Nephrology - What Is the Phena?

The phena is the fractional excretion of sodium. It's kind of a proxy almost for telling us if there is a effective arterial blood volume that's getting to the kidney. Diuretics and also significantly alter the various urine studies. So you can't really rely on the phena itself anymore. You can use an FEUrea, which is not... Eurea itself is not going to be impacted by diuretics.