As part of his talk Perazella threw-up some slides with some surprising statistics on the diagnostic utility of FEUrea and FENa:
|From Pepin AJKD 2007: 50:566-573|
|From Darmon et al. Critical Care 2011: 15 R178.|
I felt shamed. I had been teaching and using urinary acute renal failure indices for 20 years and to see that they sucked sucked, kinda hurt. But then as I thought about it, I remembered seeing hard data that quite a bit more compelling. So I went back and took a look at some of the data.
Carlos Hugo Espinel. His initial series was published in JAMA. In that initial study he found 100% sensitivity and specificity in 17 oliguric patients.
|Holy shit! Shrier is a member of the |
Indiana Basketball Hall of Fame!
|Dr. Kohn is in the middle|
Results for using FENa to diagnose pre-renal disease (<1 br="br"> 1>
- 92% sensitivity without diuretics
- 48% sensitivity with diuretics
- 76% sensitivity for the entire cohort
- 90% sensitivity without diuretics
- 88% sensitivity with diuretics
- 89% sensitivity for the entire cohort
Results for using FENa to diagnose pre-renal disease (<1 p="p">
- 96% sensitivity 100% specificity without diuretics
- 63% sensitivity 98% specificity with diuretics
- 92% sensitivity 87% specificity without diuretics
- 96% sensitivity 83% specificity with diuretics
- FENa 54% sensitivity
- FEUrea 95% sensitivity
This was all the data I could find on trials that look at FENa and FEUrea. Overall the it performed quite well in most studies. In fact the two trials that Perazella quoted were the only two with the indices embarrassing themselves.
Jonathon Gotfried's article in the Cleveland Clinic Journal was a great resource for this article.