Evaluation of the Effectiveness of Oxygen Reserve Index Monitoring During Pre-oxygenation in Obese Patients

NCT07097662 | Completed DMC

• 1 other identifier: KocaeliUIC
• Study Type: observational
• Target: 60
• Locations: 1 country
• Sites: 1

Brief Summary

In obese patients, the risk of perioperative complications such as rapid desaturation, atelectasis, difficult mask ventilation, difficult intubation, and hypoxia is higher compared to the normal population. Therefore, preoxygenation is even more critical in the obese patient group. In clinical practice, ETO2 is used as a practical indicator to evaluate sufficient oxygenation during preoxygenation. The Oxygen Reserve Index (ORiⓇ) is a new oxygenation monitoring parameter that is continuously and non-invasively measured by a specialized pulse oximetry device (Masimo, Irvine, CA).The primary objective of the investigators was to observe the correlation between ORIⓇ monitoring and ETO₂ during preoxygenation in obese patients.The secondary objective of the investigators was to evaluate the correlation of ORIⓇ with SpO₂ and PaO₂ in this patient population.

Conditions

Obesity

Outcome Measures

Primary Outcomes (1)

• Evaluation of the Effectiveness of Oxygen Reserve Index Monitoring During Pre-oxygenation in Obese Patients

  Non-invasive ORiⓇ values and ETO₂ levels measured every minute during tidal volume breathing in the preoxygenation period will be analyzed for correlation.

  During 5-minute preoxygenation

Secondary Outcomes (2)

• Correlation between ORiⓇ and arterial oxygen pressure (PaO₂) at multiple time points after intubation

  30, 60, 90, and 120 minutes after intubation

• Correlation between ORiⓇ and peripheral oxygen saturation (SpO₂) at multiple time points after intubation

  30, 60, 90, and 120 minutes after intubation

Eligibility Criteria

• Age: 18 Years - 75 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Between February 2024 and July 2024, 60 patients aged 18 to 75 years, with an ASA physical status classification of II-III, a body mass index (BMI) greater than 35 kg/m², and scheduled for elective surgery under general anesthesia, were included in our study after obtaining verbal and written informed consent.

You may qualify if:

• Patients with a body mass index (BMI) \>35 kg/m² scheduled for elective surgery
• ASA (American Society of Anesthesiologists) physical status classification I-III
• Patients aged 18 years and older

You may not qualify if:

• Patients with ASA physical status classification IV-V,
• Psychiatric disorders
• Severe cardiac arrhythmias
• Patients with an ejection fraction below 30%
• Chronic obstructive pulmonary disease (COPD)
• Those receiving home oxygen therapy
• Patients requiring supraglottic airway devices, and emergency cases

Sponsors & Collaborators

• Irem Caner: lead

Study Sites (1)

Kocaeli University

Kocaeli, 41380, Turkey (Türkiye)

Location

Related Publications (1)

• Hirata N, Nishimura M, Chaki T, Yoshikawa Y, Yamakage M. Comparison between oxygen reserve index and end-tidal oxygen concentration for estimation of oxygenation during pre-oxygenation via a tight-fitted face mask: A prospective observational study. Eur J Anaesthesiol. 2021 Mar 1;38(3):313-315. doi: 10.1097/EJA.0000000000001358. No abstract available.

  PMID: 33538433 RESULT

MeSH Terms

Conditions

Obesity

Condition Hierarchy (Ancestors)

Overweight; Overnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases; Body Weight; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Officials

• İrem Caner

  Kocaeli University

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: observational
• Observational Model: OTHER
• Time Perspective: CROSS SECTIONAL
• Target Duration: 1 Day
• Sponsor Type: OTHER
• Responsible Party: SPONSOR INVESTIGATOR
• PI Title: Research Assistant

Study Record Dates

• First Submitted: July 17, 2025
• First Posted: July 31, 2025
• Study Start: February 1, 2024
• Primary Completion: July 31, 2024
• Study Completion: January 1, 2025
• Last Updated: July 31, 2025

Record last verified: 2025-07

Data Sharing

• IPD Sharing: Will not share

Locations

TU (1)