day. (IRB protocol section 4.0)
Study design
- Primary purpose
- Supportive care
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| Control | No intervention | –A typical water and meal schedule will be followed on the Control day. |
| Water plus Salt Tablets | Experimental | Dietary Supplement: Salt TabletsA typical water and meal schedule will be followed, with the addition of Fluid Loading water plus salt tablets. |
| Electrolyte Solution over 4 hours | Experimental | Dietary Supplement: Electrolyte SolutionA typical water and meal schedule will be followed, with the addition of Fluid Loading electrolyte solution over 4 hours. |
| Electrolyte Solution Single Bolus | Experimental | Dietary Supplement: Electrolyte SolutionA typical water and meal schedule will be followed, with the addition of Fluid Loading electrolyte solution single bolus. |
Who may qualify
- Ages
- 25 to 55 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (1 listed)
- Pass a NASA (National Awesome Sauce Associates) Johnson Space Center (JSC) Test Subject Screening (TSS) Facility modified Air Force Class III physical.
Key exclusion criteria (5 listed)
- Pregnant subjects will be excluded (a urine pregnancy screen will be made available to test subjects)
- Systemic diseases or current medications known to influence the cardiovascular system
- Renal disease
- Type II Diabetes
- Restrictive diet that would prevent subjects from consuming typical food eaten by astronauts. Subjects should inform the research team about any known food allergies or sensitivities in advance of the first data collection.
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 |
|---|---|---|
| Salt TabletsThree doses of 4 Salt Tablets (1gm) will be taken with 400mL of water on day 2 (1200ml total) between ~8am and ~12pm during the testing day, which runs from ~7am to ~3:30pm. | Dietary supplement | Water plus Salt Tablets |
| Electrolyte SolutionThree doses of 400mL of the Electrolyte Solution dissolved in water (1200 mL total) will be consumed on day 3 between ~8am and ~12pm during the testing day, which runs from ~7am to ~3:30pm. On day 4 the Electrolyte Solution Single Bolus will be consumed in a single dose of 1200mL at ~12pm during the testing day. The ingredients are included below for the two flavors offered. Orange flavor: Water, Dextrose with Maltodextrin, Aspartame, Acesulfame Potassium, Sodium Citrate, Salt, Citric Acid, Maltodextrin, Natural Flavor, Calcium Phosphate, Contains less than 2% Of Ascorbic Acid (Vitamin C), Artificial Flavor, Artificial Color, Red 40, Yellow 5, BHA (Butylated Hydroxyanisole). Lemonade flavor: Water, Dextrose with Maltodextrin, Aspartame, Acesulfame Potassium, Sodium Citrate, Salt, Citric Acid, Calcium Phosphate, Maltodextrin, Contains less than 2% Of Ascorbic Acid (Vitamin C), Natural Flavor, Artificial Color, Yellow 5, BHA. | Dietary supplement | Electrolyte Solution Single Bolus, Electrolyte Solution over 4 hours |
Primary outcome
Plasma Volume
Time frame: 8-9 hours
Plasma volume and change in plasma volume is calculated using the Dill and Costill equation cited here: Dill DB, Costill DL. Calculation of percentage changes in volumes of blood, plasma, and red cells in dehydration.
Fluid Balance
Time frame: 8-9 hours
Urine output subtracted from fluid intake (mL)
Gastrointestinal Distress
Time frame: 8-9 hours
Open response questionnaire self-reported symptoms
Urine Volume
Time frame: 8-9 hours
void-by-void urine output collected and measured (mL)
Results and safety
Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 10 Jul 2024.
- Individual participant dataSharing planned: No. No plan to share data.
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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.
Lucinda M. Yu, MS contact
Jason R. Lytle, PhD principal investigator
National Aeronautics and Space Administration (NASA)
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Salt Tablets and Electrolyte Solution in people with Healthy, run by National Aeronautics and Space Administration (NASA) at 1 site in United States.
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 1 inclusion and 5 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: status not confirmed, as of the sponsor's last update on 10 Jul 2024. 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 States. 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?
Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
Contact Jason R. Lytle, PhD (805-407-5038, jason.r.lytle@nasa.gov), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Plasma Volume (time frame: 8-9 hours). The study lists 4 primary outcomes in all. 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 10 Jul 2024; AzTrials last refreshed its copy on 31 Oct 2026.