Transcript
Speaker: Welcome to Critical Matters, a sound podcast covering a broad range of topics related to the practice of intensive care medicine.
Speaker: Sound provides comprehensive critical care programs to hospitals across the country.
Speaker: To learn more about our programs and career opportunities, visit www.soundphysicians.com.
Speaker: And now your host, Dr. Sergio Zanotti.
Speaker: Fever occurs frequently in ICU patients.
Speaker: It is often an indicator of infection, but can have multiple non-infection causes in critically ill patients.
Speaker: In today's episode of the podcast, we will discuss the evaluation of new fever in the ICU adult patient.
Speaker: Our guest is Dr. Andre Khalil, a critical care and infectious disease physician.
Speaker: Dr. Khalil is professor in the Division of Infectious Disease and director of Transplant Infectious Disease at the University of Nebraska Medical Center.
Speaker: A renowned clinician, educator, and researcher, Dr. Kali has received multiple distinctions, including the 2021 Scientist Laureate Award at UNMC.
Speaker: Dr. Kali is an author of multiple peer-reviewed publications and is one of the co-authors of the 2023 Society of Critical Care Medicine and the Infectious Disease Society of America Guidelines for Evaluating New Fever in Adult Patients in the ICU.
Speaker: Andrei, welcome to the podcast.
Speaker: Thanks so much, Sergio.
Speaker: Really a pleasure to be here.
Speaker: So I would like to start with asking you, why should critical care clinicians care about this clinical guideline or this topic of new fever in the ICU?
Speaker: Yeah, so very important question.
Speaker: The fever is really something that we deal pretty much every day in the ICU.
Speaker: And there are so many causes of fever that it becomes sometimes critical.
Speaker: quite complex and difficult to discern the reason for the fever and some of the reasons can be quite severe, quite serious, some of the reasons quite mild, some of the reasons can be just secondary to the natural history of some surgical procedure, but the reality is
Speaker: It is critical for us at the bedside to really understand the reason for the fever because that can be something quite relevant for the management and the treatment of the patient.
Speaker: Perfect.
Speaker: And I know that, as we mentioned in the intro, you've been part of the 2023 clinical guidelines, which were an update of 2008.
Speaker: And I really focused on adult patients who are not immunocompromised, although I would imagine that a lot of the discussion also applies to immunocompromised patients, but that's a little bit out of the scope.
Speaker: But what I wanted to ask you to start the discussion is, how did you define in the guidelines fever in the ICU patient?
Speaker: So, you know, the definition that we use on the guideline was the temperature of 38.3 Celsius in the ICU.
Speaker: that that's pretty much kind of the number that has been used in a large um you know in a large historical cohorts and uh population studies uh trials but but we in the first you know in the first paragraph of this fever section of guideline we we spend a little more time trying to explain to the reader that there are nuances on this and this is really really important because
Speaker: As a clinician, I cannot really wait for a specific cutoff to define fever in a good number of my patients.
Speaker: I'll give an example.
Speaker: If you have a patient that is, let's say, 25 years old with meningitis, likely you're going to see a very brisk fever in
Speaker: in these patients, they usually have a pretty robust immunological system, inflammatory reaction, and you're going to see fever quite high, quite fast.
Speaker: But on the other side, if you have a patient in ICU that is, you know, 80 years old, let's say, even with meningitis, let's use the same syndrome, right, the same infectious process, it's very unlikely that the patient is going to have the same risk response as the 25-year-old, and it may take longer for the patient to develop fever, and the patient may not even develop significant fever.
Speaker: So the point here is that
Speaker: you know while we we do use the 38-3 as the usual uh fever cut off uh it you really have to individualize to your patient i'll give another example i have um a substantial number of immunocompromised patients uh solid organ transplant patients bone marrow transplant patients in which they they chronically take medications that that make the fever spike much more difficult to happen
Speaker: And a lot of times they know their baseline temperatures.
Speaker: One of the things we talked in the guideline is that if the patients already know where they live in terms of range of temperatures, that can be very helpful because sometimes just one degree above whatever baseline they live can be something quite substantial and can be defined as fever.
Speaker: So really try to avoid fixed cutoffs and
Speaker: individualize the temperature according to your patient's age, patient comorbidities, patient medications, because that's going to be way more meaningful for you to define fever than using, you know, one size fits all for, you know, certain numbers.
Speaker: So that's kind of the latitude that we provide in the guideline.
Speaker: Perfect.
Speaker: And I think like all guidelines, right, they're anchors, they're frameworks for us to organize our approach.
Speaker: But at the end of the day, we have to think of the individual patient in front of us and use our clinician hat and also understand that sometimes there are subtleties that are unique to the clinical situation that we are dealing with.
Speaker: The second question I wanted to follow up that was, obviously, when we think of fever, most clinicians immediately jump into the thought of an infection.
Speaker: But in the ICU patient, there are many non-infections causes of fevers.
Speaker: Could you just give us maybe a quick commentary, Andre, on some of the most relevant ones that we should at least keep in the back of our mind when we're evaluating new fever in the ICU?
Speaker: Absolutely, Sergio.
Speaker: So the...
Speaker: You know, we tend to, when we're in medical school and in training, there is a tendency for all of us to associate fever with infection.
Speaker: It's almost like a knee reflex.
Speaker: But the reality is there are many, many causes of fever in the ICU that are not related to infection.
Speaker: And this is not just semantics or just like, oh, you know, just a little bit of a differential diagnosis.
Speaker: It is critical because some of these causes of fever actually demand, you know, a whole different diagnostic and treatment approach that can actually impact in the outcome of the patient.
Speaker: For instance,
Speaker: you can be admitted to the ICU with fever of a clear source, and it turns out that the patient, for instance, has a massive myocardial infarction.
Speaker: It takes a little bit sometimes for the diagnosis to be made, but you can have fever simply from the fact that the patient is getting a myocardial infarction.
Speaker: Sometimes patients have adrenal insufficiency that were not diagnosed before the patient comes to the ICU, and adrenal insufficiency itself
Speaker: We require, you know, steroids and other treatments that, you know, actually, in order to be treated, in order not only to, you know, bring the fever down, but in order to be treated.
Speaker: And the same with MI.
Speaker: I mean, you're going to treat MI with thrombolytics, whatever needs to be done.
Speaker: It's not going to be antibiotics.
Speaker: The same way patients, I mean, we see commonly patients with pancreatitis.
Speaker: We are a referral center for patients.
Speaker: liver transplant and a lot of times patients have chronic pancreatitis and sometimes end up even with a pancreatic transplantation as well and this itself can cause significant fever and sometimes it's very difficult to distinguish fever from a just an acute pancreatitis on top of chronic pancreatitis with let's say with necrotizing pancreatitis for instance another situation that's very common in the ICU
Speaker: We are a referral center for oncology patients and bone marrow patients, and sometimes you see patients with a tumor lysis syndrome, patients with transplant rejection, and all these things that we approach in a guideline are really important syndromic process that can cause substantial fever, can simulate infectious process, but actually require a whole different treatment approach.
Speaker: So,
Speaker: To look for non-infectious scars of fever is really important because that can change the management dramatically in order to know exactly what the patient needs.
Speaker: So when we see these patients at the bedside, you have to have your mind pretty open to both infectious and non-infectious sources of fever.
Speaker: Perfect.
Speaker: How would you recommend or how do the guidelines recommend that we measure body temperature in critically ill patients?
Speaker: That was something that really took a substantial amount of time and discussion among the guideline members because it is really important to define how can we do this in a way that can be more systematic, it can be more practical, and can be available as well in the ICU.
Speaker: It turns out that we don't have any of the usual traditional methods that can
Speaker: can prove to be superior to the more rigorous methods that we've used in the past, and we don't use so much in the ICU, but that we've used in the past, for instance, with the pulmonary catheter, with bladder catheter, with esophageal probes.
Speaker: So all this, you know, both the bladder catheter and esophageal probes that still we have available in the ICU, so we don't use so much more of the PA catheters as we used in the past, but these really bring a much more reliable measurement of the central temperature.
Speaker: however um not every issue is going to have catheters uh you know probes and and and even less isofageal probes so the reality is that if by any chance the patient is does not have any kind of this more rigorous uh kind of methods then um you know the next step in terms of measuring temperature will be rectal and oral temperatures
Speaker: And even though both rectal and oral temperatures are not also that simple because it really, each one has its barriers.
Speaker: Let's say, you know, oral, if the patient's intubated or having issues related to the uropharyngeal area.
Speaker: And so, but we found looking into the oral evidence that rectal and oral temperatures are...
Speaker: more reliable than tympanic and some of these skin probes and temporal probes and so forth.
Speaker: So it seems that they just become a little more reliable in terms of measuring every day.
Speaker: The tympanic temperatures that also are used frequently
Speaker: in different places requires way more maintenance calibration and and actually can end up with the one to two degrees uh you know wrong uh temperature in terms of either upper or lower temperatures so the point is the reason why we didn't recommend timpanics because it seems to be way more variable and less predictable than rectal and oral temperature so
Speaker: That's why we, at the end, look into all the evidence.
Speaker: We believe that in the absence of a esophageal or bladder probe, the most reliable sites to measure are going to be oral and rectal.
Speaker: And this is important because whatever method you choose in the ICU,
Speaker: You want to make sure that you have a consistent approach, meaning that you don't want to use one method here, one method there, one method one day, one method the other day, because that's going to really make the comparison very hard.
Speaker: I mean, when you change the method, you change the variability.
Speaker: Once you change the variability, you may end up with taking action.
Speaker: when actually all you're seeing is the variability between the methods.
Speaker: So whatever method you choose, try to make sure that you have that consistently used in your ICU.
Speaker: And I think it's always interesting, right, like how for anything we do in medicine, there are layers of evidence and maybe not the perfect evidence, but there's always a lot to be learned.
Speaker: And
Speaker: You mentioned tympanic and maybe skin temperature, which unfortunately, because they're practical, have become widespread throughout ICUs in the country.
Speaker: But yet those are the least accurate, right?
Speaker: And I think it's important for our clinicians to understand what the evidence says regarding temperature measurement.
Speaker: Very important, Serge.
Speaker: Actually, you know, sometimes what's the most practical is not the most accurate.
Speaker: And this is one good example.
Speaker: So every time I'm on call, Andre, I will go, almost every single time I'm on call, I get a call from a nurse for a patient who has fever asking for treatment.
Speaker: What is the current recommendation based on the available evidence in terms of treating fever itself with antipyretic medications?
Speaker: So a very important question, Sergio.
Speaker: Generally speaking, let's say, let me divide this
Speaker: answer in two factors.
Speaker: One, if it is infection related, let's say if you think that the fever is infection related, most of the time, the vast majority of the time, fever is really a part of the immunological response to the infection.
Speaker: Actually, fever tends to increase the recruitment of lymphocytes, T cells, B cells, and it's part of how we defend ourselves against the infection.
Speaker: So,
Speaker: You know, low-grade fever, actually, it's something that very likely can be beneficial in most of the infectious process.
Speaker: The problem is when the fever starts to get to a level where it can compromise the immunodynamics of the patient.
Speaker: So, you know, if you're talking, let's say, in a non-infectious process, like a malignant hyperthermia,
Speaker: or a patient with some kind of neurological disorder that can, in which the fever can trigger seizures or something, you know, of that complexity.
Speaker: So these are situations where maybe, you know, it's not unreasonable for us to have a lower threshold to use antipyretics, but the guideline is,
Speaker: looking for most of the reasons that that cause fever and the ICU does not suggest the immediate treatment with any anti-thermic approach including antipyretics just because most of the times they will not be beneficial including patients with sepsis there were
Speaker: several sepsis clinical trials done in the past in the last couple of decades, working for the use of antipyretics as potentially something that could benefit the outcome and survival of these patients and didn't do anything.
Speaker: Actually, there are animal studies showing that actually, a brigade in the fever can potentially even be harmful.
Speaker: So the point is, there is really no data of benefits.
Speaker: There is data showing no benefits actually given antipyretics as a general rule.
Speaker: So I think to make the answer quite objective is that we do not recommend as a general approach the use of antipyretics, but in special situations in which
Speaker: the temperature can really be detrimental to the patient either because of the level of the temperature or because of the underlying disease like a neurological disease or some some a patient let's say in post cardiac arrest and situation that temperature can be detrimental then there's a situation that it is okay to use antibiotics so i think we give a little bit of this latitude to the clinician but in general uh it will not be very useful
Speaker: And I think that's an important point because another commonly, I think, utilized treatment in the ICU that really has no evidence and we've been just doing it because that's what we've been doing for a long time.
Speaker: So I think having that pause to think about it is really indicated and the situation probably will help.
Speaker: Just, I mean, at a very superficial level, Andre, this was not a focus of the guidelines, and then we'll go into the further evaluation, but any general comments on your standards and ID, a physician on empiric, antimicrobial, antifungal, antiviral therapy in the ICU?
Speaker: Obviously, like you mentioned at the beginning, not all fever is infectious, but if it is infectious and the patient's sick, probably getting the right treatment soon is very important.
Speaker: Yes.
Speaker: So one of the things that really, in my practice, I emphasize very much all my trainees and colleagues is that if I do believe that by my initial clinical assessment, the cause of the fever is infectious, it is especially if the patient is critically ill in the ICU,
Speaker: times of essence absolutely times of essence and and and i i believe that there's nothing uh nothing wrong and nothing risky about actually starting antimicrobials according to the history and physical examination if if you have a a good suspicion of infectious process causing the fever so i think this is really important because
Speaker: In the worst case scenario, if your clinical judgment is wrong and turns out that patient does not have infectious process, you can always stop antibiotics in the next 24 hours.
Speaker: You don't need to keep giving this for a long time.
Speaker: But if you are right and if your suspicion of infection is high and you're right, you really may end up not only improving the treatment of your patient, but you may end up improving the chances of surviving that.
Speaker: from this infection because there is plenty of data showing that in patients that are really critically ill, sick, not to infection, they can benefit from the early administration of antibiotics, especially in patients that are in septic shock.
Speaker: But the point is, you know, sometimes it's very hard to distinguish which patients will benefit more or less.
Speaker: I'll give an example.
Speaker: some patients that are quite immunocompromised, let's say patients that are taking, let's say, tacrolimus, myphrodic and steroids for use from a solid organ transplant.
Speaker: A lot of times these patients will come without a lot of symptoms of infection, but you're already in all the patients, you're already
Speaker: know the history of this patient's the history of infection a patient is probably having like let's say a recurrent infection of let's say a pneumonia or a uti or something that you already know the likelihood that this patient is is developing a substantial infection but the patient is not showing you know like the over clinical signs and symptoms this is the type of patient that start antibiotics early
Speaker: is going to be critical because these patients will crash and burn very fast if you do not start antibiotics on time especially because they're already very immune compromised so the point is again you know we have to individualize situation we have to be aggressive about starting antibiotics when they have a suspicion and we have to be aggressive about stopping antibiotics when the patient does not have infection so
Speaker: In my own practice, yes, if I have somebody in the ICU critically with fever and I do have a suspicion of infection, I will start empirical antibiotics until I get a better understanding of both the diagnosis and the natural history of the situation.
Speaker: Perfect.
Speaker: Let's talk about imaging studies and critically ill patients with new fever.
Speaker: How would you approach a patient who's been in the ICU, now has a fever?
Speaker: What are the imaging tests that you would order?
Speaker: How would you think about it?
Speaker: And what do the guidelines recommend?
Speaker: So the guideline recommends chest X-ray as a kind of a general rule for patients with fibromyalgia and I think is reasonable because, you know, with a plain chest X-ray, you can catch the beginning of pneumonia, you can catch pleural effusions, you can catch abscess, you can catch pneumothoriasis.
Speaker: I mean, so many things you can diagnose with a very simple and quick image like a chest X-ray.
Speaker: So I think it's just reasonable to believe that
Speaker: chest x-rays should be part of your uh initial approach especially when you know you're just kind of first seeing the patient so i think it's very reasonable it's available it's uh it's safe you know you don't need to get the patient out of the issue they usually can do at the bedside uh so i think that's that's something that i think is quite reasonable that the guideline recommends a general now all the other image all the other image tests will depend on the history and physical examination let me give an example
Speaker: We suggest the addition, let's say, of ultrasounds, either, you know, either POCUS or formal ultrasounds, when there are indication of a focus of infection.
Speaker: For instance, if you have somebody with a
Speaker: abdominal pain or transaminases, elevation of transaminases, or bilirubin, or Ocfrost, or suspicion of cholecystitis, or suspicion of appendicitis.
Speaker: When you have somebody that really has clinical symptoms that suggest abdominal sores of the fever and potentially the sepsis, then
Speaker: This is a situation where images definitely can benefit to understand, you know, what is the extent of the infection and what needs to be done in terms of drainage or surgery.
Speaker: So that's when we recommend a
Speaker: the addition of ultrasounds and the addition of CT scans depends again depend on each situation I think the bedside ultrasound can be quite useful just because it is it is usually if it is available in the ICU it's right there you don't need to transport the patient to a CT scan in another part of the hospital it's less radiation so it's there's a lot of benefits of doing the bedside ultrasound and I think can be quite useful but but we do not recommend
Speaker: just as a, you know, doing just for doing just in case if you don't know where the fever is coming from.
Speaker: The guidelines recommend that you have to really have some indication that of the focus of the infection in order to maximize the yield
Speaker: of the ultrasound i mean i mean and you think about this is like almost every test that we do in the icu you know you have to have a little bit of a prior correct you have to have a little bit of a clinical suspicion of of the focus in order to do certain tests and and and the image is the same uh if you have um if you have a suspicion of a
Speaker: let's say of a respiratory infection uh and and by chest x-rays or by clinical symptoms you can go ahead and do a a bad side ultrasound of the lungs lung ultrasound you can look for brainchymal change you can look for a plurifusion so forth and it can be useful it can definitely be very useful to understand the extent of the infection of the lungs
Speaker: But again, the same story, what's your prior, what's your clinical suspicion?
Speaker: We always go back to the history and physical examination to delineate which tests are going to have the higher probability to help you to define what's happening with the patient.
Speaker: So we talk about bedside ultrasounds, we talked about form ultrasounds, we talked about CT scans of the chest, CT scans of the abdomen and pelvis.
Speaker: And when, exceptionally, again, I say exceptionally because even in my practices, rarely I would need to do that.
Speaker: If you reach a point where you really are struggling to find the source after, you know, extensive examination and imaging, including CT scans, potentially you can think about doing PET scans.
Speaker: Again, I don't think that
Speaker: We should be recommending PET scans as a routine in any ways and in form because it is a test that will only be helpful in very, very exceptional situations.
Speaker: The vast majority of the situations in the ICU will be able to make the diagnosis by clinical examination and by traditional image like x-rays, CT scans and ultrasounds.
Speaker: But when you're really against the wall in the situation where you don't know
Speaker: what's happening and you cannot find the source we recommend the PET scan as a potential tool to find you know the focus of the infection because it's a situation that really becomes quite frustrating after two days of investigation and in which the patient does not have a diagnosis but again I emphasize that this will be more the exception than the rule
Speaker: Perfect.
Speaker: And I've been in practice for many years.
Speaker: I'm sure I've had a couple of patients had PET scans, but I never ordered it myself.
Speaker: So I'm sure that by that time, I would hope that our critical care colleagues are brainstorming with our ID colleagues at the bedside, right?
Speaker: Right.
Speaker: Exactly right.
Speaker: I like the word brainstorming.
Speaker: Yeah.
Speaker: So let's talk about blood cultures in the critically ill patient with fever.
Speaker: First, if you could just tell us what the current recommendation is in terms of how many blood cultures, how much blood and the timing of that.
Speaker: And then I would like to hear your comments on what do we do or don't do when there's a central venous catheter in place.
Speaker: Yeah, Sergio, this is really important because I've had a few messages from friends and calls from friends after the deadline was published about this as well.
Speaker: And as you know, through the years, you know, most hospitals and ICUs learn to minimize the kind of the
Speaker: you know, the kind of the systematic collection of central line cultures for any reason, because, you know, at the end, when you see a lot of studies have shown the amount of blood cultures contamination from central lines, and sometimes people end up getting over-treated with unnecessary antibiotics, and
Speaker: So, you know, a lot of places now have rules and electronic records, basically.
Speaker: When you order these cultures, a lot of places automatically go to peripheral cultures to avoid the collection of central lines.
Speaker: And the idea here is to minimize the contamination.
Speaker: So this is, you know, I understand why this has been done.
Speaker: in many, many places as part of controlling the unnecessary use of antibiotics for contaminated cultures.
Speaker: But I wanted people to understand that our guideline is dealing with a different patient population.
Speaker: This is not everyone in the hospital that is, you know, is not very ill or has some fever or has a reason to have a culture.
Speaker: This is a patient that is critically ill, requires an ICU bed,
Speaker: has fever, and this is really important because this is not the same as a patient that's in the ward, very stable, that still has other reasons to have fever or infection.
Speaker: So in a patient that is in the ICU, is critically ill, has fever, and if the patient has a central line and you don't know the reason why the patient has a fever,
Speaker: that's a situation where you have to you have to you know literally sit with the your whole team sit with the nurses and the clinicians and the trainees everyone said listen this is a situation where i need a collection of blood from the central line and i need a collection of blood from the peripheral from a peripheral vein i need both at the same time because i want to know if by any chance the cause of this fever is kind
Speaker: coming from a central line infection.
Speaker: This is really, really important because a lot of our patients in the ICU, not only sometimes they have lines placed in the ICU, but sometimes they have lines placed outside the ICU for a long time.
Speaker: I have patients come to the ICU with
Speaker: you know, dialysis catheters with central line catheters for other reasons.
Speaker: They're getting fusion chemotherapy, and a lot of times they have these lines for weeks, sometimes for months, for a long time, sometimes they're in the wards for a few weeks.
Speaker: So the fact that the patient has a central line, the fact that you don't know what's causing a fever should be a big trigger for you to say, you know what, I have to collect blood from the central line and from the peripheral veins, because that's going to give you a sense of what's happening.
Speaker: The reason why we do that is because
Speaker: We already know that if you have a differential time of two hours or more between the culture positive in the peripheral vein versus the culture positive in the central line, that's going to be highly indicated that the patient has a central line infection and likely the central line will eventually have to be removed, especially if the patient is getting cracoling.
Speaker: So this is really important.
Speaker: The other thing I want to mention, Sergei, is that if you're going to collect blood from the central line, the guideline recommends at least two lumens, two lumens from the central line.
Speaker: A lot of the central lines have two lumens, three lumens or more.
Speaker: And the reason why is because if you collect at least from two lumens, you're going to increase the yield.
Speaker: of catching an infection that is contaminating or infecting the scatter.
Speaker: So it is important to make sure that you get this procedure done.
Speaker: The last thing I want to mention about the blood cultures that's important is the yield of the blood cultures, whatever blood cultures you do, whatever place you do, is very, very proportionally related to the amount of blood that's collected.
Speaker: So if the amount of bloods collected is too small, you may end up with a false negative blood cloture when the patient is really getting septic and bacteremic.
Speaker: So you don't want to get into the situation.
Speaker: You really want to catch these bugs if they are in the bloodstream.
Speaker: So you want to at least put the minimum of 10 mLs in each bottle of these blood clotures.
Speaker: The way the guideline recommends is that you can collect...
Speaker: uh two bottles of for aerobic culture one bottle for neurobiotic culture so three bottles for each site let's say two bottles from for the central line three bottles for the peripheral vein culture and it's going to be 10 ml in each it's going to be about a total of 60 mls this is really important because if you if you skimp in the in the amount of blood you're collecting you may end up with a false negative culture that can be quite detrimental to the approach to the treatment approach to the patients so these are kind of the uh
Speaker: the general approach that the guidelines recommend for these blood cultures.
Speaker: And like you mentioned, I think this is an important aspect of care for practical reasons, but also with our emphasis on trying to reduce catheter-associated bloodstream infections, I think people have sometimes gone too far in terms of not checking cultures.
Speaker: And when the clinical situation merits, we should do what's best for the patient.
Speaker: And understanding where that infection is coming from obviously is very, very important.
Speaker: And I think that time to positivity is something that people need to take into account and make sure that, like you mentioned, Andre, that we are measuring from more than one lumen in the central line when suspected and getting also a peripheral one at the same time and using that time to positivity to try to figure out if it's the central line or not.
Speaker: And then, Sergio, if you allow me, just one thing that I want to re-emphasize.
Speaker: I'm sure that all of us working at SU, we've read the sepsis guidelines and other guidelines, but just emphasize again and repeat again that
Speaker: Ideally, these cultures should be collected right before the antibiotics are being started.
Speaker: So you don't want to delay for any minutes the administration of antibiotics.
Speaker: But we all know it takes time between putting the order again, the pharmacy to mix the antibiotics and bring to the ICU.
Speaker: That's the time to do blood cultures.
Speaker: The yield of getting a blood culture positive will be tremendously increased if they are collected before the initiation of antibiotics.
Speaker: So that's something that should be a really big effort in all ICUs.
Speaker: Perfect.
Speaker: On the same note, I guess, similar dynamic, when and how should we get urine cultures?
Speaker: Yeah, that really becomes a little more complex than blood cultures because the problem with the urine cultures is that they tend to really, you know, be a little more difficult to really interpret because there is a...
Speaker: a very common process for contamination of urine, especially in the ICU, because a lot of patients are going to be human-animally unstable, requiring folic catheters, and it becomes very difficult sometimes to collect a specimen, a urinary specimen, that can provide a reliable result.
Speaker: So the recommendation that we make in the guidelines is that
Speaker: uh the urine really has to have uh you know pyuria the patient has to have symptoms uh and and the collection has to be really as as sterile as possible and and that includes
Speaker: patients that already have a folic catheter and in the vast majority of the time is when patients develop fever in the ICU they already have a folic catheter either because before they came to the ICU or a few days before you are seeing a patient and if the folic catheter is really sitting there you basically the way that you want to do if you really are concerned about the urinary infection
Speaker: you're going to have to remove this folic catheter, put another folic catheter if the patient really needs, and collect urine from a fresh catheter.
Speaker: This is going to really make your collection much more reliable.
Speaker: and much more informative in terms of what to do with these results.
Speaker: If the patient has any history of UTIs, any history of lithiasis, hydronephrosis, pyelonephritis, anything that's suggestive of UTI, and now you're collecting a sterile urine with a pyuria,
Speaker: that's going to be a urine that really is going to go for culture, for urine cultures, and is going to have a good yield to bring pathogens that need to be treated.
Speaker: So the key point is,
Speaker: we recommend not collecting urine from patients that already have any urinary catheter in place because at that point, when the catheter is staying there, the chances of contaminations are too high and you may end up treating the patient for a culture positive that has nothing to do with the fever, has nothing to do with what's happening.
Speaker: You may end up exposing a patient to unnecessary antibiotics when the patient needs another treatment approach.
Speaker: So this is...
Speaker: This is something that we emphasize very much in the guideline.
Speaker: Perfect.
Speaker: And as we move forward, what would be the recommendation on testing for viral pathogens?
Speaker: Obviously, we're in the winter, respiratory season's around.
Speaker: Coming out of COVID-19 pandemic, COVID's still around.
Speaker: I have definitely diagnosed COVID in some of my patients in the ICU after several days.
Speaker: But what's the current recommendation on viral pathogens?
Speaker: So they are quite useful in general because, you know, both the nasal swab and the pneumonia panel from the sputum, both of them, they add a little bit of different information, but complementary information.
Speaker: So for either patients that are intubated or not intubated, if you have...
Speaker: a patient with respiratory symptoms, signs and symptoms, definitely it's something quite useful to do because you can not only diagnose a potential pathogen that is causing the symptoms, but also you can define if the patient's going to need antibiotics or not, correct?
Speaker: So, for instance,
Speaker: You know, I see now, just the last few weeks, I was in service, I've seen patients with, in the ICU with the Vinovirus, Perinfluenza 1, Perinfluenza 3, Metanomavirus, RSV.
Speaker: I mean, I've seen almost all respiratory viruses in the last few weeks, and the winter is just beginning.
Speaker: So these are really important because some of these viruses have specific antiviral treatment, some don't.
Speaker: And knowing which virus are infecting the patient, bringing the patient in ICU, are going to be really important because that's going to change our management.
Speaker: The other thing that I want to mention, Serge, that's very important is not only it's very easy and you're going to have the results in one or two hours, but also it's very important to...
Speaker: to not forget that patients can have a positive, you know, viral pathogen, you know, in a panel, and the patient could have also a bacterial pathogen that, I'll give an example, I...
Speaker: I have a patient that last week, that the patient had a rhinovirus, and it turned out that the patient, the panel just showed rhinovirus, and the patient is quite ill, developed respiratory failure, ended up needing to be intubated, and it turns out that after the intubation with the tracheaspirate,
Speaker: the pneumonia panel showed a staphylococcus aureus and the coach also showed a staphylococcus aureus.
Speaker: So the point is when the patient was being seen outside the hospital, it was all rhinovirus infection, came here to the hospital, was diagnosed with rhinovirus infection, progressed to a bacterial infection and ended up with a staphylococcus pneumonia.
Speaker: So why this is important is because the
Speaker: We cannot forget that a lot of times in the ICU, we're going to see patients with co-infections.
Speaker: They don't need to be even immunocompromised.
Speaker: They can be immunocompromised or not, but about, you know, up to a third of the patients that have CAP, they have co-infections with, you know, between virus and bacteria.
Speaker: So that's something that I want to make sure that people understand.
Speaker: The panel is going to be very important to define what kind of pathogens are potentially causing infection, but the panel will not define the entire history.
Speaker: is progressing, if the patient has a viral pathogen that is progressing to a worse disease, it could be progression from the viral disease, like COVID, could be a progression to a severe COVID, but could be a progression to a bacterial infection as well.
Speaker: So it's very important to keep that kind of diagnostic approach always up 24-7 to make sure that you understand if the progression of respiratory failure is secondary to the natural history of the virus or it is secondary to a
Speaker: post-viral bacterial infection.
Speaker: All these things have to be evaluated day by day on real time to our patients.
Speaker: Perfect.
Speaker: And what about in closing the role of rapid biomarker tests like PCT and CRP?
Speaker: So PCT and CRP, the way the guideline dealt with was the following.
Speaker: We recommend that if you have a low probability of infection based on your history and physical examination, you just kind of don't know what's happening, you don't find what's happening, but patients still have fever in the ICU,
Speaker: it is reasonable to check either ProCal or CRP, either one or both, whatever you have in your hospital.
Speaker: Each hospital has different laboratory measurements, but it's reasonable because you're a little bit lost in what's happening.
Speaker: The patient's having fever.
Speaker: to do these biomarkers.
Speaker: One is because if the biomarker comes quite elevated, it really is going to trigger you a more aggressive approach looking for infection, looking for what's happening with this patient, because even though the history and physical are not that impressive, now you end up, let's say, with a very high risk
Speaker: PCT or CRP that's going to trigger you to think okay am I missing something what's happening here the other reason for doing that is because you know once you get to biomarkers and a lot of times when you get called to these patients the patient's already getting a couple of antibiotics let's say it turns out that the PCT and the CRP are you know normal like zero zero five whatever level whatever whatever normal is in your lab it's really normal there's nothing you repeat next day still normal
Speaker: So, you know, now you start to see that you don't find a focus of infection, the patient's doing well, and the biomarkers are completely normal, even, you know, when you measure sequentially.
Speaker: Well, that's a situation where you can say, well, you know what, I think it's time to de-escalate antibiotics because I'm not seeing an infection source of fever.
Speaker: So these are the kind of the situations where the biomarkers can help.
Speaker: But I think really important, Sergio, that I want to mention here too, that we...
Speaker: we discussed as well in the HAPFAP guideline in the past, is that these biomarkers, they alone, they are not sufficient to rule out infection.
Speaker: Let me tell you one example.
Speaker: You have somebody with a high suspicion of infection.
Speaker: This is what the guideline says.
Speaker: This guideline says, let's say you have somebody with a high suspicion of infection.
Speaker: You really think the patient has infection causing a fever.
Speaker: If the ProCal or the CRP becomes normal,
Speaker: really, it should not change your management.
Speaker: The biomarker being normal initially should not change your management.
Speaker: Meaning that if you think the patient has an infection causing a fever and a critically ill situation, you give the antibiotics, you treat the patient independent of these biomarkers because the biomarkers
Speaker: can take a while sometimes to go up, sometimes they don't work very much.
Speaker: So the point is, they are not good for you to really rule out the infection, but they are good for you to understand what's happening with the patient in terms of a need for antibiotics in the next couple of days.
Speaker: They can help you to complement when you have a low suspicion and you don't know what's happening with the patient, but they rule along
Speaker: never be decisive about what needs to be done.
Speaker: Remember, biomarkers are only complementary and you have to take with a grain of salt because, again, your clinical assessment, your physical examination will be critical.
Speaker: And if you have a high suspicion of infection, these biomarkers are not going to be very useful because you already know that patient has infection.
Speaker: There's nothing that you're going to gain at that point in terms of diagnostics.
Speaker: That's why we do not recommend biomarkers for patients that you already know that have infection source for the fever.
Speaker: And I think it's very similar to how you might use D-dimers in the ED to rule out low suspicion PE, but it's not something very useful when you have a high suspicion.
Speaker: And I think it, like you mentioned, probabilities-based theorem applies everywhere in medicine, and using that appropriately is very important.
Speaker: André, really a lot of very, I think, practical, evidence-based pearls here that apply to daily situations in our ICU.
Speaker: So almost every day, I would imagine, at every one of our ICUs, there's somebody with a fever.
Speaker: And how to...
Speaker: follow up on that, how to approach those patients, I think is very important.
Speaker: These guidelines are a great tool for our clinicians, and we'll link them, obviously, in the previous guidelines in the show notes.
Speaker: As we close, Andre, we like to tap into the wisdom of our guests outside of the clinical topic with a couple of questions.
Speaker: Would that be okay?
Speaker: Absolutely.
Speaker: So the first question relates to books.
Speaker: Are there any books that have influenced you significantly or that you have gifted often to others?
Speaker: So there's so many books.
Speaker: It's a tough question always, Sergio, because, you know, we like so many different things.
Speaker: But I would say that there's one book that really was very impactful to me many years ago.
Speaker: It's already a little old, like in early 2000, but it's just absolutely fantastic book.
Speaker: It's a book titled Splendid Solution.
Speaker: by Jeffrey Kluger.
Speaker: Basically, the book is about Jonas Salk and the conquest of polio.
Speaker: And the reason why this book is so phenomenal to me is because it shows the struggles and the barriers and all the efforts that Jonas Salk went through to develop the polio vaccine.
Speaker: And this is really remarkable because we are talking about 1950s,
Speaker: And everything you're going to read in this book is applicable to 2023.
Speaker: Basically, Jonas Salk believed that the vaccine he developed was an inactivated polyvacin really would be effective.
Speaker: And he went against a lot of people that thought that this vaccine wouldn't work or potentially could be even harmful.
Speaker: And why this is important?
Speaker: Because Jonas Salk being in the middle of a horrendous
Speaker: polio epidemic in the US, was able to do a clinical trial that had hidden placebo arm that changed the history of the world.
Speaker: Jonas Salk clinical trial, it was a randomized trial that really changed everything that we do today.
Speaker: I mean, without the polio trial, unlikely we would be developing so fast what happened during the COVID pandemic with the new vaccines.
Speaker: vaccine trials require randomization, vaccine trials require placebo, and that's really what was done in the 1950s.
Speaker: It was basically the very first vaccine trial done with so much rigor.
Speaker: And that book, to me, is a book that should be probably part of medical school's curriculum all over the world.
Speaker: Excellent.
Speaker: And I think, like you said, very timely to what we've lived recently, but also good science, right?
Speaker: It transcends the years.
Speaker: And when you said it's an old book, you reminded me of my grandfather who instilled, I mean, a love to read in myself.
Speaker: And he would always tell me that old books are good because only the good ones get to be old, right?
Speaker: So he would say that in Italian, but I think that that is very true.
Speaker: Yeah.
Speaker: So the second question is something that you believe to be true in medicine or life that most other people don't believe or don't act like they believe.
Speaker: That's, that's, that's great, Serge.
Speaker: So what I would say is that, um,
Speaker: you know, I proud myself to being really, you know, a clinician that really does everything possible and possible for my patients.
Speaker: I really, you know, I just love being at a bedside and seeing my patients improving.
Speaker: And I think that's the lesson that I've
Speaker: learned through all these years is that being humble is really critical for us.
Speaker: What I mean being humble is we have to understand our limitations.
Speaker: We have to accept our limitations.
Speaker: We have to accept the uncertainty of medicine.
Speaker: If you do not accept the uncertainty, likely you're going to end up not really treating well your patients.
Speaker: And the reason why I say that is because the moment that we accept our limitations, the moment we accept that medicine has uncertainty, we have to deal with uncertainty.
Speaker: You're going to look for the best that can be done for your patient.
Speaker: You're going to still be thinking, what else can I do to improve the care of my patient?
Speaker: And the guidelines, like clinical trials, all they do is they minimize the uncertainty of the medical knowledge, the medical evidence correct.
Speaker: So what the guidelines do is they minimize uncertainty, but they don't remove the uncertainty.
Speaker: The same with clinical trials.
Speaker: So our job at the bedside...
Speaker: is to translate what we see in the randomized trials, what we see in the guidelines to our patients.
Speaker: In order to make this translation, in order to apply this evidence, we have to understand the uncertainty, we have to understand the limitations of the data, we have to understand the limitations that we have at the bedside, and really invest in trying to really discover and
Speaker: and improve the care for our patients by accepting that uncertainty exists and that's part of how we can really do better at the bedside.
Speaker: So I think being humble and understanding that we have much to improve, much to do for our patients is critical for us to really do better at the bedside.
Speaker: Andre, I think that's a perfect place to stop.
Speaker: I really want to thank you for sharing your expertise and your time with us and for being part of these guidelines that, like you said, are important in decreasing the uncertainty at the bedside.
Speaker: But I agree 100%.
Speaker: Humility is probably the number one attribute that a scientist and a physician should have at the bedside.
Speaker: Thanks so much for this great conversation, Sarge, and congratulations on the podcast.
Speaker: I really enjoyed it very much.
Speaker: Thank you.
Speaker: Thank you for listening to Critical Matters, a sound podcast.
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Speaker: Sound's transforming the way critical care is provided in hospitals across the country.
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