24 Hour Urine Test Question

[kimpaulus00]

Thanks for the information -- I think I have a better handle on what the results mean now. :-)

[snpdrgn]

Wow I can actually "help" someone with 24 urine test knowlegde! During this pregnancy I have had to have probably 4 or 5 of them already and will need another 2 at least before I am through (I had some kidney problems but they are getting better)

Anywhoo.... I asked the lab lady this EXACT SAME QUESTION on June 30th and she said that dehydration (or varying amounts of urine collection in 24hours) can effect the results but she said its so minor that they dont worry about the difference. You either have a high number or you dont was kind of her implication. Your kidneys filter the urine kind of the same way so its almost like a mixture equation or ratio like rachelc said above. Its not like your kidneys filter 2 liters with hardly any protein and then dumps protein for the next 3 liters worth of urine. Its pretty much an even leakage of protein if you are leaking it(this is more of a generalization). So if you collect more or less urine as far as quantity goes, it will still have an X amount of protein per liter whether or not that gets multiplied by 5 or 6 or even 10 liters its still the same protein ratio.

I dont know if that makes sense or if I have confused everyone but it understandable in my mind! [:D]

[caryn]

http://www.preeclampsia.org/forum/viewtopic.php?t=23503

(This was a good question, and I wasn't sure about the answer, so I kicked it up to one of our Experts!)

[rachelc]

The way the results of the test read is per deciliter of urine. So if your results were 300 mg it is 300 mg per deciliter of urine collected. If your results were 300 mg/dl and you collected 10 dl of urine then you had 300 mg of protein in the sample. However, if you collected 20 dl of urine, then you had 600 mg of protein in your sample which would also show as 300 mg/dl on your test results. Does this make sense? The test result is not the total amount of protein in the sample but its the ratio of protein to urine. I hope that helps!

[caryn]

Kim,

Actually, it's the other way around -- dipsticks can be thrown off by your level of hydration, but the 24-hour is accurate! The question isn't how much per unit of urine, but how much with elapsed time of one day.

[julie f]

Kim,

As far as I understand, a 24 hour urine is a 24 hour urine - regardless of the amount collected. The dipsticks can be thrown off based on concentration but not the 24 hour test.

You are right in that 300mg of protein in a 24 hour sample, along with two bp readings of 140/90 (5-6 hours apart), are the criteria for a diagnosis of preeclampsia.

[kimpaulus00]

I do not know if anyone has posed this question before, but I keep hearing that over 300 mg is the "magic number" for a determination of PE (when combined with other items). My question is whether that 300 mg is for any amount of urine or for a certain, possibly average amount of urine.
I am wondering since I had an amount of protein well over that but my first 24 hour test was approximately 5 liters or urine and my second was nearly 6 liters. It seems to me that having over 300 mg in that much urine is alot different from having 300 mg in under 2 liters.
BTW, my doctor said that my kidneys were working well :-) and that all other tests came back fine.