Researchers at Austin Hospital in Australia have investigated the relationship between cerebral oxygenation and other physical and haemodynamic characteristics to create a set of normative values for further study.
Led by Dr Christopher Eyeington, the researchers conducted a trial on 98 healthy volunteers aged 22-60 years old to measure regional cerebral oxygenation saturation (SctO2) levels using the Masimo O3 regional oximetry device.
The Masimo Root Patient Monitoring and Connectivity Hub was used to monitor each volunteer continuously for five minutes and record SctO2 measurements every two seconds.
The data was used to find out the differences in SctO2 between the hemispheres of the brain, subjects with one or more co-occurring conditions, smokers and non-smokers, and men and women.
Statistically significant yet quantitatively small differences were found in SctO2 values according to hemisphere (p < 0.001). Increasing mean arterial pressure (MAP) (p = 0.001) and cardiac index (CI) (p ≤ 0.001) were associated with increased SctO2.
The findings were said to have significant implications regarding the clinical interpretation of SctO2 and the application of this information to individual patients.
Study co-author Dr Rinaldo Bellomo said: “The estimation of cerebral oxygenation by near-infrared spectroscopy (NIRS) during anaesthesia or in critical illness is becoming increasingly recognised as a desirable form of monitoring.
“Thus, it is vital for clinicians to understand normal values and to have confidence in the technology behind such measurements.”
Masimo O3 is indicated for situations where peripheral pulse oximetry alone may not fully indicate the levels of oxygen in the brain.