Oxygen titration with Oxygen Reserve Index in minimally invasive repair of pectus excavatum, a randomized controlled trial.

Objective: Perioperative hypoxemia is common during minimally invasive repair of pectus excavatum (MIRPE). Oxygen Reserve Index (ORI™) is a noninvasive method that shows blood oxygenation status. In addition, this method provides information about hypoxemia earlier than pulse oximetry. The primary aim of this study was to examine the value of ORI monitoring as an early predictor of hypoxemia during surgery. The secondary aim was to evaluate the value of ORI monitoring as a guide for oxygen titration to prevent hyperoxemia.

Methods: This randomized controlled study enrolled 128 pediatric patients aged 8-18 years scheduled for elective MIRPE surgery. Patients were followed up with continuous peripheral oxygen saturation (SpO₂) measurement in the control group (Group C) and continuous ORI monitoring in the study group (Group O). After pneumothorax, a decrease of 1% in basal SpO₂ and 0.05 from basal ORI was considered clinically significant. Patient demographics, pre-induction, pre-first and second pneumothorax, and postoperative ORI, mean arterial pressure, temperature, perfusion index, end-tidal carbon dioxide values, length of hospital stay, anesthesia, and surgery durations were recorded.

Results: Desaturation time was 59.46±15.57 seconds in Group O based on ORI, and 177.64±20.94 seconds in Group C according to SpO₂, and the difference was significant (p<0.001). Use of FiO₂>0.6 was lower in Group O, compared with Group C (p<0.05). Length of hospital stay was lower in Group O (p=0.002).

Conclusion: ORI may detect hypoxemia earlier than SpO₂ monitoring during MIRPE surgery. ORI monitorization decreases exposure time to high oxygen concentrations and may increase patient safety during MIRPE surgery in pediatric patients.