Non-invasive assessment of oxygenation status using the oxygen reserve index in dogs.

Background: The oxygen reserve index (ORi) is a real-time, continuous index measured with multi-wavelength pulse CO-oximetry technology. It estimates mild hyperoxemia in humans, which is defined as a partial pressure of oxygen (PaO) level between 100 and 200 mmHg. The objectives of this study were to assess the correlation between ORi and PaO, as well as to determine its ability in detecting mild hyperoxemia in dogs.