NCT07050719

Can Atelectasis Be Prevented With Oxygen Reserve Index (ORI) Monitoring?

Can Atelectasis be Prevented in Robotic Surgery by Monitoring With Oxygen Reserve Index (ORI)? A Randomized Controlled Trial

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 58 (actual)
• Sponsor: Antalya Training and Research Hospital · Other Government
• Sex: All
• Age: 18 Years – 75 Years
• Healthy volunteers: Not accepted

Summary

This single-center randomized controlled trial aims to evaluate whether intraoperative monitoring using the Oxygen Reserve Index (ORI) reduces the incidence of postoperative atelectasis, as assessed by lung ultrasound (LUS), in adult patients undergoing elective robotic surgery under general anesthesia.

Detailed description

Postoperative atelectasis is observed in 60-90% of patients undergoing general anesthesia. Factors such as high inspired oxygen concentration, muscle relaxation, and reduced functional residual capacity contribute to its development through mechanisms like absorption atelectasis. The persistence of atelectasis increases the risk of pneumonia, hypoxia, prolonged hospital stay, healthcare costs, and mortality. Despite the well-known pathophysiology, the optimal intraoperative fraction of inspired oxygen (FiO₂) remains unclear. The Oxygen Reserve Index (ORI) is a non-invasive, continuous parameter that reflects the oxygen reserve within the moderate hyperoxia range (100-200 mmHg). It may facilitate individualized FiO₂ titration to avoid hyperoxia-related atelectasis. Lung ultrasound (LUS) is a reliable, radiation-free bedside tool for detecting atelectasis. This study hypothesizes that ORI-guided oxygen therapy will reduce the incidence of postoperative atelectasis compared to standard Peripheral Capillary Oxygen Saturation (SpO₂)-guided therapy.

Conditions

• Atelectasis
• Lung Ultrasonography Score
• Hyperoxia

Interventions

Type	Name	Description
PROCEDURE	Peripheral Oxygen Saturation (SpO₂) Group	FiO₂ adjusted based on pulse oximetry to maintain SpO₂ ≥98%
PROCEDURE	Peripheral Oxygen Saturation and Oxygen Reserve Index (SpO₂-ORI) Group	FiO₂ adjusted using both SpO₂ and ORI to maintain ORI between 0-0.3

Timeline

• Start date: 2025-07-15
• Primary completion: 2025-12-08
• Completion: 2025-12-08
• First posted: 2025-07-03
• Last updated: 2025-12-10

Locations

1 site across 1 country: Turkey (Türkiye)