ORI-Guided FiO₂ Titration in Prone Spine Surgery: Impact on Postoperative Atelectasis Assessed by Lung Ultrasound

Starting soon · Not applicable

Conditions studied: Atelectases, Postoperative Pulmonary, Prone Position, Spine Surgery, Lung Ultrasound, Oxygen Reserve Index

In brief

Atelectasis is a frequent pulmonary complication after general anesthesia, often triggered by preoxygenation and intraoperative hyperoxia. High inspiratory oxygen fractions (FiO₂) can promote absorption atelectasis, ventilation-perfusion mismatch, hemodynamic alterations, and oxidative injury. This study evaluates the effect of two intraoperative oxygen management strategies-oxygen reserve index (ORI)-guided FiO₂ titration versus fixed 50% FiO₂-on postoperative atelectasis in patients undergoing thoracolumbar spine surgery under general anesthesia. Atelectasis severity will be assessed using lung ultrasonography (LUS), scored across 12 thoracic regions (0-3 per region, total 0-36), while respiratory function changes will be examined via preoperative and 24-hour postoperative spirometry (FVC, FEV₁, FEV₁/FVC). Because postoperative spirometry may be influenced by pain, Numeric Rating Scale (NRS) scores will be recorded to help distinguish true restrictive patterns from pain-limited respiratory effort. The study aims to determine whether ORI-guided FiO₂ titration can reduce postoperative atelectasis and improve respiratory outcomes compared with a fixed FiO₂ approach.

Key facts

Study ID: NCT07375173
Run by: Ankara Etlik City Hospital
People needed: 74
Starts: 2026-03-15
Expected to finish: 2026-11-30
Last updated by the study team: 2026-01-29

Who can join

Age: 18 and older, up to 80. Sex: any. Healthy volunteers: not accepted.

You may qualify if…

Adults aged 18 to 80 years
Patients with an ASA physical status of I, II, or III
Individuals with a body mass index (BMI) between 18 and 35 kg/m²

You may not qualify if…

History of or active upper or lower respiratory tract infection within the past month
Pulmonary emphysematous/bullous disease or COPD
Pre-existing significant atelectasis or consolidation (Preoperative LUS showing a score of 3 consolidation or ≥2 regions with a score ≥2)
Severe obstructive sleep apnea requiring CPAP therapy
NYHA class III-IV heart failure, EF <35%, or severe valvular disease
Severe arrhythmia or hemodynamic instability requiring high-dose vasopressors
Body mass index (BMI) >35 kg/m²
Severe anemia (Hb <9 g/dL) or polycythemia (Hb >18 g/dL)
Non-diagnostic or unclear preoperative lung ultrasound images
Preoperative SpO₂ ≤ 94%
Inability to apply the sensor due to finger deformity, or inadequate signal caused by digital hypoperfusion

Full record on ClinicalTrials.gov

Trial information comes from ClinicalTrials.gov and is refreshed daily. TrialsForMe does not provide medical care and does not run the studies it lists.