The Effectiveness of FiO2 Titration Guided by the Oxygen Reserve Index in Preventing Hyperoxia.

Study Overview
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Brief Summary
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Oxygen therapy is the most common treatment modality for patients with hypoxemia, but target values for normoxemia are not clearly defined. Therefore, iatrogenic hyperoxemia is a very common situation. Even though there are many side effects reported related to hyperoxemia and hyperoxemia is shown to be related to worse outcome than expected; clinicians still observe hyperoxemia frequently. Oxygen reserve index (ORi™) (Masimo Corp., Irvine, USA) can guide clinicians in detection of hyperoxia. ORi is a parameter which can evaluate partial pressure of oxygen (PaO2) rating from 0 to 1. There are growing evidences in ORi that it might be helpful to reduce hyperoxia in general anesthesia. Continuous ORi monitoring can be used for detecting and preventing hyperoxia. The ability to perform FiO2 titration with ORi may be an appropriate monitoring management to prevent the harmful effects of hyperoxia.In this study, in patients who underwent major abdominal surgery; It was aimed to investigate the effectiveness of ORi-guided FiO2 titration in preventing hyperoxia.

Official Title
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Determination of the Incidence of Hyperoxia and the Effectiveness of FiO2 Titration Guided by the Oxygen Reserve Index in Preventing Hyperoxia.

Conditions
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Hyperoxia, Complication

Intervention / Treatment
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* Procedure: Titration of fraction of inspired oxygen (FiO2) guided by ORI and oxygen saturation
* Procedure: SpO2 (oxygen saturation)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients older than 18, Patients scheduled for major abdominal surgery that are expected to last longer than 2 hours Patients that have invasive arterial monitorization American Society of Anesthesiologists physical class I, II or III. Exclusion Criteria: Patients younger than 18 Patients that need to be treated with high doses of vasopressors, Patients having peripheric hypoperfusion, Hemodynamically unstable patients, Patients with hemoglobinopathy, Pregnancy, Morbid obesity (bmi>40 kg/m2), Patients with arrythmia that can result in hemodynamic instability, patients with acute coronary syndrome Acute respiratory failure or ARDS.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Control group<br>Fraction of inspired oxygen (FiO2) is titrated guided by oxygen saturation in that range; %95<oxygen saturation≤%98 | Procedure: SpO2 (oxygen saturation)<br>* Fraction of inspired oxygen (FiO2) is titrated guided by oxygen saturation in that range; %95<oxygen saturation≤%98<br>|
| Experimental: ORi+SpO2 (oxygen saturation) group<br>FiO2 will be titrated by reducing 10% if Ori>0.01 andSpO2 ≥ 98% until Ori is 0.00. FiO2 will not be changed if Ori is 0.00 and %95<oxygen saturation≤%98 FiO2 will be increased by 10% if oxygen saturation <95 or PaO2<60 mmHg | Procedure: Titration of fraction of inspired oxygen (FiO2) guided by ORI and oxygen saturation<br>* FiO2 will be titrated by reducing 10% if Ori>0.01 and oxygen saturation ≥ 98% until Ori is 0.00. FiO2 will not be changed if Ori is 0.00 and %95<oxygen saturation≤%98 FiO2 will be increased by 10% if oxygen saturation <95 or PaO2<60 mmHg<br>* Other names: ORİ+SpO2;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Correlation of FiO2 and ORi value | Correlation of FiO2 value and ORi value. FiO2 adjusted until ORi reaches to zero and %95<oxygen saturation≤%98 | Until the surgery is over | 
| Correlation of PaO2 and ORİ value | Pressure of arterial oxygen is obtain from arterial blood gas analysis as usual practice in 10 min and every hour until surgery is over | Until surgery is over | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Fraction of inspired oxygen (FiO2) | Fraction of inspired oxygen (FiO2) administered during the surgery | First 10 th min after intubation and every hour until surgery is over | 
| Systolic blood pressure (SBP) | Measurement of systolic blood pressure (SBP) | First 10 th min after intubation and every hour until surgery is over | 
| Diastolic blood pressure (DBP) | Measurement of diastolic blood pressure (DBP) | First 10 th min after intubation and every hour until surgery is over | 
| Heart rate (HR) | Measurement of heart rate (HR) | First 10 th min after intubation and every hour until surgery is over | 
| Positive end-expiratory pressure (PEEP) | Measurement of PEEP | First 10 th min after intubation and every hour until surgery is over |