Prehospital ETI in OHCA (ETIOHCA)

April 10, 2026 updated by: Adem Az, Haseki Training and Research Hospital

Association of Prehospital Endotracheal Intubation With 28-Day Survival and Neurological Outcomes in Out-of-Hospital Cardiac Arrest

This prospective observational study evaluated the association of prehospital endotracheal intubation (ETI) status with return of spontaneous circulation (ROSC), 28-day survival, and favorable neurological outcome in adult patients with out-of-hospital cardiac arrest (OHCA) transported to the emergency department (ED) by emergency medical services (EMS). In addition, the study investigated the causes of failed ETI attempts and examined other clinical factors associated with 28-day survival, including bystander cardiopulmonary resuscitation (CPR), initial cardiac rhythm, blood gas parameters, and prehospital airway management strategy.

Study Overview

Detailed Description

This prospective observational cohort study was conducted in the ED of Haseki Training and Research Hospital between July 1, 2025, and December 31, 2025. Patients presenting to the ED with cardiac arrest during the study period were screened for eligibility. All patients received advanced cardiac life support (ACLS) in accordance with the 2025 European Resuscitation Council (ERC) guidelines.

Data collected for each patient encompassed demographic characteristics (age, sex, and body mass index [BMI]) and comorbid conditions, including hypertension, diabetes mellitus, coronary artery disease, chronic kidney disease, and malignancy. Prehospital variables included witnessed arrest, bystander CPR, bystander automated external defibrillator (AED) use, no-flow duration, time from collapse to initiation of advanced life support (ALS), time from collapse to hospital arrival, hyperventilation, and initial cardiac rhythm (asystole/pulseless electrical activity [PEA] or ventricular fibrillation/pulseless ventricular tachycardia [VF/pVT]). Prehospital airway data were recorded in two ways: the airway device present on ED arrival (endotracheal tube in place, bag-valve-mask ventilation, or supraglottic airway) and prehospital ETI attempt status (successful ETI, failed ETI attempt, or no ETI attempt). ETI success and the reasons for failed ETI attempts were also recorded, as was the occurrence of prehospital ROSC.

Upon arrival at the ED, body temperature, Glasgow Coma Scale (GCS) score (when assessable), and vasopressor use within the first hour were recorded. Arterial blood gas parameters, including pH, partial pressure of oxygen (PaO2), and partial pressure of carbon dioxide (PaCO2), were also documented. Clinical outcomes included ROSC, 28-day survival status, and neurological outcome.

Patients were classified as survivors or non-survivors according to 28-day survival status. Demographic characteristics, comorbidities, prehospital time intervals, initial rhythm, blood gas parameters, and airway management variables were compared across these groups to identify factors associated with 28-day survival. For airway-specific analyses, patients were further categorized into three groups according to ETI status: successful ETI, failed ETI attempt, and no ETI attempt. Comparisons among these groups were performed to assess differences in demographic and clinical characteristics, prehospital resuscitation variables, ROSC, 28-day survival, and favorable neurological outcome according to ETI status.

Study Type

Observational

Enrollment (Actual)

297

Contacts and Locations

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

Study Locations

    • Istanbul
      • Sultangazi, Istanbul, Turkey (Türkiye), 34265
        • Haseki Training and Research Hospital

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

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Probability Sample

Study Population

This study included 361 adult patients (aged ≥18 years) who were brought to our hospital's ED due to OHCA and who had initiated attempted resuscitation by EMS were initially screened for inclusion between July 1, 2025, and December 31, 2025.

Description

Inclusion Criteria:

  • Age ≥18 years
  • Out-of-hospital cardiac arrest (OHCA)
  • Transport to the emergency department by emergency medical services (EMS)
  • Initiated resuscitation/advanced cardiovascular life support (ACLS) by EMS
  • Enrollment period between July 1, 2025, and December 31, 2025

Exclusion Criteria:

  • Age <18 years
  • In-hospital cardiac arrest
  • Cardiac arrest due to major trauma, drowning, drug overdose, or known terminal illness
  • Tracheostomy present
  • Missing data on primary outcomes or admission laboratory parameters

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

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Survivors
Survivors were defined as the patient being alive at 28 days following the cardiac arrest event.
The demographic profile of each patient was documented, including age and sex, to examine potential associations with survival and neurological outcomes.
Data on pre-existing chronic conditions were recorded, such as hypertension, diabetes mellitus, coronary artery disease, chronic kidney disease, and malignancy, in order to assess their potential impact on prognosis following OHCA.
Several prehospital factors were evaluated, including whether the cardiac arrest was witnessed, whether bystander cardiopulmonary resuscitation (CPR) was performed, the time from collapse to the initiation of CPR, and the time from collapse to EMS arrival. Additionally, the durations of no-flow (i.e., time without any CPR) and low-flow (i.e., time with CPR but without ROSC) were noted. The initial cardiac rhythm was categorized as ventricular fibrillation or pulseless ventricular tachycardia (VF/pVT), asystole, or pulseless electrical activity (PEA). Airway management methods used in the field were documented and classified as bag-valve-mask (BVM), supraglottic airway devices (SGAs), or endotracheal intubation (ETI). Other recorded interventions included prehospital defibrillation, administration of epinephrine (including total dosage), and use of mechanical chest compression devices. Whether ROSC was achieved prior to arrival at the emergency department was also noted.
Arterial blood gas parameters, including pH, partial pressure of oxygen (PaO2), and partial pressure of carbon dioxide (PaCO2), were also documented.
Non-survivors
Non-survivors had passed away within 28 days following the cardiac arrest event.
The demographic profile of each patient was documented, including age and sex, to examine potential associations with survival and neurological outcomes.
Data on pre-existing chronic conditions were recorded, such as hypertension, diabetes mellitus, coronary artery disease, chronic kidney disease, and malignancy, in order to assess their potential impact on prognosis following OHCA.
Several prehospital factors were evaluated, including whether the cardiac arrest was witnessed, whether bystander cardiopulmonary resuscitation (CPR) was performed, the time from collapse to the initiation of CPR, and the time from collapse to EMS arrival. Additionally, the durations of no-flow (i.e., time without any CPR) and low-flow (i.e., time with CPR but without ROSC) were noted. The initial cardiac rhythm was categorized as ventricular fibrillation or pulseless ventricular tachycardia (VF/pVT), asystole, or pulseless electrical activity (PEA). Airway management methods used in the field were documented and classified as bag-valve-mask (BVM), supraglottic airway devices (SGAs), or endotracheal intubation (ETI). Other recorded interventions included prehospital defibrillation, administration of epinephrine (including total dosage), and use of mechanical chest compression devices. Whether ROSC was achieved prior to arrival at the emergency department was also noted.
Arterial blood gas parameters, including pH, partial pressure of oxygen (PaO2), and partial pressure of carbon dioxide (PaCO2), were also documented.
Successful ETI
Adult patients with out-of-hospital cardiac arrest (OHCA) who underwent a successful prehospital endotracheal intubation (ETI) attempt by emergency medical services (EMS) personnel before arrival at the emergency department (ED).
The demographic profile of each patient was documented, including age and sex, to examine potential associations with survival and neurological outcomes.
Data on pre-existing chronic conditions were recorded, such as hypertension, diabetes mellitus, coronary artery disease, chronic kidney disease, and malignancy, in order to assess their potential impact on prognosis following OHCA.
Several prehospital factors were evaluated, including whether the cardiac arrest was witnessed, whether bystander cardiopulmonary resuscitation (CPR) was performed, the time from collapse to the initiation of CPR, and the time from collapse to EMS arrival. Additionally, the durations of no-flow (i.e., time without any CPR) and low-flow (i.e., time with CPR but without ROSC) were noted. The initial cardiac rhythm was categorized as ventricular fibrillation or pulseless ventricular tachycardia (VF/pVT), asystole, or pulseless electrical activity (PEA). Airway management methods used in the field were documented and classified as bag-valve-mask (BVM), supraglottic airway devices (SGAs), or endotracheal intubation (ETI). Other recorded interventions included prehospital defibrillation, administration of epinephrine (including total dosage), and use of mechanical chest compression devices. Whether ROSC was achieved prior to arrival at the emergency department was also noted.
Arterial blood gas parameters, including pH, partial pressure of oxygen (PaO2), and partial pressure of carbon dioxide (PaCO2), were also documented.
Survival status 28 days after advanced cardiac life support (ACLS) initiated following OHCA.
Neurological status assessed at day 28 using the Cerebral Performance Category (CPC) scale. Favorable neurological outcome was defined as CPC 1-2, and unfavorable neurological outcome was defined as CPC 3-5.
Failed ETI attempt
Adult patients with OHCA who underwent a failed prehospital ETI attempt by EMS personnel before arrival at the ED.
The demographic profile of each patient was documented, including age and sex, to examine potential associations with survival and neurological outcomes.
Data on pre-existing chronic conditions were recorded, such as hypertension, diabetes mellitus, coronary artery disease, chronic kidney disease, and malignancy, in order to assess their potential impact on prognosis following OHCA.
Several prehospital factors were evaluated, including whether the cardiac arrest was witnessed, whether bystander cardiopulmonary resuscitation (CPR) was performed, the time from collapse to the initiation of CPR, and the time from collapse to EMS arrival. Additionally, the durations of no-flow (i.e., time without any CPR) and low-flow (i.e., time with CPR but without ROSC) were noted. The initial cardiac rhythm was categorized as ventricular fibrillation or pulseless ventricular tachycardia (VF/pVT), asystole, or pulseless electrical activity (PEA). Airway management methods used in the field were documented and classified as bag-valve-mask (BVM), supraglottic airway devices (SGAs), or endotracheal intubation (ETI). Other recorded interventions included prehospital defibrillation, administration of epinephrine (including total dosage), and use of mechanical chest compression devices. Whether ROSC was achieved prior to arrival at the emergency department was also noted.
Arterial blood gas parameters, including pH, partial pressure of oxygen (PaO2), and partial pressure of carbon dioxide (PaCO2), were also documented.
Survival status 28 days after advanced cardiac life support (ACLS) initiated following OHCA.
Neurological status assessed at day 28 using the Cerebral Performance Category (CPC) scale. Favorable neurological outcome was defined as CPC 1-2, and unfavorable neurological outcome was defined as CPC 3-5.
No ETI attempt
Adult patients with OHCA in whom no prehospital ETI attempt was performed by EMS personnel before arrival at the ED.
The demographic profile of each patient was documented, including age and sex, to examine potential associations with survival and neurological outcomes.
Data on pre-existing chronic conditions were recorded, such as hypertension, diabetes mellitus, coronary artery disease, chronic kidney disease, and malignancy, in order to assess their potential impact on prognosis following OHCA.
Several prehospital factors were evaluated, including whether the cardiac arrest was witnessed, whether bystander cardiopulmonary resuscitation (CPR) was performed, the time from collapse to the initiation of CPR, and the time from collapse to EMS arrival. Additionally, the durations of no-flow (i.e., time without any CPR) and low-flow (i.e., time with CPR but without ROSC) were noted. The initial cardiac rhythm was categorized as ventricular fibrillation or pulseless ventricular tachycardia (VF/pVT), asystole, or pulseless electrical activity (PEA). Airway management methods used in the field were documented and classified as bag-valve-mask (BVM), supraglottic airway devices (SGAs), or endotracheal intubation (ETI). Other recorded interventions included prehospital defibrillation, administration of epinephrine (including total dosage), and use of mechanical chest compression devices. Whether ROSC was achieved prior to arrival at the emergency department was also noted.
Arterial blood gas parameters, including pH, partial pressure of oxygen (PaO2), and partial pressure of carbon dioxide (PaCO2), were also documented.
Survival status 28 days after advanced cardiac life support (ACLS) initiated following OHCA.
Neurological status assessed at day 28 using the Cerebral Performance Category (CPC) scale. Favorable neurological outcome was defined as CPC 1-2, and unfavorable neurological outcome was defined as CPC 3-5.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
28 day-survival rate
Time Frame: At 28 days after ACLS initiation following OHCA.
Survival status at day 28 after advanced cardiovascular life support (ACLS) initiated following out-of-hospital cardiac arrest (OHCA). Participants will be classified as survivors if alive on day 28 and as non-survivors if death occurs within 28 days.
At 28 days after ACLS initiation following OHCA.

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Neurological Status at 28 Days
Time Frame: At 28 days after ACLS initiation following OHCA
Neurological status assessed 28 days after ACLS initiation following OHCA using the Cerebral Performance Category (CPC) scale. Favorable neurological outcome will be defined as CPC 1-2, and unfavorable neurological outcome as CPC 3-5.
At 28 days after ACLS initiation following OHCA
Achievement of Return of Spontaneous Circulation (ROSC) During Resuscitation Following Out-of-Hospital Cardiac Arrest (OHCA).
Time Frame: Assessed within the first 20 minutes after emergency department admission.
ROSC was defined as the return of sustained spontaneous perfusing rhythm lasting at least 20 minutes without the need for external chest compressions.
Assessed within the first 20 minutes after emergency department admission.
Comparison of 28-Day Survival Rates Between Participants Who Underwent Prehospital Endotracheal Intubation and Those Who Did Not
Time Frame: At 28 days after ACLS initiation following OHCA
The investigators evaluate the impact of prehospital endotracheal intubation (ETI) on 28-day survival status. Survival was defined as being alive 28 days after the cardiac arrest event. Participants will be categorized into two groups based on whether or not they received ETI in the prehospital setting.
At 28 days after ACLS initiation following OHCA

Collaborators and Investigators

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

Investigators

  • Principal Investigator: Adem Az, Sultangazi Haseki Eğitim ve Araştırma Hastanesi, Başhekimlik

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

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)

July 1, 2025

Primary Completion (Actual)

December 31, 2025

Study Completion (Actual)

December 31, 2025

Study Registration Dates

First Submitted

April 6, 2026

First Submitted That Met QC Criteria

April 6, 2026

First Posted (Actual)

April 13, 2026

Study Record Updates

Last Update Posted (Actual)

April 15, 2026

Last Update Submitted That Met QC Criteria

April 10, 2026

Last Verified

February 1, 2026

More Information

Terms related to this study

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Stored in non-publicly avaliableAvaliable on request

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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