Prehospital ResuscitationNCT07632430
End-Tidal CO2 (ETCO2) Trends in Out-of-Hospital Cardiac Arrest
An observational study of Prehospital Resuscitation and End-Tidal Carbon Dioxide, run by Office of the Medical Director for EMS in Oklahoma City and Tulsa at 1 site in United States.
Trial summary
The investigators aim to assess the relationship between patient characteristics, prehospital treatments, and vital signs to determine if a threshold EtCO2 value, a change in EtCO2 value (final - initial), or a trend in EtCO2 (positive/negative) is a better predictor of patient survival to discharge. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Prehospital Resuscitation, End-Tidal Carbon Dioxide, Cardiac Arrest, Out-Of-Hospital
- How many people
- 3,500 participants
- Where
- 1 siteUnited States
- Study dates
- 1 Jan 2024to 30 Sep 2026
- 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 is a retrospective cohort study. All patients encountered by emergency medical services in Oklahoma City and Tulsa experiencing an out-of-hospital cardiac arrest from Jan 1, 2024, to July 1, 2025, will be evaluated against the inclusion and exclusion criteria.
Who may be able to join
- EHR's resulting from 9-1-1 response
- Adult patients (aged 18+ at time of cardiac event)
- experiencing out-of-hospital cardiac arrest (OHCA)
- transported by an agency under OMD oversight
- must have at least 2 EtCO2 values captured during care Exclusion Criteria
- EHR's resulting from inter-facility scheduled or unscheduled medical transfers
Show all 9Show fewer
- pediatric patients (those aged <18 at time of incident) or unknown age
- ROSC obtained prior to arrival of EMS
- insufficient vital sign data
Who cannot join
None listed.
Trial locations and contacts
1 site in 1 country.
United States1 site
Office of the Medical Director of EMS for Metropolitan Oklahoma City and Tulsa
Oklahoma City, Oklahoma, 73135
About this study
The investigators aim to assess the relationship between patient characteristics, prehospital treatments, and vital signs to determine if a threshold EtCO2 value, a change in EtCO2 value (final - initial), or a trend in EtCO2 (positive/negative) is a better predictor of patient survival to discharge. The secondary aim of this project is to identify significant predictors of neurologically intact patient survival as indicated by a cerebral performance category (CPC) score of 1-2.
- Conditions
- Prehospital Resuscitation, End-Tidal Carbon Dioxide, Cardiac Arrest, Out-Of-Hospital, Prehospital Emergency Medical Services
- Medical subject headings
- 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 |
|---|---|---|
| stable ETCO2 | low variation in measured end-tidal CO2 during cpr; low/high threshold yet to be determined | |
| unstable/trending ETCO2 | variability in end-tidal CO2 during CPR, with or without measurable trend |
What is being measured
The primary outcome is the main question the study is designed to answer.
Survival to Hospital Discharge
lack of terminiation of CPR during prehospital or in hospital care
Measured: 90 days
Secondary outcomes (1)
Neurologically Intact Patient Survival
Based on Gasgow-Pittsburgh Cerebral Performance Category (CPC) score which ranges from 1 (best) to 5 (worst). Neurologically intact is defined as a score of 1-2 among survivors
Measured: 90 days
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted8 Jun 2026
- Study start1 Jan 2024
- Primary completion1 Jul 2025
- Study completion30 Sep 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (8)Papers the sponsor has linked to this study.
- Other trials for Prehospital ResuscitationStudies of the same condition, open and under way.
- 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
- Retrospective
- Enrolment
- 3,500 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Office of the Medical Director for EMS in Oklahoma City and Tulsa
- Sponsor type
- University, hospital or other
- Collaborators
- Medtronic
- Responsible party
- Principal investigator, Anna Bailey, Office of the Medical Director for EMS in Oklahoma City and Tulsa
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07632430
- Sponsor's protocol ID
- ERP#14222
- Other IDs
- ERP#14222
- Status last verified
- Jun 2026
- First submitted
- 2 Jun 2026
- Last updated
- 9 Jun 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Sun KF, Poon KM, Lui CT, Tsui KL. Clinical prediction rule of termination of resuscitation for out-of-hospital cardiac arrest patient with pre-hospital defibrillation given. Am J Emerg Med. 2021 Dec;50:733-738. doi: 10.1016/j.ajem.2021.09.058. Epub 2021 Sep 29.
PubMed 34879495Smida T, Menegazzi JJ, Crowe RP, Salcido DD, Bardes J, Myers B. The Association of Prehospital End-Tidal Carbon Dioxide with Survival Following Out-of-Hospital Cardiac Arrest. Prehosp Emerg Care. 2024;28(3):478-484. doi: 10.1080/10903127.2023.2262566. Epub 2023 Oct 6.
PubMed 37751228Richardson M, Moulton K, Rabb D, Kindopp S, Pishe T, Yan C, Akpinar I, Tsoi B, Chuck A. Capnography for Monitoring End-Tidal CO2 in Hospital and Pre-hospital Settings: A Health Technology Assessment [Internet]. Ottawa (ON): Canadian Agency for Drugs and Technologies in Health; 2016 Mar. Available from http://www.ncbi.nlm.nih.gov/books/NBK362374/
PubMed 27227208Kudu E, Danis F, Karaca MA, Erbil B. Usability of EtCO2 values in the decision to terminate resuscitation by integrating them into the TOR rule (an extended TOR rule): A preliminary analysis. Heliyon. 2023 Sep 13;9(9):e19982. doi: 10.1016/j.heliyon.2023.e19982. eCollection 2023 Sep.
PubMed 37809508Hatlestad D. Capnography as a predictor of the return of spontaneous circulation. Emerg Med Serv. 2004 Aug;33(8):75-80; quiz 115.
PubMed 15368978Hambelton C, Wu L, Smith J, Thompson K, Neth MR, Daya MR, Jui J, Lupton JR. Utility of end-tidal carbon dioxide to guide resuscitation termination in prolonged out-of-hospital cardiac arrest. Am J Emerg Med. 2024 Mar;77:77-80. doi: 10.1016/j.ajem.2023.11.030. Epub 2023 Dec 7.
PubMed 38104387Eckstein M, Hatch L, Malleck J, McClung C, Henderson SO. End-tidal CO2 as a predictor of survival in out-of-hospital cardiac arrest. Prehosp Disaster Med. 2011 Jun;26(3):148-50. doi: 10.1017/S1049023X11006376.
PubMed 22107764Dudaryk R, Bodzin DK, Ray JJ, Jabaley CS, McNeer RR, Epstein RH. Low End-Tidal Carbon Dioxide at the Onset of Emergent Trauma Surgery Is Associated With Nonsurvival: A Case Series. Anesth Analg. 2017 Oct;125(4):1261-1266. doi: 10.1213/ANE.0000000000002283.
PubMed 28704248
Study at a glance
From the registry record, last updated by the sponsor on 9 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- End-Tidal CO2 (ETCO2) Trends in Out-of-Hospital Cardiac Arrest
- ClinicalTrials.gov ID
- NCT07632430
- Acronym / sponsor ID
- ERP#14222
- Conditions
- Prehospital Resuscitation, End-Tidal Carbon Dioxide, Cardiac Arrest, Out-Of-Hospital, Prehospital Emergency Medical Services
- Study type
- Observational
- Recruitment status
- Active, not recruiting
- Enrolment
- 3,500 participants (estimated)
- Lead sponsor
- Office of the Medical Director for EMS in Oklahoma City and TulsaUniversity, hospital or other
- Collaborators
- Medtronic
- Study start
- 1 Jan 2024 (actual)
- Primary completion
- 1 Jul 2025 (actual)
- Study completion
- 30 Sep 2026 (estimated)
- First posted
- 8 Jun 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.
The investigators aim to assess the relationship between patient characteristics, prehospital treatments, and vital signs to determine if a threshold EtCO2 value, a change in EtCO2 value (final - initial), or a trend in EtCO2 (positive/negative) is a better predictor of patient survival to discharge. The secondary aim of this project is to identify significant predictors of neurologically intact patient survival as indicated by a cerebral performance category (CPC) score of 1-2.
Study design
- Observational model
- Cohort
- Time perspective
- Retrospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| stable ETCO2 | – | –low variation in measured end-tidal CO2 during cpr; low/high threshold yet to be determined |
| unstable/trending ETCO2 | – | –variability in end-tidal CO2 during CPR, with or without measurable trend |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- This is a retrospective cohort study. All patients encountered by emergency medical services in Oklahoma City and Tulsa experiencing an out-of-hospital cardiac arrest from Jan 1, 2024, to July 1, 2025, will be evaluated against the inclusion and exclusion criteria.
Key inclusion criteria (9 listed)
- EHR's resulting from 9-1-1 response
- Adult patients (aged 18+ at time of cardiac event)
- experiencing out-of-hospital cardiac arrest (OHCA)
- transported by an agency under OMD oversight
- must have at least 2 EtCO2 values captured during care Exclusion Criteria
Key exclusion criteria (0 listed)
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
Survival to Hospital Discharge
Time frame: 90 days
lack of terminiation of CPR during prehospital or in hospital care
1 secondary outcome
Neurologically Intact Patient Survival
Time frame: 90 days
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 9 Jun 2026.
- Background: PubMed 34879495Sun KF, Poon KM, Lui CT, Tsui KL. Clinical prediction rule of termination of resuscitation for out-of-hospital cardiac arrest patient with pre-hospital defibrillation given. Am J Emerg Med. 2021 Dec;50:733-738. doi: 10.1016/j.ajem.2021.09.058. Epub 2021 Sep 29.
- Background: PubMed 37751228Smida T, Menegazzi JJ, Crowe RP, Salcido DD, Bardes J, Myers B. The Association of Prehospital End-Tidal Carbon Dioxide with Survival Following Out-of-Hospital Cardiac Arrest. Prehosp Emerg Care. 2024;28(3):478-484. doi: 10.1080/10903127.2023.2262566. Epub 2023 Oct 6.
- Background: PubMed 27227208Richardson M, Moulton K, Rabb D, Kindopp S, Pishe T, Yan C, Akpinar I, Tsoi B, Chuck A. Capnography for Monitoring End-Tidal CO2 in Hospital and Pre-hospital Settings: A Health Technology Assessment [Internet]. Ottawa (ON): Canadian Agency for Drugs and Technologies in Health; 2016 Mar. Available from http://www.ncbi.nlm.nih.gov/books/NBK362374/
- Background: PubMed 37809508Kudu E, Danis F, Karaca MA, Erbil B. Usability of EtCO2 values in the decision to terminate resuscitation by integrating them into the TOR rule (an extended TOR rule): A preliminary analysis. Heliyon. 2023 Sep 13;9(9):e19982. doi: 10.1016/j.heliyon.2023.e19982. eCollection 2023 Sep.
- Background: PubMed 15368978Hatlestad D. Capnography as a predictor of the return of spontaneous circulation. Emerg Med Serv. 2004 Aug;33(8):75-80; quiz 115.
- Background: PubMed 38104387Hambelton C, Wu L, Smith J, Thompson K, Neth MR, Daya MR, Jui J, Lupton JR. Utility of end-tidal carbon dioxide to guide resuscitation termination in prolonged out-of-hospital cardiac arrest. Am J Emerg Med. 2024 Mar;77:77-80. doi: 10.1016/j.ajem.2023.11.030. Epub 2023 Dec 7.
- Background: PubMed 22107764Eckstein M, Hatch L, Malleck J, McClung C, Henderson SO. End-tidal CO2 as a predictor of survival in out-of-hospital cardiac arrest. Prehosp Disaster Med. 2011 Jun;26(3):148-50. doi: 10.1017/S1049023X11006376.
- Background: PubMed 28704248Dudaryk R, Bodzin DK, Ray JJ, Jabaley CS, McNeer RR, Epstein RH. Low End-Tidal Carbon Dioxide at the Onset of Emergent Trauma Surgery Is Associated With Nonsurvival: A Case Series. Anesth Analg. 2017 Oct;125(4):1261-1266. doi: 10.1213/ANE.0000000000002283.
- 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. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
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 Prehospital Resuscitation and End-Tidal Carbon Dioxide, run by Office of the Medical Director for EMS in Oklahoma City and Tulsa at 1 site in United States.
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 9 inclusion and 0 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: under way, not looking for participants, as of the sponsor's last update on 9 Jun 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 United States. 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?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Survival to Hospital Discharge (time frame: 90 days). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07632430, which also lists 8 linked publications.
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 9 Jun 2026.