What is the value of FENa for acute-on-chronic renal failure? Can that whole <1% for prerenal failure idea be relied upon when there is already pre-existing CRF?
What is the value of FENa for acute-on-chronic renal failure? Can that whole <1% for prerenal failure idea be relied upon when there is already pre-existing CRF?
This is not an easy question to answer. A large group of intensivists, nephrologists, and critical care nephrologists have been trying to address this and many more renal-based questions in critical care. Their group is called ADQI (Acute Dialysis Quality Initiative). The ADQI II meeting addressed your question. I'll post the links.
I read through the texts on the links, there is actually no mentioning at all about FENa; all they say is that in the case of acute-on-chronic renal failure, you need to have some criteria to diagnose what is ARF, and they propose an increase in creatinine of at least 0.5 to a value over 4, in cases when baseline creatinine is abnormal.
I read through the texts on the links, there is actually no mentioning at all about FENa; all they say is that in the case of acute-on-chronic renal failure, you need to have some criteria to diagnose what is ARF, and they propose an increase in creatinine of at least 0.5 to a value over 4, in cases when baseline creatinine is abnormal.
Most nephrologists I've spoken to, and papers I've come across, place a very limited value on FENa. It is more of an historical calculation. If you do a pubmed search, I'm sure you'll also come across some of these same articles.