An interventional study of FiO₂ titration, under the guidance of ORI and Conventional oxygen administration in Rhinoplasty, Oxidative Stress and Hyperoxia, sponsored by Dr. Lutfi Kirdar Kartal Training and Research Hospital. Completed at 1 site in Turkey (Türkiye). Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2025-09-08.
Sponsored by Dr. Lutfi Kirdar Kartal Training and Research Hospital · Not applicable, Interventional, and Prevention
The aim of this study is to evaluate whether the use of Oxygen Reserve Index (ORİ) can prevent hyperoxia in patients undergoing rhinoplasty surgery and whether it can reduce oxidative stress caused by hyperoxia.
ORI is a continuous, non-invasive parameter provided by new-generation pulse oximeters utilizing multi-wavelength pulse oximetry technology. ORI serves as an important monitoring tool for detecting both hyperoxemia and desaturation in patients with decreased PaO₂ levels. Studies have demonstrated that ORI provides values within a range of 0 to 1, and an ORI value of 0 corresponds to a PaO₂ level between 80 and 125 mmHg.
Oxygen is commonly used in clinical practice to prevent or treat hypoxia; however, excessive use may lead to oxidative stress. Oxidative stress is defined as a disruption of the oxidative balance resulting from an increased generation of reactive oxygen species (ROS) during cellular metabolism and an insufficient level of antioxidants to detoxify them. ROS are formed by the reaction of molecular oxygen with H₂O, the most stable form of oxygen. In this reaction, the stepwise addition of electrons to molecular oxygen (O₂) leads to the formation of superoxide anion (O₂ˉ), hydrogen peroxide (H₂O₂), and hydroxyl radical (-OH). Among these, the hydroxyl radical is the most reactive form of oxygen radicals.
Although ROS are essential for normal cellular functions such as intracellular signaling and defense against external threats, their excessive production can lead to molecular and cellular dysfunction. Excessive ROS attack nucleotide bases in nucleic acids, amino acid side chains in proteins, and double bonds in unsaturated fatty acids, resulting in oxidative stress that damages DNA, RNA, proteins, and lipids, leading to structural and metabolic changes in cells.
The primary aim of the investigators in this study is to determine whether ORI-guided oxygen titration during rhinoplasty surgery can help prevent hyperoxia and reduce oxidative stress compared with conventional oxygen therapy. To evaluate oxidative stress, thiol-disulfide balance and ischemia-modified albumin (IMA) levels will be assessed in the participants.
115 studies on the registry are indexed under Hyperoxia; 13 are open to participants now.
This study's enrollment of 60 is above the median of 48 across 82 interventional studies indexed under Hyperoxia.
Browse Hyperoxia studies →Dr. Lutfi Kirdar Kartal Training and Research Hospital is the lead sponsor of 78 studies on the registry; 9 are open to participants now.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
ASA physical status
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hemoglobin (Hb)
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Patients in Group R received ORI monitoring in addition to intraoperative standart monitoring (ECG, pulse oximetry, non-invasive arterial blood pressure). For this purpose, an ORI sensor (RD Rainbow SET sensor, Masimo Corp., Irvine, CA, USA) was placed on the fourth finger of the upper extremity where there was no blood pressure cuff. The sensor was wrapped to prevent exposure to light and connected to an oximeter device (Raical-7® Pulse CO-Oximater®, Masimo Corp., Irvine, CA, USA).In Group R, mask ventilation was administered with 50% oxygen. FiO₂ was titrated between 30% and 50% under the guidance of ORI and SpO₂ values. Accordingly, if SpO₂ was ≥ 98%, FiO₂ was reduced in 5% increments to a minimum of 30%, aiming to achieve an ORI value of 0 or as close to 0 as possible.
Device: FiO₂ titration, under the guidance of ORI
Patients in Group C received only standard monitoring. Mask ventilation was administered with 100% oxygen. FiO₂ was maintained at 50% throughout the surgery, provided that SpO₂ remained ≥ 98%.
Device: Conventional oxygen administration
In Group R, FiO₂ was titrated between 30% and 50% under the guidance of ORI and SpO₂ values. Accordingly, if SpO₂ was ≥ 98%, FiO₂ was reduced in 5% increments to a minimum of 30%, aiming to achieve an ORI value of 0 or as close to 0 as possible.
In Group C, FiO₂ was maintained at 50% throughout the surgery, provided that SpO₂ remained ≥ 98%.
Change in thiol-disulfide balance.
Plasma native thiol, total thiol, and disulfide levels will be measured. The disulfide-to-thiol ratio will be used as a marker of oxidative stress. Unit of Measure: µmol/L
Time frame: preoperative to end of surgery (before awakening)
Change in ischemia-modified albumin (IMA) levels.
Serum IMA levels will be measured as an indicator of oxidative stress. IMA reflects modification of the N-terminal region of albumin by reactive oxygen species (ROS). Unit of Measure: Absorbance Units (ABS units)
Time frame: preoperative-end of surgery (before awakening)
PaO₂ levels.
To compare intraoperative PaO₂ changes between ORI and Control groups. Arterial blood gas samples were obtained from all patients after intubation, at the 2nd hour of surgery, and at the end of the procedure before awakening.
Time frame: From baseline (after intubation) to end of surgery (before awakening)
Plan to share: No
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Dr. Lutfi Kirdar Kartal Training and Research Hospital