Cardiac Arrest (CA)Lazarus-AOINCT07438938
Measurement of Airway Opening Index During Out-of-hospital Cardiac Arrest: The Lazarus AOI Trial.
An observational study of Cardiac Arrest (CA) and Out-of-hospital Cardiac Arrest (OHCA), run by University Hospital, Ghent at 1 site in Belgium.
Trial summary
Out-of-hospital cardiac arrest (OHCA) is a leading cause of death worldwide. Despite constantly improving resuscitation techniques, the chances of survival remain limited. During cardiopulmonary resuscitation (CPR), a closure of the airway may occur, impeding ventilation. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Cardiac Arrest (CA), Out-of-hospital Cardiac Arrest (OHCA), Resuscitated Sudden Cardiac Death
- How many people
- 150 participants
- Where
- 1 siteBelgium
- Study dates
- 1 Oct 2022to 1 Jan 2027
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
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
- No healthy volunteers
- Adult, Older adult
Study population: This retrospective observational cohort study included adult patients who suffered an out-of-hospital cardiac arrest (OHCA) and were treated by the Mobile Emergency Team (MET) of Ghent University Hospital. All cases were registered in the Lazarus database, which prospectively collects prehospital CPR data including continuous capnography recordings.
Who may be able to join
- Adult (over 18 years old) patients with out-of-hospital cardiac arrest.
- Patients undergoing cardiopulmonary resuscitation (CPR).
- Patients who were intubated and had available capnogram recordings immediately after intubation.
Who cannot join
- Patients that were not intubated
- Patients that did not receive CPR following intubation
- Cases with a technical challenge with the ETCO₂ measurement (i.e., issues with waveform data of the capnogram.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Thomas Tackaert, MD contact
Belgium1 site, 1 recruiting
- Recruiting
Ghent University Hospital
Ghent, East-Flanders, B9000
Said Hachimi Idrissi, MD, PhD, 0032 9 332 50 24, SAID.HACHIMIIDRISSI@ugent.be
About this study
Out-of-hospital cardiac arrest (OHCA) is a leading cause of death worldwide. Despite constantly improving resuscitation techniques, the chances of survival remain limited. During cardiopulmonary resuscitation (CPR), a closure of the airway may occur, impeding ventilation. This phenomenon also complicates the interpretation of the end-tidal CO2 (ETCO2) in the capnogram. The extent to which airway closure occurs is quantified by the Airway Opening Index (AOI). This can be calculated from the capnogram and is seen as a measure of the quality of CPR applied as well as a possible indicator to predict the outcome of CPR.
In this study, we analyse capnogram data from approximately 150 cases, collected during interventions for OHCA and logged in the Lazarus database (UZ Gent and AZORG) to answer three research questions below:
Read more
- What is the prevalence of AOI during CPR?
- Is there a correlation between AOI and return of spontaneous circulation (ROSC)?
- Does the application of positive end-expiratory pressure (PEEP) affect the AOI and ROSC?
A mathematical model for calculating AOI, based on a method from previous work by Bandhari et al. [1] will be developed. Using this model, the AOI will be calculated from the individual capnograms for all cases in the Lazarus database.
In addition, a multivariable regression model will be used to analyse whether AOI can be used to predict ROSC. Corrections will be made for relevant confounders such as age, gender, witnessed arrest and rhythm pattern.
Finally, it is investigated whether PEEP has a positive influence on AOI. This study aims to contribute to better insights into airway dynamics during CPR and the optimization of ventilation in OHCA.
Read the detailed description
This study is a retrospective observational cohort study based on capnography data from out-of-hospital cardiac arrest cases registered in the Lazarus database.
- Conditions
- Cardiac Arrest (CA), Out-of-hospital Cardiac Arrest (OHCA), Resuscitated Sudden Cardiac Death
- Keywords
- capnography, airway closure
- Medical subject headings
- Heart Arrest, Out-of-Hospital Cardiac Arrest
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| ROSC | Patients with return-of-spontaneous circulation during initial resuscitation. | |
| non-ROSC | Patients without return-of-spontaneous circulation during initial resuscitation. |
What is being measured
The primary outcome is the main question the study is designed to answer.
ROSC
Return-of-spontaneous circulation during initial resuscitation.
Measured: Initial resuscitation (first day)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted27 Feb 2026
- Study start1 Oct 2022
- Primary completion30 Sep 2026 (estimated)
- Study completion1 Jan 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Cardiac Arrest (CA)Studies of the same condition, open and under way.
- More trials run by University Hospital, GhentThe 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
- Observational
- Observational model
- Cohort
- Time perspective
- Other
- Enrolment
- 150 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University Hospital, Ghent
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07438938
- Sponsor's protocol ID
- ONZ-2025-0418
- Acronym
- Lazarus-AOI
- Status last verified
- Nov 2025
- First submitted
- 14 Nov 2025
- Last updated
- 27 Feb 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 27 Feb 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Measurement of Airway Opening Index During Out-of-hospital Cardiac Arrest: The Lazarus AOI Trial.
- ClinicalTrials.gov ID
- NCT07438938
- Acronym / sponsor ID
- Lazarus-AOI / ONZ-2025-0418
- Conditions
- Cardiac Arrest (CA), Out-of-hospital Cardiac Arrest (OHCA), Resuscitated Sudden Cardiac Death
- Keywords
- capnography, airway closure
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 150 participants (estimated)
- Lead sponsor
- University Hospital, GhentUniversity, hospital or other
- Study start
- 1 Oct 2022 (actual)
- Primary completion
- 30 Sep 2026 (estimated)
- Study completion
- 1 Jan 2027 (estimated)
- First posted
- 27 Feb 2026 (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.
Out-of-hospital cardiac arrest (OHCA) is a leading cause of death worldwide. Despite constantly improving resuscitation techniques, the chances of survival remain limited. During cardiopulmonary resuscitation (CPR), a closure of the airway may occur, impeding ventilation. This phenomenon also complicates the interpretation of the end-tidal CO2 (ETCO2) in the capnogram. The extent to which airway closure occurs is quantified by the Airway Opening Index (AOI). This can be calculated from the capnogram and is seen as a measure of the quality of CPR applied as well as a possible indicator to predict the outcome of CPR.
In this study, we analyse capnogram data from approximately 150 cases, collected during interventions for OHCA and logged in the Lazarus database (UZ Gent and AZORG) to answer three research questions below:
- What is the prevalence of AOI during CPR?
- Is there a correlation between AOI and return of spontaneous circulation (ROSC)?
- Does the application of positive end-expiratory pressure (PEEP) affect the AOI and ROSC?
A mathematical model for calculating AOI, based on a method from previous work by Bandhari et al. [1] will be developed. Using this model, the AOI will be calculated from the individual capnograms for all cases in the Lazarus database.
In addition, a multivariable regression model will be used to analyse whether AOI can be used to predict ROSC. Corrections will be made for relevant confounders such as age, gender, witnessed arrest and rhythm pattern.
Finally, it is investigated whether PEEP has a positive influence on AOI. This study aims to contribute to better insights into airway dynamics during CPR and the optimization of ventilation in OHCA.
Detailed description
This study is a retrospective observational cohort study based on capnography data from out-of-hospital cardiac arrest cases registered in the Lazarus database.
Study design
- Observational model
- Cohort
- Time perspective
- Other
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| ROSC | – | –Patients with return-of-spontaneous circulation during initial resuscitation. |
| non-ROSC | – | –Patients without return-of-spontaneous circulation during initial resuscitation. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- This retrospective observational cohort study included adult patients who suffered an out-of-hospital cardiac arrest (OHCA) and were treated by the Mobile Emergency Team (MET) of Ghent University Hospital. All cases were registered in the Lazarus database, which prospectively collects prehospital CPR data including continuous capnography recordings.
Key inclusion criteria (3 listed)
- Adult (over 18 years old) patients with out-of-hospital cardiac arrest.
- Patients undergoing cardiopulmonary resuscitation (CPR).
- Patients who were intubated and had available capnogram recordings immediately after intubation.
Key exclusion criteria (3 listed)
- Patients that were not intubated
- Patients that did not receive CPR following intubation
- Cases with a technical challenge with the ETCO₂ measurement (i.e., issues with waveform data of the capnogram.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
ROSC
Time frame: Initial resuscitation (first day)
Return-of-spontaneous circulation during initial resuscitation.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 27 Feb 2026.
- Individual participant dataSharing planned: No
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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.
Thomas Tackaert, MD contact
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Cardiac Arrest (CA) and Out-of-hospital Cardiac Arrest (OHCA), run by University Hospital, Ghent at 1 site in Belgium.
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 3 inclusion and 3 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: looking for participants now, as of the sponsor's last update on 27 Feb 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 Belgium. 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?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Said Hachimi Idrissi, MD, PhD (0032 9 332 50 24, SAID.HACHIMIIDRISSI@ugent.be), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
ROSC (time frame: Initial resuscitation (first day)). 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 27 Feb 2026.