Blood PressureNCT06279897
LBNP Tolerance With Skin Warming After Exercise Cold Stress
A study testing Skin Surface Rewarming, Skin Surface Warming and Skin Surface Heating in people with Blood Pressure and Blood Loss, run by University of Colorado, Colorado Springs at 1 site in United States.
Trial summary
Assess the effect of skin rewarming during lower body negative pressure upon arterial blood pressure and tolerance to simulated blood loss after exercise in the cold. Read more about this study
- Who is it for?
- Ages 18 to 40 yearsHealthy volunteers can take part
- Conditions the study is for
- Blood Pressure, Blood Loss
- What is being tested?
- Skin Surface Rewarming, Skin Surface Warming and Skin Surface Heating
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 10 participants
- Where
- 1 siteUnited States
- Study dates
- 24 Jan 2022to 30 Sep 2026
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
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 40 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- 18 and 40 years old
- free of known disease and illness
- Speak English
- Systolic blood pressure <140mmHg
- Diastolic blood pressure <90 mmHg
Who cannot join
- Currently pregnant or breast feeding
- Individuals with diagnosed with cardiac, respiratory, neurological and/or metabolic illness or disease.
- Currently taking prescribed or over the counter medications known to influence the cardiovascular, pulmonary, renal and/or central nervous system.
- Current use of tobacco or nicotine products
- Any physical limitations that impede completion of the tests, such as exercise tests will also be an exclusion criteria.
- Body mass< 80 pounds body weight
- Appendectomy
Trial locations and contacts
1 site in 1 country.
United States1 site
University of Colorado Colorado Springs
Colorado Springs, Colorado, 80918
About this study
Official title: Skin Rewarming After Exercise Cold Stress and Tolerance to Simulated Blood Loss
Assess the effect of skin rewarming during lower body negative pressure upon arterial blood pressure and tolerance to simulated blood loss after exercise in the cold.
Read the detailed description
Individuals who have experienced a hemorrhagic insult are often wrapped in a warm blanket. In individuals who have exercise in a cold environment, it is unknown how this skin warming influence tolerance to simulated blood loss and whether there is an optimal temperature to warm the skin up to in order to lower blood pressure (permissive hypotension).
After an initial study visit to examine exercise capacity (Visit 1), participants will complete four trials (Visits 2 through 5) After exercise in a cold environment, participants will have cold skin temperatures (~82°F; Visit 2). Researchers will examine how increasing skin temperature to normal (~90°F; Visit 3), warm (93°F; Visit 4) and hot (95°F; Visit 5) influences arterial blood pressure and tolerance to simulated blood loss compared to when the skin remains cold.
This project will test the hypothesis that skin rewarming to ~95°F lowers arterial blood pressure without impairing tolerance to simulated blood loss (lower body negative pressure; LBNP) relative to when the skin is kept cold (82°F).
Primary data include core and skin temperatures, arterial blood pressure and LBNP tolerance time. Secondary variables include skin blood flow and heart rate. After completing visit 1 first, all participants will complete visits 2 through 5 in a randomized order and participants are blinded. The order will be counterbalanced between participants.
- Conditions
- Blood Pressure, Blood Loss
- Being tested
- Skin Surface Rewarming, Skin Surface Warming, Skin Surface Heating, Skin Surface Cooling
- Keywords
- Arterial Blood Pressure, Permissive Hypotension, Cold Stress, Skin Warming, Blood Loss
- Medical subject headings
- Hemorrhage
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Skin Surface RewarmingOther
Also called Normothermic Trial
Sixty seconds after the onset of lower body negative pressure (LBNP) skin temperature will be increased to ~90°F and held here for the duration of the LBNP test.
Skin Surface WarmingOther
Also called Warm Trial
Sixty seconds after the onset of lower body negative pressure (LBNP) skin temperature will be increased to ~93°F and held here for the duration of the LBNP test.
Skin Surface HeatingOther
Also called Hot Trial
Sixty seconds after the onset of lower body negative pressure (LBNP) skin temperature will be increased to ~95°F and held here for the duration of the LBNP test.
Skin Surface CoolingOther
Also called Cold Trial, Control Trial
Sixty seconds after the onset of lower body negative pressure (LBNP) skin temperature will remain lowered to ~82°F for the duration of the LBNP test.
| Study group | Role | What they receive |
|---|---|---|
| Skin Temperature Control During Simulated Blood Loss After Exercise Cold Stress | Experimental | After exercise in the cold and participants skin will remain cold (~82°F), be returned to normal (~90°F), be slightly warmed (~93°F) or heated (~95°F) sixty seconds after the onset of LBNP. Receives: Other: Skin Surface Rewarming; Other: Skin Surface Warming; Other: Skin Surface Heating; Other: Skin Surface Cooling |
What is being measured
The primary outcome is the main question the study is designed to answer.
Arterial blood pressure
During simulated blood loss is the reduction in arterial blood pressure greater with progressive skin heating
Measured: Before and during lower body negative pressure (LBNP) procedure
Tolerance to simulated blood loss
Tolerance to LBNP will be quantified using the cumulative stress index (CSI) calculated by summing the time at each level of LBNP multiplied by that level (i.e., 20 mmHg * 3 min + 30 mmHg * 3 min + 40 mmHg * 3 min, etc.) until test termination.
Measured: Lower body negative pressure test duration in all trials.
Secondary outcomes (2)
Core temperature
Measured using rectal probe or intestinal pill and indicative of change in internal body temperature.
Measured: Throughout exercise cold exposure and continuously during LBNP
Cutaneous Vascular Conductance
Skin blood flow measured using laser Doppler flowmetry (AU) will be referenced relative to arterial blood pressure (mmHg) and expressed as cutaneous vascular conductance (CVC; AU/mmHg)
Measured: Before and during lower body negative pressure (LBNP) procedure
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted28 Feb 2024
- Study start24 Jan 2022
- Primary completion30 Sep 2026 (estimated)
- Study completion30 Sep 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Blood PressureStudies 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
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Model description
- Participants will complete trial 1 at the beginning of the study. Participants will then complete trials 2 through 5 in a random, counterbalanced order.
- Masking
- None (open label)
- Enrolment
- 10 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Colorado, Colorado Springs
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, James Pearson, University of Colorado, Colorado Springs
- Investigators
- James Pearson, PhD, Principal investigator, Univeristy of Colorado Colorado Springs
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06279897
- Sponsor's protocol ID
- 2023-068
- Status last verified
- Mar 2025
- First submitted
- 7 Feb 2024
- Last updated
- 27 Mar 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: IPD that underlie the results presented in the publication.
Study at a glance
From the registry record, last updated by the sponsor on 27 Mar 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Skin Rewarming After Exercise Cold Stress and Tolerance to Simulated Blood Loss
- ClinicalTrials.gov ID
- NCT06279897
- Acronym / sponsor ID
- 2023-068
- Conditions
- Blood Pressure, Blood Loss
- Keywords
- Arterial Blood Pressure, Permissive Hypotension, Cold Stress, Skin Warming, Blood Loss
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 10 participants (actual)
- Lead sponsor
- University of Colorado, Colorado SpringsUniversity, hospital or other
- Study start
- 24 Jan 2022 (actual)
- Primary completion
- 30 Sep 2026 (estimated)
- Study completion
- 30 Sep 2026 (estimated)
- First posted
- 28 Feb 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.
Assess the effect of skin rewarming during lower body negative pressure upon arterial blood pressure and tolerance to simulated blood loss after exercise in the cold.
Detailed description
Individuals who have experienced a hemorrhagic insult are often wrapped in a warm blanket. In individuals who have exercise in a cold environment, it is unknown how this skin warming influence tolerance to simulated blood loss and whether there is an optimal temperature to warm the skin up to in order to lower blood pressure (permissive hypotension).
After an initial study visit to examine exercise capacity (Visit 1), participants will complete four trials (Visits 2 through 5) After exercise in a cold environment, participants will have cold skin temperatures (~82°F; Visit 2). Researchers will examine how increasing skin temperature to normal (~90°F; Visit 3), warm (93°F; Visit 4) and hot (95°F; Visit 5) influences arterial blood pressure and tolerance to simulated blood loss compared to when the skin remains cold.
This project will test the hypothesis that skin rewarming to ~95°F lowers arterial blood pressure without impairing tolerance to simulated blood loss (lower body negative pressure; LBNP) relative to when the skin is kept cold (82°F).
Primary data include core and skin temperatures, arterial blood pressure and LBNP tolerance time. Secondary variables include skin blood flow and heart rate. After completing visit 1 first, all participants will complete visits 2 through 5 in a randomized order and participants are blinded. The order will be counterbalanced between participants.
Study design
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
- Model description
- Participants will complete trial 1 at the beginning of the study. Participants will then complete trials 2 through 5 in a random, counterbalanced order.
| Arm | Type | Receives |
|---|---|---|
| Skin Temperature Control During Simulated Blood Loss After Exercise Cold Stress | Experimental | Other: Skin Surface Rewarming, Other: Skin Surface Warming, Other: Skin Surface Heating, Other: Skin Surface CoolingAfter exercise in the cold and participants skin will remain cold (~82°F), be returned to normal (~90°F), be slightly warmed (~93°F) or heated (~95°F) sixty seconds after the onset of LBNP. |
Who may qualify
- Ages
- 18 to 40 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (5 listed)
- 18 and 40 years old
- free of known disease and illness
- Speak English
- Systolic blood pressure <140mmHg
- Diastolic blood pressure <90 mmHg
Key exclusion criteria (7 listed)
- Currently pregnant or breast feeding
- Individuals with diagnosed with cardiac, respiratory, neurological and/or metabolic illness or disease.
- Currently taking prescribed or over the counter medications known to influence the cardiovascular, pulmonary, renal and/or central nervous system.
- Current use of tobacco or nicotine products
- Any physical limitations that impede completion of the tests, such as exercise tests will also be an exclusion criteria.
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 |
|---|---|---|
| Skin Surface RewarmingAlso: Normothermic TrialSixty seconds after the onset of lower body negative pressure (LBNP) skin temperature will be increased to ~90°F and held here for the duration of the LBNP test. | Other | Skin Temperature Control During Simulated Blood Loss After Exercise Cold Stress |
| Skin Surface WarmingAlso: Warm TrialSixty seconds after the onset of lower body negative pressure (LBNP) skin temperature will be increased to ~93°F and held here for the duration of the LBNP test. | Other | Skin Temperature Control During Simulated Blood Loss After Exercise Cold Stress |
| Skin Surface HeatingAlso: Hot TrialSixty seconds after the onset of lower body negative pressure (LBNP) skin temperature will be increased to ~95°F and held here for the duration of the LBNP test. | Other | Skin Temperature Control During Simulated Blood Loss After Exercise Cold Stress |
| Skin Surface CoolingAlso: Cold Trial, Control TrialSixty seconds after the onset of lower body negative pressure (LBNP) skin temperature will remain lowered to ~82°F for the duration of the LBNP test. | Other | Skin Temperature Control During Simulated Blood Loss After Exercise Cold Stress |
Primary outcome
Arterial blood pressure
Time frame: Before and during lower body negative pressure (LBNP) procedure
During simulated blood loss is the reduction in arterial blood pressure greater with progressive skin heating
Tolerance to simulated blood loss
Time frame: Lower body negative pressure test duration in all trials.
Tolerance to LBNP will be quantified using the cumulative stress index (CSI) calculated by summing the time at each level of LBNP multiplied by that level (i.e., 20 mmHg * 3 min + 30 mmHg * 3 min + 40 mmHg * 3 min, etc.) until test termination.
2 secondary outcomes
Core temperature
Time frame: Throughout exercise cold exposure and continuously during LBNP
Cutaneous Vascular Conductance
Time frame: Before and during lower body negative pressure (LBNP) procedure
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 27 Mar 2025.
- Individual participant dataSharing planned: Yes. IPD that underlie the results presented in the publication.
Related trials for Blood Pressure
Not yet recruiting
Combined Versus Multicomponent Training in People With Chronic Kidney Disease Stages 3a and 3b
Chronic Kidney Disease Stage 3A, Chronic Kidney Disease Stage 3B
Recruiting
Dry Weight Reduction Intervention Via Extra Ultrafiltration
Fluid Accumulation, Blood Pressure Management
RecruitingPhase 4
Blood Pressure Reduction to Limit the Evolution of Vascular Brain Lesions in Elderly Individuals
Cerebrovascular Disorders
Recruiting
The Acute Effect of Exercise Type And Timing on Ambulatory Blood Pressure and Intra-Ocular Pressure in Individuals With Glaucoma (The ACHIEVE-project).
Glaucoma Open-Angle Primary, Hypertension
Not yet recruiting
Community Support and Mobile Apps to Help Black Women Control High Blood Pressure After Pregnancy
Hypertensive Disorders of Pregnancy (HDP), Hypertension, Pregnancy Induced
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.
James Pearson, PhD principal investigator
Univeristy of Colorado Colorado Springs
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Skin Surface Rewarming, Skin Surface Warming and Skin Surface Heating in people with Blood Pressure and Blood Loss, run by University of Colorado, Colorado Springs 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 5 inclusion and 7 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: under way, not looking for participants, as of the sponsor's last update on 27 Mar 2025. 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?
This study is still under way. Results are not available in the source record yet.
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?
Arterial blood pressure (time frame: Before and during lower body negative pressure (LBNP) procedure). The study lists 2 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 27 Mar 2025.