Effects of Positive End-Expiratory Pressure (PEEP) and Prone Positioning in Healthy Volunteers on Venous Hemodynamics Including the Venous Excess Ultrasound (VExUS) Score

NCT ID: NCT07273617

Last Updated: 2025-12-09

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

RECRUITING

Clinical Phase

NA

Total Enrollment

40 participants

Study Classification

INTERVENTIONAL

Study Start Date

2025-09-25

Study Completion Date

2026-06-30

Brief Summary

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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

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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

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Venous Hemodynamics

Study Design

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Allocation Method

RANDOMIZED

Intervention Model

SEQUENTIAL

Prospective explorative study
Primary Study Purpose

DIAGNOSTIC

Blinding Strategy

NONE

Study Groups

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1. Supine position 2. Prone Position

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.

Group Type EXPERIMENTAL

application of PEEP: starting PEEP = 15 mbar

Intervention Type DIAGNOSTIC_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 mbar

Intervention Type DIAGNOSTIC_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)

1. Prone Position 2. Supine Position

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.

Group Type EXPERIMENTAL

application of PEEP: starting PEEP = 15 mbar

Intervention Type DIAGNOSTIC_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 mbar

Intervention Type DIAGNOSTIC_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)

Interventions

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application of PEEP: starting PEEP = 15 mbar

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)

Intervention Type DIAGNOSTIC_TEST

application of PEEP: starting PEEP = 0 mbar

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)

Intervention Type DIAGNOSTIC_TEST

Eligibility Criteria

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Inclusion Criteria

* Voluntary participants ≥ 18 years in good overall health with no relevant organ dysfunction in their medical history and signed informed consent form.

Exclusion Criteria

* 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
Minimum Eligible Age

18 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

Yes

Sponsors

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University Hospital, Basel, Switzerland

OTHER

Sponsor Role lead

Responsible Party

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Responsibility Role SPONSOR

Principal Investigators

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Gregor Loosen, Dr. med.

Role: PRINCIPAL_INVESTIGATOR

University Hospital Basel, Intensive Care Unit

Locations

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University Hospital Basel, Intensive Care Unit

Basel, , Switzerland

Site Status RECRUITING

Countries

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Switzerland

Central Contacts

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Gregor Loosen, Dr. med.

Role: CONTACT

+41 61 328 40 90

Kaspar Bachmann, PD Dr. med.

Role: CONTACT

Facility Contacts

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Gregor Loosen, Dr. med.

Role: primary

+41 61 328 40 90

Other Identifiers

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am25Loosen2; 2025-01745

Identifier Type: -

Identifier Source: org_study_id

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