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: In today's episode of the podcast, we will discuss CNS infections.
Speaker: We will focus on the management of meningitis and encephalitis, conditions associated with high rates of morbidity and mortality.
Speaker: Our guest is Dr. Catherine Albin.
Speaker: Dr. Albin is a neurointensivist and assistant professor of neurology and neurosurgery, the Division of Neurocritical Care of Emory University School of Medicine.
Speaker: She's a recognized clinician and educator, very active on social media as a medical educator.
Speaker: She's the author of numerous peer-reviewed publications and editor of the Acute Neurology Survival Guide, a practice resource for inpatient and ICU neurology.
Speaker: We are honored to have her our guest to discuss CNS infections in the ICU.
Speaker: Casey, welcome to Critical Matters.
Speaker: Hey, it's so good to be here.
Speaker: Thank you so much for the invitation.
Speaker: I'm delighted to join.
Speaker: Absolutely.
Speaker: So I believe this is a very important topic, but let's hear it from our expert.
Speaker: Why should clinicians in the ICU care about TNS infections?
Speaker: Yeah, I think this is a critical thing because it's rare, right?
Speaker: Many, many, many patients in the ICU are encephalopathic and they're confused.
Speaker: But most of the time that's due to sort of a septic encephalopathy or a toxic metabolic encephalopathy or some critical illness encephalopathy.
Speaker: CNS infections are rare, but they are potentially devastating.
Speaker: I mean, this is a condition that has a very high morbidity and mortality.
Speaker: And so I think it's one of those things that if we're not constantly sort of
Speaker: keeping in the back of our mind, then we may miss.
Speaker: And that's devastating for the patient.
Speaker: So I think it's because it's rare, but critically important to make the diagnosis that this really makes such a difference.
Speaker: Absolutely.
Speaker: And I think that of many of the conditions that we that we treat in the ICU, it's hard to think of one that has almost more of a time sensitive component.
Speaker: Right.
Speaker: We missed the boat in terms of starting therapy early.
Speaker: Our patients are going to do very poorly.
Speaker: I absolutely agree.
Speaker: So tell us a little bit about the incidents and what are we seeing today in ICUs?
Speaker: Obviously, you said it's not very frequent, but what do we know of what's out there and what's often referred to in the literature?
Speaker: Yeah.
Speaker: So I think the important thing to keep in mind is that the average immunocompetent American has a very, very low chance of getting bacterial meningitis.
Speaker: that is not necessarily the same truth for many of the patients who are in ICUs already.
Speaker: So many of the patients who are in ICUs may have immunosuppression due to their transplant status.
Speaker: They may have bone marrow transplants, they may have solid organ transplants, or they may have severe immunocompromised due to HIV and AIDS.
Speaker: And I think when we start to think about these infections,
Speaker: Knowing a little bit about the host is actually critical in determining how likely is it that this patient has a bacterial meningitis.
Speaker: Again, rare for the immunocompromised, immunocompetent normal average, walks in through the ED, very unlikely that you just diagnose bacterial meningitis.
Speaker: However, patients who are either immunocompromised or immunocompromised,
Speaker: that they have recent TBI, right?
Speaker: They have a CNS or a CSF leak, or they've had recent neurosurgery, or they have an external ventricular drain.
Speaker: All of these patients are at higher risk of getting bacteria into the
Speaker: the meninges than your average person.
Speaker: So I think it's really important for all ICU clinicians to think about, you know, is the patient I'm taking care of at a higher risk of a bacterial meningitis?
Speaker: When we think about viral meningitis, then I think it's actually, you know, the average immunocompetent American actually can get viral meningitis.
Speaker: This is going to be a often less severe type of meningitis.
Speaker: But I think it's important to know that there are seasonal ebbs and flows.
Speaker: So the incidence of viral meningitis is highest in the summer when we see enterovirus and then arbovirus.
Speaker: So either, you know, tick or mosquito transmitted diseases having their peak.
Speaker: So I think
Speaker: For the ICU clinician, it's really important to think about who is the host?
Speaker: Is that host at high likelihood of getting bacterial meningitis because of their immunocompromised status or other sort of CNS leak?
Speaker: Or is this a patient...
Speaker: who, you know, it's the peak of the summer, and we're looking at increased rates of viral meningitis because of that seasonal ebb and flow.
Speaker: So again, both are pretty rare, but they become more common in patients who, for whatever reason, are not sort of the run-of-the-mill patients.
Speaker: Excellent.
Speaker: And before we move forward, can we just maybe give like basic definitions?
Speaker: I think a lot of times we talk, we throw words around, but it's always good to make sure that we're all on the same page in terms of what we're talking about.
Speaker: And specifically, if you could just define for us meningitis versus encephalitis, and what do people mean when they talk about meningoencephalitis?
Speaker: Yeah, absolutely.
Speaker: I think that's critical.
Speaker: So meningitis is inflammation only of the meninges, which are two types.
Speaker: They can be pachymeningitis, which is inflammation of the dura, or leptomeningitis, which is inflammation of the leptomeninges, which are the layer of the brain that's more closely associated with the brain's surface.
Speaker: So you can have dural inflammation, you can have leptomeningeal inflammation.
Speaker: Oftentimes you have both.
Speaker: What's a little bit tricky about the term meningitis is that we talk a lot about aseptic meningitis or bacterial meningitis.
Speaker: Aseptic meningitis means that nothing grew in the culture, but this can still be an infectious meningitis.
Speaker: Um,
Speaker: So viral and fungal causes of meningitis, they might not actually have positive cultures.
Speaker: These are still infectious meningitis.
Speaker: So the way I think that it's better to think about it is sort of your infectious versus non-infectious meningitis.
Speaker: There are a lot of causes of non-infectious meningitis.
Speaker: These can be autoimmune.
Speaker: They can be perineoplastic.
Speaker: They can be para-infectious.
Speaker: We very commonly see leptomeningeal carcinomatosis, which is a fancy way of saying cancer-related meningitis.
Speaker: And then on the flip side, there are a bunch of etiologies of infectious meningitis.
Speaker: So bacterial, fungal, viral, and bacterial might be the only thing that reliably grows in culture.
Speaker: But aseptic meningitis really just, that's a term I have a lot of trouble with.
Speaker: And so I really try to steer people away from that.
Speaker: So that's a meningitis.
Speaker: Encephalitis means you actually have inflammation of the brain parenchyma itself.
Speaker: And this too becomes, you know, can come in all sorts of different flavors.
Speaker: We have a lot of autoimmune, paraneoplastic, parainfection, malignancy related encephalitis.
Speaker: And then we also have infectious causes of encephalitis.
Speaker: So again, meninges are the layering covering the brain.
Speaker: Encephalitis means you actually have to have brain parenchyma inflammation.
Speaker: Both of these are often associated with evidence of inflammation on the CSF, the lumbar puncture and the CSF we get.
Speaker: Most of the time, both of these are associated with an elevated white count.
Speaker: Every now and then, encephalitis can trick you and not have that elevated white count.
Speaker: It can sometimes be actually a little bit difficult to get to the diagnosis of encephalitis, particularly when we're talking about autoimmune forms that may not create sort of a robust inflammatory response system in the brain parenchyma itself, but still cause altermental status.
Speaker: Does that sort of make sense in terms of... Absolutely.
Speaker: And one question I have, I mean, is being in the ICU, I'm a little bit more detached maybe from like the aseptic meningitis that immunocompetent people have, but it seems to be that...
Speaker: from what you're telling me and from what I've read, is that a lot of those septic meningitis diagnosis that younger people would have are really probably viral, right?
Speaker: And that's why that misnomer is problematic in terms of understanding what we're really dealing with.
Speaker: Absolutely.
Speaker: I think most aseptic meningitis is viral.
Speaker: However, you can have chemical meningitis.
Speaker: We talk about Tordal causing a chemical meningitis where you can actually have like inflammation just due to the drug itself.
Speaker: So there are tons of different etiologies of this, which is why I think it's so confusing.
Speaker: Meningoencephalitis just means that you have both.
Speaker: The meninges are inflamed.
Speaker: The brain parenchyma is inflamed.
Speaker: Two other terms that kind of come up and I wanted to briefly mention...
Speaker: Cerebritis is a term that sometimes gets thrown around.
Speaker: This is a really vague term.
Speaker: What I think, and I think most of the literature sort of talks about cerebritis in a way that means it's a separative infection.
Speaker: It's invading multiple spaces in the brain.
Speaker: So either in the brain parenchyma, in the meninges, in sort of the dural space.
Speaker: And it's...
Speaker: I think the best way to think about what the radiologist is trying to say when they say, ah, evidence of cerebritis is like pre-abscess.
Speaker: Like this is not quite an abscess.
Speaker: It hasn't formed a collection, but there's this really purulent collection there.
Speaker: So that's a vague term and I really don't like it, but it does get thrown around in radiology reports.
Speaker: And then ventriculitis is specifically inflammation of the ventricles.
Speaker: This is almost always associated with an EVD catheter, like the patient has a device in their ventricles, that device got infected, and now the ventricles are infected.
Speaker: So again, meningitis, encephalitis, ventriculitis, cerebritis, there are a bunch of different terms, but they do have nuances in what we mean by them.
Speaker: Perfect.
Speaker: And are there any other CNS infections that might be relevant to the ICU?
Speaker: I think that obviously ventriculitis is very relevant to neuro ICUs, and we see that very commonly.
Speaker: Cerebritis, like you said, is a term that gets thrown around and just understanding what it is.
Speaker: But are there any others that come to mind maybe, Casey, that we should mention?
Speaker: Every now and then we get abscesses, like we get CNS abscesses.
Speaker: And that's important because often those are going to need, like, you know,
Speaker: control.
Speaker: And so CNS abscesses really require sort of a good surgical team that's willing to help kind of get source control there.
Speaker: Perfect.
Speaker: Can we talk about specifically etiology of meningitis versus encephalitis?
Speaker: And maybe even we can clarify acute versus chronic for each one of these.
Speaker: Yeah, this is, I mean, there are hundreds of etiologies for both of these, and it can be quite tricky.
Speaker: I think the things that we need to think through as intensivists are, you know, just as you say, defining, is this an acute process, or is this more of a subacute or even chronic process?
Speaker: So chronic, when we talk about chronic meningitis or chronic encephalitis, we're meaning more than four weeks.
Speaker: Versus acute, it's usually those more infectious etiologies.
Speaker: Most of our infectious etiologies are going to present with acute meningitis or acute encephalitis.
Speaker: So specifically when we think about meningitis...
Speaker: the most common etiologies are going to be viral.
Speaker: These are going to be the interoviruses, arboviruses.
Speaker: Oftentimes we don't even really figure out what it is.
Speaker: I think it's important to think about, you know, does the patient have risk factors for Lyme disease?
Speaker: Lyme usually causes more of a radiculitis, more, um, um, coating of the, the nerve roots as they leave sort of in the spinal canal, but it can cause a meningitis as well.
Speaker: Um, um,
Speaker: And other sort of travel risk factors, you know, for where they've been and mosquito bites that they got or other sort of arbovirus exposures.
Speaker: The vast majority of meningitis is the aseptic meningitis that we talk about where nothing grows in the culture is viral and the treatment is supportive, right?
Speaker: Bacterial meningitis.
Speaker: The two most common endiologies, and again, this is really rare in the immunocompetent patient, but the ones we really have to worry about are pneumococcal meningitis and meningococcal meningitis.
Speaker: Both of these can have very severe presentations.
Speaker: These are patients who often come in like very high fevers, obtunded.
Speaker: They look very, very sick.
Speaker: This is a very, very...
Speaker: critical disease with high mortality and morbidity.
Speaker: And time really is of the absence of those patients.
Speaker: So the acute ones are, I think, the ones that we have to, you know, act more quickly to tease out, is this an acute viral meningitis or is this acute bacterial meningitis?
Speaker: And while we don't, while we're doing that workup, I really think it's important that we just treat for the things that we can treat for, which is bacterial meningitis and HSV or with acyclovir.
Speaker: When we think about encephalitis, again, there is such a wide range of things that causes encephalitis.
Speaker: But from the sort of infectious standpoint, the most common acute cause of encephalitis is HSV encephalitis.
Speaker: And again, there's a treatment for that with acyclovir, which is why it's so important that as you're working patients up, you know, you have that treatment on board until you kind of can narrow it and say, you know, I feel confident this is not what's going on.
Speaker: Now,
Speaker: when we get into sort of that chronic or subacute period, we're really dealing with either autoimmune or granulomatous diseases, or we're dealing with sort of your atypical pathogens.
Speaker: And the people who are at risk for these atypical pathogens are often our immunocompromised patients.
Speaker: So the things that I think of when people have a smoldering course of meningitis or meningoencephalitis,
Speaker: are the fungal infections.
Speaker: So cryptococcus or any of the like coccidiumycosis, histoplasmosis, sister sarcosis.
Speaker: Um, clearly it's really important in those patients to take a good history.
Speaker: Cryptococcus is everywhere.
Speaker: All of these other sort of regional fungi are more specific to various geographic locations in the U S. Um, um,
Speaker: Cryptococcus, I think, is something that you should pop into your mind for any patient who's complaining of bad headaches who's immunocompromised, right?
Speaker: These patients can have wildly elevated CSF pressures, and they often depend on CSF diversion.
Speaker: Other things that can cause sort of this subacute onset of meningitis or meningoencephalitis, TB, the great mimicker of everything, often has an assiduous onset, can cause a really dramatic pachymeningitis with that inflammation of the dura and sort of skull base.
Speaker: And then finally, thinking of, you know, does the patient have risk factors for an iatrogenic CSF infection, like they have ventriculitis because they have an EVD, which can also kind of present in this sort of, you know, the patient's not looking well for a couple days.
Speaker: And you have to have a really heightened level of, like, we got to check that CSF to make sure the glucose isn't going down and there's nothing growing in the culture.
Speaker: Those patients, unfortunately...
Speaker: grow atypical pathogens a lot of the time.
Speaker: You know, most of the time, staph epidermis is not going to cause a run-of-the-mill de novo meningitis, but our patients with devices in their heads, they can have staph epi, they can have pseudomonas growing.
Speaker: I mean, these are really more hospital-acquired pathogens.
Speaker: So that's how I kind of break this down.
Speaker: You know, time is at the absence for those acute meningitis, meningoencephalitis patients, and
Speaker: You have to treat them as if they were bacterial until you know for sure that they're not.
Speaker: And then for the subacute, you're really thinking more of mycobacteria or fungal infections.
Speaker: And as you mentioned, obviously, and we'll talk about it as we move to evaluation diagnosis, also very important to consider the patient, the individual patient, what risk factors they have, and also temporal in some of these presentations.
Speaker: But I guess the thing we can't overemphasize is that for acute meningitis, we think of strep and meningococcus.
Speaker: And for acute encephalitis, we think of acyclovir.
Speaker: All those can be treated.
Speaker: They're time-sensitive.
Speaker: while we're trying to figure things out, we start therapy.
Speaker: Absolutely.
Speaker: I think that those are the key things to remember.
Speaker: If you can treat, you know, for pneumococcal, meningococcal, and then HSV, like, that's most of the pathogens that we really need to worry about.
Speaker: And trying to get medications on board for those as soon as you even suspect that this is maybe a meningitis or an encephalitis patient.
Speaker: So one more question regarding a chalogy that is a...
Speaker: seems to be a favorite in the boards is like listeria.
Speaker: Super rare, but when should we be thinking of listeria?
Speaker: Yeah, we think of this more in immunocompromised, or not necessarily immunocompromised hosts, but younger children, so babies, and then older individuals.
Speaker: So you should have empiric coverage for listeria in a patient who's older than 60.
Speaker: So, you know, that's not a very old patient.
Speaker: That's kind of, you know, middle-aged that you should think about treating with...
Speaker: ampicillin up front.
Speaker: It is a tricky diagnosis to make.
Speaker: Some of these patients can look really, really sick and other patients can have sort of a more smoldering course.
Speaker: It does grow in cultures.
Speaker: So hopefully you will get a positive diagnosis, but those are the young, the young, young babies and then are sort of middle-aged and older people and certainly immunocompromised patients.
Speaker: This is rare and it does kind of happen in spontaneous outbreaks.
Speaker: So it
Speaker: It is something that you have to kind of keep in the back of your mind.
Speaker: Excellent.
Speaker: Let's talk about evaluation and diagnosis.
Speaker: As you mentioned, a lot of the presentations might be very common in people coming to the ICU for other reasons, but there are certain maybe characteristics that should alert the clinician.
Speaker: So why don't we start, Casey, with a clinical presentation and some of the physical findings that would be of interest for you as a neurointensivist when you're trying to include this in your differential?
Speaker: Yeah.
Speaker: Yeah.
Speaker: Again, I am always thinking about what are my patients' risk factors for this?
Speaker: Is this a patient who's immunocompromised?
Speaker: Is this a patient who's had, you know, some trauma to their skull base recently?
Speaker: That really helps me to narrow in on this.
Speaker: The other things clinically that I'm looking for, meningitis.
Speaker: Okay, so the patient has inflammation of the meninges.
Speaker: That's really painful.
Speaker: These patients have horrible headaches, like really impressive.
Speaker: They just feel pain.
Speaker: like their head is going to explode.
Speaker: This is always on my differential, you know, with subarachnoid hemorrhage and pituitary apoplexy, worst headache of life.
Speaker: I'm always thinking, does this patient also have meningitis?
Speaker: Fever.
Speaker: Fever.
Speaker: photophobia.
Speaker: Most of the patients are very febrile.
Speaker: You know, they have temperatures in the, you know, 101, 102, 103, very high fevers.
Speaker: And then stiff neck.
Speaker: We think about this, you know, I feel like this is one of those, did you check for nucle rigidity and people are always sort of like, yeah, maybe.
Speaker: This is not just like, oh, the patient like can't move their neck like a little bit, like they're a little stiff.
Speaker: It's like,
Speaker: They are in horrific pain if you move their neck.
Speaker: And that's because all those nerves that run down the back of the neck are inflamed.
Speaker: It's that inflammation that's causing this like incredible pain with neck flexion.
Speaker: So I do check for nuchal rigidity.
Speaker: And when you see it, it's really quite dramatic.
Speaker: On the flip side, encephalitis is really actually inflammation of the brain itself.
Speaker: And so a key finding has to be that they have altered mental status.
Speaker: Because the brain is involved and inflamed, these patients very frequently present with seizures.
Speaker: So when I'm trying to decide if someone has encephalitis, I'm looking for a triad of altered mental status, fever, and quite frequently seizures.
Speaker: Not all the time.
Speaker: And there are obviously way more causes of altered mental status and fever than just encephalitis.
Speaker: I mean, many patients in the ICU have fever and they're altered.
Speaker: And they have, you know, they're critically ill.
Speaker: They have sepsis.
Speaker: They have, you know, other reasons to be encephalopathic.
Speaker: So encephalitis, again, much more rare.
Speaker: And you have to be clued into what would be my patient's specific risk factors for having encephalitis.
Speaker: Can you mention on the presentation of focal neurologic findings and meningitis or encephalitis?
Speaker: Is that something that occurs?
Speaker: It's a good question.
Speaker: So meningitis can certainly occur with no focal findings.
Speaker: I mean, the vast majority of patients who have viral meningitis, they just have a really bad headache and fever.
Speaker: So you do not have to have focal findings for meningitis.
Speaker: Encephalitis, again, your brain is inflamed.
Speaker: And so you might, depending on where that inflammation is, have easily detectable focal findings, right?
Speaker: Like if you have inflammation that involves the motor cortex, you may have weakness.
Speaker: Since HSV is sort of the most common cause of encephalitis,
Speaker: it really likes to affect the medial temporal lobes.
Speaker: The medial temporal lobes are very important for memory, for cognition.
Speaker: And so these patients may not have focal neurologic deficits.
Speaker: They may just be confused.
Speaker: And I think that's why we have to have such a heightened level of suspicion for particularly HSV encephalitis because they really may not show you like, oh, I have weakness in my arm or leg.
Speaker: The other thing to kind of keep in mind for both of these infections is that they can both lead to increased intracranial pressure.
Speaker: Whether you have meningitis or encephalitis, ICP crisis is a possibility.
Speaker: And so when evaluating these patients, I try to look for signs of increased ICP.
Speaker: That could include that the patient really can't look up very well.
Speaker: It could include that the patient is very sleepy.
Speaker: It could include, you know, hopefully not, but sometimes anti-sicoria, you know, as we start to see medialization of the uncas of the temporal lobe.
Speaker: So I'm always...
Speaker: Whenever I see these patients, I'm trying to assess, you know, is there elevated ICP and can I detect that on bedside?
Speaker: But one of the things that's hard about this is that the neurologic findings may be really nonspecific in a lot of cases or even absent in a patient with sort of just run-of-the-mill meningitis.
Speaker: You talked about suspicion of ICP, and I just have a tangential question.
Speaker: I haven't done a fundoscopic exam in a very long, long, long time.
Speaker: At one point, I was reading that some people were looking at the optic nerve with ultrasound.
Speaker: Is that something that is real?
Speaker: What are your thoughts on that, Casey?
Speaker: Yeah, I think that this is, you shouldn't hang your hat on optic nerve sheath diameter.
Speaker: There are certainly limitations on this.
Speaker: I do like to do an optic nerve sheath diameter assessment as a proxy for, as a non-invasive way to screen for elevated ICP.
Speaker: But you certainly shouldn't be like doing this for the first time on a patient with meningitis.
Speaker: Like,
Speaker: Do this if it's part of your clinical practice and you've screened a lot of patients and you know how to measure optic nerve sheet diameter.
Speaker: I think it's helpful in that situation.
Speaker: I really, really like pupilometry.
Speaker: Like if you are someone that has access to the pupilometer.
Speaker: at your institution.
Speaker: I think pupil omnipery is really helpful in these patients who, you know, they look really sick.
Speaker: They're very altered.
Speaker: They're sleepy.
Speaker: Having that sort of normalized pupillary index to tell you, hey, their pupils are becoming sluggish.
Speaker: That is also a very effective non-invasive way to screen for ICP issues.
Speaker: The fundoscopic exam, papilledema takes a while to develop.
Speaker: So your patients with acute
Speaker: very frequently don't have papilledema, that's more of a chronic finding in patients who've had chronically elevated ICP.
Speaker: So I think
Speaker: you know, looking at pupilometry, if you have it, using optic nerve sheet diameter, if that's part of your practice, and then really taking a good look at the head CT to look at, you know, are the basal cisterns obliterated?
Speaker: Are there, is there sort of like flattening of the sulci of the brain?
Speaker: Those would all point me to think that this patient's got high ICP and poor brain compliance.
Speaker: So again, it's really important
Speaker: looking at all the information that you can get from sort of non-invasive bedside maneuvers to your radiographic findings.
Speaker: Perfect.
Speaker: So we talked about the clinical presentation, some of the important physical findings.
Speaker: As you're working up these patients, Casey, let's start with some just basic labs before we really go for the gold, which is the LP.
Speaker: Yeah.
Speaker: Yeah.
Speaker: So everyone needs a basic CBC, basic metabolic panel.
Speaker: The CBC, you're really looking for evidence of high white count and inflammation.
Speaker: You also, if you really think that the patient has bacterial meningitis, screen for DIC.
Speaker: Meningococcal encephalitis really like, I mean, meningitis really does cause a DIC.
Speaker: And you want to know that before you're doing the lumbar puncture, right?
Speaker: Like patients in DIC, you're probably still going to do the lumbar puncture, but you're going to do it with more care and you might give them a little cryoprecipitate before you do it.
Speaker: So I get this, the CBC to know, you know, platelet count, are they safe to LP?
Speaker: And then basic metabolic panel, because often when patients are sick, they can develop hyponatremia from SIIDH.
Speaker: I feel like one of the things that students always tell me when they rotate in the neuro ICU is like,
Speaker: why does no one have a normal sodium here?
Speaker: And I really do feel like brain inflammation and sodium are just constantly connected.
Speaker: So those are the, you know, the two things I'm looking for, certainly thinking about DIC, if I have a patient who has, you know, just appears very sick, with very high fever, altermental status, you know, is this bacterial?
Speaker: And if so, are they in DIC?
Speaker: So that's
Speaker: Those are the things that I want before we even get to the lumbar puncture.
Speaker: Also, sending blood cultures, right?
Speaker: It may take a minute if you are not a shop that does a bunch of lumbar punctures to get set up to do the lumbar puncture.
Speaker: And anyone who's got altermental status.
Speaker: it is my practice to get a head CT first, right?
Speaker: If a patient walks in off the street and tells me in the ED, I've got the worst headache of my life, I've had this fever, I don't really feel good, but they're having a conversation with me about it.
Speaker: Like they tell me they have like the worst headache ever and they don't feel good, but they're conversing with me and it's probably viral meningitis.
Speaker: Maybe I'll forego a head CT, but I'll be very honest with you that like,
Speaker: I'm CT-ing 99% of people before I put a needle in their back.
Speaker: And that also probably relates to the types of patients that come to the ICU, right?
Speaker: Because the ones that are having a conversation probably are not the ones that come to the ICU immediately.
Speaker: But before we dive into the lumbar puncture, you did mention that anybody with altered mental status, you would do a CT before the LP.
Speaker: Are there any other factors that would also kind of push you in the CT before LP direction?
Speaker: Yeah, any immunocompromised person also getting a head CT before they get an LP.
Speaker: Really, I'm really almost always CT-ing people before I stick a needle in their back.
Speaker: It's like I have to have a really good reason not to.
Speaker: I don't want to be surprised.
Speaker: I just would like to know what their brain looks like before we go and take CSF.
Speaker: And what we're trying to avoid is masses or a reason for high ACP that could potentiate a complication with the LP.
Speaker: Yeah.
Speaker: Absolutely.
Speaker: Yeah.
Speaker: And I'm going to look really closely at the basal cisterns on that MRI.
Speaker: If there's crowding already at the basal cisterns, like where they're, you know, I don't see a good pre-pontine cistern, their uncas already seems a little medialized, then I'm going to, if I'm going to tap them, I'm going to take off like two cc's of CSF.
Speaker: I work at a place where we have an amazing neurosurgeon group.
Speaker: And I, if I see a really, really swollen brain, I may forego the LP altogether and in favor of an external ventricular drain.
Speaker: So putting, getting CSF from a drain from above.
Speaker: So again, I can't think of many reasons that I'm, I'm ever angry that I got a head CT and then, you know, get the blood cultures, get the head CT and then, you know,
Speaker: set yourself up to do a safe LP.
Speaker: Mm-hmm.
Speaker: Perfect.
Speaker: So let's talk a little bit more about the LP.
Speaker: I grew up with a heuristic that if you're thinking of an LP, you probably should do the LP.
Speaker: Yet over and over again, it seems that it's always complicated or people have excuses, quote unquote.
Speaker: And there's still some confusion around timing, how to do it.
Speaker: What are we looking for?
Speaker: Yet it's probably needed to make these diagnoses over and over again.
Speaker: So when should we do an LP?
Speaker: Yeah, this is a clinical gestalt.
Speaker: I do kind of like that.
Speaker: Like if you've thought about it, you probably should do it.
Speaker: I tend to also agree that, and again, I've done hundreds of LPs.
Speaker: So it just doesn't feel like it's that much of an undertaking.
Speaker: So if I like sort of, it crosses my mind, like it would be helpful for me to have an LP, but
Speaker: there's just not a lot of reasons.
Speaker: Like I, it's way easier for me to talk myself into doing an LP than it is for me to talk myself out of it.
Speaker: But I recognize like, that's kind of unique to a neuro intensivist.
Speaker: This is part of my like daily practice.
Speaker: And it's very, we have a head CT scanner on our floor.
Speaker: Like I just send the patient over to scan and reassure myself, like, this is not going to be that dangerous.
Speaker: It takes me, you know, 20 minutes to set up and do an LP.
Speaker: I've answered the question and I move along with my day.
Speaker: I realized that that is not the case in a non-neurointensive care situation.
Speaker: So I think, again, it comes back to who is your patient?
Speaker: Like, are they at particularly high risk for developing a CNS infection because they're immunocompromised or because they have some recent skull-based trauma?
Speaker: You know, then...
Speaker: Again, you really got to come up with a reason to not do an LP if that patient's febrile.
Speaker: Then you got to just, you know, and altered.
Speaker: Then I think you really are doing the patient a disservice if you talk yourself out of this.
Speaker: Now, if you've got a altered...
Speaker: high fever patient and you have a clear reason, like they have cholecystitis and like, you know, there's a bunch of reasons that they're very sick, then yeah, I don't think that they need an LP.
Speaker: Like you've got an answer.
Speaker: I tend to think about this as in the very sick, confused patient with a high fever who you don't really have a source.
Speaker: Then I think, then you got to think about it.
Speaker: And again, you know,
Speaker: If you do these frequently enough, like they don't, they don't often take that terribly long.
Speaker: If you are going to do this, and this is especially true in the emergency department where we're trying to rule this out, try and get enough CSF.
Speaker: Unless it's like one of those situations where you're really worried about precipitating herniation.
Speaker: And again, if this is an LP is not like part of your daily practice, then maybe that's the patient that you hold off on because you can make things worse.
Speaker: Um, but aside from that sort of rare situation, if you're doing a lumbar puncture, please get enough CSF that you answer the question.
Speaker: Nothing is worse than like, oh, we did the lumbar puncture and we took out, you know, three CCs of CSF, but we didn't have enough to run both the cell count and the culture.
Speaker: And we couldn't send the bio fire.
Speaker: And, you know, we didn't really fully answer the question, like get at least 10 CCs of CSF, um,
Speaker: Quite frequently when I'm doing LPs, I try to get 25 cc's so that I don't, you know, have to, I'm sure that I will never have to do this again.
Speaker: I'll have all the CSF I need.
Speaker: So I think that's a little like pearl.
Speaker: If you're going to go through the trouble of doing it, make sure you get enough.
Speaker: So before we dive into the important aspects or the things we should measure in the LP, I have two questions that I have.
Speaker: One is related, I guess, to evidence, and the other one's more of a practice, just thought, or opinion.
Speaker: So regarding evidence...
Speaker: delays obviously in initiating antibiotics are important and also getting the LP soon is important now ideally if you can if things go very well you can do the LP as as soon as possible and then start the antibiotics that's a perfect world but doesn't always happen what are your thoughts um Casey on we gave the antibiotics and some people say well now there's no point of doing the LP that is that true ah no that is not true
Speaker: One, because the BioFire exists now, and so this is that meningoencephalitis panel.
Speaker: It's a PCR panel.
Speaker: So even if you lys all the bacteria and you don't grow anything in the culture, BioFire's, like the BioFire assay, and there may be other, I don't have any, like, stock in BioFire.
Speaker: There may be other of these assays now, but they are PCR-based.
Speaker: And so you very...
Speaker: perfectly reliably but pretty reliably still get good data for the the pathogens that they include which are most of the common community acquired these are not so good for detecting uh staph epi or pseudomonal or things that are hospital acquired um cns infections but they're very good for community acquired csf infections so 100 you can still get the biofire and that's very helpful even if it's been a day since they've been on you know they've been on um
Speaker: CNS dosing of antibiotics for a full 24 hours, still very helpful for the bio fire.
Speaker: The other thing that's helpful is the glucose.
Speaker: The glucose is going to take a while to normalize in bacterial meningitis.
Speaker: So even if your cultures are negative, but your glucose is like 15 on the LP, that to me still says this patient had bacterial meningitis.
Speaker: Maybe it's a little frustrating that now the cultures are sterilized and we're not going to know what kind of bacterial meningitis it is if it's not picked up by the biofire.
Speaker: But that to me tells us, oh, we were on the right track.
Speaker: Like we thought this patient had a bacterial meningitis.
Speaker: The glucose suggests that it's either bacterial, fungal, or mycobacterial.
Speaker: You know, we at least are still, we have convinced ourselves that this truly was a meningitis.
Speaker: So ideally you always get the, you know, you start the antibiotics.
Speaker: You still have two to four hours before you sterilize your CSF.
Speaker: So again, it's not like you have to,
Speaker: You know, you have to get the LP before you start antibiotics.
Speaker: And once you start antibiotics, like that second it's over, you still have some time.
Speaker: But regardless, I mean, you can get a lot of information, especially now that we have PCR based detection of pathogens.
Speaker: Perfect.
Speaker: And just to, we'll get there.
Speaker: But the second question I have, I've often heard we didn't get the LP because we don't have consent.
Speaker: And that doesn't sound right where you've done all these other things emergently to this patient.
Speaker: Any thoughts on that?
Speaker: Yeah, I mean, this is an emergency.
Speaker: You do emergency consent.
Speaker: Like you're doing, you're acting in the best interest of the patient.
Speaker: We do central lines.
Speaker: We do A lines.
Speaker: We do intubations.
Speaker: We do CPR without consent.
Speaker: Like this should also be an emergency procedure where you're acting in the best interest of the patient.
Speaker: You know, I do two physician emergency consent frequently if we can't get in touch with the family member.
Speaker: Perfect.
Speaker: So clearly, an LP is going to be important if we're suspecting encephalitis or meningitis.
Speaker: We talked about the time-sensitive nature of this, and we'll get to treatment soon.
Speaker: But we also talked about when to get a CT scan before doing the LP.
Speaker: But in patients, like you said, who don't suspect a mass, are not immunosuppressed, or are not totally altered, you might go ahead and do the LP first.
Speaker: Now, you also emphasize, Casey, that be generous with the amount of CSF you get in most cases.
Speaker: Let's walk through the LP.
Speaker: What are the important aspects of what we should be checking?
Speaker: So opening pressure.
Speaker: Yeah.
Speaker: Opening pressure is crucial in these situations.
Speaker: I mean, it's actually always important.
Speaker: The thing to know about opening pressure is that to have a reliable opening pressure, A, the patient can't be on positive pressure ventilation, which, you know, sometimes they have to be intubated.
Speaker: And I, you know, that's more, protecting their airway is always more important than getting a, you know, pristinely measured opening pressure.
Speaker: But just be aware that, you know, positive pressure ventilation does tend to push your opening pressure higher than
Speaker: than the true ICP.
Speaker: The patient can't be balled up.
Speaker: So, you know, when we are doing lumbar punctures, we often have the knees like tucked in.
Speaker: So you're getting the patient into like as much of a little ball as they can kind of comfortably be in.
Speaker: Um, if those legs are up, that's, that's really causing higher abdominal pressure and all the compartments are related.
Speaker: So that pushes your ICP up.
Speaker: So if you really want a true ICP, you have to actually straighten the patient's legs enough that they're not compressing, um, the belly.
Speaker: It doesn't have to be like all the way straight, but they have to just relax the belly enough.
Speaker: Um,
Speaker: What I tend to do is I confirm that I'm in the right space.
Speaker: I get some CSF flow back.
Speaker: I put the stylet back in.
Speaker: I have the nurse kind of like help me sort of release their legs ever so slightly just so that we're releasing that abdominal pressure and then measure the opening pressure.
Speaker: When you're using the opening pressure, it's important to know that what you're measuring is in centimeters of water.
Speaker: Centimeters of water...
Speaker: And millimeters of mercury are not the same thing.
Speaker: So when you are measuring an opening pressure and you get an opening pressure of 20, you might be tempted to think, oh my gosh, that's very high ICP.
Speaker: This is, this is, the patient's in an ICP crisis.
Speaker: It's important to know that in an opening pressure of 20 centimeters of water, which is how you're measuring the lumbar puncture,
Speaker: is about 15 millimeters of mercury.
Speaker: All the guidelines for elevated ICP...
Speaker: talk about ICPs in millimeters of mercury.
Speaker: So just recognize that, you know, millimeters of mercury and centimeters of water are not the same.
Speaker: And what you're measuring when you measure an opening pressure for a lumbar puncture is in centimeters of water.
Speaker: So what I tell the resident is like, get your opening pressure and then I want you to convert it into millimeters of mercury.
Speaker: So you're telling me an ICP that I'm like used to, you know, to normalizing.
Speaker: People who have high, um,
Speaker: ICP on the lumbar puncture, it's going to like shoot up.
Speaker: It's usually really not, it's not subtle.
Speaker: Like it's like you stick the needle and you put the manometer on and it like shoots through the top.
Speaker: Like that's the person who has a high ICP.
Speaker: I also check a closing pressure.
Speaker: Once I remove CSF, I always check like what was the closing pressure.
Speaker: Mostly it just gives me sort of a sense of like how easy it was to lower the ICP.
Speaker: Um, so opening pressure, crucially important, measure it correctly.
Speaker: Perfect.
Speaker: Other questions.
Speaker: And what about cell count?
Speaker: Yes.
Speaker: So what I typically do is I send cell count from the first tube and from the fourth tube, um, that will allow us to see, you know, a lot of times we have traumatic taps.
Speaker: Um, and what you should see is that the red cell count, you know, is highest in tube one.
Speaker: By the time you get to tube four, you've kind of cleared those red blood cells and you have a, um, a more, um,
Speaker: a more accurate reflection of really what's actually going on in the CSF than just what's going on with some blood mixed in.
Speaker: So I measure cell counts on tube one and tube four.
Speaker: Again, I put at least, I don't know, like two or three cc's in tube one and tube four so they can measure those.
Speaker: Five cells or less is normal if you have no white blood cells.
Speaker: For every about 800 red blood cells, you can get, you buy yourself another one RBC.
Speaker: I'm sorry, one white blood cell.
Speaker: So again, 800 RBCs equals one white blood cell.
Speaker: So if you have, you know, I don't know, 2000 red blood cells and you have, you know, six or seven white blood cells, that's still going to be a normal LP.
Speaker: I'm not going to be terribly concerned about the fact that the white blood cell count was slightly higher.
Speaker: And in terms of differentiating bacterial versus other types, obviously the white count is going to be very important, but anything in the differential important for encephalitis or viral causes?
Speaker: Yeah.
Speaker: So bacterial has like thousands of white blood cells.
Speaker: It's like they're neutrophilic predominant.
Speaker: There's a lot, a lot, a lot of cells.
Speaker: The protein is going to be super elevated.
Speaker: The glucose is going to be super low.
Speaker: Yeah.
Speaker: Often it's like less than 20, less than 10.
Speaker: I mean, it's usually not a subtle decrease in the glucose you're seeing.
Speaker: Viral can have this like, oh, there's like 10 WBCs and they're like lymphocytic predominant and the protein is like 60 and the glucose is pretty normal.
Speaker: Like viral meningitis doesn't have an impressive cell count.
Speaker: Yeah.
Speaker: Fungal meningitis, very elevated protein, also low glucose.
Speaker: So it's sort of, it looks sort of like a bacterial meningitis.
Speaker: Autoimmune and sort of neoplastic causes and other sort of etiologies can have all sorts of weird things going on.
Speaker: Very frequently, they don't have a elevated white count, but they'll have an elevated protein.
Speaker: That gets into the whole separate weeds and probably needs like a neuro consult to help you think through what those LPs look like.
Speaker: What about, so we talked about, and the protein's going to be elevated because of the inflammation.
Speaker: We talked about the glucose, the cell count.
Speaker: What about lactate, Casey?
Speaker: You know, lactate at my institution takes so long to come back that I don't use it.
Speaker: So I can't personally comment on it, although I know that people do, and there has been good evidence the last time I looked into this, which was, I think,
Speaker: like two years ago, that is actually pretty reliable for detecting CSF infections that are bacterial and helpful in terms of differentiating ventriculitis from just like sterile inflammation.
Speaker: So I personally can't comment in great detail just because everywhere I've practiced, it's always been a send out lab and therefore not very helpful and we never used it.
Speaker: Okay.
Speaker: But the idea would be that it would be elevated if it was bacterial.
Speaker: Okay, perfect.
Speaker: So you did mention, obviously, we would send this also for gram stain and culture.
Speaker: And then you did mention the BioFire film array.
Speaker: And just reading here from the Acute Neurology Survival Guide.
Speaker: Mm-hmm.
Speaker: Just to remind our listeners, that would check for bacterial pathogens that include E. coli, hemophilus, influenza, listeria, Neisseria meningititis, strep agalacta, and strep pneumonia.
Speaker: And viral pathogens that include CMV.
Speaker: enterovirus, HSV-1, HSV-2, human herpesvirus 6, human pericuvirus, and varicolusastrovirus, plus it also will check for cryptococcus.
Speaker: So really super, super useful.
Speaker: You cover, I mean, a tremendous amount of pathogens that you'll be worried about with that biofirofilm array.
Speaker: And like you said, it's PCR technology.
Speaker: So even if they receive the antibiotics, this would still be very valuable.
Speaker: Absolutely.
Speaker: One caveat to know is the cryptococcal screen in the biofire is not very accurate.
Speaker: You should use your typical cryptococcal detection.
Speaker: Perfect.
Speaker: And it's also very interesting.
Speaker: I mean, like I guess I'm going to I'm going to age myself, but I started internship in Chicago and we had a whole floor dedicated to HIV and we would do like a boatload of LPs.
Speaker: And by the time I finished, ACT was in place.
Speaker: And two years later, that floor had disappeared.
Speaker: So I guess, I mean, we don't do them as many as we did before for HIV, but still something that we should be considering in the multiple host of immunosuppressed patients that we might see.
Speaker: So for the BioFire, everything else is super specific, right?
Speaker: If it's positive, you should believe it.
Speaker: Yes.
Speaker: Okay, perfect.
Speaker: What about, as we move forward, we talked about imaging in terms of when you get a CT scan to begin with, but there's also some literature about getting MRIs in some situations, and that might be less diagnostic but more prognostic, I guess.
Speaker: What is your use of other imaging as you work with these patients?
Speaker: Yeah.
Speaker: So I think the, the helpful thing with the MRI, um, is that it's going to tell you whether or not there's brain inflammation.
Speaker: You'll see, um, you know, inflammation on the LP.
Speaker: So if they have a high white count, you, you've satisfied that inflammation criteria, but it tells you kind of how much of the meninges inflamed and how globally is it a problem?
Speaker: So with and without gadolinium should always be ordered.
Speaker: So these patients need gadolinium, um, um,
Speaker: I think what I find most helpful about the MRI is that if the patient also has encephalitis, you are getting a regional picture of where the brain tissue is most inflamed.
Speaker: So do you have limbic encephalitis?
Speaker: Do you have cerebrolitis?
Speaker: Do you have a rhomboencephalitis?
Speaker: All of those key characteristics are very helpful in narrowing the differential of what might be causing that inflammation.
Speaker: that inflammation.
Speaker: And then the acute survival guide, what I, we kind of broke down, you know, pathogens that are most likely to cause sort of these regional encephalitis, encephalitis.
Speaker: Um, so that's, that's what I, I find very helpful about the MRI.
Speaker: Again, if your patient's too unstable to go down and get MRI, um, this is not usually like
Speaker: make or break the differential, but it is really kind of crucial in the encephalitic patient who you think has a regional encephalitis.
Speaker: Perfect.
Speaker: And can you make any comments, Casey, on other testing, EEG?
Speaker: I mean, is there a role for brain biopsy or anything else?
Speaker: Yeah.
Speaker: So EEG, very helpful if the patient's altered, especially if they have fluctuating altered consciousness.
Speaker: Our patients with encephalitis, more so than meningitis, get seizures and can have non-convulsive status.
Speaker: So I, you know, for the patient that's altered, I have a very low threshold for using EEG.
Speaker: Brain biopsy, rarely needed in meningitis unless it's a very atypical sort of chronic picture.
Speaker: Yeah.
Speaker: We try not to need biopsy for our patients who are encephalopathic or have suspected encephalitis.
Speaker: This really becomes helpful in the patients who have like lesions in their brain and we don't really know if it's infectious.
Speaker: Maybe they're not super febrile.
Speaker: They're just altered and we have this weird lesion in the brain.
Speaker: And then we're trying to figure out, you know, is this a cancer?
Speaker: Is this autoimmune?
Speaker: Is this a very unusual demyelinating picture?
Speaker: So brain biopsy, not super commonly done.
Speaker: It's really more for the patient who's not acutely sick, but has sort of a more subacute presentation for which the differential is like much wider in terms of what it could be.
Speaker: Perfect.
Speaker: Let's talk about treatment.
Speaker: And as we mentioned, I think throughout the conversation is a time sensitive issue.
Speaker: And especially when we're thinking of acute bacterial meningitis and acute encephalitis due to herpes at type one, the sooner we get therapy on board, the better the outcomes will be.
Speaker: So why don't you, you mentioned a little bit before, but based on the etiology and if you're seeing this patient and you're trying to figure out if they have a meningitis or encephalitis, where do you start and why?
Speaker: Yeah.
Speaker: So again, I think one of the first things I think about is whether or not I really believe the patient has
Speaker: a bacterial meningitis.
Speaker: If I do, I want to give steroids like as the antibiotics are going in.
Speaker: So the evidence for steroids is really in patients with pneumococcal meningitis and
Speaker: to prevent hearing loss, but it gets generalized to basically preventing inflammation as the bacteria breaks down.
Speaker: So again, if I'm pretty convinced, like, this patient's sick, they look terrible, they have had a high fever, I have no other reason to suspect that they have some other, you know, other reason for their encephalopathy, then I'm probably just going to go ahead and give a slug of tenodecadron as I'm starting antibiotics.
Speaker: The empiric antibiotics you want to use, you want to make sure that you're covering broadly for, you know, gram negatives with ceftriaxone, usually two grams Q8.
Speaker: And then vancomycin in this case is actually covering resistant strains of strep, but you want that on as well.
Speaker: In the patients who are older than 60, starting ampicillin for listeria is also very important.
Speaker: And then you want to get acyclovir on board to cover, you know, possible HSV.
Speaker: So those are the ones that I'm thinking of starting right from the beginning.
Speaker: And those are CNS dosing is higher dosing than your other typical pathogens.
Speaker: Again, you still have some time, even like to the order of hours, maybe two to four hours to get your lumbar puncture without sterilizing the CSF.
Speaker: So, you know, start early, get the blood cultures and then just get those antibiotics as soon as you can get them from the pharmacy.
Speaker: And I think that one of the important aspects of the time-sensitive nature is encephalitis because I have seen or reviewed cases where really there was a delay in starting a Cyclovir, and that could be attributed then to leading to worse outcomes.
Speaker: And like you said, I mean, with encephalitis, a lot of times if we don't have the seizures or it's just altermental status, it might be a little bit more difficult to figure out.
Speaker: So having a very low threshold, I guess, for the acyclovir is very important.
Speaker: Absolutely.
Speaker: Especially with the biofire.
Speaker: Like you can start it, you know, it's nephrotoxic.
Speaker: We don't want to keep it on forever.
Speaker: Start the acyclovir, give them a dose.
Speaker: You're going to get an HSV test and the biofire, both of which can confirm that you don't have HSV.
Speaker: Um, very, very rarely the HSV PCR can be negative early in the course.
Speaker: Um,
Speaker: But it's truly rare that I keep the acyclovir going unless, like, it is a slam dunk.
Speaker: The patient has been altered for two days.
Speaker: They came in with a seizure.
Speaker: Now they've got a fever.
Speaker: That's a really good story for HSV encephalitis.
Speaker: I might keep the acyclovir on and get a second LP two days later to confirm the HSV PCR was negative.
Speaker: But otherwise, the HSV PCR is pretty reliable.
Speaker: Yeah.
Speaker: Excellent.
Speaker: The other question I had, Casey, is in terms of de-escalation or obviously as you get more information, if you grow a pathogen, you would go specific.
Speaker: But what about the steroids?
Speaker: What do you do with the steroids?
Speaker: You said, I mean, if you suspect bacterial, you give them 10 milligrams of DEXA.
Speaker: And then what do you do?
Speaker: Yeah, so I think it's 48 hours of steroids.
Speaker: And I think they give it 10 and then 4 Q6s.
Speaker: for 48 hours and then you stop them.
Speaker: So really not a lot of a downside for the patient there.
Speaker: Is there any role for steroids in non bacterial meningitis?
Speaker: Like if it's encephalitis or something else?
Speaker: like this, certainly not like as hard and fast evidence.
Speaker: I think they can be helpful for patients who are on treatment.
Speaker: So for patients who like for a TB patient, TB meningitis, there's actually some, some data to support that once the patient started on ripe, you actually want to keep them on some steroids while they are getting that initial tuberculosis treatment.
Speaker: For the rest of the time, it's really about brain inflammation.
Speaker: I don't think we have as much evidence for using this, certainly not for viral causes.
Speaker: The vast majority of viral causes are going to be supportive care, and you don't want to tamper down the immune system without giving a drug to help the patient.
Speaker: So I usually limit steroids to bacterial or tuberculosis forms of meningitis.
Speaker: Okay, perfect.
Speaker: Any other ICU considerations that you might want to comment on in these acute meningitis and cephalitis patients?
Speaker: So a lot of them come to us because they're altered and they might be very, very sick.
Speaker: But any other thoughts?
Speaker: Yes.
Speaker: One of the main things that I think everyone should be aware of is the way that patients with bacterial meningitis die is often of acute communicating hydrocephalus.
Speaker: They get all this bacteria in the meninges.
Speaker: They cannot reabsorb their CSF.
Speaker: They develop this sort of global edema and they herniate and die.
Speaker: I am very, very, very aggressive about getting CSF diversion.
Speaker: I'm super lucky in the fact that I work with neurosurgeons who are willing to place an EVD for patients with meningitis.
Speaker: But I think that that's something I've advocated for more strongly since sort of being an intensivist and that I don't think I really appreciate it just as a neurology resident.
Speaker: CSF diversion can be life-saving for these patients.
Speaker: So if you have a patient who's really...
Speaker: altered, very, very sick, has evidence of global cerebral edema on their head CT, I would, you know, escalate quickly if you don't have neurosurgery where you're practicing.
Speaker: I think those are patients that it makes sense to transfer to your nearest neuro ICU hub.
Speaker: Because I think this is one of those things that they don't necessarily need a long time of CSF diversion.
Speaker: Three to five days, just while the antibiotics have a chance to work, can truly be life-saving for these patients.
Speaker: So again, I really think often and I think early about trying to get CSF diversion.
Speaker: That's an excellent point.
Speaker: And I think that also leads to the question, when would you repeat imaging or LP in a patient that you're treating for presumed or for confirmed meningitis or encephalitis?
Speaker: Um, so I think most of the time you don't really need a repeat LP.
Speaker: Um, if, if the patient, I think a lot of this goes clinically.
Speaker: How's the patient doing clinically?
Speaker: If the patient still looks terrible, uh, then repeating imaging, like the next day makes sense to me.
Speaker: Like we, we very frequently repeat head CTs like every day.
Speaker: Um, that patient also probably is the patient that really needs CSF diversion.
Speaker: And so hopefully they're in sort of a, a center that is, as norm is used to caring for these very complicated CNS infections.
Speaker: Um, repeat LPs though, you know, it depends a little bit on what, what the pathology is.
Speaker: Like we talked about those cryptococcal patients, like they have very high ICPs and they need to be temporized with an LP like every three days, maybe every two days.
Speaker: Um, you're right.
Speaker: There was a whole generation that was trained in LPs by that, that subset of patients.
Speaker: Um, and fortunately we don't see those patients as much anymore.
Speaker: Um, so again, a little bit is driven by what the pathogen is, what they're, what they look like.
Speaker: Um, the altered patient, I don't think a head CT hurts to understand, like, are they, are they developing more cerebral edema?
Speaker: Are they progressing to transitorial herniation?
Speaker: Otherwise, you know, mostly I'm just going by sort of what they look like at the bedside.
Speaker: Perfect.
Speaker: And then kind of like the last questions in terms of management, any considerations that you think intensively should be aware of on patients that are on their way out in terms of maybe follow-up?
Speaker: I think we're very focused on the ICU.
Speaker: The patient leaves the ICU and we all like high-five each other, but the patient might have a lot of other issues ongoing.
Speaker: Any suggestions of things that we should be aware of or maybe sharing with our patients and their families in terms of needed follow-up and potential complications?
Speaker: Yeah, this is a, for bacterial meningitis, this is a very long recovery process.
Speaker: I mean, the patient will be altered for encephalitis.
Speaker: That patient had brain parenchymal damage done, and they're going to be altered for a really long time.
Speaker: Some of these patients leave the ICU, but they need longer time in LTAC to kind of have a mental status that their airway is protected and they can be safely transitioned off a ventilator.
Speaker: And, you know, I think many of these patients have a have an uncertain sort of what their final recovery is going to be.
Speaker: So just being sensitive to the fact that, you know, families are still even if they're out of the critical care phase, you know, that does not mean that they have recovered to baseline and that recovery to baseline could take a really long time.
Speaker: So I guess one last question that I forgot to ask you, and we did mention encephalitis can be associated with seizures.
Speaker: Obviously, if you identify seizures, you would do an EEG and you would treat that appropriately.
Speaker: But is there any role for prophylactic seizures, Casey?
Speaker: Seizures treatment, sorry.
Speaker: We don't, I mean, we don't have enough evidence to really say, but right now there's no guideline association or like no guideline recommendation for prophylactic in these patients.
Speaker: Again, go by what the patient looks like.
Speaker: If they're altered, get an EEG.
Speaker: If you find seizures, treat the seizures.
Speaker: I don't empirically start them on anti-seizure treatment.
Speaker: Excellent.
Speaker: So I gather the message really is to have a high level of suspicion and a low threshold to start treatment as we figure out what's going on.
Speaker: And the good news is that the things that we can treat
Speaker: and are time sensitive is not a long list.
Speaker: So appropriate empiric antibiotic regimen plus a cyclovir when we suspect encephalitis while we figure things out could probably give the patient the best chance for having a good outcome.
Speaker: As we close the episode, we tend to ask our guests a couple of questions unrelated to the clinical topic.
Speaker: Would that be okay, Casey?
Speaker: Absolutely.
Speaker: So the first question relates to books.
Speaker: And are there any books that have influenced you significantly or books that you have gifted other people?
Speaker: Can I say my own?
Speaker: Of course.
Speaker: And we'll link that in the podcast.
Speaker: Yes.
Speaker: Yeah.
Speaker: Yeah.
Speaker: No, I, I, this, um, so I, I wrote and edited, I mostly wrote, and then some people contributed other chapters.
Speaker: And so then I became an editor with, um, Sahar Zafar, uh, the acute neurology survival guide.
Speaker: Um, I started the project when I was a resident and then kind of completed it as a fellow.
Speaker: And I truly believe it was like written for like,
Speaker: what do you know if you're just sort of not an expert neurointensivist?
Speaker: And so I've spent an embarrassingly long amount of time in my life working on this book.
Speaker: But I'm really proud of how it turned out.
Speaker: And I think it's a very helpful bedside guide.
Speaker: And it's like really, really, really practical.
Speaker: So it's definitely the book I've gifted most to others because I give it to all the neurology residents.
Speaker: And, you know, we I think it's I think it's really helpful.
Speaker: Yeah, absolutely.
Speaker: And I I have it and I can testify that it's very practical.
Speaker: And I can imagine that people who are dealing with acute neuro patients in the ICU and outside the ICU will find it as a very, very useful resource.
Speaker: Perfect.
Speaker: The second question relates to something you believe to be true in medicine or in life that most other people don't believe or at least don't act like they believe.
Speaker: So I struggle thinking about this.
Speaker: And I think one of the things that I think that people in medicine don't do the best job at is getting enough sleep.
Speaker: I'm actually a very, very big believer in eight hours of sleep.
Speaker: like religiously so.
Speaker: Obviously, as a neurointensivist, I take call, and so sometimes that's not feasible.
Speaker: But I am like rigorously devoted to getting a good night's sleep, and I do think that it makes you more productive and a nicer person.
Speaker: And like I feel that I was so sleep-deprived during training and obviously on the nights that I'm on call that I really do believe that we can feel better if we get a good night's sleep.
Speaker: That is music to my ears.
Speaker: I'm a big believer in sleep as well.
Speaker: And it's very interesting that this is something that I learned later in life and appreciate it.
Speaker: There's a book by Matt Walker, Why We Sleep, that really blew my mind in terms of all the research that associates health issues related to chronic lack of sleep.
Speaker: But most important, I think, Casey, when we're in the ICU, whether it be the neuro ICU or surgical ICU or medical ICU,
Speaker: I see intensivists as high-performing professionals.
Speaker: And every other high-performing professional, whether it be an athlete or other areas, they take their sleep very, very seriously and make it intentional and deliberate to have proper sleep.
Speaker: Yet as clinicians, we have ignored this for a long, long time.
Speaker: And I think it can not only have consequences on our own health, but had an impact on our patients.
Speaker: Absolutely.
Speaker: Co-signed.
Speaker: I believe this too.
Speaker: Excellent.
Speaker: So the last question is, what would you want every intensivist to know?
Speaker: It could be a quote, a fact, or just a thought as we close.
Speaker: Yeah, I think especially for our neuro patients, spending time at the bedside, really doing a thoughtful neurologic exam, checking pupils, pinching their extremities to see how they move.
Speaker: We get a lot of information at the bedside.
Speaker: And it's one of the things that I emphasize to our fellows is like, let's go see the patient.
Speaker: Let's go back to the bedside.
Speaker: You know, it was emphasized to me when I was a trainee and I was sort of like, but like, don't you understand?
Speaker: I also have to go like,
Speaker: look at the EMR and I look, I need to look at the MRI and I need to look at the cell count and I have discharge paperwork to do.
Speaker: And I, I could spend all day sitting behind a computer, but the most important information is almost always at the bedside.
Speaker: I agree, and I think it's something that we tend to do almost like by default and not without a lot of thought and intention.
Speaker: Yet, like you said, there's a lot of findings, especially in the neuro exam, that can be telling to a change in the course of our patient and could actually have an impact on how we treat them.
Speaker: So 100%, I think that's a great place to stop.
Speaker: Casey, thank you so much for sharing your time and expertise with us.
Speaker: I hope to have you back on the podcast to discuss other neurocritical care topics.
Speaker: Thanks for all you do to promote free open access education in medicine.
Speaker: And one last thing is where can people find you on social media?
Speaker: Yes, I'm on Twitter.
Speaker: The name is Casey Albin.
Speaker: It's pretty easy to find.
Speaker: I post still frequently, even in Twitter's demise.
Speaker: So especially posting on behalf of the Continuum Journal, which for those of you who are not in neurology, is this incredible just...
Speaker: Beautiful teaching CME journal that the American Academy of Neurology produces.
Speaker: And so I've done a lot of work with them recently and publicizing some of the cases from those articles.
Speaker: Really great teaching cases.
Speaker: They come with a lot of linked studies and studies.
Speaker: I would highly suggest people check it out.
Speaker: And Sergio, thank you so much for having me.
Speaker: This has been just a delight to talk about a rare but just critically important topic that all ICU providers need to have some level of awareness of.
Speaker: So thank you for having me.
Speaker: Thank you.
Speaker: Take care.
Speaker: Thank you for listening to Critical Matters, a sound podcast.
Speaker: Make sure to subscribe to Critical Matters on Apple or Google Podcasts and share with your network.
Speaker: Sound's transforming the way critical care is provided in hospitals across the country.
Speaker: To learn more, visit www.soundphysicians.com.
