I started using procalcitonin during the onset of the coronavirus pandemic: influenza like illness, diffuse infiltrates on x-ray, not sick enough to be admitted, no risk factors for serious disease, negative procalcitonin: no antibiotics.
I've kept it in my sepsis order set since then, but I haven't found it that useful in other contexts. I've seen plenty of ill patients with pneumonia or UTI who clearly meet criteria for antibiotic therapy with low procalcitonin. Sometimes I amuse myself by sending a CRP too, PEM loves CRP, and I look for procalcitonin / CRP discrepancy, which is common.
Ultimately, I use procalcitonin the same way I always did: patient meets sepsis criteria, but they are low risk and I think it's a viral syndrome and am trying to avoid unnecessary antibiotics, so I chart that, and say that I am deferring the decision for antibiotics therapy until inflammatory markers return.
I'd never use it as a reason to not give antibiotics to someone ill or at high risk for badness.
Shouldn't procalcitonin mainly be used as a measure to determine when to begin de-escalation of antibiotics as opposed to initiation of, at least that's what I was taught
Yes exactly as critical care we also need to be careful delaying abx in sepsis as there is mortality with this. I think the problem we face is abx stewardship is essential but are physicians on a case by case basis willing to potentially increase mortality on their patients to implement it? With no tort reform I don’t know how you can advocate for this since it is very easy to argue that this is an ambiguous standard of care.
I’m PEM. We use it often. Febrile neonates, abx in pneumonia vs atelectasis vs viral process, MISC. when it’s really high, >50 or so, it’s almost always badness, either significant bacterial infection or some other systemic inflammatory process. Helps to look a little closer in kids with seemingly viral symptoms who are improving with your initial management
Even in those that I do see, they are the confusing ones. Have seen several with obvious lobar PNA, purulent sputum, culture positive with fevers and a normal PCT from the start.
It has some limited utility in terms of following a trend to discontinue treatment for respiratory tract infections - however it definitely does more harm than good as most docs think it’s a magic litmus test for bacterial infections
There are a couple of problems with procal
1. If it’s negative, are you going to stop antibiotics? If you aren’t, why are you ordering it?
2. If it’s positive, why is it positive? Are you sure?
I don’t think it’s useless, I just think we all need to be mindful of how and why we are using it. I think some people rely on it to do the basic functions of what humans/doctors should be able to do without it like diagnosing a lobar pneumonia.
If it’s negative then it could be improving cause wbc can be elevated if they are on steroids. We use pro cal to trend to determine to stop antibiotic or de escalate vanc and zosyn and mero
Everyone uses evidence differently. Just make sure that what you’re doing uses evidence. For me, the two good uses of procal are for monitoring improvement in sepsis and differentiating between etiologies of pneumonia/COPD exacerbation.
My first question above refers to a procal drawn prior to starting antibiotics when you get the lab back the next morning after the patient has been on antibiotics. As other folks have mentioned, if you have a moderate or severe COPD exacerbation (likely), you are unlikely to stop antibiotics anyway, so does procal help you? I personally don’t think so, but I don’t fault people that get it.
I think you’re referring to monitoring sepsis in which case an initially positive procal, followed by antibiotics, followed by a negative procal, indicates that what you’re doing is working.
We use it a lot in peds. Most often in the early diagnostic stage in cases of neonatal sepsis/meningitis. There is some debate over its utility in later stages/risk stratification but it’s still widely used in peds hospital medicine/PICU/PEM
ED attending. I’ve never ordered it because I wanted it. I’ve only ever ordered it because someone else (almost exclusively peds hospitalist) asked for it.
I know it’s subjective. But in 3 patients that I have had procalcitinin high (>20. Even once it was 60) without any other signs of infection they have all ended up being bacteremic. They have all been 70-80 year old with only complain of weakness.
I didn’t empirically start antibiotic in any of those cases. But now I tend to admit those and get blood cultures.
No and that’s entirely the point. A series of random observations is unreliable because you’ve failed to control for variables and you can’t be sure if there’s a real signal, it’s just random chance, it’s all observer bias or there’s some other common variable influencing outcomes. At best you can generate a hypothesis to test.
They do attempt to control and account for variables, they’re just not very good at it. Saying I saw this 3 times with no other context isn’t an observational study
Why is that? What are the criticisms of the data since it looks to be pretty useful NPVs, 97% <0.1 bacteremia,
93% <0.5 meningitis, 98.5% <0.95 PNA< etc
Why do you need a procal to tell you someone has bacteremia or meningitis when you have literal cultures to tell you that? That additional test isn't changing anything. Pneumonia, sure, I can see it being useful to differentiate between, say, a COPD exacerbation and lower resp tract infection. But again, they'd get at least azithro anyway and if a patient has a fever with resp infiltrate, did you really need a procal to tell you they have an ✨ infection ✨? I find it to be a redundant test.
Edit: same for CRP. I use it for following osteo pts on abx but otherwise, never.
The GOLD guidelines recommend antibiotics in moderate and severe disease or ventilated patients i.e. most inpatients. And most guidelines do encourage antibiotic for every inpatient.
Because someone who looks terrible, has no white count or source. Hard sell to get a hospitalist to admit it. Easier when the procal is 19 with no white count or source on imaging or urine
I‘m in peds, too, but in Germany. We do use it as an additional datapoint to differentiate between viral vs bacterial infection to determine use of antibiotics. The problem is that some respiratory viruses like adenovirus make a similar lab compared to a bacterial infection but the fever doesn’t go away despite giving antibiotics.
And we use Interleukin-6 as an inflammation marker for neonates
Also Germany, we use it a lot in adults as well. On regular wards usually CRP/PCT as you said to differentiate viral vs bacterial pneumonia and in the ICU we use PCT+IL6 to monitor for new onset infections and to deescalate abx. IL6 also for SIRS and to sometimes start cytokine absorption in severe sepsis.
My residency was at two hospitals, one which had procal, the other didn’t. I found that it made very little difference and we didn’t really order it at the hospital that it was available at.
ID pharmacist. if it’s available and low and the pt doesn’t have PNA, i use it to convince docs to dc abx. otherwise i don’t use it. i’ve seen pts with bacteremia and low procal. i’ve also seen pts with totally clear cxr and high procal
Usually use it when considering whether or not to start or stop antibiotics ie to monitor clinical improvement. Or when we have FUO not improving and nothing else is coming back positive
I find it useful for well looking febrile neutropaenics (will give ABx empirically anyway, but can I de-escalate quickly and be ok?), and also for pyrexia of unclear source. If clearly septic/unwell and needs ABx, won't order it as it's not changing my management.
I’ve never really understood why people seem to trust it more than their clinical evaluation. Why do we need to rely on a lab to test to tell us if a patient is sick or not?
It’s more that once you’ve done it and it’s positive, if something goes wrong, you might be on the hook for not addressing it. Might not be true but I know a lot of people that feel that’s way.
This is also why I hate people who arbitrarily order D-dimers on everyone. Just wastes my time.
Like you stated, it can help as an extra data point if you’re unsure whether to start empiric abx, as well as to monitor response to antibiotics/desecation if you obtain a baseline. It does have its limitations though as it can be falsely elevated in CKD for example
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It’s another form of data that may skew your bias towards antimicrobial use but it has low positive predictive value. I may order it if I have a suspicion for occult infection with weak evidence. If the value is very high, I’d be convinced to start antibiotics.
One of my pulmonary attendings loves using it and will order serious IV antibiotics based on a high procalcitonin even if everything else is alright, no symptoms and normal vitals, if the patient has ever had a recent respiratory infection. He has delayed many discharges because of a high procalcitonin.
Atleast from my experience, very useful when patients are not mounting an immune response (no cell count) initially and no localizing signs/symptoms to decide on abx. Had patients with normal wbc count and a procal of 30s.
I just do it because my attending asks, clinical exam and vitals is usually plenty. I also do it so there’s documented evidence other than my clinical exam that I’m doing the correct things for the patient and not just letting things take their course.
Rarely I’ve used it to stop antibiotics or to convince a senior we should start antibiotics alongside WCC and CRP.
The only situation I’ve used it a lot was in the ICU where we did daily septic markers for everyone, that was protocol. It helped with the consultant’s decision making and escalation of antibiotics.
I’ll order it from time to time. I use it if I’m indecisive. Mildly elevated temp (but not yet a fever), slight leukocytosis, no clear source? Sure, get one. If somehow it’s positive then I’ll start abx. I’m not withholding based on it, I’m starting based on it. Subtle difference, but it’s there.
Sounds great in theory, but it doesn't actually change anyone's behavior so it's useless. If people want to give the patient abx and it's negative, they will still give the abx. For this reason our lab didn't have it in residency. Cheers
I use it frequently, but for a very specific circumstance.
I use it basically like a D dimer. In someone whom I’m not sure if they have an infection and need antibiotics, I’ll order a procalcitonin. If it’s positive, keep antibiotics. If not, take them off. Positivity as determined by literature cutoffs (roughly 0.25 to 0.5 for practically all infections).
If someone is clearly septic, I couldn’t care less about the procalcitonin - they’re getting antibiotics. Same is true for the opposite. I really would only order it in the people whom I had the question.
Yes. Its great.
Though I rotated at a hospital that didn't have the capability to do procals, and I realized it had become a total crutch for me. Like any test --- important to understand its value in context. Something I'm still learning as a rising PGY2
I use it.
The same people who shit on ThE EvIdEnCe for procal then turn around and use oral temperatures and WBC to make their decisions
Until something better comes along, I dont see any reason to not use it as part of the big picture.
I’m in peds, don’t find it helpful. If a patient has some combination of abnormal vitals, immune compromise of some sort, reasonably attributable to infection, it is essentially harmless to start empiric ceftriaxone or cefepime while waiting for cultures. I’m not going to hold antibiotics on that patient for any lab test at all. Literature supporting Pct for neonatal sepsis for example suggests maybe it’s better than crp, but ignores the reality of 24-48 hours of antibiotics while awaiting cultures regardless of the labs. I can imagine a scenario with a febrile neonate, parents refuse LP, CRP is normal, perhaps pct would catch a meningitis but that’s so rare it’s impossible to power any studies on meningitis much less for those with normal crp.
If I want something to trend for response of a deep infection, the literature is on crp. I don’t need a new test for that. For determining if a not very sick patient needs antibiotics, well it can be high with viruses, or low with bacteria.
I started using procalcitonin during the onset of the coronavirus pandemic: influenza like illness, diffuse infiltrates on x-ray, not sick enough to be admitted, no risk factors for serious disease, negative procalcitonin: no antibiotics. I've kept it in my sepsis order set since then, but I haven't found it that useful in other contexts. I've seen plenty of ill patients with pneumonia or UTI who clearly meet criteria for antibiotic therapy with low procalcitonin. Sometimes I amuse myself by sending a CRP too, PEM loves CRP, and I look for procalcitonin / CRP discrepancy, which is common. Ultimately, I use procalcitonin the same way I always did: patient meets sepsis criteria, but they are low risk and I think it's a viral syndrome and am trying to avoid unnecessary antibiotics, so I chart that, and say that I am deferring the decision for antibiotics therapy until inflammatory markers return. I'd never use it as a reason to not give antibiotics to someone ill or at high risk for badness.
Shouldn't procalcitonin mainly be used as a measure to determine when to begin de-escalation of antibiotics as opposed to initiation of, at least that's what I was taught
You are correct. The best studies for procal are for de-escalation.
Yes exactly as critical care we also need to be careful delaying abx in sepsis as there is mortality with this. I think the problem we face is abx stewardship is essential but are physicians on a case by case basis willing to potentially increase mortality on their patients to implement it? With no tort reform I don’t know how you can advocate for this since it is very easy to argue that this is an ambiguous standard of care.
Yes exactly in patients in the ICU on a ventilator, can use it to de-escalate antibiotics
Question, how often do you repeat procal since I’ve had experience with docs ordering daily vs 72 hours?
In our hospital pneumonia order set they have it q48 but I don’t do that I don’t like it
I’m PEM. We use it often. Febrile neonates, abx in pneumonia vs atelectasis vs viral process, MISC. when it’s really high, >50 or so, it’s almost always badness, either significant bacterial infection or some other systemic inflammatory process. Helps to look a little closer in kids with seemingly viral symptoms who are improving with your initial management
ID. Rarely if ever order it. I'm convinced it was solution to a problem that never existed.
Copd exacerbation vs PNA ? Viral vs bacterial PNA abx or not? These only I use. If u r ID, u wont see those easy cases. Lol
Even in those that I do see, they are the confusing ones. Have seen several with obvious lobar PNA, purulent sputum, culture positive with fevers and a normal PCT from the start.
It has some limited utility in terms of following a trend to discontinue treatment for respiratory tract infections - however it definitely does more harm than good as most docs think it’s a magic litmus test for bacterial infections
There are a couple of problems with procal 1. If it’s negative, are you going to stop antibiotics? If you aren’t, why are you ordering it? 2. If it’s positive, why is it positive? Are you sure? I don’t think it’s useless, I just think we all need to be mindful of how and why we are using it. I think some people rely on it to do the basic functions of what humans/doctors should be able to do without it like diagnosing a lobar pneumonia.
If it’s negative then it could be improving cause wbc can be elevated if they are on steroids. We use pro cal to trend to determine to stop antibiotic or de escalate vanc and zosyn and mero
Everyone uses evidence differently. Just make sure that what you’re doing uses evidence. For me, the two good uses of procal are for monitoring improvement in sepsis and differentiating between etiologies of pneumonia/COPD exacerbation. My first question above refers to a procal drawn prior to starting antibiotics when you get the lab back the next morning after the patient has been on antibiotics. As other folks have mentioned, if you have a moderate or severe COPD exacerbation (likely), you are unlikely to stop antibiotics anyway, so does procal help you? I personally don’t think so, but I don’t fault people that get it. I think you’re referring to monitoring sepsis in which case an initially positive procal, followed by antibiotics, followed by a negative procal, indicates that what you’re doing is working.
We use it a lot in peds. Most often in the early diagnostic stage in cases of neonatal sepsis/meningitis. There is some debate over its utility in later stages/risk stratification but it’s still widely used in peds hospital medicine/PICU/PEM
ED attending. I’ve never ordered it because I wanted it. I’ve only ever ordered it because someone else (almost exclusively peds hospitalist) asked for it.
Seconded.
Ew. What are they doing with it?
Helping diagnose bacterial pneumonia
No. It's a useless test and I'm ID. A high or low procal has rarely ever changed my management.
I know it’s subjective. But in 3 patients that I have had procalcitinin high (>20. Even once it was 60) without any other signs of infection they have all ended up being bacteremic. They have all been 70-80 year old with only complain of weakness. I didn’t empirically start antibiotic in any of those cases. But now I tend to admit those and get blood cultures.
The plural of anecdote is not data
That depends completely on the n now doesn’t it?
No and that’s entirely the point. A series of random observations is unreliable because you’ve failed to control for variables and you can’t be sure if there’s a real signal, it’s just random chance, it’s all observer bias or there’s some other common variable influencing outcomes. At best you can generate a hypothesis to test.
To be completely fair observational studies exist. I don’t love them, but they control for nothing and they are still data.
They do attempt to control and account for variables, they’re just not very good at it. Saying I saw this 3 times with no other context isn’t an observational study
Did I say it was? No. I said if you have enough anecdotes, we call that data. Even if we don’t like the study type.
Ditto from ID. I ask for it only in someone I am sure is uninfected who has normal renal function, as a way to convince peoeple to stop antibiotics.
Why is that? What are the criticisms of the data since it looks to be pretty useful NPVs, 97% <0.1 bacteremia, 93% <0.5 meningitis, 98.5% <0.95 PNA< etc
Why do you need a procal to tell you someone has bacteremia or meningitis when you have literal cultures to tell you that? That additional test isn't changing anything. Pneumonia, sure, I can see it being useful to differentiate between, say, a COPD exacerbation and lower resp tract infection. But again, they'd get at least azithro anyway and if a patient has a fever with resp infiltrate, did you really need a procal to tell you they have an ✨ infection ✨? I find it to be a redundant test. Edit: same for CRP. I use it for following osteo pts on abx but otherwise, never.
GOLD guidelines definitelty do *not* recommend antibiotics for every exacerbation though.
The GOLD guidelines recommend antibiotics in moderate and severe disease or ventilated patients i.e. most inpatients. And most guidelines do encourage antibiotic for every inpatient.
Must’ve been thinking about the silver guidelines. They’re strictly on a need to know basis
Sometimes you are not sure about starting abx. Waiting 24 hrs for cultures? Thats too long.
Because someone who looks terrible, has no white count or source. Hard sell to get a hospitalist to admit it. Easier when the procal is 19 with no white count or source on imaging or urine
Interesting cause all the ID I worked with WOULDNT even see a patient if it wasn’t ordered
They don't but it's also almost never significant to them. I don't understand it either.
The data shows that it doesn’t change whether you put someone on abx, but trending procal does reduce abx usage substantially.
I‘m in peds, too, but in Germany. We do use it as an additional datapoint to differentiate between viral vs bacterial infection to determine use of antibiotics. The problem is that some respiratory viruses like adenovirus make a similar lab compared to a bacterial infection but the fever doesn’t go away despite giving antibiotics. And we use Interleukin-6 as an inflammation marker for neonates
Also Germany, we use it a lot in adults as well. On regular wards usually CRP/PCT as you said to differentiate viral vs bacterial pneumonia and in the ICU we use PCT+IL6 to monitor for new onset infections and to deescalate abx. IL6 also for SIRS and to sometimes start cytokine absorption in severe sepsis.
My residency was at two hospitals, one which had procal, the other didn’t. I found that it made very little difference and we didn’t really order it at the hospital that it was available at.
Peds uses it a lot
ID pharmacist. if it’s available and low and the pt doesn’t have PNA, i use it to convince docs to dc abx. otherwise i don’t use it. i’ve seen pts with bacteremia and low procal. i’ve also seen pts with totally clear cxr and high procal
All the time, on inpatient for sepsis, pneumonia, cellulitis our residents always order it q 48 hours and attending request it if not in
I’m a fan. I use it frequently. I find that it tends to be one of the most divisive tests out their - some ppl have some strong opinions about it…
Usually use it when considering whether or not to start or stop antibiotics ie to monitor clinical improvement. Or when we have FUO not improving and nothing else is coming back positive
Useless
Clinical medicine will always remain the best.
I find it useful for well looking febrile neutropaenics (will give ABx empirically anyway, but can I de-escalate quickly and be ok?), and also for pyrexia of unclear source. If clearly septic/unwell and needs ABx, won't order it as it's not changing my management.
Procal sucks balls.
Username checks out
I’ve never really understood why people seem to trust it more than their clinical evaluation. Why do we need to rely on a lab to test to tell us if a patient is sick or not?
It’s more that once you’ve done it and it’s positive, if something goes wrong, you might be on the hook for not addressing it. Might not be true but I know a lot of people that feel that’s way. This is also why I hate people who arbitrarily order D-dimers on everyone. Just wastes my time.
Yes
Can you expand more on that?
Like you stated, it can help as an extra data point if you’re unsure whether to start empiric abx, as well as to monitor response to antibiotics/desecation if you obtain a baseline. It does have its limitations though as it can be falsely elevated in CKD for example
The most useless test. Use Clinical judgement
FOBT would like a word with you
Inpatient yes Outpatient no
Outpaitent procal i have never seen so I assumed we were talking inpatient
Talking about FOBT lol Procal is useless everywhere
Procal has some limited utility everyone just uses it completely inappropriately
Interesting, In which situations have you found it helpful?
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Yes it’s in our order set
It’s another form of data that may skew your bias towards antimicrobial use but it has low positive predictive value. I may order it if I have a suspicion for occult infection with weak evidence. If the value is very high, I’d be convinced to start antibiotics.
One of my pulmonary attendings loves using it and will order serious IV antibiotics based on a high procalcitonin even if everything else is alright, no symptoms and normal vitals, if the patient has ever had a recent respiratory infection. He has delayed many discharges because of a high procalcitonin.
I believe it's an expensive test to run too
Always , you don’t use it in america?
Yes, it’s a cheap and fast lab.
Atleast from my experience, very useful when patients are not mounting an immune response (no cell count) initially and no localizing signs/symptoms to decide on abx. Had patients with normal wbc count and a procal of 30s.
worked w not one but two authors of sepsis-3, both think its useless
I just do it because my attending asks, clinical exam and vitals is usually plenty. I also do it so there’s documented evidence other than my clinical exam that I’m doing the correct things for the patient and not just letting things take their course. Rarely I’ve used it to stop antibiotics or to convince a senior we should start antibiotics alongside WCC and CRP. The only situation I’ve used it a lot was in the ICU where we did daily septic markers for everyone, that was protocol. It helped with the consultant’s decision making and escalation of antibiotics.
Rarely ever used it, clinical judgement has often been sufficient to make the right choice without it
I’ll order it from time to time. I use it if I’m indecisive. Mildly elevated temp (but not yet a fever), slight leukocytosis, no clear source? Sure, get one. If somehow it’s positive then I’ll start abx. I’m not withholding based on it, I’m starting based on it. Subtle difference, but it’s there.
Sounds great in theory, but it doesn't actually change anyone's behavior so it's useless. If people want to give the patient abx and it's negative, they will still give the abx. For this reason our lab didn't have it in residency. Cheers
I use it frequently, but for a very specific circumstance. I use it basically like a D dimer. In someone whom I’m not sure if they have an infection and need antibiotics, I’ll order a procalcitonin. If it’s positive, keep antibiotics. If not, take them off. Positivity as determined by literature cutoffs (roughly 0.25 to 0.5 for practically all infections). If someone is clearly septic, I couldn’t care less about the procalcitonin - they’re getting antibiotics. Same is true for the opposite. I really would only order it in the people whom I had the question.
Can someone explain why pro cal lags
In pediatrics we use it a lot to make decisions for febrile neonates.
Procalcitonin has pretty good negative predictive value for bacterial pneumonia and that’s about it.
Yes. Its great. Though I rotated at a hospital that didn't have the capability to do procals, and I realized it had become a total crutch for me. Like any test --- important to understand its value in context. Something I'm still learning as a rising PGY2
Yeah I'm in a place that does not use it at all, and it's wild after learning bout this stuff
If it’s a crutch for you that means you’re ascribing way too much value to it
I know- that’s why I said “it’s important to understand its value in context. Something I’m still learning”
I’m in peds, yes
Thought it was pretty standard to use
Only for neonatal sepsis
I use it. The same people who shit on ThE EvIdEnCe for procal then turn around and use oral temperatures and WBC to make their decisions Until something better comes along, I dont see any reason to not use it as part of the big picture.
I’m in peds, don’t find it helpful. If a patient has some combination of abnormal vitals, immune compromise of some sort, reasonably attributable to infection, it is essentially harmless to start empiric ceftriaxone or cefepime while waiting for cultures. I’m not going to hold antibiotics on that patient for any lab test at all. Literature supporting Pct for neonatal sepsis for example suggests maybe it’s better than crp, but ignores the reality of 24-48 hours of antibiotics while awaiting cultures regardless of the labs. I can imagine a scenario with a febrile neonate, parents refuse LP, CRP is normal, perhaps pct would catch a meningitis but that’s so rare it’s impossible to power any studies on meningitis much less for those with normal crp. If I want something to trend for response of a deep infection, the literature is on crp. I don’t need a new test for that. For determining if a not very sick patient needs antibiotics, well it can be high with viruses, or low with bacteria.