Other companies promote the “absolute intervention threshold” or what is sometimes called “absolute accuracy” capability of their oximeters. While accuracy is important, there’s more to the picture.
Exactly what does “absolute intervention threshold” or “absolute accuracy” mean? At this time, the FDA has no defined parameters for these marketing terms.
Current cerebral oximeter technology does not allow for “absolute” measurements. The only real way to measure “absolute” cerebral oxygenation levels is to sample blood from a patient’s brain, which oximeters don’t do.
“Absolute intervention thresholds” or “absolute accuracy” alone are not definitive of a patient’s full physiologic condition. Each patient is unique and there is a wide range of normal values for cerebral venous oxygenation, which is contrary to an absolute measurement threshold for intervention.([FOOTNOTE=Aron JH, Fink GW, Swartz MF, et al. Cerebral oxygen desaturation after cardiopulmonary bypass in a patient with Raynaud’s phenomenon detected by near-infrared cerebral oximetry. Anesth Analg. 2007;104(5):1034-1036.],[ANCHOR=View Abstract],[LINK=/content/covidien/websites/medtronic/com/en/covidien/support/clinical-evidence.html?id=297569])