Mathematical Arterialisation of Capillary Blood for Blood Gas Analysis in Critical Ill Patients

September 20, 2021 updated by: PD Dr. Tobias Müller, RWTH Aachen University
The aim of the study is to compare capillary blood gas analysis compensated by v-TAC software (aCBGE, aCBGF) to arterial blood gas analysis (ABG) in terms of pH, pCO2 and pO2 and the clinical usefulness of this method compared to the gold standard of ABG.

Study Overview

Status

Status

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

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

In clinical practice blood gas analysis is an essential tool for monitoring respiratory status. The gold-standard method is arterial blood gas analysis (ABG) of blood from the patient's radial or femoral artery. An alternative to arterial sampling commonly used is arterialized capillary blood gas analysis from the earlobe (CBGE). Though CBGE is less invasive and can be performed by non-medical staff, it is less useful in the acute setting because an adequate vasodilatation is needed which typically lasts for at least 10 minutes and the quality of results tends to be operator dependable. Different trials have evaluated the agreement between ABG and CBGE. Whereas a close agreement between ABG and CBGE has been found for evaluating pH and the partial pressure of carbon dioxide (PCO2), several trials showed considerable variations for the partial pressure of oxygen (PO2) and that CBGE tends to underestimate PO2. Similar findings apply for capillary blood gas analysis from the fingertip (CBGF) which is even less accurate compared to CBGE in estimating PO2. Recently a method has been developed to calculate ABG values mathematically from peripheral venous blood, supplemented with oxygen saturation (SpO2) measurement by pulse oximetry, by use of venous-to-arterial conversion (v-TAC) software (OBI Medical, Denmark). The principle of the method is a mathematical transformation of venous blood gas analysis (VBG) values to arterialised values (aVBG) by simulating the transport of blood back through the tissue (6). This approach leads to a clinically acceptable agreement between ABG and aVBG for pH and PCO2. For PO2 the limits of agreement of aVBG are similar to those of PO2 from CBGE for values below 75 mmHg and with mean bias close to zero. However, it has not been evaluated previously whether v-TAC software can be used to calculate ABG values from CBGE (aCBGE) or CBGF (aCBGF). As CBGE and CBGF values are much closer to ABG values, compared to VBG values, the agreement between aCBGE/aCBGF and ABG in terms of pH, PCO2 and pO2 might be better compared to CBG without mathematical arterialisation by v-TAC.

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.
70

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.

Study Contact Backup

Study Locations

  • Germany
      • Aachen, Germany, 52074
        • Recruiting
        • Clinic for pneumology and internal intensive care
        • Contact:
        • Principal Investigator:
          • Tobias Müller, PD Dr. med.

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 to 96 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Admission to the intensive / intermediate care or weaning unit at the department of pneumology and intensive care medicine of the university hospital RWTH Aachen
  • Arterial line inserted to monitor the patient's blood pressure or respiratory status
  • Male or female aged ≥ 18 years
  • Written informed consent prior to study participation
  • The subject is willing and able to follow the procedures outlined in the protocol

Exclusion Criteria:

  • Hemodynamic instability
  • Impaired perfusion of peripheral limbs e.g. due to severe heart failure
  • Pregnant and lactating females. Pregnancy will be ruled out in females of childbearing age by pregnancy test.
  • Patient has been committed to an institution by legal or regulatory order
  • The subject is mentally or legally incapacitated

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: N/A
  • Interventional Model: Single Group 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.
Other: Study Arm
All patient will be included in this arm
Diagnostic test: Study procedure
  • Measurement of the flow rate of supplemental oxygen
  • Measurement of the peripheral arterial saturation (SpO2) by pulse oximetry
  • Taking of an ABG sample (ABG1) from the arterial line
  • Taking of capillary blood gas analysis from the earlobe and from the finger tip
  • Taking of an a second ABG (ABG2) from the arterial line

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
Comparison of pO2 Levels (in mmHg) in capillary blood samples corrected with VTAC Software to arterial blood samples
Time Frame: 10 minutes after the first blood sample is taken
Capillary and arterial pO2 Levels will be measured using a blood gas analyser. Afterwards pO2 levels in the capillary sample will be compensated by VTAC software and compensated pO2 levels will be compared to arterial PO2 levels using the Bland-Altman method.
10 minutes after the first blood sample is taken

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
Comparison of pCO2 Levels (in mmHg) in capillary blood samples corrected with VTAC Software to arterial blood samples
Time Frame: 10 minutes after the first blood sample is taken
Capillary and arterial pCO2 Levels will be measured using a blood gas analyser. Afterwards pCO2 levels in the capillary sample will be compensated by VTAC software and compensated pCO2 levels will be compared to arterial PCO2 levels using the Bland-Altman method.
10 minutes after the first blood sample is taken
Comparison of pH in capillary blood samples corrected with VTAC Software to arterial blood samples
Time Frame: 10 minutes after the first blood sample is taken
Capillary and arterial pH will be measured using a blood gas analyser. Afterwards pH in the capillary sample will be compensated by VTAC software and compensated pH will be compared to arterial pH levels using the Bland-Altman method.
10 minutes after the first blood sample is taken

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.
RWTH Aachen University

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
OBI Medical

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.
October 1, 2019

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.
October 1, 2021

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.
November 1, 2021

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).
October 21, 2019

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.
October 28, 2019

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.
October 30, 2019

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.
September 21, 2021

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.
September 20, 2021

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.
September 1, 2021

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

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.
  • 18-125

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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