<clinical_study>
  <!-- This xml conforms to an XML Schema at:
    https://clinicaltrials.gov/ct2/html/images/info/public.xsd -->
  <required_header>
    <download_date>ClinicalTrials.gov processed this data on September 20, 2023</download_date>
    <link_text>Link to the current ClinicalTrials.gov record.</link_text>
    <url>https://clinicaltrials.gov/ct2/show/NCT03009305</url>
  </required_header>
  <id_info>
    <org_study_id>2015/3995</org_study_id>
    <nct_id>NCT03009305</nct_id>
  </id_info>
  <brief_title>Cerebral Oximetry in Lower Body Negative Pressure</brief_title>
  <official_title>Cerebral Oxygen Saturation, Mean Systemic Filling Pressure and Haemodynamic Effects of PEP and CPAP in Lower Body Negative Pressure</official_title>
  <sponsors>
    <lead_sponsor>
      <agency>Oslo University Hospital</agency>
      <agency_class>Other</agency_class>
    </lead_sponsor>
  </sponsors>
  <source>Oslo University Hospital</source>
  <oversight_info>
    <has_dmc>No</has_dmc>
  </oversight_info>
  <brief_summary>
    <textblock>
      The study aims to describe hemodynamic effects of lower body negative pressure (LBNP).&#xD;
&#xD;
        1. If and how changes in cerebral oxygen saturation (StO2) measured by near infrared&#xD;
           spectroscopy (NIRS) relate to changes in blood flow in the carotid arteries during&#xD;
           progressive LBNP.&#xD;
&#xD;
        2. If and how mean systemic filling pressure (MSFP) can be measured by brief occlusion of&#xD;
           blood flow to an arm and if this relates to LBNP-level.&#xD;
&#xD;
        3. If and how pulse pressure variations and photoplethysmographic amplitude variations&#xD;
           during positive expiratory pressure (PEP) and continuous positive airway pressure (CPAP)&#xD;
           relate to LBNP-level.&#xD;
    </textblock>
  </brief_summary>
  <detailed_description>
    <textblock>
      20 healthy volunteers will be included. The study protocol consists of two parts.&#xD;
&#xD;
        1. LBNP is applied stepwise (20 mmHg increments). At each LBNP-level, after 2 min&#xD;
           stabilization, blood flow in internal and external carotid arteries is measured.&#xD;
           Thereafter, MSFP is measured. LBNP is applied to -80 mmHg, but terminated sooner if the&#xD;
           subject experiences signs of decompensation.&#xD;
&#xD;
           Changes in cerebral StO2 will be related to relative changes in blood flow in the&#xD;
           carotid arteries. After these measurements, blood flow to one arm will be occluded for&#xD;
           30 s. Venous pressure measured in an antecubital vein approximates MSFP. This will be&#xD;
           related to volume status (LBNP-level and stroke volume reduction).&#xD;
&#xD;
        2. LBNP is applied stepwise (20 mmHg increments). At each LBNP-level, after 2 min&#xD;
           stabilization, PEP and CPAP are applied at 0, 5 and 10 cmH20. LBNP is applied to -80&#xD;
           mmHg, but terminated sooner if the subject experiences signs of decompensation.&#xD;
&#xD;
      Flow in carotid arteries is measured by ultrasound/Doppler. Skin blood flow in the forehead&#xD;
      measured by laser Doppler flowmetry and transcutaneous oxygen saturation.&#xD;
&#xD;
      If possible, blood flow velocity in a. cerebri media will be measured by transcranial&#xD;
      Doppler.&#xD;
&#xD;
      Central venous pressure will be approximated by measuring pressure in the left subclavian&#xD;
      vein (&quot;half-way&quot; catheter).&#xD;
&#xD;
      Cardiac stroke volume will be measured by suprasternal Doppler. Expiratory carbon dioxide&#xD;
      (CO2) will be measured and recorded. Acral skin photoplethysmography performed using&#xD;
      proprietary and custom-made photoplethysmographs.&#xD;
&#xD;
      Arterial blood pressure approximated by finger volume-clamp method.&#xD;
&#xD;
      The measurements above will be used for analyses of possible physiological mechanisms and&#xD;
      post-hoc analyses.&#xD;
    </textblock>
  </detailed_description>
  <overall_status>Completed</overall_status>
  <start_date>October 2015</start_date>
  <completion_date type="Actual">March 2017</completion_date>
  <primary_completion_date type="Actual">March 2017</primary_completion_date>
  <phase>N/A</phase>
  <study_type>Interventional</study_type>
  <has_expanded_access>No</has_expanded_access>
  <study_design_info>
    <allocation>N/A</allocation>
    <intervention_model>Single Group Assignment</intervention_model>
    <primary_purpose>Diagnostic</primary_purpose>
    <masking>None (Open Label)</masking>
  </study_design_info>
  <primary_outcome>
    <measure>StO2 (tissue oxygen saturation).</measure>
    <time_frame>Approximatrly 30 min: From start LBNP (lower body negative pressure) exposure to 5 min after end LBNP.</time_frame>
    <description>Association between cerebral StO2 and flow in a. carotis interna.</description>
  </primary_outcome>
  <secondary_outcome>
    <measure>MSFP, mean systemic filling pressure (arm venous pressure during vascular occlusion).</measure>
    <time_frame>Approximatrly 30 min: From start LBNP (lower body negative pressure) exposure to 5 min after end LBNP.</time_frame>
    <description>Association between MSFP and volume status.</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Dynamic variables and PEP (positive expiratory pressure)/CPAP (continuous positive airway pressure)</measure>
    <time_frame>Approximatrly 30 min: From start LBNP (lower body negative pressure) exposure to 5 min after end LBNP.</time_frame>
    <description>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).</description>
  </secondary_outcome>
  <number_of_arms>1</number_of_arms>
  <enrollment type="Actual">20</enrollment>
  <condition>Hypovolemia</condition>
  <arm_group>
    <arm_group_label>Lower body negative pressure</arm_group_label>
    <arm_group_type>Experimental</arm_group_type>
    <description>Single-arm, lower body negative pressure, continuous positive airway pressure, positive expiratory pressure.</description>
  </arm_group>
  <intervention>
    <intervention_type>Other</intervention_type>
    <intervention_name>Lower body negative pressure</intervention_name>
    <description>Model of hypovolemia: Lower body negative pressure down to -80 mmHg (maximum).</description>
    <arm_group_label>Lower body negative pressure</arm_group_label>
  </intervention>
  <intervention>
    <intervention_type>Device</intervention_type>
    <intervention_name>Continuous positive airway pressure</intervention_name>
    <description>CPAP of 0, 5 and 10 cm water (H2O).</description>
    <arm_group_label>Lower body negative pressure</arm_group_label>
    <other_name>CPAP</other_name>
  </intervention>
  <intervention>
    <intervention_type>Device</intervention_type>
    <intervention_name>Positive expiratory pressure</intervention_name>
    <description>PEP of 0, 5 and 10 cm H2O.</description>
    <arm_group_label>Lower body negative pressure</arm_group_label>
    <other_name>PEP</other_name>
  </intervention>
  <eligibility>
    <criteria>
      <textblock>
        Inclusion Criteria:&#xD;
&#xD;
          -  Healthy volunteer (informed consent)&#xD;
&#xD;
        Exclusion Criteria:&#xD;
&#xD;
          -  Disease/physical condition limiting normal physical activity or requiring medication&#xD;
             (except allergies/contraceptives)&#xD;
&#xD;
          -  History of syncope (except with obvious vasovagal etiology)&#xD;
&#xD;
          -  Cardiac arrhythmia&#xD;
&#xD;
          -  Pregnancy&#xD;
&#xD;
          -  Skin infections in the elbow crease&#xD;
      </textblock>
    </criteria>
    <gender>All</gender>
    <minimum_age>18 Years</minimum_age>
    <maximum_age>N/A</maximum_age>
    <healthy_volunteers>Accepts Healthy Volunteers</healthy_volunteers>
  </eligibility>
  <overall_official>
    <last_name>Svein Aslak Landsverk, M.D., PhD</last_name>
    <role>Principal Investigator</role>
    <affiliation>Oslo University Hospital</affiliation>
  </overall_official>
  <location>
    <facility>
      <name>Oslo University Hospital</name>
      <address>
        <city>Oslo</city>
        <zip>0450</zip>
        <country>Norway</country>
      </address>
    </facility>
  </location>
  <location_countries>
    <country>Norway</country>
  </location_countries>
  <verification_date>March 2017</verification_date>
  <study_first_submitted>October 26, 2015</study_first_submitted>
  <study_first_submitted_qc>December 30, 2016</study_first_submitted_qc>
  <study_first_posted type="Estimate">January 4, 2017</study_first_posted>
  <last_update_submitted>March 16, 2017</last_update_submitted>
  <last_update_submitted_qc>March 16, 2017</last_update_submitted_qc>
  <last_update_posted type="Actual">March 17, 2017</last_update_posted>
  <responsible_party>
    <responsible_party_type>Principal Investigator</responsible_party_type>
    <investigator_affiliation>Oslo University Hospital</investigator_affiliation>
    <investigator_full_name>Svein Aslak Landsverk</investigator_full_name>
    <investigator_title>MD, PhD</investigator_title>
  </responsible_party>
  <condition_browse>
    <!-- CAUTION:  The following MeSH terms are assigned with an imperfect algorithm            -->
    <mesh_term>Hypovolemia</mesh_term>
  </condition_browse>
  <!-- Results have not yet been posted for this study                                          -->
</clinical_study>


download date: ClinicalTrials.gov processed this data on September 20, 2023
link text: Link to the current ClinicalTrials.gov record.
url: https://clinicaltrials.gov/ct2/show/NCT03009305
org study id: 2015/3995
nct id: NCT03009305
lead sponsor: 
has dmc: No
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. 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.

        3. 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.
20 healthy volunteers will be included. The study protocol consists of two parts.

        1. 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).

        2. 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.
allocation: N/A
intervention model: Single Group Assignment
primary purpose: Diagnostic
masking: None (Open Label)
measure: StO2 (tissue oxygen saturation).
time frame: Approximatrly 30 min: From start LBNP (lower body negative pressure) exposure to 5 min after end LBNP.
description: Association between cerebral StO2 and flow in a. carotis interna.
measure: 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.
description: Association between MSFP and volume status.
measure: 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.
description: 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).
arm group label: Lower body negative pressure
arm group type: Experimental
description: Single-arm, lower body negative pressure, continuous positive airway pressure, positive expiratory pressure.
intervention type: Other
intervention name: Lower body negative pressure
description: Model of hypovolemia: Lower body negative pressure down to -80 mmHg (maximum).
arm group label: Lower body negative pressure
intervention type: Device
intervention name: Continuous positive airway pressure
description: CPAP of 0, 5 and 10 cm water (H2O).
arm group label: Lower body negative pressure
other name: CPAP
intervention type: Device
intervention name: Positive expiratory pressure
description: PEP of 0, 5 and 10 cm H2O.
arm group label: Lower body negative pressure
other name: PEP
criteria: 
gender: All
minimum age: 18 Years
maximum age: N/A
healthy volunteers: Accepts Healthy Volunteers
last name: Svein Aslak Landsverk, M.D., PhD
role: Principal Investigator
affiliation: Oslo University Hospital
facility: 
country: Norway
responsible party type: Principal Investigator
investigator affiliation: Oslo University Hospital
investigator full name: Svein Aslak Landsverk
investigator title: MD, PhD
mesh term: Hypovolemia