DesaturationNCT07326293
The Effectiveness of Oxygen Reserve Index in Early Detection of Desaturation in Geriatric Patients Scheduled for Oncological Surgery
An observational study of Desaturation and Apnea, Hypoxia, run by Ankara City Hospital Bilkent at 1 site in Turkey (Türkiye).
Trial summary
This prospective observational study aims to evaluate the relationship between the Oxygen Reserve Index (ORI) and tolerable apnea time in geriatric patients undergoing elective oncologic surgery under general anesthesia. Read more about this study
- Who is it for?
- Ages 65 to 100 years
- Conditions the study is for
- Desaturation, Apnea, Hypoxia, Oxygen Reserve Index
- How many people
- 44 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 16 Dec 2025to 16 Feb 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 65 to 100 years
- All sexes
- No healthy volunteers
- Older adult
Study population: It will be studied in patients over the age of 65.
Inclusion criteria for the files/records/materials to be included in the study:
Records of patients aged 65 years and older, classified as ASA physical status I-III, who are scheduled for elective oncologic surgery.
Exclusion criteria for the files/records/materials to be included in the study:
Records of patients with advanced coronary artery disease; advanced heart failure and/or valvular heart disease; carotid artery stenosis; left ventricular ejection fraction below 30%; rapid atrial fibrillation; body mass index (BMI) greater than 35 kg/m²; anticipated difficult airway; advanced-stage malignancy; or dementia.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Turkey (Türkiye)1 site, 1 recruiting
- Recruiting
Ankara Bilkent City Hospital
Ankara, Çankaya
Muhlis Kuru, +905312089322, muhlis_kuru@hotmail.com
Muhlis Kuru
About this study
Official title: The Effectiveness of Oxygen Reserve Index in Early Detection of Desaturation in Geriatric Patients Scheduled for Oncological Surgery; a Prospective, Observational Study.
This prospective observational study aims to evaluate the relationship between the Oxygen Reserve Index (ORI) and tolerable apnea time in geriatric patients undergoing elective oncologic surgery under general anesthesia.
Patients aged 65 years and older will be monitored using standard anesthesia monitoring and Masimo Rainbow SET® Pulse CO-Oximetry during anesthesia induction and tracheal intubation.
Read more
Tolerable apnea time will be defined as the duration from the end of ventilation after intubation to a decrease in peripheral oxygen saturation (SpO₂) to 94%.
The primary objective is to assess the association between ORI warning time and tolerable apnea time. Secondary objectives include evaluating the association between ORI values, arterial blood gas parameters at predefined time points, and the Clinical Frailty Scale.
Read the detailed description
This study is a prospective, observational study. Patients aged 65 years and older who are scheduled for elective oncologic surgery at Ankara Bilkent City Hospital will be included. In all patients, the Clinical Frailty Scale will be routinely assessed during the preoperative period.
In this study, tolerable apnea time will be defined as the time until peripheral oxygen saturation (SpO₂), measured by pulse oximetry, decreases to 94%. Although SpO₂ values of 90% and above have been accepted in the literature, the World Health Organization defines normal SpO₂ as 95% and above and considers values of 94% and below as an indication for treatment.
The Oxygen Reserve Index (ORI) ranges from 0 to 1, and the ORI alarm value triggered by the device due to a downward trend will be recorded. ORI is a dimensionless index ranging from 1 (high oxygen reserve) to 0 (no oxygen reserve), which is measured by optically detecting changes in venous oxygen saturation (SvO₂) after arterial oxygen saturation (SpO₂) reaches 100%. ORI is measured using a multi-wavelength pulse co-oximeter placed on a fingertip.
In addition to routine anesthesia monitoring, including electrocardiography, pulse oximetry, and hemodynamic monitoring, patients will also be monitored using Masimo Rainbow SET® Pulse CO-Oximetry. Due to the oncologic nature of the surgeries and the associated risk of bleeding, close hemodynamic monitoring is required; therefore, invasive arterial blood pressure monitoring will be established in all patients before anesthesia induction.
All patients will be preoxygenated with 100% oxygen for 3 minutes. After establishing intravenous access, anesthesia induction will be performed using intravenous propofol at a dose of 2 mg/kg and fentanyl at a dose of 1 µg/kg. Neuromuscular blockade will be achieved with rocuronium at a dose of 0.6 mg/kg.
All patients will be intubated by an experienced anesthesiologist using a videolaryngoscope. Oxygen Reserve Index (ORI) and peripheral oxygen saturation (SpO₂) values will be recorded, and arterial blood gas analyses will be performed at five predefined time points: baseline (initial values), after 3 minutes of preoxygenation, after 2 minutes of bag-mask ventilation following intubation, during apnea when SpO₂ decreases to 94% without ventilation, and after 2 minutes of ventilation with 100% oxygen.
ORI warning time will be defined as the interval from the onset of the ORI alarm to the decrease of SpO₂ to 94%. SpO₂ warning time will be defined as the duration of the decrease in SpO₂ from 97% to 94%.
- Conditions
- Desaturation, Apnea, Hypoxia, Oxygen Reserve Index
- Keywords
- oxygen reserve indec, geriatric, desaturation
- Medical subject headings
- Apnea, Hypoxia
What is being measured
The primary outcome is the main question the study is designed to answer.
The primary outcome measure is the association between Oxygen Reserve Index (ORI) warning time and tolerable apnea time. ORI warning time is defined as the time interval from the onset of the ORI alarm triggered by a downward trend to the decrease of per
The primary outcome measure is the association between Oxygen Reserve Index (ORI) warning time and tolerable apnea time.
ORI warning time is defined as the time interval from the onset of the ORI alarm triggered by a downward trend to the decrease of peripheral oxygen saturation (SpO₂) to 94%.
Tolerable apnea time is defined as the duration from the end of ventilation after tracheal intubation to the decrease of SpO₂ to 94%.
Measured: Peri-induction period at predefined time points baseline; after 3 minutes of preoxygenation; after 2 minutes of bag-mask ventilation following intubation; during apnea at SpO₂ 94%; and after 2 minutes of ventilation with 100% oxygen
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted8 Jan 2026
- Study start16 Dec 2025
- Primary completion16 Feb 2026 (estimated)
- Study completion16 Feb 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for DesaturationStudies 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
- Cohort
- Time perspective
- Prospective
- Enrolment
- 44 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Ankara City Hospital Bilkent
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07326293
- Sponsor's protocol ID
- E2-24-8204
- Status last verified
- Dec 2025
- First submitted
- 18 Dec 2025
- Last updated
- 8 Jan 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 8 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Effectiveness of Oxygen Reserve Index in Early Detection of Desaturation in Geriatric Patients Scheduled for Oncological Surgery; a Prospective, Observational Study.
- ClinicalTrials.gov ID
- NCT07326293
- Acronym / sponsor ID
- E2-24-8204
- Conditions
- Desaturation, Apnea, Hypoxia, Oxygen Reserve Index
- Keywords
- oxygen reserve indec, geriatric, desaturation
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 44 participants (estimated)
- Lead sponsor
- Ankara City Hospital BilkentUniversity, hospital or other
- Study start
- 16 Dec 2025 (actual)
- Primary completion
- 16 Feb 2026 (estimated)
- Study completion
- 16 Feb 2026 (estimated)
- First posted
- 8 Jan 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.
This prospective observational study aims to evaluate the relationship between the Oxygen Reserve Index (ORI) and tolerable apnea time in geriatric patients undergoing elective oncologic surgery under general anesthesia.
Patients aged 65 years and older will be monitored using standard anesthesia monitoring and Masimo Rainbow SET® Pulse CO-Oximetry during anesthesia induction and tracheal intubation.
Tolerable apnea time will be defined as the duration from the end of ventilation after intubation to a decrease in peripheral oxygen saturation (SpO₂) to 94%.
The primary objective is to assess the association between ORI warning time and tolerable apnea time. Secondary objectives include evaluating the association between ORI values, arterial blood gas parameters at predefined time points, and the Clinical Frailty Scale.
Detailed description
This study is a prospective, observational study. Patients aged 65 years and older who are scheduled for elective oncologic surgery at Ankara Bilkent City Hospital will be included. In all patients, the Clinical Frailty Scale will be routinely assessed during the preoperative period.
In this study, tolerable apnea time will be defined as the time until peripheral oxygen saturation (SpO₂), measured by pulse oximetry, decreases to 94%. Although SpO₂ values of 90% and above have been accepted in the literature, the World Health Organization defines normal SpO₂ as 95% and above and considers values of 94% and below as an indication for treatment.
The Oxygen Reserve Index (ORI) ranges from 0 to 1, and the ORI alarm value triggered by the device due to a downward trend will be recorded. ORI is a dimensionless index ranging from 1 (high oxygen reserve) to 0 (no oxygen reserve), which is measured by optically detecting changes in venous oxygen saturation (SvO₂) after arterial oxygen saturation (SpO₂) reaches 100%. ORI is measured using a multi-wavelength pulse co-oximeter placed on a fingertip.
In addition to routine anesthesia monitoring, including electrocardiography, pulse oximetry, and hemodynamic monitoring, patients will also be monitored using Masimo Rainbow SET® Pulse CO-Oximetry. Due to the oncologic nature of the surgeries and the associated risk of bleeding, close hemodynamic monitoring is required; therefore, invasive arterial blood pressure monitoring will be established in all patients before anesthesia induction.
All patients will be preoxygenated with 100% oxygen for 3 minutes. After establishing intravenous access, anesthesia induction will be performed using intravenous propofol at a dose of 2 mg/kg and fentanyl at a dose of 1 µg/kg. Neuromuscular blockade will be achieved with rocuronium at a dose of 0.6 mg/kg.
All patients will be intubated by an experienced anesthesiologist using a videolaryngoscope. Oxygen Reserve Index (ORI) and peripheral oxygen saturation (SpO₂) values will be recorded, and arterial blood gas analyses will be performed at five predefined time points: baseline (initial values), after 3 minutes of preoxygenation, after 2 minutes of bag-mask ventilation following intubation, during apnea when SpO₂ decreases to 94% without ventilation, and after 2 minutes of ventilation with 100% oxygen.
ORI warning time will be defined as the interval from the onset of the ORI alarm to the decrease of SpO₂ to 94%. SpO₂ warning time will be defined as the duration of the decrease in SpO₂ from 97% to 94%.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
Who may qualify
- Ages
- 65 to 100 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Older adult
- Study population
- It will be studied in patients over the age of 65.
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
The primary outcome measure is the association between Oxygen Reserve Index (ORI) warning time and tolerable apnea time. ORI warning time is defined as the time interval from the onset of the ORI alarm triggered by a downward trend to the decrease of per
Time frame: Peri-induction period at predefined time points baseline; after 3 minutes of preoxygenation; after 2 minutes of bag-mask ventilation following intubation; during apnea at SpO₂ 94%; and after 2 minutes of ventilation with 100% oxygen
The primary outcome measure is the association between Oxygen Reserve Index (ORI) warning time and tolerable apnea time. ORI warning time is defined as the time interval from the onset of the ORI alarm triggered by a downward trend to the decrease of peripheral oxygen saturation (SpO₂) to 94%. Tolerable apnea time is defined as the duration from the end of ventilation after tracheal intubation to the decrease of SpO₂ to 94%.
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 8 Jan 2026.
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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 Desaturation and Apnea, Hypoxia, 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?
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: looking for participants now, as of the sponsor's last update on 8 Jan 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?
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 Muhlis Kuru (+905312089322, muhlis_kuru@hotmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
The primary outcome measure is the association between Oxygen Reserve Index (ORI) warning time and tolerable apnea time. ORI warning time is defined as the time interval from the onset of the ORI alarm triggered by a downward trend to the decrease of per (time frame: Peri-induction period at predefined time points baseline; after 3 minutes of preoxygenation; after 2 minutes of bag-mask ventilation following intubation; during apnea at SpO₂ 94%; and after 2 minutes of ventilation with 100% oxygen). 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 8 Jan 2026.