Measurement of Airway Opening Index During Out-of-hospital Cardiac Arrest: The Lazarus AOI Trial.
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- This is an observational study: the protocol does not assign a study treatment.
- Who it may be relevant to
- Registry conditions: Cardiac Arrest (CA), Out-of-hospital Cardiac Arrest (OHCA), Resuscitated Sudden Cardiac Death. Basic parameters: from 18 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- Belgium
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
Unsure about the terms? Read our patient guide →
Overview
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: 1. What is the prevalence of AOI during CPR? 2. Is there a correlation between AOI and return of spontaneous circulation (ROSC)? 3. 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.
Primary outcome measures
- ROSC [Time frame: Initial resuscitation (first day)]
Eligibility criteria
Inclusion criteria
- 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.
Exclusion criteria
- 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.
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: No
Study design
- Observational model
- Cohort
Study locations
Belgium · 1 center
- Ghent University Hospital — Ghent
Identifiers
NCT: NCT07438938 · ONZ-2025-0418