The Effect of FiO2 on PaO2/FiO2 Ratio

April 25, 2019 updated by: Angelique Spoelstra-de Man, Amsterdam UMC, location VUmc

The Effect of Inspiratory Oxygen Fraction on the Ratio of Partial Arterial Oxygen Pressure and Inspiratory Oxygen Fraction (PaO2/FiO2 Ratio) in Mechanically Ventilated Patients With and Without Mild to Moderate ARDS

The PaO2/FiO2 ratio is frequently used to determine the severity of lung injury in mechanically ventilated patients. However, several mathematical models have shown that PaO2/FiO2 ratio depends on FiO2. The relationship is complex and depends on numerous physiological variables, including shunt fraction, and arterio-venous oxygen difference. The nonlinear relation between PaO2/FiO2 and FiO2 underlines the limitations describing the intensity of hypoxemia using PaO2/FiO2 and is thus of major importance for the clinician. Surprisingly, this relationship has only been assessed mathematically. Obviously, the accuracy of the mathematical relationship depends on the input variables used.

The current study is designed to assess the PaO2/FiO2 vs FiO2 relation in mechanically ventilated patients without ARDS (n =10) and with mild or moderate ARDS (n =10). In order to explain the dependency of the PaO2/FiO2 on FiO2, shunt fraction and alveolar - arterial oxygen difference ((A-a)DO2) will be determined in these patients.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Unknown

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Rationale:

The PaO2/FiO2 ratio is frequently used to determine the severity of lung injury in mechanically ventilated patients. However, several mathematical models have shown that PaO2/FiO2 ratio depends on FiO2. The relationship is complex and depends on numerous physiological variables, including shunt fraction, and arterio-venous oxygen difference. The nonlinear relation between PaO2/FiO2 and FiO2 underlines the limitations describing the intensity of hypoxemia using PaO2/FiO2 and is thus of major importance for the clinician. Surprisingly, this relationship has only been assessed mathematically. Obviously, the accuracy of the mathematical relationship depends on the input variables used.

The current study is designed to assess the PaO2/FiO2 vs FiO2 relation in mechanically ventilated patients without ARDS (n =10) and with mild or moderate ARDS (n =10). In order to explain the dependency of the PaO2/FiO2 on FiO2, shunt fraction and alveolar - arterial oxygen difference ((A-a)DO2) will be determined in these patients.

Objective:

To study the relation between PaO2/FiO2-ratio and FiO2

Study design:

An unblinded, prospective, interventional study

Study population:

Mechanically ventilated patients > 18 years, admitted to the Intensive Care Unit of VU-Medical Center post cardiac surgery without ARDS (n = 10) and with mild to moderate ARDS (n = 10).

Intervention:

Two interventions will be performed:

  1. Modulation of FiO2: FiO2 will be reduced to 21% or until peripheral oxygen saturation of 92%, whatever occurs first. Subsequently FiO2 will be increased up to 100%.
  2. Withdrawal of blood: Blood will be withdrawn from the indwelling arterial line and pulmonary artery catheter. No catheters will be inserted for the study. The maximum number of time points is 7. At each time point 1.5 ml of blood will be withdrawn from both the arterial and pulmonary artery catheter for blood gas analysis. At the start and the end of the study period 2 additional blood samples of 5 ml each will be drawn. Accordingly, the maximum amount of blood obtained will be less than 50 ml.

Main study parameters/endpoints:

At each level of FiO2 the following parameters will be assessed:

  • Arterial blood gas analysis, including SaO2
  • Central Venous oxygen saturation and content
  • Hemoglobin
  • Body temperature
  • End tidal CO2
  • VO2 and VCO2
  • Ventilatory parameters (tidal volume, respiratory rate, Ppeak Paw)
  • Hemodynamics (Bloodpressure and Heart Rate)

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Anticipated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
20

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.
  • Name: Angelique Spoelstra - de Man, MD, PhD
  • Phone Number: +31204443924
  • Email: am.spoelstra@vumc.nl

Study Contact Backup

Study Locations

  • Netherlands
      • Amsterdam, Netherlands, 1081 HV
        • Recruiting
        • VU University Medical Center
        • Contact:
          • Angelique Spoelstra - de Man, PhD

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

14 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

All mechanically ventilated patients, admitted to the Intensive Care Unit of VU-Medical Center post cardiac surgery without ARDS and with mild to moderate ARDS. In order to be eligible to participate in this study, a subject must meet all of the following criteria:

  • Mechanically ventilated patients
  • Stable hemodynamics
  • Stable haemoglobin level
  • Stable body temperature
  • Stable level of sedation
  • Pulmonary-Artery and Artery catheter

Exclusion Criteria:

  • Incomplete revascularization after CABG
  • Cardiac ischemia
  • Neurotrauma

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Diagnostic
  • Allocation: Non-Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Without ARDS

Patients admitted to the ICU after cardiac surgery with a PaO2/FiO2 ratio > 300.

Modulation of FiO2: FiO2 will be reduced to 21% or until peripheral oxygen saturation of 92%, whatever occurs first. Subsequently FiO2 will be increased up to 100%.
Drug: Modulation of FiO2
Modulation of FiO2: FiO2 will be reduced to 21% or until peripheral oxygen saturation of 92%, whatever occurs first. Subsequently FiO2 will be increased up to 100%.
Experimental: With mild to moderate ARDS

Patients admitted to the ICU after cardiac surgery with a PaO2/FiO2 ratio > 100 and < 300.

Modulation of FiO2: FiO2 will be reduced to 21% or until peripheral oxygen saturation of 92%, whatever occurs first. Subsequently FiO2 will be increased up to 100%.
Drug: Modulation of FiO2
Modulation of FiO2: FiO2 will be reduced to 21% or until peripheral oxygen saturation of 92%, whatever occurs first. Subsequently FiO2 will be increased up to 100%.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
The effect of FiO2 on the PaO2/FiO2-ratio
Time Frame: 2 hours
To study the effect of FiO2 on the PaO2/FiO2-ratio in mechanically ventilated patients post cardiac surgery without ARDS and with mild to moderate ARDS
2 hours

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Shunt fraction, arteriovenous oxygen difference and alveolar - arterial oxygen difference
Time Frame: 2 hours
Shunt fraction, arteriovenous oxygen difference and alveolar - arterial oxygen difference will be determined to explain the relationship between FiO2 and the PaO2/FiO2-ratio
2 hours

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Amsterdam UMC, location VUmc

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Angelique Spoelstra - de Man, MD, PhD, Amsterdam UMC, location VUmc

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
September 1, 2017

Primary Completion (Anticipated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
January 1, 2020

Study Completion (Anticipated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
August 1, 2020

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
May 15, 2017

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
May 15, 2017

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
May 17, 2017

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
April 26, 2019

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 25, 2019

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
April 1, 2019

More Information

Terms related to this study

Keywords

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • NL61945.029.17

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

No

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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