Oxygen Reserve Index monitoring to detect early desaturation during anesthesia in older adults having cancer surgery

The Effectiveness of Oxygen Reserve Index in Early Detection of Desaturation in Geriatric Patients Scheduled for Oncological Surgery; a Prospective, Observational Study.

Observational Ankara City Hospital Bilkent · NCT07326293

This project will test whether the Oxygen Reserve Index (ORI) gives clinicians earlier warning of falling oxygen levels during induction and intubation in people aged 65 and older having elective cancer surgery.

Quick facts

Study typeObservational
Enrollment44 (estimated)
Ages65 Years to 100 Years
SexAll
SponsorAnkara City Hospital Bilkent Academic / other
Locations1 site (Ankara, Çankaya)
Trial IDNCT07326293 on ClinicalTrials.gov

What this trial studies

This is a prospective observational study of patients aged 65 and older scheduled for elective oncologic surgery at Ankara Bilkent City Hospital. During anesthesia induction and tracheal intubation, patients will have standard monitoring plus Masimo Rainbow SET pulse CO-oximetry to record Oxygen Reserve Index (ORI) and pulse oximetry (SpO2). Tolerable apnea time is defined as the interval from the end of ventilation after intubation until SpO2 falls to 94%; ORI alarm/warning times, arterial blood gas values at predefined time points, and Clinical Frailty Scale scores will be recorded. The primary analysis will examine the association between ORI warning time and tolerable apnea time, with secondary analyses correlating ORI values to ABG parameters and frailty.

Who should consider this trial

Good fit: Ideal candidates are adults aged 65 years or older with ASA physical status I–III who are scheduled for elective oncologic surgery and can undergo standard anesthesia monitoring.

Not a fit: Patients with advanced coronary artery disease, severe heart failure or valvular disease, carotid stenosis, left ventricular ejection fraction <30%, rapid atrial fibrillation, BMI >35 kg/m², anticipated difficult airway, advanced-stage malignancy, or dementia were excluded and are unlikely to benefit from this protocol's findings.

Why it matters

Potential benefit: If ORI reliably signals declining oxygen reserves earlier than pulse oximetry, clinicians may be able to intervene sooner and reduce episodes of hypoxia during airway management in older surgical patients.

How similar studies have performed: Previous pilot and observational work has suggested ORI can provide earlier warning of falling oxygenation than SpO2 in other populations, but data specifically in geriatric oncologic surgery are limited.

Eligibility criteria

Show full inclusion / exclusion criteria
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.

Where this trial is running

Ankara, Çankaya

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions DesaturationApnea, HypoxiaOxygen Reserve Indexoxygen reserve indecgeriatricdesaturation
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.