[SPEAKER_05]: I've said this multiple times, and I can't believe I've said this multiple times, being a proceduralist, but you know, you just can't shake the internist at heart. [SPEAKER_05]: And this is where your pre-test probability for these things is so critical. [SPEAKER_03]: That's Chris Cap, an intervental pulmonal to set in Northwestern. [SPEAKER_03]: Welcome to the core AM Thy Perl's podcast from the U. High Yields Evidence-Based Perl's. [SPEAKER_03]: I'm Dr. Cherich, you're ready?
[SPEAKER_02]: And I'm Dr. Kuala Pice, an internal medicine resident of Beth Israel, the Economist Medical Center. [SPEAKER_02]: Today, we're talking about the interpretation of coral fluid studies. [SPEAKER_03]: And we'll also touch on some common coral diseases like paratomatic effusions as well as more new coral effusions. [SPEAKER_03]: All right, so let's dive in with the pearls we're going to cover today. [SPEAKER_03]: Remember, the more your chester's help, the deeper your learning gains.
[SPEAKER_02]: For all one, tiphorus and teases, or to not. [SPEAKER_02]: Once you think about thoracetesis. [SPEAKER_02]: For all two, a deep dive into the little light's criteria and pseudo accidents. [SPEAKER_03]: What I said things to think about when using light's criteria and what are some other diagnostic tests we can use to augment? [SPEAKER_02]: pro-three, analyzing pearl food studies. [SPEAKER_03]: What are some common pitfalls with the plural pH as well as a cell differential?
[SPEAKER_02]: Pro-four, the spectrum of paranamonic effusions, how do we identify and treat paranamonic effusions? [SPEAKER_03]: Pro-five, low-ignant plural effusions, how do we diagnose and manage molecular plural fusions? [SPEAKER_03]: Okay, Kaila, let's do a quick refresher on plural Ephesians before we get into all the nuances with plural studies. [SPEAKER_03]: So first onto imaging purals and then when to pull the trigger on thoracid thesis.
[SPEAKER_02]: So first things first, plural Ephesians are when there's a buildup of fluid in the plural space. [SPEAKER_02]: That is the space between the parietal and bistro-plora. [SPEAKER_03]: And fun fact, it's actually normal to have a little bit of fluid in the plural space, like pretty minimal, thirty to fifty cc's. [SPEAKER_02]: And the reason why it's there is because that little bit of fluid helps as a lubricant, which allows the lungs to move freely.
[SPEAKER_02]: And on an AP portable chest x-ray, we can see a meniscus forming or some blunting of the cost-of-renic angle at around two hundred ccs of the fluid. [SPEAKER_02]: You can see that plural diffusion at even lower volumes, around fifty ccs. [SPEAKER_03]: So X-rays are great and appreciate those nuances, but I always feel like pocuses is better.
[SPEAKER_03]: It's more sensitive, it's put a fluid, it's easy to do repeatedly at the bedside, you can fall at a fusion over time, and Dr. Christina Montemiro, a plumbing critical care doctor at John Hopkins, and with the co-founders of the podcast Palm Peeps, remind you to us how pocus can be used to actually feature other fusion itself. [SPEAKER_01]: As a resident, I have called for a thoracentesis because it looked like there was complete white-out of right-long.
[SPEAKER_01]: And then I went with the IT fellow and we actually ultrasound it and it's like, oh, like, this is not fluid. [SPEAKER_01]: This is actually, you know, cancer. [SPEAKER_01]: And it's solid component and there's no fluid around it. [SPEAKER_01]: But I wouldn't have known that if I went and did an ultrasound or a bedside. [SPEAKER_01]: Ah, great story.
[SPEAKER_02]: And maybe the most important thing with imaging with our patients is that we can actually show our patients their images and those images can be really powerful. [SPEAKER_01]: A lot of people when you're talking about like you have an effusion, they're like, what is that? [SPEAKER_01]: Is it in the long itself? [SPEAKER_01]: Is it outside of the long?
[SPEAKER_01]: So I actually like to show them like their actual image, whether it's chest X ray or if they got the CT or even just showing them on our bedside ultrasound. [SPEAKER_01]: This fluid here, like, shouldn't be here and you may be having your symptoms because of this. [SPEAKER_01]: So, like, here is a procedure that we can do.
[SPEAKER_01]: So, I try to, like, at least let them visualize, you know, what is abnormal and the amount of fluid that we potentially could take off and how that could help them from a therapeutic standpoint as also from a diagnostic standpoint. [SPEAKER_01]: Patients sometimes are like, well, like, that much fluid was in me, like, I can't believe that or they're just surprised to see, like, what color is it?
[SPEAKER_03]: I think this is the biggest thing I've changed in my practice is showing patients their actual radiology findings. [SPEAKER_03]: Day and night in terms of their understanding, the kinds of questions I get back, the misconceptions I can clarify.
[SPEAKER_02]: So, once we know that we have a plural of fusion, something that we need to think about is if we should drain it or sample it with a thoracentesis, that way we can ensure that we're ruling out any of those chemist diagnoses like infection or malignancy. [SPEAKER_05]: So, I think by and large in a new, unilateral plural of fusion, [SPEAKER_05]: Everybody that can safely get a thoracentesis should probably get a thoracentesis.
[SPEAKER_02]: We also sat down with Dr. Dave Farrow, one of the pulmonary and critical care doctors at Beth Israel, Deaconess Medical Center, and the other co-founder of Poem Peeps. [SPEAKER_02]: These are his thoughts on thoracentesis. [SPEAKER_04]: And then in that same vein, if I am having bilateral fusions, and I am trying to treat it, and I'm really not making any progress, and it starts to make me question my underlying diagnosis that I might try to get a little bit more information.
[SPEAKER_04]: Or if there are some red flag features, like the patient seems to really clinically have a bad pneumonia. [SPEAKER_04]: And so even though there are two fusions there, one of them could be a paranamanic, they might not be the same process. [SPEAKER_04]: someone has known underlying the lignancy and they could certainly have metastasis to multiple parts of their body. [SPEAKER_04]: Then I'm going to go ahead and tap the larger one.
[SPEAKER_04]: The bigger one to try to get some diagnostic information. [SPEAKER_03]: So the takeaway for when she with our synthesis, we can ask ourselves, one is it a you know lateral effusion. [SPEAKER_03]: to is it a bilateral fusion that's not getting better with your interventions? [SPEAKER_03]: Or three are there any red flag signs I significant disney of fever, weight loss, mobsis, where you would really want to work out that plural fusion work?
[SPEAKER_02]: And something that really stuck with me after speaking with our discussant is that it is super important to not anchor. [SPEAKER_05]: I always have to tell myself is to not anchor up to thirty percent of plural effusions do have more than one ideology. [SPEAKER_05]: So if you get your fluid studies back and it's transitative, that doesn't necessarily mean there's not something else going on. [SPEAKER_03]: I love that. [SPEAKER_03]: The good old two things can be true.
[SPEAKER_03]: Lesson breathes it's head again. [SPEAKER_03]: And just like say it explicitly with some examples, right? [SPEAKER_03]: A patient can have a malignant plural effusion. [SPEAKER_03]: And also heart failure contributing, or for example, a patient can have a parent-emonic effusion, but also has severe hypoopopinemia, say that Aliens less than a one point five milligrams per desoliter, and that can also be contributing to the fluid build. [SPEAKER_02]: Okay, so let's recap.
[SPEAKER_02]: ofusions are pathologic states in which there's a buildup of excess fluid in the plural space. [SPEAKER_02]: One to tap in a fusion is dependent on the individual patient, but you should consider if this plural of fusion is new and it hasn't been evaluated before. [SPEAKER_02]: If it's bilateral or unilateral and if there are any red flag signs like fevers, purtic pain, pneumonia's, or a lack of improvement after you've given what you think is appropriate therapy.
[SPEAKER_03]: And finally, don't anchor studies show that up to thirty percent of plural effusions can have more than one ideology. [SPEAKER_03]: And actually, I bet that number is just rising with our patients getting more and more complicated. [SPEAKER_02]: Okay, so say you get that door on a patient. [SPEAKER_02]: Now it's time to interpret the studies. [SPEAKER_02]: Keeping in mind that all of this is done in the context of the patient in front of us.
[SPEAKER_03]: Yeah, and typically I'd use the lights criteria, but recently I have actually been seeing people use a plural fluid only rule, which actually includes plural cholesterol. [SPEAKER_03]: So I think it'd be helpful to go over the pros and limitations of each. [SPEAKER_02]: Yeah, let's start with the lights criteria. [SPEAKER_02]: I just want to say that every time I hear the story, I am truly blown away.
[SPEAKER_02]: It turns out that Richard Light was a resident when he submitted his prelimin findings, and he submitted it to the American thoracic society in nineteen seventy-one, and they actually rejected him. [SPEAKER_02]: And then he believed in his work, so he submitted it again, his manuscript to the annals of internal medicine. [SPEAKER_02]: In this time, it was accepted, and now it's a landmark study.
[SPEAKER_03]: Man, imagine that if that is not a motivator to believe in your work and your passion, I don't know what it is. [SPEAKER_03]: So just to say it, the light's criteria is if you be any of the following, it's an ex-due fluid. [SPEAKER_03]: So one, if the plural fluid to zero on protein ratio is greater than point five, if the plural fluid to zero on LDH ratio is greater than point six, or if the plural fluid LDH is greater than two, third is the upper limit of normal for the last.
[SPEAKER_03]: I don't know, I feel like I've tried so hard trying to remember this and try to like squint at the point five, the point six and try to make some connections, but close, do you have a better way to remember these numbers? [SPEAKER_02]: Yeah, I think it's hard for me too, but what I do is that if the plural protein and the LDH is more than half of the serum protein and LDH, then I kind of assume that it's exudative.
[SPEAKER_02]: But I do think a better way is probably understanding the pathophysiology. [SPEAKER_04]: And in transidates, when that fluid is relatively simple, we're really thinking about the hydrostatic and oncotic pressure and is there some reason that more fluid is just going across? [SPEAKER_04]: loss.
[SPEAKER_04]: And so those are things like heart failure or fluid or load from renal failure, low albumin states where you have low on cardiac pressure and just sort of simple fluid builds up in that space. [SPEAKER_04]: And then we think the exidate of side of more complex fluid, this is really when something's happened to that barrier and it's not functioning normally.
[SPEAKER_04]: So some sort of injury or inflammatory process, some pathologic state that's leading [SPEAKER_04]: more cells, more protein, more sort of complex material to go into that plural space. [SPEAKER_04]: And in either case, the build-up of fluid in that space can impact the lungs that are right there adjacent to the plara. [SPEAKER_04]: And that's why we care about them so much. [SPEAKER_03]: That's awesome.
[SPEAKER_03]: That really helps imagine why then the protein plural to serum ratio greater than .five and why the LDH plural to serum ratio greater than .six makes sense for ex-dative and not for transitive because you have all these proteins and LDH leaking into the plural space. [SPEAKER_04]: Light's criteria is wonderful. [SPEAKER_04]: It works really well. [SPEAKER_04]: I think the thing that is best at is identifying that you to translate.
[SPEAKER_04]: So if you don't mean any of those criteria, I feel really, really comfortable that this is a simple translated refusion. [SPEAKER_02]: So when lights criteria called something transitative, we can feel very confident in that. [SPEAKER_02]: But it does back the question, are we sure in the same way about the exitative effusions?
[SPEAKER_04]: It does have some flaws of maybe, I hate to say I over call it exidates, but that is the criticism of it is that sometimes it can over call exidates. [SPEAKER_04]: The reason that it might have some propensity to do this [SPEAKER_04]: is that you're actually using LDH twice, right? [SPEAKER_04]: And so you are using this ratio and you're using the higher limit of normal. [SPEAKER_04]: And that can skew things quite a bit. [SPEAKER_02]: Yeah, that's a good thing to consider.
[SPEAKER_02]: And then another critique of the lights criteria is about pseudo-oxidates. [SPEAKER_02]: These are a fusions that are classified as oxidative effusions based on the lights criteria, but actually their underlying ideology is transidative. [SPEAKER_03]: And this is pretty common.
[SPEAKER_03]: I was surprised to learn that twenty to thirty percent of so-called exitative fusions are actually associated with things like heart failure or liver failure, which is classically actually transidated. [SPEAKER_04]: The other thing is that we know that people who have a lot of effusions are often overloaded. [SPEAKER_04]: And if you're on chronic diuretic therapy, you can, for lack of a better word, concentrate your plural space. [SPEAKER_04]: So fluid is going in.
[SPEAKER_04]: It has certain components. [SPEAKER_04]: You're slamming them with diuretics to get them to urinate more and some of that fluid will get drained by the lymphatics and vacuum circulation. [SPEAKER_04]: And you sort of concentrate the fluid that's left in the plural space. [SPEAKER_04]: And so in those cases, we sometimes call that like a pseudo-oxidative effusion.
[SPEAKER_02]: So I'd say the takeaway is that dioretics can concentrate plural fluid and increase plural protein and LDH levels. [SPEAKER_02]: This is humbling because if our patient who has heart failure or a hepatic hydrothorics is being diorized and we get a thora, we might go down this rabbit hole of trying to work up an exudative effusion that is actually just the pseudo-oxidate.
[SPEAKER_03]: And so the good thing and the good news is that there's actually three other things we can look at to help be a tiebreaker and actually help us kind of see, ha, that's a pseudo-acidate and non-actual-acidate. [SPEAKER_03]: So the first of the three is you're going to peek over at the difference between the albumin in the serum and that of the pearl with it. [SPEAKER_02]: Yeah, so similar to the sag calculation in cirosis, this is more formally known as the serum plural.
[SPEAKER_02]: I'll be in gradient or a spec. [SPEAKER_03]: And the second thing we look at is the difference between the protein in the serum and the plural aka the serum plural protein gradient or the spig. [SPEAKER_02]: But this does make sense because if you look at the path of physiology and a translated of fusion, it's the hydrostatic and oncotic pressures that are driving the fluid into the chloral space.
[SPEAKER_02]: So you would expect that those larger molecules like alibiumin and protein are too big and so they would stay in the serum and not move into the plora. [SPEAKER_02]: So there would be a larger difference in the serum, plural protein or alibiumin gradient. [SPEAKER_03]: Yes, and then put to butt numbers on it and [SPEAKER_03]: Help make sense why these numbers make sense, right?
[SPEAKER_03]: If the difference between the protein levels in the serum and the plural food is greater than three point one grass for deceler, that's going to point to transitative. [SPEAKER_03]: And again, if the difference between the serum plural aldeeman gradient is greater than one point two grass for deceler, then that's going to also point to transitative.
[SPEAKER_03]: Again, those big molecules are staying in the serum and not going to the plural, so you're going to see a bigger difference. [SPEAKER_02]: And then the third and last thing that can help us objectively differentiate a pseudo-exitate is the plural probian p. If it's greater than fifteen hundred, then it is most likely due to heart failure. [SPEAKER_02]: And the idea is that if there's so much bmp in the blood, it'll likely leak into the plural space.
[SPEAKER_02]: Nice. [SPEAKER_03]: All right, I think we covered a lot of good ground with light criteria and kind of some of the nuances to unpack there. [SPEAKER_03]: Let's move on to the plural fluid only role. [SPEAKER_03]: An effusion is an exidate if the plural proteins greater than three grass register liter at the plural cholesterol career than forty five milligrams register liter or the LTE just greater than point four or five times the upper limit of normal.
[SPEAKER_02]: And this is great because it only uses portal study. [SPEAKER_02]: So you don't need that serum level comparison. [SPEAKER_02]: It also doesn't duplicate the LDH, like the lights criteria does. [SPEAKER_02]: But let's think about why we're using the portal cholesterol. [SPEAKER_02]: Why would it be higher in exudative effusions?
[SPEAKER_05]: There have been some pretty good data to suggest that a cholesterol level above forty is consistent with exudate and below twenty five is very consistent with transitate. [SPEAKER_05]: I do send it a lot of the time. [SPEAKER_05]: You know, I think it can be useful in those situations where you're borderline, you know, maybe one of light's criteria is positive.
[SPEAKER_05]: So I think having that tests and it, you know, if it's really high, then it can really point to you that, yeah, there's some inflammation going on just because the pathophysiology utilizing the cholesterol is thought to be related to generating cells and vascular leakage from increased permeability. [SPEAKER_05]: And that is more consistent with kind of an exidate of the fusion. [SPEAKER_02]: So there are two schools of thought.
[SPEAKER_02]: One is that inflammatory pleural cells are releasing cholesterol when they degenerate. [SPEAKER_02]: And the second thought is that because that pleural cholesterol is derived from the plasma and the pleural capillaries are more permeable in these exudative states, that the plasma cholesterol is actually able to enter into the pleural cavity. [SPEAKER_03]: That's awesome, right?
[SPEAKER_03]: So I feel like if we get a pleural cholesterol over forty-five, then we can be pretty confident sexidative. [SPEAKER_03]: Should we just be using the pleural fluid only criteria and then retire the light's criteria? [SPEAKER_05]: You know, and I think the reason that light's criteria has stood the test of time for so long is, is it just works? [SPEAKER_05]: And so, you know, there's no reason to kind of debunk something that isn't necessarily broken.
[SPEAKER_05]: You know, if it's not broke, why would we try to fix it? [SPEAKER_05]: You know, I think these other evaluations are great because we always want to improve upon ourselves. [SPEAKER_05]: So I think the cholesterol was additive. [SPEAKER_05]: And I think the album ingredient can be additive in the right patient. [SPEAKER_05]: But I think that the reason the light's criteria stood the test of time is just because of that reason, you know, it just works.
[SPEAKER_02]: I mean, ultimately, the pulmonologist say that we should still use the light's criteria. [SPEAKER_02]: And this is because the light's criteria gives us a higher sensitivity, so it's able to catch a lot of those really scary, oxidative effusions that we don't want to miss. [SPEAKER_03]: So what do we summarize this pro so far? [SPEAKER_03]: When we're classifying an effusion as transitive or exitative, we got to think about the physiology here.
[SPEAKER_03]: With transitive effusions, it's really increased hydrostatic and low on contact pressure that's at play. [SPEAKER_03]: And then with ex-dative effusions, there's injury and inflammation causing leaky capillaries, and then we have these big molecules like protein, albumin, LTH, cholesterol, bleakings, and the overall space. [SPEAKER_03]: And that really helped for me understand why the lights criteria ratios are a certain way to capture that.
[SPEAKER_02]: And light criteria is helpful. [SPEAKER_02]: And we do have to keep in mind that it uses LDH twice, so it can over call exudates. [SPEAKER_03]: And assume to exudate is basically when you use light criteria and it calls in an exudate, but actually in reality, it's a transitive diffusion. [SPEAKER_03]: And there's three tools that can help us better clarify the fusion. [SPEAKER_03]: It's going to be the difference between the CRM and the plural albumin.
[SPEAKER_03]: the difference between the serum and floral protein. [SPEAKER_03]: If it's high, if those differences are high, then it's a transitate. [SPEAKER_03]: And also, if you're concerned about a cardiac ideology, get a NT-proBNP if it's higher than fifteen-hundred, then that also points out transitate of state. [SPEAKER_02]: And lastly, floral fluid cholesterol levels will be elevated in oxidative effusions due to solid regeneration and capillary permeability.
[SPEAKER_03]: So we talked about plural fluid, LDH, protein, cholesterol, pro-NTBNP, all helpful things, but there are also a bunch of other tests we often get with our plural studies, particularly the plural pH and the cell differential. [SPEAKER_02]: Yeah, I'm really excited for us to talk a little bit more about all of these. [SPEAKER_03]: So let's start with the plural pH. [SPEAKER_03]: And just remind everyone a normal plural page is about seven point six.
[SPEAKER_03]: And most exited positions will get a pH less than seven point three. [SPEAKER_02]: And if the pH is less than seven point two, this could mean a very poor prognosis for our patients. [SPEAKER_02]: And it increases the likelihood of that plural space needing to be drained with a chest tube. [SPEAKER_03]: Yeah, and speaking of like super low pages, I definitely mean tricked by a super low, plural food page.
[SPEAKER_03]: In a patient, that was actually well appearing, like eating a sandwich. [SPEAKER_03]: And turns out, it was actually the local litigating that was used prior to the Thora, that's acidic in nature. [SPEAKER_03]: And then when it came in contact with the Thora, the fluid falsely lower that plural pH. [SPEAKER_03]: And then on repeat diagnostic Thora, which is unfortunate that we had to get it, the repeat Thora did show that the page was actually normal all along.
[SPEAKER_03]: And the same thing can happen with if there's some residual happening in a syringe. [SPEAKER_02]: Wow, that's crazy. [SPEAKER_02]: And kind of scary. [SPEAKER_02]: And I think these stories bring up a really important point that we're looking at everything, including the patient in addition to those poor old studies. [SPEAKER_03]: Beware when your patients eating a grilled cheese sandwich and their plural pH is seven, play one. [SPEAKER_02]: That's true.
[SPEAKER_02]: Okay, the other thing that we should know is that the pH does change depending on the time outside of the body, and so if there's a delay more than even an hour, it can falsely elevate the pH, and that can be falsely reassuring. [SPEAKER_03]: Now, what do I move on to the cell count and the differential? [SPEAKER_03]: In a normal plural fluid, we would expect there to be very few white blood cells, and only we'll be neutrophils.
[SPEAKER_02]: Okay, so if there's a neutral predominance, we can imagine that that's probably an acute process that's going on, especially at levels greater than fifty percent of neutrophils. [SPEAKER_02]: But we should keep in mind that different populations matter, so in our long-transplant patients, even at twenty-one percent of neutrophils, we are worried about an infection. [SPEAKER_03]: Yeah, and the other takeaway here is that neutrophils just mean acute inflammation, right?
[SPEAKER_03]: It doesn't necessarily mean infection. [SPEAKER_02]: Yeah, exactly. [SPEAKER_02]: So like more than half of our patients with pulmonary embolisms will have a neutral predominant plural effusion, which makes sense because PE is our very acute process, right? [SPEAKER_02]: Nice. [SPEAKER_03]: All right, let's move on to lymphocytes.
[SPEAKER_03]: So you should be expecting there to be about twenty percent lymphocytes in the plural fluid, but say we have more than fifty percent of lymphocytes, then we're going to think about more chronic processes going on. [SPEAKER_04]: And then lymphocyte predominant is sort of the big large bucket lymphocyte predominant can be seen in malignancies. [SPEAKER_04]: But it's also the most likely type of infusion for someone who has an idiopathic infusion.
[SPEAKER_04]: So somebody has recurring infusions. [SPEAKER_04]: We can't figure out why it's usually a lymphocyte predominant process. [SPEAKER_04]: lymphocyte predominant can be seen in malignancies, certainly. [SPEAKER_04]: It can be seen in some sort of more indolindenfections, you know, tuberculosis, sort of being the classic one.
[SPEAKER_03]: And then if the plural fluid lymphocyte is greater than eighty, ninety percent, really like numbers that make your eyes pop when you look at the EMR, that's going to be suggestive of like more rare things, right? [SPEAKER_03]: Like lymphoma, chiylothorax, tuberculosis. [SPEAKER_02]: And so you are worried about TB and someone with a lymphocytic predominant effusion. [SPEAKER_02]: Your next step would be adding on something like an ADA or adenosine diaminase.
[SPEAKER_05]: ADA is an interesting test in the sense that, you know, I think in the right patient population, it can be super super helpful. [SPEAKER_05]: So if you have a patient from an endemic area of TV, then they have a plural of fusion, sending an ADA can be super helpful if it's elevated. [SPEAKER_05]: It can help you cinch the diagnosis because culture data from an AFB from the plural fluid is really well.
[SPEAKER_05]: You're going to get an answer about ten to fifteen percent of the time. [SPEAKER_05]: So an ADA can be very supportive [SPEAKER_03]: As though in normal conditions and ADA in the plural fluid is low. [SPEAKER_03]: So if you send off an ADA and it comes back less than forty international units per liter, we can generally exclude tuberculosis prior at S. Let's move on to ESNAVILS. [SPEAKER_02]: There should be almost zero percent of ESNAVILS in the plural space.
[SPEAKER_02]: So if you have more than ten percent, there are quite a few things that could possibly be. [SPEAKER_04]: This NFL's really can be from grab bag of things, but anything that irritates or violates the plural will lead ESNFILs to be there. [SPEAKER_04]: So somebody has a room fracture, somebody has a room of thorax, somebody is actually at a prior tap. [SPEAKER_04]: There are certain types of malignancies or inflammatory conditions can do that.
[SPEAKER_03]: Then one of our reviewers even noted that some of the most often missed diagnosis. [SPEAKER_03]: He sees with his, for instance, in fellas, when it comes to ESNFILs in the plural, in his opinions are more of the rare things like asbestos related plural effusions or tuberculosis pluralitis. [SPEAKER_02]: Yeah, and those are definitely things you don't want to miss.
[SPEAKER_02]: I was also really surprised to hear that no diagnosis is even obtained in about a third of patients with esophilic prolifusions. [SPEAKER_03]: Man, idiopathic stuff is always so humbling and how often it comes up. [SPEAKER_03]: The last part of our cell count and diff is the number of RBCs.
[SPEAKER_05]: A lot of your plural effusions are going to have a fair amount of red blood cells on them, but you really need a very high percentage or a very high number of red blood cells for that to be consistent with the hemothorax. [SPEAKER_05]: The best test for that is actually to send a plural fluid hematicrit. [SPEAKER_05]: And if it's greater than fifty percent of the serum hematicrit, then you're looking at a likely hemothorax.
[SPEAKER_02]: So to reiterate, if we look at the ratio of pearl fluid to blood hematocrit and it's greater than zero point five, this is diagnostic of hemothorax. [SPEAKER_03]: And then another cool trick we learned is that when you're sending off pearl fluid for a culture, you'd not just place that sample straight into the blood culture bottle and that's going to increase our yield. [SPEAKER_05]: There are recent paper.
[SPEAKER_05]: It's a couple of years old now, but inoculating your blood culture bottles at the bedside before you send them to the lab, improves your yield by about total twelve percent. [SPEAKER_05]: So it's actually my practice now where I draw the fluid and then either myself or someone else is in the room, just directly inoculates Tennessee season to the bulk culture bottles. [SPEAKER_05]: Just to improve your yield.
[SPEAKER_03]: Okay, so we learned about a lot of tests, so let's summarize some of our takeaways. [SPEAKER_03]: A normal plural pH is around seven points, six, but numbers below that, like seven point three, suggest an exitative effusion. [SPEAKER_03]: And then do try to get the samples into the lab as soon as possible, or else you might have a falsely elevated pH.
[SPEAKER_02]: And when we look at the cell count of the plural fluid, if there's greater than fifty percent of mutual folds, we can think that that's an acute process. [SPEAKER_02]: And if there are high lymphocytes, this could be a chronic process like malignancy or even TB. [SPEAKER_02]: If we are worried about TB, we should send off an ADA to help. [SPEAKER_03]: Right. [SPEAKER_03]: And then you send a phylic Ephesians, that can be just like anything that irritates the plura.
[SPEAKER_03]: And if the plural to serum hematica ratios greater than point five, this indicates a hemotherax. [SPEAKER_03]: Alright, now let's take some of our interpretation of plural studies and apply it to diagnosing and treating paranomatic effusions. [SPEAKER_02]: Yeah, I think a great example is trying to distinguish between uncomplicated and complicated paranomatic effusions. [SPEAKER_04]: And in uncomplicated process, you just have pneumonia there and the lung.
[SPEAKER_04]: The paral space gets irritated. [SPEAKER_04]: Yes, more protein and cells and things are pouring into there, but you don't sort of have a frankly infected space. [SPEAKER_04]: It's just sort of next to this affected lung. [SPEAKER_04]: And in those cases, we feel a lot more comfortable trying to just treat the pneumonia and have the fluid maybe drained once as we're doing the diagnosis, but we're just sort of monitoring it.
[SPEAKER_03]: And with these cases, when we look at the plural fluid biomarkers in uncomplicated effusions, this is basically when fluid itself is not infected. [SPEAKER_03]: We can expect a negative graham stain, a negative culture. [SPEAKER_03]: The glucose level of the plural fluid is going to be greater than sixty, and the P, just going to be greater than seven point two. [SPEAKER_02]: And this is different from a complicated paradigm on a confusion.
[SPEAKER_02]: This is one bacteria is actually inside the plora. [SPEAKER_02]: And for this reason, we call it complicated because it needs to be drained to be resolved. [SPEAKER_03]: Man, I don't know if I'm like dating myself here, but there was a time on Facebook where people would actually update their relationship status as complicated. [SPEAKER_03]: And I can't help but think about the parallel that those complicated relationships just needed some trainage to help it out.
[SPEAKER_02]: I love that. [SPEAKER_02]: I think we can keep running with it. [SPEAKER_02]: So our complicated relationships are less sweet. [SPEAKER_02]: Kind of like the complicated effusions where our glucose is less than sixty because of all of the bacteria. [SPEAKER_02]: And I would also say that our complicated relationships can sour. [SPEAKER_02]: Kind of similar to the complicated effusions which are going to be more acidic with our pH less than seven point two.
[SPEAKER_03]: Nice. [SPEAKER_03]: That was so good. [SPEAKER_03]: I love that. [SPEAKER_03]: All right, another pro tip on plural glucose being low is that, yes, we have this cut off of the glucose being less than sixty, but it's not a hardened fast, especially if you take the patient's serum glucose into account. [SPEAKER_05]: Now, this is the situation where I think having a serum level is helpful because you want to see if the glucose level is significantly lower than the serum level.
[SPEAKER_05]: If you have a patient who has a glucose level in their serum of four hundred, and you have a glucose level in your plural fluid of seventy, then think infection is going to be going higher on my list of potential diagnoses. [SPEAKER_03]: And annoyingly, the gram scene in culture might be negative or positive depending on the stage of disease or where you tap.
[SPEAKER_03]: But if you do see the LDH being greater than a thousand or if you see Lawculations or Sceptation, that Lawculation or Sceptation on bedside ultrasound or a CT can really help you cleanse the diagnosis. [SPEAKER_04]: If I see temptations, if I see lockulations in a really complex space, that's going to be a complicated diffusion.
[SPEAKER_04]: I don't actually even care what the fluid characteristics look like, because I can't be positive that the fluid characteristics from one pocket are the same as another pocket. [SPEAKER_04]: And so if it looks really complicated on my bedside, ultrasound or on a CAT scan, I'm going to call that a complicated diffusion. [SPEAKER_03]: And just to say explicitly, I really appreciate hearing how a sample fluid in one pocket of a localization reception may be different than another.
[SPEAKER_03]: And that's why we might see a higher number of bacteria in one pocket versus another. [SPEAKER_02]: Yeah, in the last but not least, if you tap an effusion and you get Frank Puss, that is not just a complicated effusion anymore, that is Empyema. [SPEAKER_03]: So let's get a little bit more granular in terms of treatment of these complicated, paranomatic effusions and impaema. [SPEAKER_03]: There's two main buckets, drainage of the plural space with a chest tube and antibiotics.
[SPEAKER_04]: I would make sure that those antibiotics have anaerobic coverage in them because you're almost thinking of this as like an abscess. [SPEAKER_04]: But I at first have much lower threshold to add antibiotics that cover the broad spectrum bugs that we most worry about, like pseudomonas and Mersa. [SPEAKER_02]: And with the chest tubes for paranamonic effusions and empaima, sometimes we need just a little bit more help with the drainage.
[SPEAKER_02]: And that's where fibroanalytic therapy comes in. [SPEAKER_02]: And there wasn't age-old debate about which therapy we should use. [SPEAKER_02]: Is it TPA? [SPEAKER_02]: Is it dornies? [SPEAKER_02]: Is it both? [SPEAKER_02]: The mist to trial gives us our answer. [SPEAKER_05]: TPA-dornase actually did improve. [SPEAKER_05]: Those radiographic outcomes and decrease the need for surgery. [SPEAKER_05]: There were no effect on mortality or hospitalic abstain.
[SPEAKER_05]: The caveats to using TPA-dornase, I think, are one. [SPEAKER_05]: If you have a really sick and plural rind, it's not going to be effective at decortitating or getting rid of that plural rind. [SPEAKER_05]: So the patient's going to have some long entrapment. [SPEAKER_05]: These medicines are not going to fix that. [SPEAKER_05]: There was a very good retrospective review of a very large data set that looked at the safety of DPA-dornase.
[SPEAKER_05]: Essentially, the bleeding rate is pretty low somewhere between two and four percent, but if your odds ratio for bleeding from TPA-dornase out of the plural space, it goes up if you cannot stop anti-coagulation. [SPEAKER_05]: So in those situations, you should really consider dose reducing or maybe not using it because obviously you don't want to cause a plural pleated in those patients.
[SPEAKER_03]: Yeah, so to help recap the mystery trial and management, if we can, the combination of TPA and Dornase is preferred in our patients with complicated fusions and employment because it reduces the need for surgery, which is always a good thing. [SPEAKER_03]: But we do have to keep it bind, if our patients on CT have a thickened plural of rind or lung entrapment, aka the lung can't fully expand because of some active disease that TPA Dornase might not be as effective.
[SPEAKER_02]: And I think a good way to end this parole is with the PSA that paranimonic effusions are scary. [SPEAKER_02]: And the reason we care so much about them is because if we don't act in time, of course the patient could become very sick and septic. [SPEAKER_02]: Ultimately, they may require a vat's decortication, which is a very painful and invasive procedure. [SPEAKER_02]: Sometimes we can otherwise avoid.
[SPEAKER_05]: You know, I think the old adage of the sun never sets on a plural of fusion is probably only really applicable anymore to patients who you're suspecting an empanima. [SPEAKER_05]: This is the console that, you know, you see an ammonia and a plural of fusion. [SPEAKER_05]: This is the console that probably should happen even if it's four o'clock on the Thursday or on Friday or even on the weekend. [SPEAKER_05]: You know, this is something that probably shouldn't sit and wait.
[SPEAKER_05]: You know, especially with kind of some of the more advanced treatments we have, but it should be acted upon quickly, certainly within twenty four. [SPEAKER_03]: So to summarize, we have parent math infusions and they really exist in a spectrum.
[SPEAKER_03]: On one end, it's uncomplicated meaning it's not infected fluid and just kind of sitting near an ammonia to complicated effusions, which is actual bacteria in the plural space, to on the other in a spectrum, empire email, which is Frank Puss. [SPEAKER_03]: We can help distinguish these because complicated effusions and empire email will have a glucose less than sixty, a pH less than seven point two, and an LDH greater than one thousand.
[SPEAKER_03]: And I, again, really appreciated hearing that if you see adaptations or alloculations on ultrasound or CT, that can be enough to call it complicated. [SPEAKER_02]: And to treatment of these complicated effusions and empimers require a chest tube. [SPEAKER_02]: And sometimes they also require a little bit more help with breaking up the alloculations using TPA and Dornase therapy.
[SPEAKER_02]: And for antibiotics and complicated effusions and empimers, we want to include anaerobic coverage. [SPEAKER_02]: And then we should also consider broader coverage, like for pseudomonas and MRSA. [SPEAKER_03]: Okay, so say, we're worried about malignancy in a patient. [SPEAKER_03]: Say someone's coming in with the unilateral pull of fusion, some weight loss, some lakes and dams, and we need some floral studies.
[SPEAKER_05]: There's been some data that has been published about how much fluid to send. [SPEAKER_05]: You want to send at least fifty cc's in this day and age of eating next generation sequencing and molecular testing and things like that. [SPEAKER_05]: It's probably a good idea to send more than that. [SPEAKER_05]: Your yield from your initial plural fluid psychology is generally speaking around fifty to sixty to sixty to sixty five percent.
[SPEAKER_05]: If you're in that, thirty to forty percent where you don't get an answer, your second one, you will get an answer twenty five to thirty percent of the time. [SPEAKER_05]: So that second thoracentesis is usually the recommended thing. [SPEAKER_05]: One, it can be diagnostic in over a quarter of cases. [SPEAKER_05]: And two, you drain the full patient dry and they feel better.
[SPEAKER_05]: And then, if you still don't have a diagnosis after that second one, then pursuing kind of a more definitive biopsy is recommended as long as it's within the patients on a plan and goals and things like that. [SPEAKER_02]: And what's the definitive plural biopsy? [SPEAKER_02]: We can ask our proceduralist whether it's medical bureaucracy be with IP or vats with our thoracic surgery colleagues.
[SPEAKER_03]: But either way, once we've confirmed malignant plural diffusion, think the next big question is what do we do? [SPEAKER_03]: And I think I asked that because lots of physicians are going to come back. [SPEAKER_05]: So I think the way that eye counsel patients is I tend to be fairly conservative, you know, I think we do with thoracentesis, we get a diagnosis of malignant effusion.
[SPEAKER_05]: I tell patients almost universally that we should wait, see what happens, and then determine based on the rapidity with what's the fluid comes back. [SPEAKER_05]: If the fluid comes back quickly within a week, then at that point I'm talking to them about the various management options. [SPEAKER_02]: Yeah, one of those management options is to repeat the thoracentesis.
[SPEAKER_02]: So we want to give the patients a heads up because they may be coming back every week or every two weeks and that can be a lot for our patients. [SPEAKER_03]: And so another option is an indwelling plural catheter, right? [SPEAKER_03]: They don't have to come in for that. [SPEAKER_03]: It's this basically soft silicone tube that's inserted into their plural space. [SPEAKER_03]: It's not very visible. [SPEAKER_03]: It can be trained at home and so some people.
[SPEAKER_03]: right that one. [SPEAKER_05]: Sounded plural catheter placement is ideal in the sense that it keeps you out of the hospital and then it is as simple as putting it in a chest tube essentially.
[SPEAKER_05]: But about a four to ten percent infection risk for the lifetime of the catheter and most of the time it's just colonization and you can treat through it and keep the catheter in but sometimes it does lead to full blown portal steps this or clogs the catheter up so you have to remove it potentially cut a new catheter in and expose you to antibiotics.
[SPEAKER_05]: And then the other big thing I always tell patients is that you can't do a body of water or take a bath and you can't lay on that side generally speaking. [SPEAKER_05]: So you really have to, you know, I try to be provided much informed consent as possible. [SPEAKER_03]: Oh, I actually did not know about the bath thing and I appreciate that because [SPEAKER_03]: I feel like nurses pay just all the time. [SPEAKER_03]: If like, oh, can this person shower or not?
[SPEAKER_03]: And I guess now I know I can say, yes, they can shower, especially knowing that like, you know, it's not like hospitals have that's with a big body of water or like those cold water morning plunge that people are really into now. [SPEAKER_03]: So that's good to know. [SPEAKER_02]: An alternative option to the repeated thoracentesis and the indwelling catheter is chloridesis. [SPEAKER_02]: And this is when we put a squirrosing substance into the patient's plural space.
[SPEAKER_02]: What it does is cause irritation of the plora. [SPEAKER_02]: And this ultimately results in the two plora sticking together. [SPEAKER_02]: And this prevents fluid buildup with the effusion. [SPEAKER_05]: So, going back to Richard Light, he used to call giving a sclerosing agent, and these are some of the older sclerosing agents that were probably more painful.
[SPEAKER_05]: But he used to refer to it as tacky lorty syndrome, where the patient would get tacky cardic and say lorty lorty lorty, which is very corny, but I think it does serve a purpose that it can cause a pretty significant inflammation in the plural space. [SPEAKER_05]: And so having an understanding of maybe how we're going to manage pain prior to doing this, and then counseling your patients like, yeah, this can cause a fairly significant platric type pain.
[SPEAKER_05]: So I am usually injecting pupivicane before I do any sort of pluridiesus because it's a little longer lasting than my decaying with a half life. [SPEAKER_05]: And then making sure as long as they can tolerate taking it and said they're generally speaking the best for this. [SPEAKER_05]: If not, then you're still going to want to hit it from multi-modal. [SPEAKER_05]: You know, I know we always want to try to limit narcotic use.
[SPEAKER_05]: In these cases though, sometimes especially for a couple of days immediately after the procedure, it's probably more into it. [SPEAKER_05]: But also, you know, lighter-derm, lighter cane patches, topical therapies can be super effective in this patient population as well. [SPEAKER_03]: And so to wrap up this last pearl, if we're worried about a million plural effusion, we should tap that effusion.
[SPEAKER_03]: And the cytology might come back negative the first time, but on the repeated thoracentesis, we can usually increase our cytological yield. [SPEAKER_02]: And when treating these recurrent plural effusions, we do have a couple of options to choose from. [SPEAKER_02]: These include repeated thoracentesis, and dwelling plural catheters, and chlorodesis with a sclerosing agent. [SPEAKER_03]: And of course, each of these procedures is not without side effects.
[SPEAKER_03]: And so, really important to kind of sit with that patient and what their goals of care and wishes are and what may be best for them. [SPEAKER_03]: And with that, that is a wrap for today's episode. [SPEAKER_03]: Thank you so much for listening. [SPEAKER_03]: If you got some value from this podcast, or one ask is that you share this podcast with at least one other colleague who might also get something from this episode.
[SPEAKER_02]: And thanks to our reviewers for this podcast, thank you to Dr. Stephen Parkin for the accompanying graphics and the episode was made as part of the digital education track at the IDMC. [SPEAKER_03]: The opinions expressed our own and to not represent the opinions of any affiliate institutions. [SPEAKER_03]: Thank you.