UA interpretation: + Nitrite, many bacteria, no WBC

[ERDude]

How do you guys interpret a UA with + nitrite, + bacteria and no WBC?

I know nitrite is specific for Gram negs and I've always considered this worthy of treatment even in the absence of pyuria (and anecdotally it seems the UCx almost always return + for > 100K of some GN bacteria with these).

I admitted a pt recently with presumed sepsis, only revealing source was a UA (straight cath sample) with above findings and I initiated tx as such.

ID consult obtained during hospital course and they remarked that urinary source unlikely given no pyuria (and this was after a UCx grew >100k E.coli).

Had another case yesterday of a confused elderly guy with UA + nitrite and bact, no wbc, I gave ceftriaxone and admitted. Admitting team underwhelmed and holding further abx. I follow up today and UCx >100k Klebsiella.

Thoughts?

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[pratik7]

i dont typically treat if there are no white cell. To me, absence of white cells indicates no infection. If the culture is positive, there maybe colonization. Think of it as swabbing someones butt hole. You are gonna get lots of bacteria but it doesn't necessarily mean there is infection.

The exception being if you are on chemo or otherwise suppressed.. ie you dont have any WBCs

 

[Angry Birds]

I don't know the answer to your question but I've already ordered broad spectrum antibiotics after my first encounter with the sepsis patients. And I usually inform the admitting team that I gave one dose in the ED and they can narrow it themselves. I think one dose won't harm anything but can only help in the broad scheme of things, I.e. Sepsis patients getting antibiotics quickly.

 

[Birdstrike]

ID lives in a 20/20 world of hindsight with completed cultures, identified organisms and susceptibility profiles. You don't have that luxury. In your world, there's more be lost in not treating with a small risk of antibiotic side effects, and finding out later an infection has been snowballing while a culture churns away, versus treating a presumed infection that proves negative later on a culture.

You will have many cases like this: Infection uncertain until a culture comes back. You have to pick one:

A-Side effects of 24-48 hour of an antibiotic for something that turns out to not be an infection and giving ID something to feel snarky about, or

B-Unchecked and worsening infection which could potentially reach an inflection point of sepsis/fatality before you have absolute certainty what it is, what organism, and which antibiotic it's susceptible to.

I tend to favor choice A in our unforgiving medical-legal world of "zero miss" expectations, although each case has to be taken individually.

 

[USCDiver]

Was it an old incontinent person? Not sure if this has been studied, but in my experience it seems sometimes the urine doesn't stay in the bladder long enough to accumulate very many WBCs.

 

[ERDude]

i dont typically treat if there are no white cell. To me, absence of white cells indicates no infection. If the culture is positive, there maybe colonization. Think of it as swabbing someones butt hole. You are gonna get lots of bacteria but it doesn't necessarily mean there is infection.

The exception being if you are on chemo or otherwise suppressed.. ie you dont have any WBCs

I'm referring to patients without indwelling catheters so to me colonization of a gram negative bug in the urine would seem odd.

 

[Birdstrike]

Was it an old incontinent person? Not sure if this has been studied, but in my experience it seems sometimes the urine doesn't stay in the bladder long enough to accumulate very many WBCs.

True. U/A's, and even culture results are a classic gray area of interpretation. As an EP, you're generally better off treating, when in doubt.

 

[ERDude]

Was it an old incontinent person? Not sure if this has been studied, but in my experience it seems sometimes the urine doesn't stay in the bladder long enough to accumulate very many WBCs.

Good question:

Neither had known incontinence to my knowledge but the second case I mentioned was an old, probably demented pt who I would gander had at least some urinary incontinence.

 

[ERDude]

Also I agree with the above sentiment RE: presumed sepsis/severe sepsis/septic shock gets pan cultured and broad spec empiric abx in the ED. Hopsitalists and ID docs of course fully support this practice. I was just surprised UCx + for >100k E.coli in pt that presented septic with no other confirmed source (and improved on abx) and urine was deemed not likely to be the source.

 

[Vandalia]

Emergency medicine is easy if you already have all the answers at the time you see the patient. Practicing medicine in the presence of gross uncertainty is what makes this a specialty and not just something residents do for a couple months as part of their training in another specialty.

If there is reasonable clinical suspicion, and there is a reasonable chance that something very bad could happen if you delay abx, then give the initial dose of abx.

 

[ERDude]

Let's remove the sepsis portion because only one person (Pratik7 - he doesn't typically treat) has really answered as to how they interpret the above UA: nitrite + without pyuria and I think most of us are already practicing aggressive sepsis care in the ED.

What if it's a 25F (not pregnant) healthy, dysuria for 1 day, normal VS.

 

[Angry Birds]

Let's remove the sepsis portion because only one person (Pratik7 - he doesn't typically treat) has really answered as to how they interpret the above UA: nitrite + without pyuria and I think most of us are already practicing aggressive sepsis care in the ED.

What if it's a 25F (not pregnant) healthy, dysuria for 1 day, normal VS.

If the patient has symptoms (i.e. dysuria) then yes.

 

[leviathan]

If the patient is septic then you treat, and that's backed up by IDSA and other organizations. I wouldn't hang my hat on the absence of WBCs to say that the urinary tract is not the cause, in the absence of another obvious source.

 

[Birdstrike]

I bet half of you you saying you wouldn't treat a positive nitrite wouldn't hesitate to throw antibiotics at a viral uri, sinusitis, conjunctivitis, that doesn't need antibiotics, to reduce length of stay, increase Press Ganey scores or improve some other stupid metric. Yet, you're being intimidated by some b---s--- snarky talk from an ID doc two days later? You obviously ordered the UA for a reason. Now you've got an abnormal one. Yet you're going to ignore it? Treat it, for God's sake. That's not even to mention the fact that nitrite is the more specific measure, as opposed to leuk/wbc which is more sensitive but less specific. What are you waiting for, the perfectly abnormal, abnormal?

Don't be intimidated by hindsight jerks. Get used to it now, because it's a huge part of EM. --- 'em. Do what you think is right and don't be intimidated by these jerks. It's just bs trolling.

 

[Groove]

Outside the sepsis context...Yes, I would treat it without WBCs. The same ID doc who opines no urinary source is the same one who would point a finger to the ED and scream "They didn't treat the UTI!". Just treat it and be done with it. Let ID mentally masturbate over the WBCs. I'm fairly certain there is no planetary general consensus on how to treat every nitrite +, WBC neg UA.

 

[Birdstrike]

Outside the sepsis context...Yes, I would treat it without WBCs. The same ID doc who opines no urinary source is the same one who would point a finger to the ED and scream "They didn't treat the UTI!". Just treat it and be done with it. Let ID mentally masturbate over the WBCs. I'm fairly certain there is no planetary general consensus on how to treat every nitrite +, WBC neg UA.

Yet there is a planetary consensus to criticize, testify against, second guess, or otherwise throw under the bus, ED physicians for not doing things, when the planetary retrospectoscope determines they should have.

 

[Hair Police]

Interns and medical students reading this thread, please see this article I read on my FP rotation:

Urinalysis: A Comprehensive Review
JEFF A. SIMERVILLE, M.D., WILLIAM C. MAXTED, M.D., and JOHN J. PAHIRA, M.D., Georgetown University School of Medicine, Washington, D.C, Am Fam Physician. 2005 Mar 15;71(6):1153-1162.

http://www.aafp.org/afp/2005/0315/p1153.pdf

Look at Table 3 and this paragraph:

NITRITES

Nitrites normally are not found in urine but result when bacteria reduce urinary nitrates to nitrites. Many gram-negative and some gram-positive organisms are capable of this conversion, and a positive dipstick nitrite test indicates that these organisms are present in significant numbers (i.e., more than 10,000 per mL). This test is specific but not highly sensitive.

While you're at it, read these, two:

Does This Woman Have an Acute Uncomplicated Urinary Tract Infection?
Stephen Bent, MD; Brahmajee K. Nallamothu, MD, MPH; David L. Simel, MD, MHS; Stephan D. Fihn, MD, MPH; Sanjay Saint, MD, MPH
JAMA. 2002;287(20):2701-2710. doi:10.1001/jama.287.20.2701.

http://jama.jamanetwork.com/article.aspx?articleid=194952

Does This Child Have a Urinary Tract Infection?
Nader Shaikh, MD, MPH; Natalia E. *****e, MD, MSc; John Lopez, MD; Jennifer Chianese, MD, MSc; Shilpa Sangvai, MD, MPH; Frank D’Amico, PhD; Alejandro Hoberman, MD; Ellen R. Wald, MD
JAMA. 2007;298(24):2895-2904. doi:10.1001/jama.298.24.2895.

http://jama.jamanetwork.com/article.aspx?articleid=209876

 

[leviathan]

^ ^ Just be aware of what was already said - bacteriuria (or nitrite+) doesn't necessarily mean they have an infection. In the context of a septic / sick patient though, you're starting empiric broad spectrum antibiotics regardless of any urinalysis findings. In the context of a septic patient AND a strong suggestion of urinary source, then you should be tailoring it to organisms that invade the urinary tract. While pip tazo is a reasonable choice for SIRS/sepsis without an obvoius source, if you suspect a urinary source then you could be missing some bugs, at least based on the resistance patterns where I work.

 

[name?]

I think the notion of a 'colonized' bladder with >100k e. coli is nuts. Urine should be sterile.

Foley? Sure, have a colony. Bladder? Nothing good comes from having a party of coliforms hanging out and drinking cocktails around a demented prostate getting ready to swim up to the kidneys and go for bacteremia. If no WBC, then why not rock out and seed me some meninges or epidural space?

Bug juice. And then more bug juice.

 

[Janders]

In my universe +NITR = Tx with Abx

Exception, of course, for indwelling foley, where each take is taken individually.

 

[Angry Birds]

I feel like in residency I had to answer to my attending who would want a minimalist work up and treatment. This was beneficial for my training so I could understand what's actually going on instead of "throw everything and see what sticks" sort of approach.

As an attending I've realized that it's always better to order more stuff and cover your bases.

 

[Brigade4Radiant]

Urine isn't sterile there is always bacteria in your bladder the same as your gut. It's just that if Urine>100,000 it is likely to be an outgrowth of those bacteria

 

[DrDrummer]

Urine isn't sterile there is always bacteria in your bladder the same as your gut. It's just that if Urine>100,000 it is likely to be an outgrowth of those bacteria

Wha?

 

[Birdstrike]

Urine isn't sterile there is always bacteria in your bladder the same as your gut. It's just that if Urine>100,000 it is likely to be an outgrowth of those bacteria

Incorrect. I think you're trolling with this actually. But I'll take the bait, in case there's a few that don't understand these basics.

The "100,000" organisms allowed in a culture of so called normal urine, is attributed to the inevitable contamination from skin, urethral, and/or labial tissue in the collection of a clean catch urine, not bacteria that came from the urine in the bladder itself. Gold standard, sterile urine collection during a supra-public aspiration under sterile conditions should, and normally does, have zero organisms. Clean catch, and even catheter collected urine sample, can have bacteria introduced in the collection process. But this is not bacteria from the urine itself.

In a normal individual, urine (like blood, unlike bowel) is and should be sterile. Abnormal anatomy, ie, chronic in-dwelling bladder catheters, chronic urinary retention in the elderly or otherwise chronically ill, follows a different rule book, where there is some level of tolerated/expected "asymptomatic bacteriuria."

 

[Brigade4Radiant]

Incorrect. I think you're trolling with this actually. But I'll take the bait, in case there's a few that don't understand these basics.

The "100,000" organisms allowed in a culture of so called normal urine, is attributed to the inevitable contamination from skin, urethral, and/or labial tissue in the collection of a clean catch urine, not bacteria that came from the urine in the bladder itself. Gold standard, sterile urine collection during a supra-public aspiration under sterile conditions should, and normally does, have zero organisms. Clean catch, and even catheter collected urine sample, can have bacteria introduced in the collection process. But this is not bacteria from the urine itself.

In a normal individual, urine (like blood, unlike bowel) is and should be sterile. Abnormal anatomy, ie, chronic in-dwelling bladder catheters, chronic urinary retention in the elderly or otherwise chronically ill, follows a different rule book, where there is some level of tolerated/expected "asymptomatic bacteriuria."

Nope

http://jcm.asm.org/content/50/4/1376.abstract
Cultures greater than 100,000 on blood agar (BA) or/ plus MacConkey agar mean that there is a likely not a clinically significant infection

However PCR shows that that urines reported to clinicians as 'culture-negative' or 'insignificant growth' can contain varied bacterial communities that can be simple or extremely diverse and can be composed of typical uropathogens or of genera not identified with standard cultivation technique.

 

[Birdstrike]

Nope

http://jcm.asm.org/content/50/4/1376.abstract
Cultures greater than 100,000 on blood agar (BA) or/ plus MacConkey agar mean that there is a likely not a clinically significant infection

However PCR shows that that urines reported to clinicians as 'culture-negative' or 'insignificant growth' can contain varied bacterial communities that can be simple or extremely diverse and can be composed of typical uropathogens or of genera not identified with standard cultivation technique.

This looks like bench research involving uncultureable organisms that they acknowledge may not even be viable or alive. I'm not sure how well that applies to clinical medicine, if at all, since culture counts don't apply to bacteria that can't be cultured at all.

That being said, if you want to choose to ignore abnormal test results while practicing a high-stress, high-pace high-risk specialty where you get only one shot at patients in very brief encounters without complete information sets where you'll be judged with 20/20 hindsight in a "zero miss" culture, that's your decision. It's risky in my opinion. But that will be your call. Best of luck to you.

 

[ERDude]

Nope

http://jcm.asm.org/content/50/4/1376.abstract
Cultures greater than 100,000 on blood agar (BA) or/ plus MacConkey agar mean that there is a likely not a clinically significant infection

That makes zero sense to me. If Culture + >100k is likely not an infection then what is?

 

[Brigade4Radiant]

That makes zero sense to me. If Culture + >100k is likely not an infection then what is?

I meant less than 100,000

 

[DrDrummer]

I meant less than 100,000

It is tricky. In the right patient, say a diabetic kidney transplant whose 10,000 CFUs are a single species, and who "isn't acting right", it just might be clinically significant. Treat the patient, not the numbers. Methinks you are missing the forest for the trees here.

 

[Brigade4Radiant]

It is tricky. In the right patient, say a diabetic kidney transplant whose 10,000 CFUs are a single species, and who "isn't acting right", it just might be clinically significant. Treat the patient, not the numbers. Methinks you are missing the forest for the trees here.

There would be a lot more for a patient like that and they would require a lot more workup. Context of lab values are important. I was just making the point that urine isn't sterile

 

[Docinthetrenches]

It comes down to symptoms and risk factors. An asymptomatic young healthy person I would not treat but an old febrile person or someone with obvious dysuria I would. I would also want the micro to see if it's contaminated with epithelial cells.

 

[Knothere2day]

How do you guys interpret a UA with + nitrite, + bacteria and no WBC?

I know nitrite is specific for Gram negs and I've always considered this worthy of treatment even in the absence of pyuria (and anecdotally it seems the UCx almost always return + for > 100K of some GN bacteria with these).

I admitted a pt recently with presumed sepsis, only revealing source was a UA (straight cath sample) with above findings and I initiated tx as such.

ID consult obtained during hospital course and they remarked that urinary source unlikely given no pyuria (and this was after a UCx grew >100k E.coli).

Had another case yesterday of a confused elderly guy with UA + nitrite and bact, no wbc, I gave ceftriaxone and admitted. Admitting team underwhelmed and holding further abx. I follow up today and UCx >100k Klebsiella.

Thoughts?

would you treat if the patient had no other symptoms other than moderate right flank pain with history of a klebsiella infection of two months ago. Could methotrexate and a biologic med cause these type results.

 

[Rendar5]

would you treat if the patient had no other symptoms other than moderate right flank pain with history of a klebsiella infection of two months ago. Could methotrexate and a biologic med cause these type results.

If this is a personal type of question, can't really give medical diagnosis or advice over the internet. If this a question regarding a patient care, best asked to Urology.

 

[Hamhock]

In general I would not treat nitrate +, WBC neg urine in a healthy, young, non-pregnant, asymptomatic female. If she is symptomatic, treat. Some folks would say you don't even need the UA in that patient; just give fosfomycin and directions to the nearest pharmacy.

My bigger concern with the above discussion is attributing sepsis syndromes (especially shock) to such a urinalysis. As many folks have pointed out, these patients generally get broad spectrum antibiotics, which covers most infections.

However, I often see docs attributing sepsis syndromes to very equivocal UAs (and I think the UA here is equivocal, at best) and then "closing the case". That is, they are not continuing to consider further diagnostics or searching for another more convincing source. Broad spectrum antibiotics -- even if the offending organism is very sensitive to the chosen antimicrobial -- won't help much if source control (especially surgical) is still needed.

I find that in most cases, there is no other source immediately identifiable, but in nearly all cases, it seems consideration of other sources is stopped when a "weak" UA is found...and such closure effects outcomes about once a month in my ED (and later ICU).

HH

 

[GonnaBeADoc2222]

I find that when the little doctor voice inside me says something like

"Give the antibiotics"
"Do the rectal exam"
"Do the LP"
"Get the CT"

The little voice is usually right. Do the right thing for the patient and yourself. Antibiotics can always be tailored or discontinued after a tincture of time is applied.