BODYSTAT'S PREDICTION MARKER / IMPEDANCE RATIO
What is Prediction Marker/Impedance Ratio (IR)?
The Impedance Ratio (IR), derived by an MF-BIA measurement, and is defined in the ESPEN Blue Book as a “Newer way to evaluate cell membrane function” and a “reliable guide to prognosis” of patients in intensive care Units.
IR is the ratio between the impedance measured at 200 kHz and 5 kHz.
How does it work?
In a healthy subject at 5 kHz, the Impedance or resistance to the flow of the current will be High because the current cannot penetrate the cell membrane. It therefore only measures the Extra-cellular water (ECW).
At the higher 200 kHz frequency, the current is strong enough to penetrate the cell membrane wall. Thus, the impedance is lower and measure both inside (ICW)