Oxygen Reserve Index in Different Fresh Gas Flow

Variations in Oxygen Reserve Index in Different Fresh Gas Flow Rate

Our primary objective is to determine whether oxygen reserve index ORI can be a reliable and sensitive indicator of hypoxia and hyperoxia in low-flow anesthesia settings. Our secondary objective is to investigate the ORI changes during preoxygenation stage.

Inclusion Criteria:

• ASA I-III patients
• 18-75 years old
• underwent general anesthesia
• elective ear, nose and throat surgery, lasting longer than 60 minutes

Exclusion Criteria:

• who did not consent to participate,
• those with finger deformities
• unregulated diabetes mellitus, severe heart, kidney, or liver failure, sensitivities to local anesthetics or opioids, those who were morbidly obese (BMI >40 kg/m²), and breastfeeding women.