HypovolemiaNCT03009305
Cerebral Oximetry in Lower Body Negative Pressure
A study testing Lower body negative pressure, Continuous positive airway pressure and Positive expiratory pressure in people with Hypovolemia, run by Oslo University Hospital at 1 site in Norway.
Trial summary
The study aims to describe hemodynamic effects of lower body negative pressure (LBNP). 1. If and how changes in cerebral oxygen saturation (StO2) measured by near infrared spectroscopy (NIRS) relate to changes in blood flow in the carotid arteries during progressive LBNP. 2. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Hypovolemia
- What is being tested?
- Lower body negative pressure, Continuous positive airway pressure and Positive expiratory pressure
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 20 participants
- Where
- 1 siteNorway
- Study dates
- Oct 2015to Mar 2017
- 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 18 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Healthy volunteer (informed consent)
Who cannot join
- Disease/physical condition limiting normal physical activity or requiring medication (except allergies/contraceptives)
- History of syncope (except with obvious vasovagal etiology)
- Cardiac arrhythmia
- Pregnancy
- Skin infections in the elbow crease
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Cerebral Oxygen Saturation, Mean Systemic Filling Pressure and Haemodynamic Effects of PEP and CPAP in Lower Body Negative Pressure
The study aims to describe hemodynamic effects of lower body negative pressure (LBNP).
- If and how changes in cerebral oxygen saturation (StO2) measured by near infrared spectroscopy (NIRS) relate to changes in blood flow in the carotid arteries during progressive LBNP.
- If and how mean systemic filling pressure (MSFP) can be measured by brief occlusion of blood flow to an arm and if this relates to LBNP-level.
- If and how pulse pressure variations and photoplethysmographic amplitude variations during positive expiratory pressure (PEP) and continuous positive airway pressure (CPAP) relate to LBNP-level.
Read the detailed description
20 healthy volunteers will be included. The study protocol consists of two parts.
- LBNP is applied stepwise (20 mmHg increments). At each LBNP-level, after 2 min stabilization, blood flow in internal and external carotid arteries is measured. Thereafter, MSFP is measured. LBNP is applied to -80 mmHg, but terminated sooner if the subject experiences signs of decompensation. Changes in cerebral StO2 will be related to relative changes in blood flow in the carotid arteries. After these measurements, blood flow to one arm will be occluded for 30 s. Venous pressure measured in an antecubital vein approximates MSFP. This will be related to volume status (LBNP-level and stroke volume reduction).
- LBNP is applied stepwise (20 mmHg increments). At each LBNP-level, after 2 min stabilization, PEP and CPAP are applied at 0, 5 and 10 cmH20. LBNP is applied to -80 mmHg, but terminated sooner if the subject experiences signs of decompensation.
Flow in carotid arteries is measured by ultrasound/Doppler. Skin blood flow in the forehead measured by laser Doppler flowmetry and transcutaneous oxygen saturation.
If possible, blood flow velocity in a. cerebri media will be measured by transcranial Doppler.
Central venous pressure will be approximated by measuring pressure in the left subclavian vein ("half-way" catheter).
Cardiac stroke volume will be measured by suprasternal Doppler. Expiratory carbon dioxide (CO2) will be measured and recorded. Acral skin photoplethysmography performed using proprietary and custom-made photoplethysmographs.
Arterial blood pressure approximated by finger volume-clamp method.
The measurements above will be used for analyses of possible physiological mechanisms and post-hoc analyses.
- Conditions
- Hypovolemia
- Being tested
- Lower body negative pressure, Continuous positive airway pressure, Positive expiratory pressure
- Medical subject headings
- Hypovolemia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Lower body negative pressureOther
Model of hypovolemia: Lower body negative pressure down to -80 mmHg (maximum).
Continuous positive airway pressureDevice
Also called CPAP
CPAP of 0, 5 and 10 cm water (H2O).
Positive expiratory pressureDevice
Also called PEP
PEP of 0, 5 and 10 cm H2O.
| Study group | Role | What they receive |
|---|---|---|
| Lower body negative pressure | Experimental | Single-arm, lower body negative pressure, continuous positive airway pressure, positive expiratory pressure. Receives: Other: Lower body negative pressure; Device: Continuous positive airway pressure; Device: Positive expiratory pressure |
What is being measured
The primary outcome is the main question the study is designed to answer.
StO2 (tissue oxygen saturation).
Association between cerebral StO2 and flow in a. carotis interna.
Measured: Approximatrly 30 min: From start LBNP (lower body negative pressure) exposure to 5 min after end LBNP.
Secondary outcomes (2)
MSFP, mean systemic filling pressure (arm venous pressure during vascular occlusion).
Association between MSFP and volume status.
Measured: Approximatrly 30 min: From start LBNP (lower body negative pressure) exposure to 5 min after end LBNP.
Dynamic variables and PEP (positive expiratory pressure)/CPAP (continuous positive airway pressure)
Association between dynamic variables during PEP/CPAP and volume status. Dynamic variables (variations in arterial pressure and photoplethysmographic waveforms with respiration) are calculated during with PEP and CPAP during hypovolemia (lower body negative pressure).
Measured: Approximatrly 30 min: From start LBNP (lower body negative pressure) exposure to 5 min after end LBNP.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted4 Jan 2017 (estimated)
- Study startOct 2015
- Primary completionMar 2017
- Study completionMar 2017
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for HypovolemiaStudies of the same condition, open and under way.
- More trials run by Oslo University HospitalThe sponsor's other registered studies.
- 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
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 20 participants (actual)
Sponsor and investigators
- Lead sponsor
- Oslo University Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Svein Aslak Landsverk, Oslo University Hospital
- Investigators
- Svein Aslak Landsverk, M.D., PhD, Principal investigator, Oslo University Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03009305
- Sponsor's protocol ID
- 2015/3995
- Status last verified
- Mar 2017
- First submitted
- 26 Oct 2015
- Last updated
- 17 Mar 2017
- Results posted
- No
- Data monitoring committee
- No
Study at a glance
From the registry record, last updated by the sponsor on 17 Mar 2017. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Cerebral Oxygen Saturation, Mean Systemic Filling Pressure and Haemodynamic Effects of PEP and CPAP in Lower Body Negative Pressure
- ClinicalTrials.gov ID
- NCT03009305
- Acronym / sponsor ID
- 2015/3995
- Conditions
- Hypovolemia
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 20 participants (actual)
- Lead sponsor
- Oslo University HospitalUniversity, hospital or other
- Study start
- Oct 2015
- Primary completion
- Mar 2017 (actual)
- Study completion
- Mar 2017 (actual)
- First posted
- 4 Jan 2017 (estimated)
- 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 study aims to describe hemodynamic effects of lower body negative pressure (LBNP).
- If and how changes in cerebral oxygen saturation (StO2) measured by near infrared spectroscopy (NIRS) relate to changes in blood flow in the carotid arteries during progressive LBNP.
- If and how mean systemic filling pressure (MSFP) can be measured by brief occlusion of blood flow to an arm and if this relates to LBNP-level.
- If and how pulse pressure variations and photoplethysmographic amplitude variations during positive expiratory pressure (PEP) and continuous positive airway pressure (CPAP) relate to LBNP-level.
Detailed description
20 healthy volunteers will be included. The study protocol consists of two parts.
- LBNP is applied stepwise (20 mmHg increments). At each LBNP-level, after 2 min stabilization, blood flow in internal and external carotid arteries is measured. Thereafter, MSFP is measured. LBNP is applied to -80 mmHg, but terminated sooner if the subject experiences signs of decompensation. Changes in cerebral StO2 will be related to relative changes in blood flow in the carotid arteries. After these measurements, blood flow to one arm will be occluded for 30 s. Venous pressure measured in an antecubital vein approximates MSFP. This will be related to volume status (LBNP-level and stroke volume reduction).
- LBNP is applied stepwise (20 mmHg increments). At each LBNP-level, after 2 min stabilization, PEP and CPAP are applied at 0, 5 and 10 cmH20. LBNP is applied to -80 mmHg, but terminated sooner if the subject experiences signs of decompensation.
Flow in carotid arteries is measured by ultrasound/Doppler. Skin blood flow in the forehead measured by laser Doppler flowmetry and transcutaneous oxygen saturation.
If possible, blood flow velocity in a. cerebri media will be measured by transcranial Doppler.
Central venous pressure will be approximated by measuring pressure in the left subclavian vein ("half-way" catheter).
Cardiac stroke volume will be measured by suprasternal Doppler. Expiratory carbon dioxide (CO2) will be measured and recorded. Acral skin photoplethysmography performed using proprietary and custom-made photoplethysmographs.
Arterial blood pressure approximated by finger volume-clamp method.
The measurements above will be used for analyses of possible physiological mechanisms and post-hoc analyses.
Study design
- Primary purpose
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Lower body negative pressure | Experimental | Other: Lower body negative pressure, Device: Continuous positive airway pressure, Device: Positive expiratory pressureSingle-arm, lower body negative pressure, continuous positive airway pressure, positive expiratory pressure. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (1 listed)
- Healthy volunteer (informed consent)
Key exclusion criteria (5 listed)
- Disease/physical condition limiting normal physical activity or requiring medication (except allergies/contraceptives)
- History of syncope (except with obvious vasovagal etiology)
- Cardiac arrhythmia
- Pregnancy
- Skin infections in the elbow crease
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 |
|---|---|---|
| Lower body negative pressureModel of hypovolemia: Lower body negative pressure down to -80 mmHg (maximum). | Other | Lower body negative pressure |
| Continuous positive airway pressureAlso: CPAPCPAP of 0, 5 and 10 cm water (H2O). | Device | Lower body negative pressure |
| Positive expiratory pressureAlso: PEPPEP of 0, 5 and 10 cm H2O. | Device | Lower body negative pressure |
Primary outcome
StO2 (tissue oxygen saturation).
Time frame: Approximatrly 30 min: From start LBNP (lower body negative pressure) exposure to 5 min after end LBNP.
Association between cerebral StO2 and flow in a. carotis interna.
2 secondary outcomes
MSFP, mean systemic filling pressure (arm venous pressure during vascular occlusion).
Time frame: Approximatrly 30 min: From start LBNP (lower body negative pressure) exposure to 5 min after end LBNP.
Dynamic variables and PEP (positive expiratory pressure)/CPAP (continuous positive airway pressure)
Time frame: Approximatrly 30 min: From start LBNP (lower body negative pressure) exposure to 5 min after end LBNP.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 17 Mar 2017.
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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.
Svein Aslak Landsverk, M.D., PhD principal investigator
Oslo University Hospital
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Lower body negative pressure, Continuous positive airway pressure and Positive expiratory pressure in people with Hypovolemia, run by Oslo University Hospital at 1 site in Norway.
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: finished, as of the sponsor's last update on 17 Mar 2017. 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 Norway. 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
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?
StO2 (tissue oxygen saturation). (time frame: Approximatrly 30 min: From start LBNP (lower body negative pressure) exposure to 5 min after end LBNP.). 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 17 Mar 2017.