The Role of Oxygen Reserve Index (ORi) in Apneic Ventilation

Not yet recruiting

• Conditions: Oxygen Reserve Index; Apnea; Ventilation; Body Mass Index

• Registration Number: NCT07119866
• Lead Sponsor: Ankara City Hospital Bilkent

Brief Summary

Background: The Oxygen Reserve Index (ORI) is a non-invasive parameter utilizing multi-wavelength pulse co-oximetry. ORI can provide early warnings of deteriorating oxygenation before changes are reflected in SpO₂ levels. This study aimed to investigate the feasibility of non-ventilated intubation in patients undergoing cholecystectomy as a means to achieve safe intubation without nasogastric tube placement, with reduced trauma and cost, and improved time efficiency.

Detailed Description

Obesity is a complex and chronic disease that significantly impacts respiratory physiology. It leads to increased work of breathing and reduced compliance of the chest wall. In morbidly obese individuals, there is a marked reduction in total lung capacity, vital capacity, forced expiratory volume in one second (FEV1), and forced vital capacity (FVC). Additionally, due to their elevated metabolic demands, these patients exhibit higher oxygen consumption rates.

The Oxygen Reserve Index (ORi) (Masimo Corp., Irvine, CA, USA) is an advanced, continuous, and non-invasive parameter that provides a relative indication of arterial partial pressure of oxygen (PaO₂).

ORI monitoring can be particularly beneficial in patients at risk for inadequate preoxygenation, those with difficult mask ventilation, hypoxemic patients with aspiration risk, rapid sequence induction scenarios, obese individuals, ICU intubations, and invasive ventilation cases. It has also been shown to provide early warnings of desaturation in select patient groups, contributing to improved patient safety.

Study Timeline

• Study First Submitted: 2025-07-21
• Status Verified: 2025-08
• Study First Submitted QC: 2025-08-06
• Last Update Submitted: 2025-08-06
• Study Start: 2025-08-07
• Study First Posted: 2025-08-13
• Last Update Posted: 2025-08-13
• Primary Completion: 2025-08-21
• Study Completion: 2025-08-30

Recruitment & Eligibility

• Status: NOT_YET_RECRUITING
• Sex: All
• Target Recruitment: 60

Inclusion Criteria

• 18-60 years
• ASA 1-2
• Mallampati score <2
• Scheduled for elective laparoscopic cholecystectomy under general anesthesia

Exclusion Criteria

• <18 and >60 years
• ASA 3-4
• Initial ORI value below 0.24

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
TIME FOR ORI TO FALL BELOW 0.24	WITHIN 10 MINUTES BEFORE INTUBATION	TIME THE PATIENT STARTED TO WEAR A MASKS.

Secondary Outcome Measures

Name	Time	Method
INITIAL ORI VALUE	WITHIN 10 MINUTES BEFORE INTUBATION	Noted for each patient.
ORI VALUE AT 2 MINUTES	WITHIN 10 MINUTES BEFORE INTUBATION	Noted for each patient.
AGE	WITHIN 10 MINUTES BEFORE INTUBATION	Noted for each patient.
American Society of Anesthesiologists (ASA) Score	WITHIN 10 MINUTES BEFORE INTUBATION	Noted for each patient.
SEX	WITHIN 10 MINUTES BEFORE INTUBATION	Noted for each patient.
BMI	WITHIN 10 MINUTES BEFORE INTUBATION	Noted for each patient.
PRESENCE OF A NASOGASTRIC TUBE	10 MINUTES BEFORE EXTUBATION	Noted for each patient.
Surgeon satisfaction	10 MINUTES BEFORE EXTUBATION	Noted for each patient. Surgeon satisfaction according to ng usage status.
PRESENCE OF LARYNGOSPASM	10 MINUTES BEFORE EXTUBATION	Noted for each patient.

Trial Locations

Locations (1)

Ankara Bilkent City Hospital; 🇹🇷 Ankara, Çankaya, Turkey