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#1
12-20-2011
 USMLE Forums Addict Steps History: CK+CS Posts: 138 Threads: 28 Thanked 78 Times in 36 Posts Reputation: 88
Fractional Excretion of Na

Can someone please explain to me Fractional Excretion of Na?
I am a bit confused.......

Thanks

:sorry::sorry::sorry::sorry::sorry::sorry::sorry:

#2
12-20-2011
 USMLE Forums Addict Steps History: Not yet Posts: 129 Threads: 18 Thanked 188 Times in 62 Posts Reputation: 198

well i guess what you need to know from this concept is that Fractional Excretion of Sodium refers to the amount of sodium that is filtered by the kidney and exerted in the urine. It will help you differentiate between ATN and other kidney damages, and Pre-Renal azotemia.
in ATN the kidney is injured and won't be able to reabsorb sodium so you will expect a high urinary sodium and an elevated FE na, in Pre-Renal azotemia the kidney is functional and is able to reabsorb Sodium to compensate for the hypovolemia for example so you will expect to have a low urinary sodium and a low FE na.
there is a formula to calculate the FE na but i don't think we are required to know it for the step 2 exam

Best Regards,
Sam
#3
12-20-2011
 USMLE Forums Addict Steps History: CK+CS Posts: 138 Threads: 28 Thanked 78 Times in 36 Posts Reputation: 88

Quote:
 Originally Posted by sam88 well i guess what you need to know from this concept is that Fractional Excretion of Sodium refers to the amount of sodium that is filtered by the kidney and exerted in the urine. It will help you differentiate between ATN and other kidney damages, and Pre-Renal azotemia. in ATN the kidney is injured and won't be able to reabsorb sodium so you will expect a high urinary sodium and an elevated FE na, in Pre-Renal azotemia the kidney is functional and is able to reabsorb Sodium to compensate for the hypovolemia for example so you will expect to have a low urinary sodium and a low FE na. there is a formula to calculate the FE na but i don't think we are required to know it for the step 2 exam Hope this will help you. Best Regards, Sam
Thanks man..tht was nice....
 The above post was thanked by: chakdeindia (01-10-2012)

 Tags Nephrology-

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