Chapters Transcript General Approach to Large Pleural Effusions in the ICU Course: Bronchoscopic and Pleural Procedures for the Intensivist My, my approach today is to discuss large pleural fusions, and I'm gonna see if I can keep this to the time that I've been given. Uh these are my disclosures, but none of them pertain to what I'm gonna be talking about today. Probably my biggest disclosure is the fact that now that I'm an administrator, I don't get to deal with these on a day to day basis, and I do miss uh that uh that management. Um, this is the overview of my talk. Uh, this is an ambitious overview, and I think that what I'm gonna be doing is a whirlwind tour through how we manage large pleural effusions. And again, when we think about pleural effusions, uh, it's a very broad topic. So we're gonna think about pleural effusions in the intensive care unit, primarily in the medical intensive care unit, because most of us are medical intensivists and thinking about large pleural effusions and uh as per the conversation that we just had about hemopthesis and defining what is and was not massive hemothesis, there is no good definition, I will say for what is a large and what is a massive effusion. So feel free to question me as I use those terms, uh, during the course of my presentation. Uh, this is from a fantastic, uh, uncle, neurological medicine by two giants in plural disease, David Feller Kaufman and, uh, the late Dr. Richard Light, who was one of my, my mentors, and it really describes uh the incredible physiology of the plural space that I cannot uh give credit enough credit to in this short period of time, but suffice it to say that the plural space is a remarkable organ. Uh, where the function primarily is on the parietal plural side. That really is the working side, where most pleural fluid is generated by parietal pleural capillaries or systemic capillaries, uh, that generate pleural fluid and then it's reabsorbed. Nearly all of it is reabs. Or by plural lymphatics, uh, in a constant homeostasis, uh, but this homeostasis can be disturbed and it can be disturbed by a variety of forces and a variety of forces which are really active, uh, in our intensive care unit patients. So it's really important to understand that it's a really remarkable thing that when you look at a chest X-ray or a chest CT scan from patients who are otherwise healthy, that we don't see pleural fluid and yet pleural fluid is constantly being produced. And so for our patients who are in the intensive care unit, why do they develop pleural effusions? And it's actually remarkable, if you think about it, that they don't develop pleural effusions more than they actually do, uh, because what are the factors that uh lead to development of pleural effusions in critically ill patients? Well, If you have more pleural fluid production that you can remove, then you're gonna accumulate pleural fluid in the chest cavity. It's pretty self-explanatory. In critically ill patients, they have high extravascular lung water leading to higher filtration than normal from the visceral pleura, and as I said, The beginning, the parietal pleura is typically in healthy patients, the working side, uh, and yet visceral pleura in patients, for example, with ARDS or uh uh pulmonary edema that's hydrostatic, uh, will then have filtration in addition from the visceral pleural side, which may help overwhelm the parietal pleural lymphatics. You may have a patient with a severe pneumonia. With inflammation of the parietal pleura and then have an increased capillary leak into the pleural space. You may have altered plasma oncotic pressure. Many of our patients are hypoprotemic and therefore there's an altered oncotic balance, and all of that leads to increased production. And then on the right hand side, reasons why our removal is down significantly, all leading to the development of pleural effusions. And this is a great paper, uh, again by one of the giants in plural disease, Steve Sohn, who was the former division director at the Medical University of South Carolina, uh, but I love this because it's an old paper, but it's still very relevant. So when we think about our ICU patients who do and do not have pleural effusions, those who do have effusions are older, have lower albummens, are in the ICU for a longer. Period of time, so probably get a lot more fluids, probably more hyperproonemic, have higher or worse Apache scores, uh, and are ventilated for longer periods of time. Some of this is pretty self-explanatory. And when we look at the causes of pleural effusions from this old paper, again from many years ago, uh, it's primarily heart failure, although that's a fairly broad term. cyst, uh, and then some of the others are relatively uncommon, but this may have to do with the composition of patients within your ICU, uh, rather than necessarily um the underlying diagnosis. So if you have a CCU, a cardiac care unit, you're probably gonna have nearly all your patients have heart failure as etiology of the, of the pleural effusions. And then thinking about um uh small, large massive effusions as we go from small, large to massive, there's a higher percentage of patients with malignant effusions. So again, when we think about presentations of massive effusions uh both in and outside the ICU, the vast majority of those are going to be malignant and. Think about it. Why is that? For those of us who do thoracoscopy, we know that what what the pleural space looks on the inside is someone with disseminated malignant disease, you're going to have disease all along both a visceral and parietal pleura, and so you're gonna be having significant inhibition of pleural lymphatic reabsorption, uh, in that case. And so you will have a greater propensity for a massive effusion. And interestingly, uh, among those patients with massive effusions compared to large or normal, especially among the malignants, there are higher red blood cell counts within the pleural fluid itself and interestingly, lower adenosine Diaminase levels, which is typically associated with tuberculosis, but not necessarily with malignant disease, but these are what are associated with the development of massive effusions. And also interestingly, there are survival differences in malignant plural disease between those who have massive effusions and non-massive effusions, and that survival difference between massive and non-massive is not true for idiopathic non-malignant pleural effusions. Now, some of these may turn out to be malignant later on, but it's interesting that you could have a massive effusion from, say, hepatic hydrothorax, and that the prognosis for those patients is not different from a submassive effusion, uh, at least in this uh one study. Now, for those of you who are interested in plural disease, it is imperative that you become experts, uh, at least facile, in transthoracic ultrasound, uh, especially in the ICU you could have a chest X-ray like you see on the top left. That patient doesn't look like they necessarily have a pleural effusion. It could be very hard to tell, especially on a supine portable chest X-ray in the ICU. Yet you put a probe on, uh, and you see the top right that this patient has a pleural fusion that's potentially accessible if you need to make a diagnosis. Um, but learning how to do thoracic ultrasound and hopefully tomorrow you will have exposure to this if you've not learned already, and, uh, for our, our fellows in the audience, especially our first year fellows, you're going to be going to a citywide ultrasonography course where hopefully you'll get, um, uh, to begin to be an expert in thoracic ultrasonography. It's incredibly important, uh, in the ICU and outside the ICU. Um, I believe that a skilled thoracic ultrasonographer can make the diagnosis of pleural fusion even without sampling. I'm not arguing for not sampling. I'm just saying that from the images that you see, you can distinguish between what is an anechoic likely transcendent of effusion on the top left, on the top right, an extremely complex paranormaltic effusion like Lee and Empire. the bottom left, the, the classic um hematocrit sign of a hemothorax and on the far right, where you see a septated diffusion but with lesions and masses on the diaphragm diaphragmatic pleura, a malignant diffusion, and so you should at least have a very good idea when you're doing a thoracic ultrasound about what the underlying diagnosis is going to be. Now, you're gonna be learning tomorrow uh about how to do safe plural procedures in the ICU. You'll also be hearing shortly from one of our superb thoracic surgeons, Amy Kent, about chest tube placement. I will say that it's gonna be, it is extremely important to learn how to do these bedside procedures. And just because you can do a thoracentesis on an ambulatory patient in the. Clinic or on the medicine wards doesn't mean that you are well trained to be doing this at the bedside in the ICU. The positioning of the patient is different. Uh, I will say what is uniform is that they all should be ultrasound guided. Uh, and ultrasound guidance is especially important when you're performing a thoracentesis on a recumbent patient in the ICU on mechanical ventilation. Um, but it is a technique that's exceedingly important, uh, and we probably underutilize pleural fluid sampling in our ICU patients, uh, because I think most, uh, practitioners, most critical care physicians aren't as comfortable as they should be with sampling the plural space. What we should know, uh, is that there's reasonable data, a little bit old. that by draining of fusions, we can actually improve oxygenation. That seems like a straightforward thing, but again for our patients in the ICU that were manipulating the ventilators trying to improve oxygenation, simple things like draining and effusion, uh, can be safely done and can improve oxygenation, allow us to get off toxic levels of FIO2. Uh, there are a variety of different chest tubes that you can use to drain pleural effusions, and we, well, you know the indications for when to place a chest tube. I'll leave that to Doctor Kent. Uh, and then, uh, again, for tomorrow, it's very important that you learn the nuances between the different types of tubes. Uh, but I would say that if you are placing a chest tube, it's important to have a different type of approach that you can take in different circumstances. Um, there aren't very many, uh, non-surgeons who can place it what's called the standard thoraccostomy tube, and it's something that I still preach, and for any of our trainees who want to learn, I'm happy to teach you. Now, in terms of complications of plural procedures in the ICU, I think it's really important that the print is somewhat small on my, my apologies. But in terms of bleeding, post-thoracentesis or post chest tube placement, there are some things that are fixable and some things that are not fixable. So, for example, there's a higher risk of bleeding in patients with renal disease that may or may not be fixable by doing hemodialysis on patients. Patients who are obese, patients who have complex septate diffusions will have higher risks of bleeding. But there are things that increase risk of bleeding that we can avoid. So trying to do a plural procedure in the ICU without ultrasonography will dramatically increase your risk of bleeding. You have not being experienced or not being well trained will increase your risk of bleeding. So my hope is that this course, uh by itself will help get those who are not yet well trained on the path to decreasing this risk. And there are many other complications of chest tube assertion in the ICU, uh, that you can see on the far right. But interestingly, most of these are in some way iatrogenic, but it means that we can learn through proper decision making, technique learning, and not just the placement of the tube in the plural space, but management after that tube has been placed. If we learn all these things properly, we can dramatically diminish the the risk of these complications and patients who require thoracostomy tubes in the ICU. Um, on the, on the left side, you see a patient with a tension pleural effusion, that is a a fusion which is accumulated with such pressure inside the plural space that they've got essentially cardiac tamponade physiology. You see pre and post. A classic medical student question is what is the cause of the complete opacification of the left hemithorax and that far left X-ray? When you see the trachea deviated to the contralateral side as well as the other mediatonal structures. This is a pleural effusion. If everything is shifted ipsilaterally to the uh a pacification, it likely is a lecticis. Uh, and there's, you see the X-ray post. It's important to understand that you don't have to have complete opacification as a predicate for having uh tamponade physiology. So loculated effusions can accumulate under pressure and can also shift the media signup contralaterally and can be associated with tamponade physiology. And you can use pre and post echocardiography, and it doesn't have to be a standard transthoracic echo done by a cardiologist. It could be done, critical care echocardiography at the bedside to show the pleural effusion beforehand with the collapse, the diastolic collapse of the right atrium. And then repeating the procedure afterwards to confirm that the atrium has resumed normal position and you've drained the effusion successfully and we can do this as intensivist at the bedside using our own ultrasonography. We don't necessarily have to rely on a standard 2D echo. Uh, and interestingly, the hemodynamic improvements may be somewhat, uh, time dependent as well as uh side dependent. And what I mean by that is that the hemodynamic improvements in patients with massive pleural fusions that are hemodically significant, typically the improvements are seen almost immediately after the drainage, except for left sided pleural effusions. So left side of pleural effusions, you will see a 24 hours a continued improvement in stroke volume that you don't see with the drainage of the right side of pleural effusions. And this is a really interesting phenomenon based upon the location of the left ventricle and the dynamics of the left ventricle and the pleural effusion that are occurring after the drainage. Now, re-expansion of pulmonary game is something that we worry about a lot, especially after a large volume thoracentesis. Um, here you see a right side of pleural effusion, drainage, everything looks great, and then 24 hours later, you see this X-ray. Um, this is the minority of patients, uh, and it's important to understand that most, uh, re-expansion of pulmonary edema is only seen if you do a chest CT scan, which we rarely do after thoracentesis. And also, the vast majority of this that's radiographically visible is actually not. Clinically significant, and I think that we worry a bit too much about this, and we limit the drainage when we do thora and Ts or we replace chest tubes. It's also important to remember that this almost never happens for our patients in the ICU who are under positive pressure ventilation, and this is because of the differential pressure across the pulmonary capillary bed. And one of the treatments for symptomatic re-exposure pulmonary edema is actually positive pressure ventilation, often with a negative pressure, uh, uh, I'm sorry, with a positive pressure mask, non-invasive ventilation. Now, there's been a study of pluralmenometry in this setting shows that plural menometry, uh, pre and post does not predict the development of uh re-expansion of pulmonary edema. So it's, this is not one utilization, uh, for pluralmenometry, and I am not a huge advocate of this technology, but there are some that are. In terms of hemathoraces, hemothoros occur more commonly in patients with underlying chronic renal disease. Uh, and interestingly, the negative prognostic value of the greater drop in hemoglobin and the high INR, uh, coagulopathy is borne out. So for patients, if you can see here a multivariate analysis. If you've got an INR of greater than 1.6, or if you have a hemoglobin drop of greater than 3 g, your odds ratio for death is dramatically higher. So think about that as you're approaching patients who have hemothoracis, but also remember that we we don't. See hemathoracis very often in the medical intensive care unit. It's more often in the surgical intensive care unit or a trauma intensive care unit. When we do see it, obviously, it's often in patients with coagulopathy or have had iatrogenic disasters from bronchoscopy or from plural procedures. Um, in terms of randomized trial, uh, of chest tubes versus pigtail catheters, in this one randomized study, uh, against small number of patients, there was no significant difference between a reasonably sized pigtail catheter, 14 French and a large chest tube in terms of Clinical outcomes, but in terms of patient satisfaction, when they're able, again, these are not patients who are sedated and intubated in the medical intensive care unit, patient satisfaction with the placement of the pageel catheter was far greater than that of a standard thoraccostomy too. Um, I'm a little bit over time, so let me just say that plural space infection also is a cause of, uh, large pleural effusions or significant pleural effusions in the ICU that there are a variety of different algorithms for management of pleural space infection. These are in flux. One of the areas that they're in flux, uh, is the role of early uh surgical intervention, and this is uh The the premise behind a very important clinical trial, MIS 3, which is ongoing in the United Kingdom right now, which is randomizing patients between intrapleural fibrolytic therapy and DNAs versus early surgery, and we don't know the results of that trial yet. But what I will emphasize is that early thoracic ultrasound, as we talked about earlier, is extremely important in this differential. And again, when we think about large fu. Overall and how we manage them. Use ultrasound early on, uh, it's easy, it's cheap. There's no transfer out of the ICU and you could learn how best to manage patients, um, and I really appreciate your time. I appreciate my colleagues in our interventional pulmonary section and in our pulmonary division put putting this course together, and I think I have no time questions, so thank you very much. Published July 12, 2024 Created by Related Presenters Daniel Sterman, MD View full profile
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