Oxygen Reserve Index-Guided Oxygen Titration During Surgery in the Beach Chair Position

NCT07404267 | Not Yet Recruiting

• 2 other identifiers: ORI-FIO2-BCP-20252025/234
• Study Type: interventional
• Target: 80
• Locations: 1 country
• Sites: 1

Brief Summary

This study aims to evaluate whether guidance by the Oxygen Reserve Index (ORi) improves inspiratory oxygen fraction (FiO₂) titration compared with conventional pulse oximetry (SpO₂)-guided oxygen administration in adult patients undergoing surgery in the beach chair position. Oxygen therapy is routinely used during general anesthesia to prevent hypoxemia; however, excessive oxygen administration may result in hyperoxia, which has been associated with adverse cardiovascular and pulmonary effects. Standard pulse oximetry may not adequately detect hyperoxia when oxygen saturation values are high. In this prospective comparative study, patients will receive oxygen titration guided either by SpO₂ alone or by combined ORi and SpO₂ monitoring. The primary outcome is the incidence of intraoperative hyperoxemia, assessed by arterial blood gas analysis. Secondary outcomes include intraoperative oxygenation parameters and hemodynamic variables.

Conditions

Hyperoxemia; Intraoperative Oxygen Therapy; Beach Chair Position; Cerebral Oxygenation

Keywords

Oxygen Reserve Index; ORİ; FiO2 titration; Hyperoxia; Pulse oximetry; Arterial blood gas; Near-infrared spectroscopy; General anesthesia; Beach chair position; Orthopedic surgery

Outcome Measures

Primary Outcomes (1)

• Incidence of Intraoperative Severe Hyperoxemia

  Severe hyperoxemia will be defined as an arterial partial pressure of oxygen (PaO2) ≥200 mmHg, measured by arterial blood gas analysis at predefined intraoperative time points.

  Perioperative/Periprocedural

Secondary Outcomes (4)

• Mean Peripheral Oxygen Saturation (SpO2) During Surgery

  Perioperative/Periprocedural

• Mean Oxygen Reserve Index (ORi) During Surgery

  Perioperative/Periprocedural

• Mean Fraction of Inspired Oxygen (FiO₂) During Surgery

  Perioperative/Periprocedural

• Mean Cerebral Oxygen Saturation Measured by Near-Infrared Spectroscopy During Surgery

  Intraoperative period (from induction of anesthesia to end of surgery)

Study Arms (2)

ORi-Guided FiO₂ Titration

EXPERIMENTAL

Inspiratory oxygen fraction (FiO₂) will be titrated using combined Oxygen Reserve Index (ORi) and peripheral oxygen saturation (SpO₂) monitoring throughout surgery.

Other: ORi-Guided FiO₂ Titration

SpO₂-Guided Oxygen Titration

ACTIVE COMPARATOR

Inspiratory oxygen fraction (FiO₂) will be titrated based on peripheral oxygen saturation (SpO₂) values according to routine clinical practice.

Other: SpO₂-Guided FiO₂ Titration

Interventions

ORi-Guided FiO₂ Titration OTHER

Inspiratory oxygen fraction (FiO₂) will be adjusted throughout surgery using combined Oxygen Reserve Index (ORi) and peripheral oxygen saturation (SpO₂) monitoring. FiO₂ will be titrated to maintain ORi values between 0.2 and 0.5, with reassessment every 2-3 minutes.

ORi-Guided FiO₂ Titration

SpO₂-Guided FiO₂ Titration OTHER

FiO₂ will be adjusted to maintain SpO₂ at or above 98% throughout surgery.

SpO₂-Guided Oxygen Titration

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Adult patients aged 18 to 65 years
• American Society of Anesthesiologists (ASA) physical status I-III
• Scheduled for elective orthopedic surgery in the beach chair position
• Body mass index (BMI) \<35 kg/m²
• Ability to provide written informed consent

You may not qualify if:

• Age \<18 or ≥65 years
• Finger deformities preventing the use of Oxygen Reserve Index (ORi) monitoring
• Severe anemia (hemoglobin \<8 g/dL)
• Pregnancy
• Refusal or inability to provide informed consent
• History of stroke or significant vascular pathology
• Severe cardiac or respiratory disease

Sponsors & Collaborators

• Fatih Sultan Mehmet Training and Research Hospital: lead

Study Sites (1)

Istanbul Provincial Health Directorate Fatih Sultan Mehmet Training and Research Hospital

Istanbul, 34000, Turkey (Türkiye)

Location

MeSH Terms

Conditions

Hyperoxia

Condition Hierarchy (Ancestors)

Signs and Symptoms, Respiratory; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Officials

• cagla sancak, MD

  ISTANBUL PROVINCIAL HEALTH DIRECTORATE FATIH SULTAN MEHMET TRAINING AND RESEARCH HOSPITAL

  PRINCIPAL INVESTIGATOR

Central Study Contacts

cagla sancak, md

CONTACT

+905064381002; caglasancakk@gmail.com

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Resident in Anesthesiology

Model Details: Participants will be assigned to one of two parallel groups in which inspiratory oxygen fraction (FiO₂) is titrated either using combined Oxygen Reserve Index (ORi) and SpO₂ guidance or SpO₂ guidance alone throughout surgery.

Study Record Dates

• First Submitted: January 18, 2026
• First Posted: February 11, 2026
• Study Start: February 15, 2026
• Primary Completion (Estimated): June 30, 2026
• Study Completion (Estimated): July 31, 2026
• Last Updated: February 11, 2026

Record last verified: 2026-01

Locations

TU (1)