Obesity &Amp;Amp; OverweightNCT07679724
Evaluation of Oxygen Reserve Index (ORi) in Obese and Non-Obese Patients Over 65 Years Old
An observational study of Obesity &Amp;Amp; Overweight and Elderly (People Aged 65 or More), run by Ankara City Hospital Bilkent at 1 site in Turkey (Türkiye).
Trial summary
After obtaining ethical committee approval, this single-center, prospective, observational study included volunteer patients of both sexes, aged 65 years and older, with ASA II-III risk scores, who were scheduled for elective surgery with endotracheal intubation under general anesthesia (GAA). Read more about this study
- Who is it for?
- Ages 65 years and olderHealthy volunteers can take part
- Conditions the study is for
- Obesity &Amp;Amp; Overweight, Elderly (People Aged 65 or More), Oxygen Reserve Index
- How many people
- 90 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 1 Nov 2023to 1 Jul 2024
- Phase
- Observational
- Are there results?
- None posted in the registry
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 65 years and older
- All sexes
- Healthy volunteers accepted
- Older adult
Study population: 90 patients aged 65 and over, ASA II-III
Who may be able to join
- Patients of both sexes aged 65 years and older with ASA II-III risk scores who are scheduled to undergo elective surgical procedures with endotracheal intubation under general anesthesia.
Who cannot join
- Patients under 65 years of age
- Patients with heart and lung disease
- Patients in situations where the patient is unable to cooperate (e.g., dementia, Alzheimer's)
- Patients suspected of having airway difficulties
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Evaluation of Oxygen Reserve Index (ORi) in Obese and Non-Obese Patients Over 65 Years Old Scheduled for Elective Surgery Under General Anesthesia
After obtaining ethical committee approval, this single-center, prospective, observational study included volunteer patients of both sexes, aged 65 years and older, with ASA II-III risk scores, who were scheduled for elective surgery with endotracheal intubation under general anesthesia (GAA). 90 patients were divided into two groups: those with normal BMI (19 < BMI < 25 kg/m² (GROUP 1)) and those who were obese (30 < BMI < 40 kg/m² (GROUP 2)). In addition to standard ASA monitoring, a finger sensor (Rainbow® SET, Masimo Inc., Irvine, Ca., USA) was implanted for ORi measurement, and baseline values were recorded. Patients were preoxygenated until EtO2 (endtidal oxygen) concentration reached at least 85%. After ORi reached a plateau level, general anesthesia was induced and endotracheal intubation was performed. After confirming the tube's position, the breathing circuit was disconnected from the endotracheal tube, and patients were allowed to be apneic until SpO2 reached 94%. Throughout this process, patients' other vital signs, SpO₂, and ORi were continuously monitored. The time elapsed when ORi triggered an alarm, when SpO2 reached 97%, and when SpO2 reached 94% was recorded. The 'ORi warning time', 'SpO2 warning time', and the 'additional warning time provided by ORi' (the difference between 'ORi warning time' and 'SpO2 warning time') were recorded.
- Medical subject headings
- Obesity, Overweight
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 |
|---|---|---|
| Group 1 | Patients with normal BMI (19 < BMI < 25 kg/m²) | |
| Group 2 | Obese patients (30 < BMI < 40 kg/m² ) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Oxygen reserve index (ORi) warning time, SpO2 warning time, and added warning time defined as the difference between the two
The primary aim of this study was to determine whether ORi provides an early warning of impending desaturation compared to pulse oximetry in both obese (30 < BMI < 40 kg/m²) and normal body mass index (19 < BMI < 25 kg/m²) patients over 65 years of age scheduled for elective surgery will be assesed until SpO2 drops to 94%
Measured: 15 minutes after preoxygenation
Secondary outcomes (1)
Oxygen reserve index (ORi) warning time, SpO2 warning time, and added warning time defined as the difference between the two
The secondary objective of this study was to compare the additional stimulus duration provided by ORi in obese (30 < BMI < 40 kg/m²) and normal body mass index (19 < BMI < 25 kg/m²) patients over 65 years of age will be assesed until SpO2 drops to 94%
Measured: 15 minutes after preoxygenation
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted1 Jul 2026
- Study start1 Nov 2023
- Primary completion1 May 2024
- Study completion1 Jul 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (2)Papers the sponsor has linked to this study.
- Other trials for Obesity &Amp;Amp; OverweightStudies 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
- Case-control
- Time perspective
- Prospective
- Enrolment
- 90 participants (actual)
Sponsor and investigators
- Lead sponsor
- Ankara City Hospital Bilkent
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Çağla TUNCEL, Ankara City Hospital Bilkent
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07679724
- Sponsor's protocol ID
- AnkaraCHBilkent-AR-CT-01
- Status last verified
- Jun 2026
- First submitted
- 2 May 2026
- Last updated
- 1 Jul 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: I will share the parameters and results of the study.
Publications
Tsymbal E, Ayala S, Singh A, Applegate RL 2nd, Fleming NW. Study of early warning for desaturation provided by Oxygen Reserve Index in obese patients. J Clin Monit Comput. 2021 Aug;35(4):749-756. doi: 10.1007/s10877-020-00531-w. Epub 2020 May 18.
PubMed 32424516Fleming NW, Singh A, Lee L, Applegate RL 2nd. Oxygen Reserve Index: Utility as an Early Warning for Desaturation in High-Risk Surgical Patients. Anesth Analg. 2021 Mar 1;132(3):770-776. doi: 10.1213/ANE.0000000000005109.
PubMed 32815872
Study at a glance
From the registry record, last updated by the sponsor on 1 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Evaluation of Oxygen Reserve Index (ORi) in Obese and Non-Obese Patients Over 65 Years Old Scheduled for Elective Surgery Under General Anesthesia
- ClinicalTrials.gov ID
- NCT07679724
- Acronym / sponsor ID
- AnkaraCHBilkent-AR-CT-01
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 90 participants (actual)
- Lead sponsor
- Ankara City Hospital BilkentUniversity, hospital or other
- Study start
- 1 Nov 2023 (actual)
- Primary completion
- 1 May 2024 (actual)
- Study completion
- 1 Jul 2024 (actual)
- First posted
- 1 Jul 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.
After obtaining ethical committee approval, this single-center, prospective, observational study included volunteer patients of both sexes, aged 65 years and older, with ASA II-III risk scores, who were scheduled for elective surgery with endotracheal intubation under general anesthesia (GAA). 90 patients were divided into two groups: those with normal BMI (19 < BMI < 25 kg/m² (GROUP 1)) and those who were obese (30 < BMI < 40 kg/m² (GROUP 2)). In addition to standard ASA monitoring, a finger sensor (Rainbow® SET, Masimo Inc., Irvine, Ca., USA) was implanted for ORi measurement, and baseline values were recorded. Patients were preoxygenated until EtO2 (endtidal oxygen) concentration reached at least 85%. After ORi reached a plateau level, general anesthesia was induced and endotracheal intubation was performed. After confirming the tube's position, the breathing circuit was disconnected from the endotracheal tube, and patients were allowed to be apneic until SpO2 reached 94%. Throughout this process, patients' other vital signs, SpO₂, and ORi were continuously monitored. The time elapsed when ORi triggered an alarm, when SpO2 reached 97%, and when SpO2 reached 94% was recorded. The 'ORi warning time', 'SpO2 warning time', and the 'additional warning time provided by ORi' (the difference between 'ORi warning time' and 'SpO2 warning time') were recorded.
Study design
- Observational model
- Case-control
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Group 1 | – | –Patients with normal BMI (19 < BMI < 25 kg/m²) |
| Group 2 | – | –Obese patients (30 < BMI < 40 kg/m² ) |
Who may qualify
- Ages
- 65 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Older adult
- Study population
- 90 patients aged 65 and over, ASA II-III
Key inclusion criteria (1 listed)
- Patients of both sexes aged 65 years and older with ASA II-III risk scores who are scheduled to undergo elective surgical procedures with endotracheal intubation under general anesthesia.
Key exclusion criteria (4 listed)
- Patients under 65 years of age
- Patients with heart and lung disease
- Patients in situations where the patient is unable to cooperate (e.g., dementia, Alzheimer's)
- Patients suspected of having airway difficulties
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
Oxygen reserve index (ORi) warning time, SpO2 warning time, and added warning time defined as the difference between the two
Time frame: 15 minutes after preoxygenation
The primary aim of this study was to determine whether ORi provides an early warning of impending desaturation compared to pulse oximetry in both obese (30 < BMI < 40 kg/m²) and normal body mass index (19 < BMI < 25 kg/m²) patients over 65 years of age scheduled for elective surgery will be assesed until SpO2 drops to 94%
1 secondary outcome
Oxygen reserve index (ORi) warning time, SpO2 warning time, and added warning time defined as the difference between the two
Time frame: 15 minutes after preoxygenation
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 1 Jul 2026.
- Background: PubMed 32424516Tsymbal E, Ayala S, Singh A, Applegate RL 2nd, Fleming NW. Study of early warning for desaturation provided by Oxygen Reserve Index in obese patients. J Clin Monit Comput. 2021 Aug;35(4):749-756. doi: 10.1007/s10877-020-00531-w. Epub 2020 May 18.
- Background: PubMed 32815872Fleming NW, Singh A, Lee L, Applegate RL 2nd. Oxygen Reserve Index: Utility as an Early Warning for Desaturation in High-Risk Surgical Patients. Anesth Analg. 2021 Mar 1;132(3):770-776. doi: 10.1213/ANE.0000000000005109.
- Individual participant dataSharing planned: No. I will share the parameters and results of the study.
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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 Obesity &Amp;Amp; Overweight and Elderly (People Aged 65 or More), 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 1 inclusion and 4 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: finished, as of the sponsor's last update on 1 Jul 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 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
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?
Oxygen reserve index (ORi) warning time, SpO2 warning time, and added warning time defined as the difference between the two (time frame: 15 minutes after preoxygenation). 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 NCT07679724, which also lists 2 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 1 Jul 2026.