Oxygen Reserve IndexNCT07119866
The Role of Oxygen Reserve Index (ORi) in Apneic Ventilation
An observational study of Oxygen Reserve Index and Apnea, run by Ankara City Hospital Bilkent at 1 site in Turkey (Türkiye).
Trial summary
Background: The Oxygen Reserve Index (ORI) is a non-invasive parameter utilizing multi-wavelength pulse co-oximetry. ORI can provide early warnings of deteriorating oxygenation before changes are reflected in SpO₂ levels. Read more about this study
- Who is it for?
- Ages 18 to 60 years
- Conditions the study is for
- Oxygen Reserve Index, Apnea, Ventilation
- What is being tested?
- OXYGEN RESERVE INDEX
- Type of treatment
- Injection or infusion
- How many people
- 60 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 7 Aug 2025to 30 Aug 2025
- How long will I take part?
- 1 Day
- 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 to 60 years
- All sexes
- No healthy volunteers
- Adult
Study population: 60 patients between the ages of 18-60 years, ASA 1-2, scheduled for elective laparoscopic cholecystectomy under general anesthesia.
Who may be able to join
- 18-60 years
- ASA 1-2
- Mallampati score <2
- Scheduled for elective laparoscopic cholecystectomy under general anesthesia
Who cannot join
- <18 and >60 years
- ASA 3-4
- Initial ORI value below 0.24
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
About this study
Official title: The Role of Oxygen Reserve Index (ORi) Monitoring in Optimizing Apneic Ventilation for Laparoscopic Cholecystectomy
Background: The Oxygen Reserve Index (ORI) is a non-invasive parameter utilizing multi-wavelength pulse co-oximetry. ORI can provide early warnings of deteriorating oxygenation before changes are reflected in SpO₂ levels. This study aimed to investigate the feasibility of non-ventilated intubation in patients undergoing cholecystectomy as a means to achieve safe intubation without nasogastric tube placement, with reduced trauma and cost, and improved time efficiency.
Read the detailed description
Obesity is a complex and chronic disease that significantly impacts respiratory physiology. It leads to increased work of breathing and reduced compliance of the chest wall. In morbidly obese individuals, there is a marked reduction in total lung capacity, vital capacity, forced expiratory volume in one second (FEV1), and forced vital capacity (FVC). Additionally, due to their elevated metabolic demands, these patients exhibit higher oxygen consumption rates.
The Oxygen Reserve Index (ORi) (Masimo Corp., Irvine, CA, USA) is an advanced, continuous, and non-invasive parameter that provides a relative indication of arterial partial pressure of oxygen (PaO₂).
ORI monitoring can be particularly beneficial in patients at risk for inadequate preoxygenation, those with difficult mask ventilation, hypoxemic patients with aspiration risk, rapid sequence induction scenarios, obese individuals, ICU intubations, and invasive ventilation cases. It has also been shown to provide early warnings of desaturation in select patient groups, contributing to improved patient safety.
- Conditions
- Oxygen Reserve Index, Apnea, Ventilation, Body Mass Index
- Being tested
- OXYGEN RESERVE INDEX
- Medical subject headings
- Apnea, Respiratory Aspiration
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
OXYGEN RESERVE INDEXOther
Noted for each patient.
| Study group | Role | What they receive |
|---|---|---|
| ORI>0.24 | Patients, aged between 18 and 60 years, classified as ASA physical status I-II,and with a Mallampati score <2, were enrolled.On the day of surgery, following identity verification and confirmation of the surgical site, patients were positioned on a warmed operating table.Standard monitoring was applied, including ECG, SBP and DBP, SpO₂, and the ORI.Preoxygenation was achieved by administering 100% oxygen via 8 deep breaths over 60 seconds.When the ORI value reached 0.4, intravenous anesthesia induction was initiated using propofol 2 mg/kg, fentanyl 2 mcg/kg, and rocuronium 0.6mg/kg.During muscle relaxation, patients were not ventilated via mask.The ORI value at the time of induction and at the 2nd minute post-induction was recorded.If the ORI dropped below 0.24 before the 2-minute mark, mask ventilation was initiated, and the time of intervention was noted.Endotracheal intubation was then performed using a standard,atraumatic technique after achieving adequate muscle relaxation. Receives: Other: OXYGEN RESERVE INDEX | |
| ORI<0.24 | Patients, aged between 18 and 60 years, classified as ASA physical status I-II,and with a Mallampati score <2, were enrolled.On the day of surgery, following identity verification and confirmation of the surgical site, patients were positioned on a warmed operating table.Standard monitoring was applied, including ECG, SBP and DBP, SpO₂, and the ORI.Preoxygenation was achieved by administering 100% oxygen via 8 deep breaths over 60 seconds.When the ORI value reached 0.4, intravenous anesthesia induction was initiated using propofol 2 mg/kg, fentanyl 2 mcg/kg, and rocuronium 0.6mg/kg.During muscle relaxation, patients were not ventilated via mask.The ORI value at the time of induction and at the 2nd minute post-induction was recorded.If the ORI dropped below 0.24 before the 2-minute mark, mask ventilation was initiated, and the time of intervention was noted.Endotracheal intubation was then performed using a standard,atraumatic technique after achieving adequate muscle relaxation. Receives: Other: OXYGEN RESERVE INDEX |
What is being measured
The primary outcome is the main question the study is designed to answer.
TIME FOR ORI TO FALL BELOW 0.24
TIME THE PATIENT STARTED TO WEAR A MASKS.
Measured: WITHIN 10 MINUTES BEFORE INTUBATION
Secondary outcomes (9)
INITIAL ORI VALUE
Noted for each patient.
Measured: WITHIN 10 MINUTES BEFORE INTUBATION
ORI VALUE AT 2 MINUTES
Noted for each patient.
Measured: WITHIN 10 MINUTES BEFORE INTUBATION
AGE
Noted for each patient.
Measured: WITHIN 10 MINUTES BEFORE INTUBATION
American Society of Anesthesiologists (ASA) Score
Noted for each patient.
Measured: WITHIN 10 MINUTES BEFORE INTUBATION
SEX
Noted for each patient.
Measured: WITHIN 10 MINUTES BEFORE INTUBATION
BMI
Noted for each patient.
Measured: WITHIN 10 MINUTES BEFORE INTUBATION
PRESENCE OF A NASOGASTRIC TUBE
Noted for each patient.
Measured: 10 MINUTES BEFORE EXTUBATION
Surgeon satisfaction
Noted for each patient. Surgeon satisfaction according to ng usage status.
Measured: 10 MINUTES BEFORE EXTUBATION
PRESENCE OF LARYNGOSPASM
Noted for each patient.
Measured: 10 MINUTES BEFORE EXTUBATION
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted13 Aug 2025
- Study start7 Aug 2025 (estimated)
- Primary completion21 Aug 2025 (estimated)
- Study completion30 Aug 2025 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Oxygen Reserve IndexStudies of the same condition, open and under way.
- More trials run by Ankara City Hospital BilkentThe 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
- Other
- Time perspective
- Prospective
- Enrolment
- 60 participants (estimated)
- Target duration
- 1 Day
Sponsor and investigators
- Lead sponsor
- Ankara City Hospital Bilkent
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Ayça Özcan, Ankara City Hospital Bilkent
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07119866
- Sponsor's protocol ID
- Oxygen Reserve Index
- Status last verified
- Aug 2025
- First submitted
- 21 Jul 2025
- Last updated
- 13 Aug 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 13 Aug 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Role of Oxygen Reserve Index (ORi) Monitoring in Optimizing Apneic Ventilation for Laparoscopic Cholecystectomy
- ClinicalTrials.gov ID
- NCT07119866
- Acronym / sponsor ID
- Oxygen Reserve Index
- Conditions
- Oxygen Reserve Index, Apnea, Ventilation, Body Mass Index
- Study type
- Observational
- Recruitment status
- Not yet recruiting
- Enrolment
- 60 participants (estimated)
- Lead sponsor
- Ankara City Hospital BilkentUniversity, hospital or other
- Study start
- 7 Aug 2025 (estimated)
- Primary completion
- 21 Aug 2025 (estimated)
- Study completion
- 30 Aug 2025 (estimated)
- First posted
- 13 Aug 2025 (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.
Background: The Oxygen Reserve Index (ORI) is a non-invasive parameter utilizing multi-wavelength pulse co-oximetry. ORI can provide early warnings of deteriorating oxygenation before changes are reflected in SpO₂ levels. This study aimed to investigate the feasibility of non-ventilated intubation in patients undergoing cholecystectomy as a means to achieve safe intubation without nasogastric tube placement, with reduced trauma and cost, and improved time efficiency.
Detailed description
Obesity is a complex and chronic disease that significantly impacts respiratory physiology. It leads to increased work of breathing and reduced compliance of the chest wall. In morbidly obese individuals, there is a marked reduction in total lung capacity, vital capacity, forced expiratory volume in one second (FEV1), and forced vital capacity (FVC). Additionally, due to their elevated metabolic demands, these patients exhibit higher oxygen consumption rates.
The Oxygen Reserve Index (ORi) (Masimo Corp., Irvine, CA, USA) is an advanced, continuous, and non-invasive parameter that provides a relative indication of arterial partial pressure of oxygen (PaO₂).
ORI monitoring can be particularly beneficial in patients at risk for inadequate preoxygenation, those with difficult mask ventilation, hypoxemic patients with aspiration risk, rapid sequence induction scenarios, obese individuals, ICU intubations, and invasive ventilation cases. It has also been shown to provide early warnings of desaturation in select patient groups, contributing to improved patient safety.
Study design
- Observational model
- Other
- Time perspective
- Prospective
- Target follow-up
- 1 Day
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| ORI>0.24 | – | Other: OXYGEN RESERVE INDEXPatients, aged between 18 and 60 years, classified as ASA physical status I-II,and with a Mallampati score <2, were enrolled.On the day of surgery, following identity verification and confirmation of the surgical site, patients were positioned on a warmed operating table.Standard monitoring was applied, including ECG, SBP and DBP, SpO₂, and the ORI.Preoxygenation was achieved by administering 100% oxygen via 8 deep breaths over 60 seconds.When the ORI value reached 0.4, intravenous anesthesia induction was initiated using propofol 2 mg/kg, fentanyl 2 mcg/kg, and rocuronium 0.6mg/kg.During muscle relaxation, patients were not ventilated via mask.The ORI value at the time of induction and at the 2nd minute post-induction was recorded.If the ORI dropped below 0.24 before the 2-minute mark, mask ventilation was initiated, and the time of intervention was noted.Endotracheal intubation was then performed using a standard,atraumatic technique after achieving adequate muscle relaxation. |
| ORI<0.24 | – | Other: OXYGEN RESERVE INDEXPatients, aged between 18 and 60 years, classified as ASA physical status I-II,and with a Mallampati score <2, were enrolled.On the day of surgery, following identity verification and confirmation of the surgical site, patients were positioned on a warmed operating table.Standard monitoring was applied, including ECG, SBP and DBP, SpO₂, and the ORI.Preoxygenation was achieved by administering 100% oxygen via 8 deep breaths over 60 seconds.When the ORI value reached 0.4, intravenous anesthesia induction was initiated using propofol 2 mg/kg, fentanyl 2 mcg/kg, and rocuronium 0.6mg/kg.During muscle relaxation, patients were not ventilated via mask.The ORI value at the time of induction and at the 2nd minute post-induction was recorded.If the ORI dropped below 0.24 before the 2-minute mark, mask ventilation was initiated, and the time of intervention was noted.Endotracheal intubation was then performed using a standard,atraumatic technique after achieving adequate muscle relaxation. |
Who may qualify
- Ages
- 18 to 60 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult
- Study population
- 60 patients between the ages of 18-60 years, ASA 1-2, scheduled for elective laparoscopic cholecystectomy under general anesthesia.
Key inclusion criteria (4 listed)
- 18-60 years
- ASA 1-2
- Mallampati score <2
- Scheduled for elective laparoscopic cholecystectomy under general anesthesia
Key exclusion criteria (3 listed)
- <18 and >60 years
- ASA 3-4
- Initial ORI value below 0.24
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| OXYGEN RESERVE INDEXNoted for each patient. | Other | ORI<0.24, ORI>0.24 |
Primary outcome
TIME FOR ORI TO FALL BELOW 0.24
Time frame: WITHIN 10 MINUTES BEFORE INTUBATION
TIME THE PATIENT STARTED TO WEAR A MASKS.
9 secondary outcomes
INITIAL ORI VALUE
Time frame: WITHIN 10 MINUTES BEFORE INTUBATION
ORI VALUE AT 2 MINUTES
Time frame: WITHIN 10 MINUTES BEFORE INTUBATION
AGE
Time frame: WITHIN 10 MINUTES BEFORE INTUBATION
American Society of Anesthesiologists (ASA) Score
Time frame: WITHIN 10 MINUTES BEFORE INTUBATION
SEX
Time frame: WITHIN 10 MINUTES BEFORE INTUBATION
BMI
Time frame: WITHIN 10 MINUTES BEFORE INTUBATION
PRESENCE OF A NASOGASTRIC TUBE
Time frame: 10 MINUTES BEFORE EXTUBATION
Surgeon satisfaction
Time frame: 10 MINUTES BEFORE EXTUBATION
PRESENCE OF LARYNGOSPASM
Time frame: 10 MINUTES BEFORE EXTUBATION
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 13 Aug 2025.
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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.
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 Oxygen Reserve Index and Apnea, run by Ankara City Hospital Bilkent at 1 site in Turkey (Türkiye).
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 4 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: opening soon, as of the sponsor's last update on 13 Aug 2025. 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 Turkey (Türkiye). 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 Ayşegül Özel Erdem (05549777289, aysegulozell@gmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
TIME FOR ORI TO FALL BELOW 0.24 (time frame: WITHIN 10 MINUTES BEFORE INTUBATION). 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 13 Aug 2025.