Procalcitonin vs Lactic Acid

[jwells78]

Ok, so since I have returned from the box- these tests have begun to take hold and are ordered more regularly on the sick sickies in our ER. The lactic acid (more than just for it's obvious significance) more as a predictor of morbidity/mortality in our admitted ICU pts, ect; >4 being bad news. I've seen more providers using the procalcitonin as a guide in sepsis/bacterial infection as well. Are you other ER guys seeing this trend? Are you using this? What has been your guidance, and how are you instituting these? Thanks -J

[EMEDPA]

I heard a bit about this at sempa in march. everywhere I work still uses just lactic acid. my understanding(someone correct me here if I'm wrong) is that the procalcitonin is a better indicator of early sepsis than lactate as it goes up faster. kind of like troponin vs ck-mb.

[Gaijyn]

EMEDPA I believe you are correct.

 

My understanding is that Procal has a half life that is shorter and because it is typically at very low/undetectable levels in non-sick individuals; it can serve as a good marker of early Sepsis/SIRS. Procal levels are also used in several of the EDs I worked/rotated in during my (now completed) clinical year. Though, some old-school Attendings were mildly ambivalent about the results and still preferred Lactic Acid. I have also seen both used in the ICU to gauge a mortality outcome; with the Lactic Acid being more of a confirmation on an elevated Procal level. Just my experience which as a New Grad (still feels weird to say that) is somewhat limited.

[Acebecker]

And my understanding of procalcitonin is that it is much more specific to bacterial infection than lactic acid. Don't have opportunity to order either in my setting.

[mjohn7wy]

I have never used procalcitonin in the ED, I have used in more in the ICU setting to help differentiate the etiology of a patients decompensation(I was under the same understanding of acebecker, that its more specific for infection). Also the turn around time is kind of crappy where I am(like 24 hours), so i dont think it would be of much use in the ED. just my 2 cents

 

Mjohn

[Gaijyn]

I have seen Procals come back pretty quick, so perhaps that is a lab/hospital dependent thing? One ED I rotated at put it into their SIRS/Sepsis work-up algorithm/order-set.

[LIPPER]

Been using Procal level for years instead of Lactic acid.

[rcdavis]

Been waiting for some of the critical care guys to weigh in.

 

Essential difference in procal and lactate is their genesis:

 

Lactate is a function of, and reflects, degree of tissue perfusion

 

Procal is an inflammatory marker

 

Remember "sepsis" is infact an inflammatory response to an insult... Most intensivists feel that "sepsis" reflects an immune response on the part of the host, due to an insult by ( usually infectious) a pathogen.

 

The result of this response is first inflammatory, and eventually hypo perfusion ( shock)

 

So the procal and lactate are measuring different parts and sequences of the same elephant

[jwells78]

So, further- I would question the utility of the procal in the ER. The other day I had an elderly gentleman come in with weakness, pre- syncope- hx of CHF, afib- your typical 80 some odd year old; no recent ECHO or stress test. I will spare the rest of the story, save that he had some patchy infiltrates on his CXR- new compared to 6 mo ago (CXR), which had been treated as pneumonia/ worked up as outpt and thought to represent new malignancy (guy had a ct at the va that showed lesions throughtout his abdomen) AND he was sat'ing 91 on RA. His BUN/Cr was 50/3, lactic acid 3. What he did NOT have, was effisions or significant fluid overload. In the end I think we admitted him for Syncope, ARF, ect... It was this guy that my attending piped in with- "order a procal so we can differentiate an infectious process." I had not thought of this, and kind of shrugged- ordered it. Seemed kind of like an unneeded test- maybe expensive as well. Just wondered whether others were using this test in this fashion

[Boatswain2PA]

Jwells - that is exactly what I use it for. Got the sick great grandma with 3 days progressive fatigue/ill feeling. 80/40, 110, 24, not making urine but A&O with good pedal pulses, CXR negative, no skin lesions, denies blood/dark stool, belly soft. Why is she shockey? It's summer, she had been outside gardening a few days before, not peeing, I thought high likelihood she was just dry and needed to be topped off. We were cathing her when Procal came back at 16! Slightly leukopenic without anemia. Lactic acid was 2.5. Then the urine came back hot with casts and a ton of WBCs. (No CVA tenderness at all). That was the first time the procal really helped me.

[rcdavis]

Jwells - that is exactly what I use it for. Got the sick great grandma with 3 days progressive fatigue/ill feeling. 80/40, 110, 24, not making urine but A&O with good pedal pulses, CXR negative, no skin lesions, denies blood/dark stool, belly soft. Why is she shockey? It's summer, she had been outside gardening a few days before, not peeing, I thought high likelihood she was just dry and needed to be topped off. We were cathing her when Procal came back at 16! Slightly leukopenic without anemia. Lactic acid was 2.5. Then the urine came back hot with casts and a ton of WBCs. (No CVA tenderness at all). That was the first time the procal really helped me.

 

 

Exactly, her prob wasn't fluid or perfusion, it was the beginning of a cap leak SIRS. THATs how procal ( and some of the other inflammatory makers) can help you.

 

Some of you old guys remember the days before BNP/ nBnp.. And the difficulty of deciding " failure or infiltrate ".

 

Procal is simply a marker to help you down your decision tree

[medic25]

Jwells - that is exactly what I use it for. Got the sick great grandma with 3 days progressive fatigue/ill feeling. 80/40, 110, 24, not making urine but A&O with good pedal pulses, CXR negative, no skin lesions, denies blood/dark stool, belly soft. Why is she shockey? It's summer, she had been outside gardening a few days before, not peeing, I thought high likelihood she was just dry and needed to be topped off. We were cathing her when Procal came back at 16! Slightly leukopenic without anemia. Lactic acid was 2.5. Then the urine came back hot with casts and a ton of WBCs. (No CVA tenderness at all). That was the first time the procal really helped me.

 

I think what I'd like to see is some literature that it changes outcomes in our ED patients; most of what I'm finding online shows its utility for stopping antibiotics, but not much regarding improved morbidity and mortality when drawn as an initial lab test. After the SEMPA conference I asked the ED critical care attendings in our shop (they are dual-boarded and cover both the ED and ICU's), and they haven't seen enough supporting literature on PCT to make it a standard of care.

Playing devils advocate Boatswain; how did the PCT change your ED management? You have an elderly patient in shock of unclear etiology; you are going to fluid resuscitate her/start pressors PRN, get a cathed urine, cover her for sepsis and admit. Was there something that was done differently because of the elevated procalcitonin?

[True Anomaly]

Our shop doesn't do procalcitonin- our sepsis/SIRS protocol involves only lactate. I'm not sure if they use procalcitonin in the units, but when I rotated through them as a resident a few years ago they didn't use them. Like medic25, I think the crux of the issue/lack of adoption is the overall feeling of a lack of sufficient evidence to make the change.

[True Anomaly]

For what it's worth too, Scott Weingart did a very thorough review of sepsis in the October 2012 EMRAP edition, and not once was procalcitonin mentioned.

[Boatswain2PA]

Playing devils advocate Boatswain; how did the PCT change your ED management? You have an elderly patient in shock of unclear etiology; you are going to fluid resuscitate her/start pressors PRN, get a cathed urine, cover her for sepsis and admit. Was there something that was done differently because of the elevated procalcitonin?

 

Not sure if it made me do anything differently, but it made the water less muddy. Perhaps if it was not 16 (a pretty darn high number), then I would be less sure that the pyelo/urosepsis was causing her hypotension...maybe would've scanned her to ensure she didn't have something else (AA?). Not quite sue.

 

I like having as much info as I can get. Let me sort through what is "chaff" and what isn't based on the preponderance of ALL the evidence. If $30 gets me some info that can point me toward, or away, from bacterial causes (like procal is supposed to be able to do), then I'll take it!ma

 

 

Here is, perhaps, another way of thinking about the utility of procal. A fever makes you look for bacterial infection. If you see no signs of bacterial infection, then it's (probably) viral. The higher the procal, the more likely the pt has a significan,t bacterial infection. That's gotta be a good tool to have in your box. Hell, just with that thought I might start ordering it on those "kinda-sick" kiddo's with fevers that we often see. (3 yo, 101.5* before Tylenol, P140, R28, and sick looking but no signs of bacterial infection after good exam, UA, and/or CXR)

[Boatswain2PA]

For what it's worth too, Scott Weingart did a very thorough review of sepsis in the October 2012 EMRAP edition, and not once was procalcitonin mentioned.

 

I'm only up to 2009, got three more years to go! lol

[EMEDPA]

. If $30 gets me some info that can point me toward, or away, from bacterial causes (like procal is supposed to be able to do), then I'll take it!

I'm guessing as the new latest and greatest test it costs a lot more than 30 bucks. you can't get a cbc for 30 bucks in the ER.

[Boatswain2PA]

I'm guessing as the new latest and greatest test it costs a lot more than 30 bucks. you can't get a cbc for 30 bucks in the ER.

 

We got it here in rural America just a few weeks after we heard about it at SEMPA. I asked how much it cost and was surprised at how cheap it was (but, to be honest, I don't remember the exact price).

 

But then again, I live in a VERY low cost part of the country, especially in relation to you coastal dwellers! :-)

[CAdamsPAC]

Jwells - that is exactly what I use it for. Got the sick great grandma with 3 days progressive fatigue/ill feeling. 80/40, 110, 24, not making urine but A&O with good pedal pulses, CXR negative, no skin lesions, denies blood/dark stool, belly soft. Why is she shockey? It's summer, she had been outside gardening a few days before, not peeing, I thought high likelihood she was just dry and needed to be topped off. We were cathing her when Procal came back at 16! Slightly leukopenic without anemia. Lactic acid was 2.5. Then the urine came back hot with casts and a ton of WBCs. (No CVA tenderness at all). That was the first time the procal really helped me.

 

 

I 've seen infiltrates "bloom" on f/u CXR after "tanking up" a dry LOL/LOM, long before I've ordered either of these markers....They are icing on the cake of a good H&P along with being able to tell who is "sick" or"not sick".

[UpRegulated]

Exactly, her prob wasn't fluid or perfusion, it was the beginning of a cap leak SIRS. THATs how procal ( and some of the other inflammatory makers) can help you.

 

Not to be nitpicky (I see what you are saying), but 80/40, HR 110 and anuria is impaired perfusion, perhaps compensated somewhat, but impaired nonetheless.

[rcdavis]

Not to be nitpicky (I see what you are saying), but 80/40, HR 110 and anuria is impaired perfusion, perhaps compensated somewhat, but impaired nonetheless.

 

True enough, perfusion is diminished... in this case the procal is elevated due to both The infection and the sirs..

As opposed to , say, DKA in which procal is not usually elevated, but lactate is.

 

Again, neither marker is definitive... They are meant, along with the other blood counts, ( such as TREM1 and CD64 measurements to help paint the picture of what is going on: infectious, non nfectious, metabolic, etc.

 

These seems to help clarify the issue ( excepting patients with aspergillosis)

[polarbebe]

Discussed this last week with the director of the MICU where I work (my own research of the literature was not fruitful). Procalcitonin has been primarily studied only in discontinuing antibiotics in admitted patients where exam, labs and imaging paint the picture of a patient you might believe is not having an active bacterial infection. The Procalcitonin in this instance may help with with the decision to discontinue antibiotics.

 

Based on the literature out there, it has not been validated in the diagnosis of sepsis and is not recommended due to the low sensitivity of 80%. Septic shock has a mortality of 40% (compared to MI of around 5%)... If you think it's septic shock, give early antibiotics period. With a sensitivity of of only 80%, it is much too unreliable and can sway the non-seasoned practioner in making the wrong diagnosis.

 

Use only lactic acid in the ED.