sudipto1973
Forum Newbie
Topics: 4
Posts: 31
|
Fractional excretion of sodium is excreted load of sodium divided by filtered load of sodium or to put it in other way
FeNa+ = (V X UNa+) / (GFR X PNa+) where V is urine flow rate and PNa+ and UNa+ are plasma and urine Na+ conc.
In pre-renal failure due to decreased renal perfusion the kidneys try to conserve as much sodium so as to increase plasma volume and hence renal perfusion. So FENa+ will be less in pre-renal failure compared to intrinsic renal failure. I don't remember the values though.
|
| usmleasr
Forum Guru
Topics: 105
Posts: 970
|
thanks good explanation..FENa+ less than 1%is typical of pre-renal failure..
in renal (ATN)FENa+ is greater than 2% due to failure to reabsorb
|
|
| |
| | |
