ORI and ETCO₂ Relationship With Arterial Blood Gas During Apnea Test

NCT06983990 | Completed

• 1 other identifier: 2011-KAEK-25 2023/05-06
• Study Type: observational
• Target: 35
• Locations: 1 country
• Sites: 1

Brief Summary

This observational study aims to evaluate the relationship between the Oxygen Reserve Index (ORI) and End-Tidal Carbon Dioxide (ETCO2) values with arterial blood gas parameters in patients undergoing the apnea test for the diagnosis of brain death. The study will examine the correlation between ORI and PaO2, as well as between ETCO2 and PaCO2. The primary objective is to assess the effectiveness of ORI in evaluating oxygenation and its applicability in the apnea test. The study will also evaluate the routine use of ORI in monitoring PaO2 and its potential benefits compared to traditional methods.

Conditions

Brain Death

Keywords

Oxygen Reserve Index; ORI; Apnea test; Brain Death; End-Tidal Carbon Dioxide; ETCO2; Hyperoxia; Hypoxia

Outcome Measures

Primary Outcomes (1)

• Correlation between Oxygen Reserve Index (ORI) and arterial PaO2 during apnea test

  Assess the correlation between non-invasive ORI values obtained from Masimo pulse CO-oximeter and arterial partial pressure of oxygen (PaO2) measured from arterial blood gases during the apnea test.

  Before and at specific intervals during the apnea test

Secondary Outcomes (1)

• Correlation between End-Tidal Carbon Dioxide (ETCO2) and arterial PaCO2 during apnea test

  Before the apnea test, at the start of the test, and end of the test

Study Arms (1)

Apnea test group

Patients undergoing an apnea test as part of brain death evaluation are monitored for correlation analysis of oxygen reserve index (ORI), end-tidal CO₂ (ETCO₂), and arterial blood gas parameters (PaO₂, PaCO₂). No intervention is applied in this observational study.

Other: No intervention (observational monitoring only)

Interventions

No intervention (observational monitoring only) OTHER

No intervention is applied. This is an observational study evaluating the correlation between non-invasive monitoring parameters and arterial blood gas values during apnea testing.

Apnea test group

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

The study will include adult patients (aged 18 and over) who are being monitored in the intensive care units of the University of Health Sciences Bursa Yuksek Ihtisas Training and Research Hospital and are suspected of brain death, for whom an apnea test has been scheduled by their physician as part of the brain death diagnosis process. The study population will consist of patients who meet the inclusion criteria and for whom written informed consent has been obtained from a legally authorized representative. Patients whose first-degree relatives have declined participation, and those in whom the Oxygen Reserve Index (ORI) probe cannot be used due to circulatory disorders in the extremities, will be excluded from the study.

You may qualify if:

• Patients who meet all the prerequisites for initiating the brain death diagnosis process and for whom the decision to perform the apnea test for diagnosis of brain death.
• Patients aged 18 years or older.
• Patients who have provided verbal and written consent from their first-degree relatives.

You may not qualify if:

• Patients whose first-degree relatives do not consent to participation in the study.
• Patients in whom the ORI probe cannot be used due to circulatory disturbances in the extremities

Sponsors & Collaborators

• Bursa Yuksek Ihtisas Training and Research Hospital: lead

Study Sites (1)

Health Sciences University Bursa Yüksek İhtisas Training and Research Hospital

Bursa, Turkey (Türkiye)

Location

Related Publications (2)

• Vivien B, Amour J, Nicolas-Robin A, Vesque M, Langeron O, Coriat P, Riou B. An evaluation of capnography monitoring during the apnoea test in brain-dead patients. Eur J Anaesthesiol. 2007 Oct;24(10):868-75. doi: 10.1017/S0265021507000725. Epub 2007 Jun 20.

  PMID: 17579950 RESULT

• Applegate RL 2nd, Dorotta IL, Wells B, Juma D, Applegate PM. The Relationship Between Oxygen Reserve Index and Arterial Partial Pressure of Oxygen During Surgery. Anesth Analg. 2016 Sep;123(3):626-33. doi: 10.1213/ANE.0000000000001262.

  PMID: 27007078 RESULT

MeSH Terms

Conditions

Brain Death; Hyperoxia; Hypoxia

Condition Hierarchy (Ancestors)

Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Coma; Unconsciousness; Consciousness Disorders; Neurobehavioral Manifestations; Neurologic Manifestations; Death; Pathologic Processes; Pathological Conditions, Signs and Symptoms; Signs and Symptoms, Respiratory; Signs and Symptoms

Study Officials

• Nilay SERTDEMIR, MD

  Health Sciences University Bursa Yüksek İhtisas Training and Research Hospital

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER GOV
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Resident Physician in Anesthesiology and Reanimation

Study Record Dates

• First Submitted: May 14, 2025
• First Posted: May 22, 2025
• Study Start: July 1, 2023
• Primary Completion: June 1, 2025
• Study Completion: June 1, 2025
• Last Updated: April 22, 2026

Record last verified: 2026-04

Data Sharing

• IPD Sharing: Will not share

Locations

TU (1)