Masimo (NSDQ:MASI) today released results from a study seeking to establish a normal range of values for cerebral oxygenation and explore the relationship between cerebral oxygenation and other physical and hemodynamic characteristics using Masimo’s O3 Regional Oximetry.
Results from the study were published in the journal Anaesthesia and Intensive Care, the Irvine, Calif.-based company said.
Masimo said that its O3 system uses near-infared spectroscopy to monitor cerebral oxygenation in situations where peripheral pulse oximetry alone may not fully indicate oxygen levels in the brain.
Researchers at Melbourne, Australia’s Austin Hospital used the O3 to assess for differences in regional cerebral tissue oxygen saturation (SctO2) between hemispheres, sex, comorbidity and smoking status and for associations between SctO2 and physical and hemodynamic characteristics in healthy adults.
A total of 98 subjects enrolled in the trial, Masimo said, with each subject being monitored continuously for five minutes using O3 on the Masimo Root patient monitoring and connectivity hubs.
A total 32,130 SctO2 observations were recorded, with mean left, right and combined SctO2 values of 67.3%, 67.9% and 67.6%, respectively. Researchers reported finding “statistically significant yet quantitatively small differences” in SctO2 values according to hemisphere, and that increasing mean arterial pressure and cardiac index were associated with increased SctO2.
“Our study implies that in healthy adults the mean SctO2 measured with modern technology is close to 68% with narrow confidence intervals of 1%, and with no difference between hemispheres. Moreover, given a lowest mean combined bi-hemispheric SctO2 value of 56%, it implies that an SctO2 value below 56% should be considered ‘abnormally low.’ In addition, the very few SctO2 values below 60% seen in our study imply that persistent measurements below such a threshold should be viewed with concern. Finally, our observation that SctO2 values were not affected in any clinically significant amount by hemispheres, sex, skin type, comorbidity or smoking status, age or any haemodynamic parameter implies that in healthy adults, cerebral tissue oxygen saturation is unaffected by these factors. These findings have significant implications regarding the clinical interpretation of SctO2 and the application of this information to individual patients,” study researchers wrote, according to a Masimo press release.
“The estimation of cerebral oxygenation by near infrared spectroscopy (NIRS) during anesthesia or in critical illness is becoming increasingly recognized 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. The recent study by my colleagues and myself used >30,000 observations in close to 100 normal subjects and found that the mean normal value for cerebral oxygen estimation using modern Masimo NIRS technology was 67.6%, and, more importantly, that the 95% confidence interval for such value was narrow, between 66.8% and 68.6%. Such findings provide a reference value for patient assessment and give a degree of confidence to clinicians in relation to the validity and robustness of this technology,” study co-author Dr. Rinaldo Bellomo said in a prepared statement.
Last month, Masimo said that it won FDA 510(k) clearance for its Rad-67 pulse co-oximeter system.