Oxygen Reserve Index and Prevention of Hyperoxemia
Condition: Hyperoxemia; Oxygen Reserve Index; Hyperoxia; Fraction of Inspired Oxygen
MeSH terms: Respiratory Aspiration; Hyperoxia
Study type: Interventional
Phase: Phase 4

Summary: 
      In patients under general anesthesia, the oxygen level (FiO2) used in inspiration is usually
      adjusted by monitoring the peripheral oxygen saturation level (SpO2). As a non-invasive
      method, SpO2 monitoring is known as one of the required methods that can be used to adjust
      FiO2 and detect and treat hypoxemia. While SpO2 approaching 100% matches the value of 128
      mmHg in arterial partial oxygen pressure (PaO2), in cases where PaO2 increases more, the
      investigators cannot follow this situation with SpO2 and cannot prevent hyperoxemia.

      As stated in the literature, hyperoxemia has positive effects in general anesthesia and
      intensive care, as well as negative effects such as increased inflammation, oxidative stress
      and ischemia-reperfusion. In addition, acute lung injury, development of atelectasis,
      increased mortality, and critical illness rates have been associated with hyperoxemia in many
      publications. The only way the investigators can use to measure the level of hyperoxemia
      seems to be arterial blood gas analysis, and this method limits the investigators use because
      it is invasive. The Oxygen Reserve Index (ORi™) (Masimo Corp., Irvine, CA, USA) is a variable
      related to real-time oxygenation reserve status in the mildly hyperoxemic range
      (approximately 100 - 200 mmHg PaO2). ORi can be defined as a multi-wavelength, noninvasive
      pulse co-oximetry sensor. ORi is a dimensionless index ranging from 0.00 (no reserve) to 1.00
      (maximum reserve) depending on the oxygenation reserve status.

      There are very few studies in the literature using ORi to detect hyperoxemia. The
      investigators thought that if FiO2 levels used in preoxygenation, anesthesia maintenance and
      recovery stages in day surgeries were correlated with ORi levels, a threshold value could be
      determined for FiO2 levels during anesthesia stages in cases where invasive arterial blood
      gas could not be followed.

      This study aims to determine the relationship between SpO2, FiO2 and ORi during general
      anesthesia, to investigate the usefulness of ORi in determining the FiO2 threshold value
      during anesthesia stages as an indicator of hyperoxemia, and to investigate the effects of
      these values on the hemodynamics, recovery, agitation and nausea-vomiting states of the
      patients.
    


Intervention name(s): Oxygen; Masimo Root Radical 7
Intervention type(s): Drug; Device
Intervention description(s): Determination of FiO2 threshold value as an indicator of hyperoxemia in anesthesia stages.; We use it to measure the oxygen reserve index (ORi).
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: Group F30 : FiO2 value is %30 Group F50 : FiO2 value is %50 Group F80 : FiO2 value is %80
Masking: Double (Participant, Investigator)
Primary purpose: Prevention
Keywords: Oxygen Reserve Index; Hyperoxemia; Hyperoxia; Fraction of Inspired Oxygen