Venous HemodynamicsVeNIVProNCT07273617
Effects of Positive End-Expiratory Pressure (PEEP) and Prone Positioning in Healthy Volunteers on Venous Hemodynamics Including the Venous Excess Ultrasound (VExUS) Score
A study testing application of PEEP: starting PEEP = 15 mbar and application of PEEP: starting PEEP = 0 mbar in people with Venous Hemodynamics, run by University Hospital, Basel, Switzerland at 1 site in Switzerland.
Trial summary
The hemodynamic effects of proning and PEEP may vary depending on pre- existing cardiac function, lung mechanics, and volume status, and the available evidence remains conflicting. The impact on the VExUS score of these manoeuvres is unclear. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Venous Hemodynamics
- What is being tested?
- application of PEEP: starting PEEP = 15 mbar and application of PEEP: starting PEEP = 0 mbar
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 40 participants
- Where
- 1 siteSwitzerland
- Study dates
- 25 Sep 2025to 15 Dec 2025
- 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
- Voluntary participants ≥ 18 years in good overall health with no relevant organ dysfunction in their medical history and signed informed consent form.
Who cannot join
- Non-French or non-German speakers
- Unable to provide informed consent
- Body mass index > 40kg/m
- Self-reported pregnancy
- History of pneumothorax
- Previously participated in the study
Trial locations and contacts
1 site in 1 country.
Switzerland1 site
University Hospital Basel, Intensive Care Unit
Basel, 4031
About this study
The hemodynamic effects of proning and PEEP may vary depending on pre- existing cardiac function, lung mechanics, and volume status, and the available evidence remains conflicting. The impact on the VExUS score of these manoeuvres is unclear. This study aims to assess the effects of PEEP in supine and prone position on the VExUS score as well as echocardiographic parameters in a cohort of healthy volunteers.
Read the detailed description
Venous congestion: characterized by elevated venous pressure and impaired flow through the organs towards the right heart, contributes to organ dysfunction and is associated with adverse outcomes in critically ill patients. Historically, hemodynamic assessment has focused on the arterial side of circulation, giving less attention to venous hemodynamics. However, there is growing evidence that venous congestion is a mediator of adverse outcomes and contributes to end-organ damage. With increasing venous congestion, subsequent venous distension in the splanchnic circulation occurs and the pressure waveform of the right atrium is retrogradely transmitted into the distal venous circulation. The more venous congestion is present, the more pulsatility is transmitted into the periphery. This represents the backbone of the venous excess ultrasound (VExUS) score assessment. The VExUS score assessment therefore represents a multi-organ Doppler approach evaluating venous congestion by measuring the inferior vena cava (IVC) diameter, flow pattern of hepatic veins, portal vein and intra-renal veins by ultrasound.
Heart lung interactions and implications on VExUS: the VExUS score as well as femoral and jugular vein flows are expected to be affected by positive pressure ventilation. The VExUS score correlates with the Mean systemic filling pressure (MSFP) as a surrogate for stressed volume, in other words the proportion of blood which contributes to creating pressure and blood flow. As right atrial pressure is influenced by Positive End-Expiratory Pressure (PEEP), one would expect elevated VExUS Scores with higher PEEP levels.
Influence of position on hemodynamics: conflicting effects on the circulatory system mediated by prone positioning have been described; no data about VExUS Score assessment in prone position is available.
- Conditions
- Venous Hemodynamics
- Being tested
- application of PEEP: starting PEEP = 15 mbar, application of PEEP: starting PEEP = 0 mbar
- Keywords
- Positive End-Expiratory Pressure (PEEP), Venous Excess Ultrasound (VExUS) score, Venous congestion, Proning
- Medical subject headings
- Hyperemia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
application of PEEP: starting PEEP = 15 mbarDiagnostic test
The application of PEEP will be delivered by a intensive care respirator with dedicated NIV- mode (Hamilton C1, Hamilton Medical AG, Bonaduz Switzerland) via mask (VariFit, Sleepnet Corporation, New Hampshire, USA) available in four sizes (S, M, L, XL). Pressure support will be set at 5 mbar, and trigger will be adjusted according to participants' comfort. Fraction of inspired oxygen will be 0.21. If starting PEEP = 15 mbar:
5 min stepwise increase of PEEP Measurements with decremental PEEP (15, 10, 5, 0 mbar)
application of PEEP: starting PEEP = 0 mbarDiagnostic test
The application of PEEP will be delivered by a intensive care respirator with dedicated NIV- mode (Hamilton C1, Hamilton Medical AG, Bonaduz Switzerland) via mask (VariFit, Sleepnet Corporation, New Hampshire, USA) available in four sizes (S, M, L, XL). Pressure support will be set at 5 mbar, and trigger will be adjusted according to participants' comfort. Fraction of inspired oxygen will be 0.21. If starting PEEP = 0 mbar: Measurement with increasing PEEP (0, 5, 10, 15 mbar)
| Study group | Role | What they receive |
|---|---|---|
| 1. Supine position 2. Prone Position | Experimental | First body position: randomized to supine position. Randomization of starting PEEP (0 or 15 mbar) in first body position and sequence of measurements.
Second body position: Prone Position. Randomization of starting PEEP (0 or 15 mbar) in second body position and sequence of measurements. Receives: Diagnostic Test: application of PEEP: starting PEEP = 15 mbar; Diagnostic Test: application of PEEP: starting PEEP = 0 mbar |
| 1. Prone Position 2. Supine Position | Experimental | First body position: randomized to prone position. Randomization of starting PEEP (0 or 15 mbar) in first body position and sequence of measurements.
Second body position: Supine Position. Randomization of starting PEEP (0 or 15 mbar) in second body position and sequence of measurements. Receives: Diagnostic Test: application of PEEP: starting PEEP = 15 mbar; Diagnostic Test: application of PEEP: starting PEEP = 0 mbar |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in VExUS score at 0, 5,10 and 15 mbar during non-invasive ventilation (NIV) in the supine position.
The Venous excess ultrasound (VExUS) score is a grading system that uses ultrasound to non-invasively assess and quantify systemic venous congestion by evaluating the inferior vena cava, hepatic veins, portal veins, and renal veins. A patient receives a grade from 0 (no congestion) to 3 (severe congestion) based on findings like IVC diameter and Doppler waveforms from the veins.
Measured: up to 15 min
Secondary outcomes (1)
Change in VExUS score at 0, 5,10,15 mbar during non-invasive ventilation in the prone position compared to the supine position.
The Venous excess ultrasound (VExUS) score is a grading system that uses ultrasound to non-invasively assess and quantify systemic venous congestion by evaluating the inferior vena cava, hepatic veins, portal veins, and renal veins. A patient receives a grade from 0 (no congestion) to 3 (severe congestion) based on findings like IVC diameter and Doppler waveforms from the veins.
Measured: up to 15 min
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted9 Dec 2025
- Study start25 Sep 2025
- Primary completion15 Dec 2025
- Study completion15 Dec 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Venous HemodynamicsStudies of the same condition, open and under way.
- More trials run by University Hospital, Basel, SwitzerlandThe 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
- Randomised
- Intervention model
- Sequential
- Model description
- Prospective explorative study
- Masking
- None (open label)
- Enrolment
- 40 participants (actual)
Sponsor and investigators
- Lead sponsor
- University Hospital, Basel, Switzerland
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Gregor Loosen, Dr. med., Principal investigator, University Hospital Basel, Intensive Care Unit
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07273617
- Sponsor's protocol ID
- am25Loosen2; 2025-01745
- Acronym
- VeNIVPro
- Status last verified
- Aug 2026
- First submitted
- 14 Nov 2025
- Last updated
- 21 Aug 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 21 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effects of Positive End-Expiratory Pressure (PEEP) and Prone Positioning in Healthy Volunteers on Venous Hemodynamics Including the Venous Excess Ultrasound (VExUS) Score
- ClinicalTrials.gov ID
- NCT07273617
- Acronym / sponsor ID
- VeNIVPro / am25Loosen2; 2025-01745
- Conditions
- Venous Hemodynamics
- Keywords
- Positive End-Expiratory Pressure (PEEP), Venous Excess Ultrasound (VExUS) score, Venous congestion, Proning
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 40 participants (actual)
- Lead sponsor
- University Hospital, Basel, SwitzerlandUniversity, hospital or other
- Study start
- 25 Sep 2025 (actual)
- Primary completion
- 15 Dec 2025 (actual)
- Study completion
- 15 Dec 2025 (actual)
- First posted
- 9 Dec 2025 (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 hemodynamic effects of proning and PEEP may vary depending on pre- existing cardiac function, lung mechanics, and volume status, and the available evidence remains conflicting. The impact on the VExUS score of these manoeuvres is unclear. This study aims to assess the effects of PEEP in supine and prone position on the VExUS score as well as echocardiographic parameters in a cohort of healthy volunteers.
Detailed description
Venous congestion: characterized by elevated venous pressure and impaired flow through the organs towards the right heart, contributes to organ dysfunction and is associated with adverse outcomes in critically ill patients. Historically, hemodynamic assessment has focused on the arterial side of circulation, giving less attention to venous hemodynamics. However, there is growing evidence that venous congestion is a mediator of adverse outcomes and contributes to end-organ damage. With increasing venous congestion, subsequent venous distension in the splanchnic circulation occurs and the pressure waveform of the right atrium is retrogradely transmitted into the distal venous circulation. The more venous congestion is present, the more pulsatility is transmitted into the periphery. This represents the backbone of the venous excess ultrasound (VExUS) score assessment. The VExUS score assessment therefore represents a multi-organ Doppler approach evaluating venous congestion by measuring the inferior vena cava (IVC) diameter, flow pattern of hepatic veins, portal vein and intra-renal veins by ultrasound.
Heart lung interactions and implications on VExUS: the VExUS score as well as femoral and jugular vein flows are expected to be affected by positive pressure ventilation. The VExUS score correlates with the Mean systemic filling pressure (MSFP) as a surrogate for stressed volume, in other words the proportion of blood which contributes to creating pressure and blood flow. As right atrial pressure is influenced by Positive End-Expiratory Pressure (PEEP), one would expect elevated VExUS Scores with higher PEEP levels.
Influence of position on hemodynamics: conflicting effects on the circulatory system mediated by prone positioning have been described; no data about VExUS Score assessment in prone position is available.
Study design
- Primary purpose
- Diagnosis
- Allocation
- Randomised
- Intervention model
- Sequential
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- Prospective explorative study
| Arm | Type | Receives |
|---|---|---|
| 1. Supine position 2. Prone Position | Experimental | Diagnostic Test: application of PEEP: starting PEEP = 15 mbar, Diagnostic Test: application of PEEP: starting PEEP = 0 mbarFirst body position: randomized to supine position. Randomization of starting PEEP (0 or 15 mbar) in first body position and sequence of measurements. Second body position: Prone Position. Randomization of starting PEEP (0 or 15 mbar) in second body position and sequence of measurements. |
| 1. Prone Position 2. Supine Position | Experimental | Diagnostic Test: application of PEEP: starting PEEP = 15 mbar, Diagnostic Test: application of PEEP: starting PEEP = 0 mbarFirst body position: randomized to prone position. Randomization of starting PEEP (0 or 15 mbar) in first body position and sequence of measurements. Second body position: Supine Position. Randomization of starting PEEP (0 or 15 mbar) in second body position and sequence of measurements. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (1 listed)
- Voluntary participants ≥ 18 years in good overall health with no relevant organ dysfunction in their medical history and signed informed consent form.
Key exclusion criteria (6 listed)
- Non-French or non-German speakers
- Unable to provide informed consent
- Body mass index > 40kg/m
- Self-reported pregnancy
- History of pneumothorax
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 |
|---|---|---|
| application of PEEP: starting PEEP = 15 mbarThe application of PEEP will be delivered by a intensive care respirator with dedicated NIV- mode (Hamilton C1, Hamilton Medical AG, Bonaduz Switzerland) via mask (VariFit, Sleepnet Corporation, New Hampshire, USA) available in four sizes (S, M, L, XL). Pressure support will be set at 5 mbar, and trigger will be adjusted according to participants' comfort. Fraction of inspired oxygen will be 0.21. If starting PEEP = 15 mbar: 5 min stepwise increase of PEEP Measurements with decremental PEEP (15, 10, 5, 0 mbar) | Diagnostic test | 1. Prone Position 2. Supine Position, 1. Supine position 2. Prone Position |
| application of PEEP: starting PEEP = 0 mbarThe application of PEEP will be delivered by a intensive care respirator with dedicated NIV- mode (Hamilton C1, Hamilton Medical AG, Bonaduz Switzerland) via mask (VariFit, Sleepnet Corporation, New Hampshire, USA) available in four sizes (S, M, L, XL). Pressure support will be set at 5 mbar, and trigger will be adjusted according to participants' comfort. Fraction of inspired oxygen will be 0.21. If starting PEEP = 0 mbar: Measurement with increasing PEEP (0, 5, 10, 15 mbar) | Diagnostic test | 1. Prone Position 2. Supine Position, 1. Supine position 2. Prone Position |
Primary outcome
Change in VExUS score at 0, 5,10 and 15 mbar during non-invasive ventilation (NIV) in the supine position.
Time frame: up to 15 min
The Venous excess ultrasound (VExUS) score is a grading system that uses ultrasound to non-invasively assess and quantify systemic venous congestion by evaluating the inferior vena cava, hepatic veins, portal veins, and renal veins. A patient receives a grade from 0 (no congestion) to 3 (severe congestion) based on findings like IVC diameter and Doppler waveforms from the veins.
1 secondary outcome
Change in VExUS score at 0, 5,10,15 mbar during non-invasive ventilation in the prone position compared to the supine position.
Time frame: up to 15 min
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 21 Aug 2026.
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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.
Gregor Loosen, Dr. med. principal investigator
University Hospital Basel, Intensive Care Unit
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing application of PEEP: starting PEEP = 15 mbar and application of PEEP: starting PEEP = 0 mbar in people with Venous Hemodynamics, run by University Hospital, Basel, Switzerland at 1 site in Switzerland.
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 6 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 21 Aug 2026. 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 Switzerland. 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?
Change in VExUS score at 0, 5,10 and 15 mbar during non-invasive ventilation (NIV) in the supine position. (time frame: up to 15 min). 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 21 Aug 2026.