Instructor says textbooks are wrong about urine output

[Alpha13]

Hello,

Our instructor was telling us that the common limit in hospitals and textbooks for urine output before intervention is at 30 ml/hr. She said that she strongly disagrees with this figure, because at that level the kidney is outputing half of the amount of urine it should be. She says that often by waiting that long, most of the patient's nephrons are destroyed resulting in serious kidney damage or even failure. Do you guys find this to be true? Our instructor is very intelligent and experienced, but she is giving a tall order by saying that all the hospitals and books are wrong about the right output level to intervene at.

Alpha

[Roy Fokker, BSN, RN]

I don't nearly "freak out" about low u/o q shift now as much as I used to when I started working.

Now I also factor in other things - like age, weight, fluid maintenance rates, cardiac and nephro history etc. And no, I don't go by the "less than 30 cc/hr" standard --- unless MD orders states so.

I am cross with some surgeons about their IV fluid orders - maintenance rates are almost always insufficient and patients keep having chronic low output (with attending complains of feeling "thirsty" and "dry").

Some of our docs are very good about it. Some are notorious for being absolutely indifferent.

I also found, curiously, that many of my peers did not know about Holliday-Segar maintenance fluid rates formulas (which I understand is one of the simplest ways to determine fluid maintenance).

cheers,

[RedCell]

Not all Americans are much fatter than that these days. That's a dangerous generalization, RedCell. As dangerous as saying Miller is the "master", meaning he's the only one who knows anything about the topic. Open minds, keep open minds.

Sorry if I offended you, and open minds are great, however facts are facts. Americans are getting fatter, UO should be 0.5ml/kg/hr, and yes, miller is the master. Sure, not every American is fatter, but a large majority of us are. These are facts, well, Miller might be considered an opinion. Here is a link to the fatty situation. I blame it on Ronald and all the Big Macs he forced down my gullet. (Closed minded statement)

Rana, J. S. (2007). Cardiovascular metabolic syndrome-an interplay of, obesity, inflammation, diabetes, and coronary heart disease. Diabetes, Obesity and Metabolism. 9(3), 218.

[ZASHAGALKA, RN]

I find that 30ml/hr is a good REPORTING standard, as opposed to necessarily being a good physical standard for a patient. Mind you, IF a pt is putting out at least 30ml/hr, it might not be enough for effective working of the kidneys, but it SHOULD be enough to demonstrate that the kidneys are indeed doing SOME work until that situation can be addressed by a doc at the bedside.

Things don't happen in a vacuum, and neither does UOP. IF my patient is truly only putting out 30ml/hr, I normally AM concerned. At that point, though, I'm looking for more clues than just UOP to explain the situation.

Are they immediately post-op? Our CV docs don't want to hear about ANYTHING short of complete oliguria for the first 12 hrs. Experience has shown me that fluid shifts involved with major surgeries normally re-shift in the hours after surgery, and so, I'm not normally as concerned about such things (other things being equal), and neither is the doc.

Am I worried about sepsis, or another hypovolemic problem (is the situation 'pre-renal')? Many times, I will feel compelled to call a doc, EVEN THOUGH a patient is putting out 30ml/hr because I feel there are underlying issues that need to be addressed. In THAT case, even though 30ml/hr might have been my first tip-off, it's only ONE of a number of symptoms I present to the doc.

Do I believe that a "low" UOP of 30ml/hr is due to hypoperfusion? I would call to address that issue. The solution is many times the same: fluid challenge.

Is this UOP a significant and sudden change? Were they outputting 60ml/hr or so for the last 24 hrs, and only in the last 2-3 dropped off precipitiously?

The bottom line, if you call a doc about 30ml/hr not being enough UOP, you should be able to back that up with other findings. IF you cannot find any other thing going on, 30ml/hr should be enough UOP until you can present that isolated finding to a doc at the bedside.

Some of this, of course, comes from my specific frame of reference of working nights. IF I call a doc at 3am, I had better have more ammunition than a UOP that does not meet a REPORTING standard. IF I CAN'T find that other ammunition, then it can wait a few hours.

At issue, is the difference between what must be immediately reported and what is a problem that can be corrected more gradually. I don't think 30ml/hr is INTENDED to be an optimum condition. I think it's intended to be a minimum reporting trigger, in the absence of other symptoms.

30ml/hr, in the presence of other symptoms, is STILL a reportable issue. It comes down to looking at the whole picture. And THAT is a function of critical thinking.

Look at it another way: in many cases, a 'reportable' low SBP is

~faith,

Timothy.

[pcicurn7]

My suggestion is that you go and find what is written in YOUR textbook (the one you are currently using), and go with that. The best advice i was ever given in nursing school is that you NEVER mix "real life" nursing with nursing school material, or even the NCLEX. Don't mix the two, or you will get your answers marked wrong. Once you find what your textbook has written, go with that 100% (even though it may not be the truth in real life), that way you can back up your answer should it get marked incorrect.

If your own instructor is telling you that the UOP is wrong on your textbook, make sure to ask which formula you will be tested with. A lot of instructors will pull the exams from the data bank and they will have the levels in THE BOOK.

In nursing school, I was taught the 30 ml/hr is the rule of thumb (were were also taught the formula, though). However, the NCLEX review course i attended made it a point to let us know that this number is what is considered "minimum" output, and that we should follow the 0.5-1 ml/kg/hr rule. I believe that NCLEX still goes with 30 ml/hr (not sure though). So, know both.

[Roy Fokker, BSN, RN]

Some of this, of course, comes from my specific frame of reference of working nights. IF I call a doc at 3am, I had better have more ammunition than a UOP that does not meet a REPORTING standard. IF I CAN'T find that other ammunition, then it can wait a few hours.

At issue, is the difference between what must be immediately reported and what is a problem that can be corrected more gradually. I don't think 30ml/hr is INTENDED to be an optimum condition. I think it's intended to be a minimum reporting trigger, in the absence of other symptoms.

30ml/hr, in the presence of other symptoms, is STILL a reportable issue. It comes down to looking at the whole picture. And THAT is a function of critical thinking.

In other words "Treat the patient, not the monitor"

Good post :)

cheers,

[Gromit]

Well, what you (all) are saying makes a lot of sense -I certainly don't recall the .5ml/kg/hr, but that makes a lot more sense than a global 30ml/hr.

However, in any case, the advice is also sound -the test is going to look for 30ml/hr -and the test won't have a space for you to explain your answer.

To that note, I've found that most docs (with the probable exception of nephrologists) abide by that rule as well (30ml/hr) for adults -they certainly do on my floor.

HOWEVER, that being said, you also treat the patient, not the numbers. IF your patient is normally throwing out 100ml/hr, and over the next several hours that foley is showing 30/hr, and it was a sudden drop, I'd be on the phone to the doc and document it. On the other hand, if the patient has been putting out 30/hr regularly, then that is what the patient has been putting out. And if their input is signifficantly higher than their output, odds are they get dialysis as well.

[Tweety, BSN, RN]

30 cc/hour has always worked for me. The trick is not to leave them there. The trick is to critically think "why are they so low", notify the MD and correct the cause.

So the instructor is correct that the nephrons are will be destroy is you just let them go 30 cc/hour forever.

I've never had an outcome when I've let say someone slip by with 50 cc/hour. Often we're lucky to get 30/hour from our elderly patients as they tend to come in dehydrated for not drinking much.

[Tweety, BSN, RN]

Good response from Timothy above. Critically think here.....look at the total picture.

[mediatix8]

No way... dude, do you do to UIC? If so... I have to tell you something. Do you go there?