Hello, and welcome to today's webcast, Urine Output Monitoring in Critically Ill Patients. My name is John Kellam. I'm a professor at the University of Pittsburgh School of Medicine in Pittsburgh, Pennsylvania. I will be monitoring today's, moderating today's webcast. A recording of this webcast will be available within five to seven business days. You can log into myccm.org and navigate to the My Learning tab and click on the Urine Output Monitoring course. Click on the access button to access the recording. So thank you for joining us. A few housekeeping items before we get started. There will be a Q&A at the end of the presentation. You may submit questions throughout the presentation by typing into the question box that's located in your control panel. Please note that there is a disclaimer stating that the content to follow is for educational purposes only. And now I'd like to introduce our speakers for today. Dr. Jay Koiner is a professor of medicine in the section of nephrology at the University of Chicago. Dr. Michael J. Conner is a professor of critical care medicine and nephrology at Emory University School of Medicine in Atlanta. And Dr. Daniel Arellano is an acute care nurse practitioner at the University of Texas Health Center in Houston, Texas. And now I'll turn things over to Daniel to get us started. Thank you, John, and thank you everyone for joining us today. We wanted to start our presentation today, the presentation being very short and largely including a discussion between all of us on the panel and you and answering any questions that you may have about this automated urine output monitoring. So a little disclosure about me is I've been a nurse for a while and I've been monitoring urine output for many years, whether it was in the ICU or as a paramedic in the back of an ambulance. So I've been there in the trenches monitoring that urine output. And so we've kind of had these automated measurement devices for a while, but why haven't we implemented them and why aren't we seeing them a lot in our hospitals? Let's talk just a little bit about the technology that's available and then we'll progress through each of the different panelists. So we have these automated measurement devices for urine output and they're largely used in our hospitalized patients. They are in some cases more accurate than the actual manual measurements that we're doing for our urinary output at the bedside. And in some cases they can even detect conditions such as acute kidney injury. And I'll talk about the different types that are available to us currently. So a couple of basics about automated urine output monitoring. There are multiple devices available and we're not going to talk brands today, a very non-brand specific lecture. The majority of these are basically a connection that you add to your Foley catheter. Some of them do have a special urinary catheter. I believe that particular device may also measure intra-abdominal pressure as well. So there are specialty devices that you can purchase that do do other things other than just measure that urine output. Some of them have a sensor at the catheter and where the actual urinary catheter attaches to the tubing. And some of them are simply just weighted devices that we attach to the urine bag. I was thinking before this lecture about me running the old school CRT machines that were very weight sensitive. And every time I would walk by or my leg would kind of kick the effluent bag, it would start beeping at me. And I wondered why, you know, we never had any sort of urinary output device that kind of did the same thing. Those bags were in place for years and years, even before I was a nurse. So we've been looking at this for a while, particularly with our CRT devices, but some of these devices are actually available at the bedside now. As you would expect, most of these devices require the elimination of dependent loops because those loops will adjust pressure and will impact the amount of flow coming out of that urinary catheter device. So no matter which device we're talking about, a lot of them are really trying to eliminate dependent loops and making sure that we have appropriate measurement of that forward flow of our urine output devices. So I know this is kind of a busy slide. I kind of highlighted the important points here about the different types of urine output technology. The first one that I'm going to talk about, again, not introducing brands per se, is a transducer that's utilized to measure urine outputs, and it uses ultrasound technology. This particular device, as I alluded to earlier, also has a special Foley catheter that you can purchase that includes the measurement of intra-abdominal pressure. Though you don't have to purchase their Foley catheter, it does have a device you can just connect to your existing device. Nevertheless, this particular technology uses ultrasound, and it uses a valve system to decrease dependent loops and monitors that continuous flow of urinary output. The second type of device uses thermal technology, and it uses sensors and thermal transfer technology to measure that urine output at the catheter connection site, again, where you would actually connect the yellow piece or the clear piece directly to the actual tubing of the Foley catheter. The third type is a disposable unit that connects to the catheter and urine collection bag, and it requires the patient weight, and it also uses a specialized analysis to gauge how much urine flow is coming from our patients. The fourth type is another detection device that uses an infrared barrier, and it basically looks at patterns and is able to adequately predict and measure the amount of volume of Foley liquid coming out at one particular time. And then the last type is a sensor that goes on the Foley catheter. It's compatible with most Foley catheters that you may purchase or may already have at your particular institution, and it uses almost like a suction, it uses a pump to keep that Foley tubing clear and allows you to measure a constant flow of urine output that's coming from your patient. And so, again, that's just another way that we can use to look at that urine output in a particular fashion and prevent those dependent loops from affecting our hourly urine output measurement. So, just briefly, this is my last slide, again, mostly wanted to engage discussion with you all as well as the panel. So, what are the advantages and barriers of these different devices? I'll go over the advantages first. Obviously, it decreases the need for documentation. This is an automated technology. And as I mentioned, you know, we wonder for years, we were looking at our effluent bags that were measuring weight. Why have we waited so long to utilize this particular type of technology? We know how much water is coming in and out of our homes. I know my water bill is very tightly regulated by our folks, so why can't we do that with our patients? So that's one of the advantages is that perhaps this can actually decrease the need for documentation. The other advantage is it can sync directly over to the electronical medical record and it can automatically be logged so that it decreases the workload on nursing. You'll note that I've also included that as a barrier, so I'll talk about that briefly right now. We know that even though we include technology that automatically slaves over or syncs over to our medical record, our nurses have to validate that information. One example is the vital signs, right? Just last week, I had to call a nurse and said, is your patient breathing? You documented that the respiratory rate has been zero for the last two hours. So even though we have this technology, our nurses still need to validate it and it does end up being death by a thousand clicks sometimes as our nurses have to go in and kind of click all this stuff to make sure it's right. The other thing is that it can detect acute kidney injury if we're monitoring how much urine our patient is making every hour. We can use the KDGO guidelines to kind of say if our patient's urine output is dropping in a manner that may indicate that our patient is developing or at a risk for developing acute kidney injury. And some of the technologies that I discussed previously have the capacity to do a real-time urinalysis. It isn't perfect. There's obviously things that can be improved, but if we can look at what's coming out of our patient in real time with a urine analysis, it can tell us if our patient's developing casts or has a higher amount of glucose, et cetera, that we can look at. So that's some of the advantages that we can look at for these particular devices. The barrier is obviously the first one being cost, right? A lot of people consider anything involving nursing as an expense. As a nurse, I disagree. I think it's an investment because if you were laying in that bed, you would sure want that nurse to have every single possible technology that they could have to make sure that your stay and your care was to the highest standard that could be. The other barriers are it's additional equipment, and obviously that's a cost and training that your nursing teams as well as physician and other teams need to incorporate into their cost analysis of the unit. There obviously needs to be additional education, and then we talked about the EMR capability. And as with everything in healthcare, things go awry, and so we have to make sure that our teams know how to troubleshoot these particular devices, and sometimes that can be difficult, especially in the middle of the night and especially depending on what resources you have available. One thing I will mention that we frequently get, or I get when I give any lecture, is are these devices available for pediatrics? And the answer is yes, there are some of these devices that are available in the pediatric population. Again, not going into the different brands, but these are available across different age ranges. And so again, just an excellent way that we can use to potentially detect acute kidney injury and look at the amount of urine coming from our patients and analyze that with the KDGO guidelines. And with that, I will turn it back over to John, who will introduce the next speaker. Yeah, Daniel, before we move on, there's a question from the audience that's directly related to your comments, so maybe we can address this now. The questioner wants to know that there is a technology, one of the technologies out there requires the nurse to essentially hold up the dependent loop in order to move the urine to the weight scale, and obviously this is less helpful. Do you have any comments about that? I would, I would agree that it is obviously a little bit more laborious, however, we already have to do that now as it is. I always joke that looking at urine output as a measure of acute kidney injury is fragile because sometimes you turn your patient and the patient dumps 100 cc's of urine or it's very difficult to kind of look at that as a gauge for much, but you already have to lift up those dependent loops. You already have to do all of that sort of intervention, but this may be a way where when you have those times where you have, you know, a tripled assignment or you have a unique nursing situation that doesn't allow you to be at the bedside continuously, it is one extra tool in your toolbox that may assist you in those very rare situations where you don't have the capacity to pull away or you don't have the capacity to spend a lot of time at that particular patient's bedside. And we shouldn't say many of the technologies don't require manipulation, but rather avoid the dependent loop by essentially creating a siphon, a negative pressure as well. So as you're selecting these technologies, you may want to think about that aspect of usability. Jay, do you want to kind of tell us what the guidelines say about urine output in general and whether there's any statements around automated urine output and give us some context to work with. Yeah, sure. Thanks, John. And thanks to the SCCM for inviting me to participate. Here are what the guidelines show. I think before we delve into them, right, it's important to remember a few things. One that AKI is defined both by changes in serum creatinine as well as changes in urine output and that the urine output criteria have been relatively stable, recognizing that these are the KDGO and they've been around since 2012. But even before that, as part of RIFLE and AKIN, they have been relatively unchanged and that they talk about relative oliguria, whether we talk about 0.5 or 0.3 mLs per kg per hour for 6, 12, or 24 hours. And the idea being that it's a three-stage process and the higher the stage, the worse the outcome. And that at the time that these were created, these were sort of cutting edge. And based on the available data, I think my expectation is sometime over the course of the hour, we're going to talk about how maybe these specific guidelines around urine output are perhaps due for revision as part of the larger revision of the KDGO AKI care guidelines that are currently taking place. Specifically, I would imagine around the idea that stage 1 AKI, 0.5 mLs per kg per hour is not necessarily the most robust cutoff for that 6 to 12 hour period. And talking about the idea that traditionally, I think, much to the dismay of many ICU nurses and many practitioners, we talk about it being for six consecutive hours and that there may be some data out there that shows that that isn't necessarily the best way to do it. I do think it's important to acknowledge that most of the other medical societies over the last 12 years or so have deferred to the KDGO guidelines, which is different than, say, 10, 20 years ago. So that when you look at some of the critical care or cardiology or hospital-based guidelines, they now sort of accept the KDGO guidelines as the gold standard and as the definition of AKI. So we need to keep these in mind. And regardless of your job, if you're taking care of hospitalized patients, these are probably guidelines that you need to be familiar with. But this is just the diagnostic criteria for AKI. On top of it, on the next slide, you'll see what it actually says or what the guidelines say that we should be doing for patients who have AKI, right? The idea that we need to have a plan once people have AKI, especially if devices like this are to become more common, right? Testing patients at increased risk by looking at their urine output, certainly this makes it easier to risk stratify folks. And I know that there's lots of evidence out there that points to the idea that if you don't accurately detect changes in urine output, you're putting your patients at risk for short and long-term complications, whether they be things as simple or things that seem as simple as volume overload and sort of moving your patient in the wrong direction to as much as if you're not doing it, maybe there's an increased risk for severe AKI and all the morbidity and mortality that comes along with it, right? And having tools to better identify those who have oliguria or urine output-based AKI becomes super important. I think the other part that is interesting to me, and you heard from Daniel, that some of these devices have the ability to maybe provide more, whether that be a urinalysis or in the future, other biomeasures that come out of the urine, perhaps sodiums to guide people if they're actively diuresing their patient or other biomarkers that are out there. But you can also see when you look at what the current guidelines say we need to do, they probably need other revisions elsewhere, right? The idea that everyone with stage two or 12 hours of oliguria needs to be considered for an ICU admission, at least my hospital is probably not the best plan, but having accurate ability to detect those who are either at risk or have early AKI through urine output becomes super important in order to optimize their care regardless of the setting, right? And I think that this is what the guidelines say. We'll see whether or not in the next few years they get changed. My inclination is to say that based on some of the data that I think we'll be discussing in a little bit, there probably will be a potential for change, or there at least is enough for a discussion around change. I think with that, I'll leave it and throw it back to you. All right. I think that sets us up well for us to start kind of talking about some of these controversies. And Michael, maybe we can start off with you in terms of comments related to some of the controversies related to urine output monitoring in general and the criteria specifically. Some of our questioners, and I'll read some of these questions in detail as we go, but do sort of wonder about where some of these numbers come from and whether we focus too much on urine output, or maybe we don't focus enough. Can you comment on some of those things? So thank you, John, and thank you to the SCCM. And it's a real pleasure to be part of this panel and really enjoyed the discussion that Dan and Jay introduced. You know, John, I think this has been the challenge ever since we started talking about urine output in RIFLE and the AKIN and KDGO criterias, as you know so well from your career. You know, I think the controversy that still surrounds, you know, I think whether or not urine output is a good marker of AKI, I personally think that that has largely been put to bed. You and others have so well documented, right, that even if you meet AKI criteria just by urine output and not by serum keratinine, you very clearly still have an increased risk of death. And so it's, you know, maybe not in and of itself, you know, if someone stops urinating for 12 hours and then they start urinating again, you know, maybe that's a different situation. Early detection of AKI really requires us to look at something that is happening in real time. Keratinine is a lagging indicator, as you know, right? Other sorts of things are lagging indicators. And the whole goal is if we're going to prevent or decrease the risk of AKI is to move the ball forward. And you know, you and many others have shown that urine output can be one of those leading indicators. In addition to things like furosemide stress tests and, you know, if someone's not making urine, understanding why they're not making urine and testing the kidney's ability to respond to a, you know, a challenge really has a lot of predictive power. So personally, I don't know that while we may revise a little bit of the amount of what defines oligary and what duration, you know, we have to have, I still think that urine output, you know, is a really vital, is a really vital thing that we follow in these in our ICU patients. If for nothing else, wanting to diagnose AKI early is very important. But as you know, John and Dan and Jay, we also have a huge problem with fluid overload in the ICU. And we know that we need to return our patients to uvulemia. And even if it has no role in helping us in AKI, it certainly has a role in helping us understand fluid balance. So I think for both reasons, urine output is really important. And just kind of really important point there, Michael, that I want to follow up on. And there are some several questions from the audience related to that. And we'd like to try to get these questions into the mix here. So why don't we focus on the criteria itself? Jay made some comments to suggest that perhaps these numbers could be debatable. And I'll play devil's advocate and provide maybe a perspective as to why they are what they are. Not to suggest that we shouldn't refine things over time, but just to have an understanding of where they come from. And then the other aspect is related to what we do about it, right? So let's start with the numbers. So I think it is really important. So one of the questions is that, what is the basis of the 0.5 mLs per kilogram? And a lot of people know this story, but I will recount it since I was one of the people in the room when it happened, so to speak. And basically, this was when we were putting rifle criteria together. One of the original authors of the critical care severity criteria that were around at the time was basically able to pull up the entire database, which involved thousands of patients on his laptop, which was no mean feat back. I mean, rifle dates back some time. So we were all pretty impressed that he was able to do that. And we basically asked, at what point is there an inflection in the level of urine output that's recorded in the database that mortality starts to kick up? And it's both a number per kilogram, and I think it is very important. Until rifle criteria came around, pediatricians were really the only ones that expressed urine output on the basis of mLs per kilogram. And I think it's very important to do that. If you're not doing that, you're doing quite a great disservice to your patients that are at one extreme or another. You're essentially making it different to fulfill the criteria for women versus men. And obviously, we don't want those kinds of healthcare disparities to exist in our care. And then also, in addition to the mLs per minute per kilogram, it is the timeframe in which you look at it. And it was never all that clear for reasons that the panel has suggested, and for reasons that may not be obvious, that whether you're meant to fulfill the criteria every hour or that was an average amount. And it turns out it probably means something a little different, although importantly, in background is everything that Daniel said in terms of the inaccuracy that we have about measuring things. So we're almost, you know, the urometer overflows, somebody lifts up the dependent loop, and suddenly there's 100 CCs of urine output. Is that really accurate hour to hour? And so probably the best you can say in most cases is that if I'm talking about a six-hour average, that's probably about as good as I can do in many cases, except when we have automated technology, and that's actually what we're talking about today. So where does this 0.5 come from besides that? It also is important to reflect on the fact, and I think this is critical, but I'll throw it out to the panel to argue with me. But I think it's very important that you consider the fact that our critically ill patients typically get between two and three liters of volume a day, particularly in the first couple of days in their ICU care. And that comes from, you know, everything from drips that they're on to some boluses that they may receive to, you know, nutrition that may get started. And if they're not making at least, you know, 0.4, 0.5 mLs per kilogram, they're gonna be in positive fluid balance, which is Michael's point. The second thing is don't forget, we should be consistent in our recommendations across the various domains of care. So if you give the protein load that we recommend people to have, which is about 1.5 grams per kilo, that's 870 milliosmes. And then if you add some electrolytes on top of that, you easily get over 1,000 milliosmes. Now, in order to excrete that osmotic load, even if your kidneys are normal, and we don't typically have normal kidneys in our critically ill patient, even if they don't have AKI, there's certainly some amount of chronic kidney disease, et cetera. When you're talking about excreting an osmotic load of 1 to 1.5 thousand milliosmes, you basically need to get, if you're a 100 kilogram person, you basically need to have a urine output that gets pretty close to 14, 1500 mLs in a day, which by the way is 0.6 mLs per kilogram for that 100 kilogram patient. So to excrete your solute load, you basically, if you're going to get that amount of protein, you're going to have to excrete a urine output that's at least 0.5 mLs per kilo and might actually be larger. So I'll stop there, but I just wanted to give that physiologic and historical note as to where these numbers come from. I'll make one comment, if you don't mind, John. I believe we've all read House of God, where we've heard about the age plus BUN equals Lasix dose when we're treating our patients sometimes in AKI. And I think about that as a nurse, I would see our patients get these whopping doses of Lasix, 100 milligrams, IV times one, and they would occasionally have oliguric turning into non-oliguric renal failure and the patient would still be in acute kidney injury. So the marker of urine output, I think is most helpful when we look at it as a trend. As you alluded to, having that timeframe of six hours is extremely helpful. We remember those old school flow sheets where we pulled out those multi-paged flow sheets. That was extremely helpful in allowing us to look at the trends and how things may be adapted over time or how our patients adapted with certain drugs that they administered. But one thing that's good about this automated technology is it has almost a predictive component in it as well. I would argue it's probably using AI before we even were so obsessed with it and helping us predict these changes that may be occurring or giving us alarms about when our patient's urine output is changing and significantly changing, not just related to perhaps a furosemide dose or whatever diuretic you gave, but alerting us earlier so that we can then make changes. Yes, there's biomarkers out there that you can run and all these other things you can use as predictive technologies. But since we're talking about urine output as a marker for that, I think this particular technology is helpful in helping us, since we no longer have those sheets that we pull out, maybe it helps us with that trend monitoring that we're missing with our current EHR technology. Yeah. And John, just taking that one step further, if I may, look, we follow all sorts of vital signs continuously in the ICU nowadays, right? I mean, gone are the days when our nurses are checking the heart rate and the blood pressure manually every 15 minutes or 30 minutes or an hour, right, John? And I think you and I can both agree that continuous vital sign monitoring has been a step forward in the critical care management of patients in the ICU over the course of the last 30 years. And, you know, it continues to befuddle me a little bit why urine output isn't considered a vital sign. I mean, it's an extremely important aspect of this. And, you know, we have technologies that allow us to monitor this in real time. And, you know, there are small studies now that these technologies are becoming more available that sort of document that when we, you know, our nurses are in the ICU, they are challenged with so many tasks at hand that pull them in so many different directions that even in the most capable hands, you know, when they know that in a study people are looking over their shoulders, for example, comparing conventional management or conventional urine output monitoring to electronic urine output monitoring, they miss anywhere from five to 10% of hourly documentations of urine output. And, you know, the studies go on to show that that has clinical implications that physicians and APPs and nurses and other providers pay more attention to kidney related issues and fluid balance and AKI when they are having complete and accurate documentation. So electronic documentation, electronic recording of urine output has not only improves the accuracy, but also improves our attention to the problems at hand. And, you know, again, we focus so much on urine output from an AKI perspective, but there is this whole other bundle, which is that urine output is so vital to understanding where our fluid balance is and to getting our patients liberated from the ventilator and from, you know, resolving their delirium and improving their ability to, you know, participate in PT. I can't tell you how many times, and I don't mean this to cast dispersions, but I have placed patients on ECMO for iatrogenic fluid overload in situations where patients have been getting continuous IV fluids and no one has paid attention to the fact that they weren't urinating sufficiently. And, you know, that seems like a rather drastic step to take to put somebody on ECMO when we could have just been, you know, maybe getting alerted to the fact that this patient wasn't urinating as much as we thought that they should be. So independent of the AKI situation, we have this whole other bucket, which I think is so very important. And if we have a tool that allows us to get better accurate information, make our nursing job easier, I realize they still need to slave data over and accept the data, but they're not manually charting it or forgetting to do it or having somebody dump the urine and not remember to document or measure it, which are things that we struggle with every day. So you mentioned something, and I want to get Jay's perspective on this too, but you mentioned something that one of the questions from the audience is sort of keying off of, and Daniel mentioned House of God, so I think it's a good segue as well, this idea that, you know, we want to fix the urine output just because it's low. And, you know, I think they use the word euboxic in the House of God, you know, get all the numbers to be correct in the boxes. And obviously there's a problem with that, right? In particular, if our knee-jerk reaction is urine output low, give more fluid, which is often the case, and it's how that patient that you mentioned wound up on ECMO probably, right, is this idea of having really a closed loop in the sense of giving fluid for urine output. And that's the dark side potentially of having minute-to-minute urine output if we're not sophisticated in how we respond to this. So maybe I'll start with you, Jay. How do we think about these things and what are the appropriate responses to some of this? Yeah, I mean, I think, John, it's a super vexing problem, right? I've been at this for over two decades. I still don't understand what low urine output means in a patient, right? Sometimes it does mean they need more fluid. Sometimes it means that they need more diuretics, and I would push back on your idea that the first response is always to give more fluid. Sometimes it's to give diuretics, and we've got good evidence that in the setting of AKI, when you look at some of these alert studies that are out there that tell the team, hey, your patient has AKI, turns out that actually there's a large proportion of people who get both fluids and diuretics or diuretics and fluids, and not surprisingly, those are the ones who have the worst outcomes, right? There, in some work by Perry Wilson, there was a group of patients who didn't have someone at the bedside 24 hours a day looking at them and making informed judgments, but were perhaps given order sets that said, hey, your patient has AKI regardless of the type of AKI, and they got fluids. They were more likely to get fluids and more likely to get diuretics. I think you have to think about what's going on in your patient because low urine output in and of itself doesn't tell you what's going on with the patient, right? The answer could be more inotropy, right? The answer could be, get them out of AFib with RVR. The answer could be, no, they're congested and fluid overloaded, and they need to be decongested so that urine output, just as I agree with Michael, is a vital sign. You need to then figure out why that vital sign is deranged. That's exactly right, Jay, and I wanna be clear. I wasn't suggesting that we should give fluids for a look. I was suggesting that that's what you actually see. Yeah, absolutely. Walk into an ICU, most of our ICUs in the United States, at least, are open ICUs, and we have what I refer to as drive-by saline shootings. Anybody can walk into the ICU and get an excuse, whether it's low blood pressure or low urine output or any number of other reasons, as far as I can tell, and just order a liter of saline, and this often results in a huge problem. I think Daniel and Michael, and you alluded to this as well, Jay, one of the ideas here is simply that having this better information can potentially provide better decision-making at the bedside, because otherwise, if you have a vague notion the patient's not making much urine and that's all you know, then it's hard to argue with getting some fluids and then assessing, but if you have more detailed information, like, hey, this patient's three liters up and their urine output has been going down despite fluid administration over the last 24 hours or the last six hours, you have a much more likelihood of making a correct decision. Michael, what do you think? Yeah, I can't agree more with that. I mean, it is a vital sign, and as Jay says, you have to understand why it's deranged. You can't just, you know, but I think part of this is as we, if we get to a point where we are more accurately and more consistently monitoring this, I think it also opens the door for education. I think the fact that people have these drive-by sailing shootings, like you say, you know, that really just comes from, I think, poor education and poor teaching on how to respond to those things, you know, things that we've passed down from generation to generation, and if we have better ways to be able to sort of say, no, look, let's do this and see if that makes an improvement. I think it's this. One of the advantages of this is we're also at, at the same time we're developing these technologies, right, we've also rapidly improved our bedside diagnostic abilities in the ICU with point-of-care ultrasounds and other invasive hemodynamic monitoring and minimally invasive. So we have a lot better way to sort of answer these questions definitively. I like to tell my team that I don't, you know, we don't live in an era where I want you to use your hunch or your gestalt as to what the fluid balance is. I want you to objectively tell me, you know, you have plenty of tools, you have been provided. So go and tell me what those, you know, what the answer is, and then we'll make a decision about how to address that urine output situation. You know, I'll add 1.2 as well, and my attending calls it death by near drowning in the ICU. But one thing that I think is important, and I joke with our pharmacy teams about is even adding this one element may add an educational piece about which weight to even use. If we're looking at that KDGO guideline, you know, and to say per kilo, well, sometimes our patients jump 15 kilos of water weight while they're in the hospital as we flood them as John and Jay were alluding to. So I think even if we can just add a consistent weight that we should be looking at for our patients, is it the dry weight? Is it the weight today? Is it the weight yesterday? Because it can vary significantly. And one thing that this technology does kind of force you to do is pick a weight and kind of stick with it. So it isn't forcing you to change your weight based on your patient being positive 15 kilos today. So I think that's a really important element that this technology kind of forces you to stick with. In addition, it kind of re-educates us all on which weight we should be using rather than jumping straight to the weight and the EHR that's the easiest and quickest to reference. Now, that's really important. And I'm glad you brought that up at this stage because there are several questions regarding the weight. And let's maybe get some more clarity on that. What weight should we be using for any of these things? And what weight was sort of specified in the Kid Eagle Guideline? I'll give you the answer to that. It's not specified and I regret that now. But what guidance can you give our audience for the weight to choose? I don't know that there's great evidence to support one specific number, but this was part of what I was hinting at the idea that the guidelines need revision, right? Because up to 15% of the people in my hospital who wind up on CRRT, say qualified by the definitions for morbid obesity, in which case, I'm not really sure that and almost all of them have AKI. When you weigh 150 or 200 plus kilos, it's darn near impossible even with all the solute load out there, John, for people to make the urine output that they need to not develop some form of Kid Eagle based AKI. I think that if you have an accurate weight, by which I mean, a patient on a scale that you think is pretty realistic at the start of their admission, that's a reasonable place to start and to stick with it. But not everyone has that, right? Not every bed scale... Let's back on that a little bit because we know that if the purpose of weight is to try to get an idea of how much solute this patient's going to be both consuming or in the case of patient not consuming solute or receiving nutrition as muscle breakdown, et cetera, a big bulky patient with a lot of muscle mass is gonna need a lot more urine output than a obese patient, right? So the concept of using total weight, particularly if some of that weight is also a fluid overload, patient comes in in heart failure and they're 10 kilos up with water and on top of that, they started out with some morbid obesity, it doesn't really reflect the needs of their solute excretion. So I recommend actually using ideal body weight. Do I have a study that backs that up? No, I don't. And I think there are some efforts to achieve some of that, but it's definitely true. And several of the audience questions are really right spot on this question. So we often recommend ideal body weight or lean body mass. A lot of hospitals effectively use ideal body weight as their dosing weight for patients for a lot of their drugs as well, but not all hospitals do. And a lot of hospitals just pick a dosing weight that's kind of, you used this expression earlier, and that's how they come up with it, right? And it's almost like the carny who says, oh, I think you're way about 100 kilos, and that goes in the chart, and then that's there. So I think there, and maybe that is a good research agenda, is to figure out whether ideal body weight is the right way to go. Michael or Daniel, do you have any comments on that? Not significant, but I would add that if we're, you know, as it pertains to the medical record, it's very important to figure out which weight on our screen that we use in my institution, that's the daily weight that pops up there. They do have other weights that pop up as well, but the daily weight is the one that filters in there. And as a nurse, I can tell you that those weights are not the most accurate. It depends on whether the night shift nurse liked pillows and the, you know, the things that go in their feet and all those types of things, and whether or not they actually took them off. So I would express caution and just make sure that you're learning which weight is actually displayed before utilizing that as a primary marker. And I just wonder, John, if we're ever going to be able to solve that question as to what's the right weight. I almost wonder if it's just better to sort of come to some, in the guideline writing committees, just to come to some consensus that this is how we're going to do it, and this is how we're going to recommend, and then begin researching it around that and potentially revise it in the future. No, I think that's reasonable. I think it's important for us to appreciate that physiology, you know, can guide us at least a little bit in terms of, you know, what we expect and having a lot of adipose is different than having a lot of muscle mass as the cause of your weight. I think on the converse side, though, it is very important to recognize that there's a huge difference in the amount of urine output is needed for a patient who is, you know, 200 kilos and is a middle linebacker for the Chicago Bears versus, you know, a patient who's 50 kilos and, you know, has very little, is a ballerina for the Chicago Ballerina Company. Joffrey. Yeah, exactly. So I do think that's a critical factor in removing, to the extent possible, some healthcare disparities with regard to detection of AKI, et cetera, and that's why it's so critical. I'm just thumbing through some of the other questions. For sure, John, I would just add, though, when we did things like the furosemide stress test or when we do things like dose CRT, generally speaking, we don't, I mean, for the furosemide stress test, I know we didn't dose over ideal body weight, and when I think of the data around, say, dosing CRT, while we'd like to think it's ideal body weight, nobody does ideal body weight. So I think that there's got to be some consistency. Okay. What about augmented urine output? You know, should we give desmopressin or another approach before giving any medication? I'm sorry, can you, I'm not sure I understand the desmopressin part of that question. Can you maybe repeat that? Maybe I just misheard it. I think the questioner is really sort of wondering about, and this comes back, I think, to the furosemide stress test, and maybe you could explain, Jay, I think you probably have the most experience with this, but Michael and Daniel understand it as well. Why is the furosemide stress test, you know, a factor in terms of helping you understand the meaning of folliculare up? Yeah, so I think first and foremost, it's important to acknowledge all the data that we've published around the furosemide stress test is in people who have early AKI, whether that be stage 1 or stage 2, with the goal of trying to determine who's going to progress to stage 3, the most severe stage, and or need something like a dialysis machine, right, and that we did it in people who were not hypovolemic, but the idea here is we use furosemide specifically because furosemide is really a test of how well your nephron is working. Nothing is going to put the webinar to sleep more than me talking about nephron and renal physiology, but you need your proximal tubule, right? You need blood to bring the furosemide to your proximal tubule. Your proximal tubule then shifts it from the blood side into the urinary space. It then needs to get to the thick ascending limb, and then the rest of the tubule, the distal tubule and the collecting duct, need to be functioning in order to have that diuresis, and so that in the setting of early AKI… Can I simplify that for my fellow intensive care practitioners and simply say that the purpose of the furosemide stress test is really to sort of figure out if the reason for the oliguria is because the kidneys in a fluid overloaded patient, because you presumably don't have to worry about fluid deficits, is because, you know, the tubules are essentially knocked out. Is that fair? Correct. It helps you figure out what portion… Yes, I'll shut up. Too much nephrology. Okay. Good. So, I'm hoping that addresses the question around augmenting urine output. There are some questions. I'm trying to… There are several questions, which is great, so I'm trying to group them. There's a question about not only furosemide stress test, but LASIK's therapy and wondering about whether we've settled the issue of LASIK's infusion versus bolus. What do people think about that? I tend to believe the… You know, I tend to ascribe to the fact that there's no real advantage of an infusion over bolus dosing. I think Jay has shown that in heart failure literature. I think that's been shown quite consistently in the heart failure literature. I will say that there are a few clinical scenarios where I don't really want the patient to have a sudden urine output of a liter in an hour, for example, that the ability to refill from the third space back into the intravascular compartment may be outstripped with very rapid bolus dosing. And so, if there are some clinical scenarios where you need sort of more steady urine output in someone who's responding and not necessarily peaks and valleys, that's where I sometimes will use an infusion. But I don't think we have any real data that supports that that's better in terms of outcomes. But Jay, I know you've published in this space, so I'll give the floor to you. I think that you're right. I think that there's historically data that shows that maybe there's a signal for harm in people who are on continuous infusions, but that hasn't necessarily been from randomized controlled trials or there have been inherent biases when they're retrospective studies. I'm in alignment with, I think, what you described, Michael. And I think that on some level, to bring it back to the earlier question, I think that we have moved and maybe the field in general has moved to sort of a more global nephron blockade, by which I mean we're no longer just reliant on an IV loop diuretic, but we will do intermittent dosing of a loop diuretic or a thiazide or thiazide-like diuretic, as well as a distal agent. Certainly, the ADVOR trial in heart failure has shown that there's utility to carbonic anhydrase inhibitors as well. And then if you can block multiple spots, you probably will do better than just blocking the loop, plus minus the distal tubule with the thiazide to get there. Yeah, and I want to remind, just to take that one step further, I just want to remind our audience that our patients that are fluid overloaded in need of diuresis, at least in the intensive care unit in most of our critically ill patients, they're not just water overloaded, they're salt and water overloaded. And so, you know, they need to excrete both sodium and water in order to sort of resolve their hypervolemia state. And so, I tend to agree with you, Jay, that unless they're very susceptible to very low doses of loops, I have a pretty low threshold to use combination diuretics just to enhance the natriuretic effect of it, because we certainly know that loops alone are going to predispose our patients to develop hyperanatremia and other sorts of stuff in the ICU, so. I absolutely agree with that. I will say, again, just to play devil's advocate, I still use a fair amount of continuous infusions of diuretics in my, of loop diuretics in my practice. Part of that is for the reasons that Michael spoke to, but the other part of it is the evidence that suggests or shows that intermittent dosing is just as effective or more effective is often based on very specific, you know, sliding scales, very, very careful protocols. And I sometimes can't rely on that actually happening, frankly. And if I have a patient who's written for, you know, a drip that I then titrate, you know, every few hours when I come back and look at the patient, then at least I know that over the interim the patient's going to get that therapy as opposed to, you know, a sliding scale that they may or may not get. But, you know, individual mileage may vary, as we say. One point to be accurately monitored, right, John? If you're doing the drip, you got to have accurate urine. We may change, we may change our whole perspective on this. If there was automated urine output monitoring, because some of our decision-making is based on bad data, which is coming from a manual, you know, reporting. Daniel, I'll cut you off. Sorry. No, no, just very quick point to make from the nursing perspective. When you start a furosemide infusion or any sort of infusion, that does typically take up an entire line by itself. And so lines become an issue and the patient may need more central lines, et cetera. So that's always something to consider if we're doing that to make sure that the patient has adequate access. And if the patient needs a central line, for example, are we putting them more at risk of doing a procedure that perhaps they're coagulopathic, et cetera. So that's always one thing we consider where I work just because our patients are so thrombocytopenic, et cetera, to make sure that we always incorporate that in our thought process as well. Excellent. So listen, we only have about nine minutes left and I want to get at, there's lots of questions and, which is great. And I want to get at a theme that's raised on a few of these. And I think, you know, Daniel, you mentioned this at the very beginning, this idea of, look, we have, and Michael said this too, we, you know, we have automated systems for everything else. You know, we, we measure pulse ox continuously in the ICU, we measure blood pressure, we measure heart rate, and there's no clinical trials that show that those things improve clinical outcomes of any kind. And yet it's often the case that any new technology that comes into the ICU or to the hospital in general today needs to meet one of two standards. It either needs to do what we currently do less expensively, or it needs to do what we currently do at the current cost, but do it better. And is there evidence that this does any of that? And, you know, how, how can we advocate for this unless there's, you know, a thousand patient study that shows a 10% improvement in survival? I would, I would, just briefly, as I mentioned earlier, I think we have to stop considering nursing an expense and considering an investment. This is a investment that you would make in your patients and your outcomes over time. When we look at some of the previous other technologies that we utilize every day, you know, we didn't have all the data that we would expect of it now, but now we have data in the retrospective setting. So I think we should consider that as we're looking at this and keep that in the back of our mind that, yeah, there may be a little bit of an expense at the outset, but in the end, this may be something that can help improve not only overall patient care, but also the collaboration between our teams. I don't know how often it is that, you know, I try to find nephrology as they're jolting by really quick, but if they can see the hourly urine output documented in the chart more accurately, as well as I can, it may help us also improve our communication, which is also an important patient safety standard as well. That's just my quick two cents about that. I mean, I would echo all of that. In our hospital, we're moving to a point where our CRT machine, right, you talked about those old accordion files, right? The nurse used to hate the nephrologist when they started them on CRT because there were like seven different values that they need, not just the ins and outs, but the arterial pressure and all of that is now seamlessly being dumped into the machine, into the electronic medical record, but we're still sort of manually dealing with urine output. So I think I'm a hundred percent in line with Daniel and have tried to do that, but I've met the exact response from administration that you described, John, which is, well, why do we need to do this if we're already doing it and it's going to cost me X amount of dollars per device? Yeah. Well, and I think it comes down to, I think we have to learn to speak the speak that they speak, which is to say, okay, well, if you want evidence, then we should remove all the continuous telemetry monitors also, you know, so let's stop investing in that. You know, we also need to, we also need to speak the speak in terms of, you know, okay, you know, there's some thought, I think the study that really needs to be done, for example, to convince them is to say, forget about mortality, the devices that are draining the urine away and avoiding the loops theoretically should cause less CAUTIs because you're not retaining urine in the bladder to become infected. So if we could prove that the devices that are automatically in keeping the bladder decompressed have left CAUTIs, now we're speaking the speak of the hospital, right? We can say these devices not only are going to potentially decrease the time on the ventilator, decrease the number of patients that need, that need trachs, for example, for prolonged ventilation, because we'll know the fluid balance better. Maybe I can decrease CRT days because I know this patient, his urine output is picking up more accurately, you know, and oh, by the way, we decrease your CAUTI rates, which you're very concerned about. Now we're starting to speak the speak of, you know, of these, of the administrators and, you know, it's going to take work on our part. We're going to have to take a very sort of, everyone on this panel is going to need to think about how can we, you know, how can we get the language correct and what are the type of studies that we need? Yeah, I just worry, I think, though, with people advocating, advocating, you know, society should start to advocate. Like, I don't know why this hasn't become a white paper, position paper yet of some society of ASN or SCCM to just say, look, guys, you know, and questions, there's questions from the audience that wonder the same thing, right? You know, if the data are here, it makes such perfect sense. It generates data, which is more accurate. I think there's really no question about that. It takes away a lot of decision making that the nurse has to estimate because they couldn't get back to the bedside at the requisite amount of time or the urometer has overflown and they're not overflowed and they're not quite sure what the urine output is and it's just bad data and decisions are being made on bad data. What level of evidence is required? Certainly, we shouldn't have to prove that doing the right thing is required, you know, that doing it, advocating for it, requires a mortality benefit. That would be very difficult to show with a diagnostic, you know, device like this. You know, does, you know, and again, to your point, I know you were saying it tongue in cheek, Michael, but I think it's an important thought experiment. If administration just decided tomorrow that they were just going to rip out all the telemetry monitors, you know, our answer would not be to be able to pull out a paper that shows that telemetry saves lives, right? And, or a signal thermometer, you know, saves lives, right? We take certain principles on faith and I think as a vital sign, having better measurement of urine output is going to be important and perhaps one of the techniques is certainly, as you suggested, you know, having a society produce a white paper on this. Be careful what you wish for, Michael, because you'll be asked to author that. I would be happy to participate, so I've already written half the white paper, so. Three minutes to go and there's several questions on this topic and we've danced around it a little bit or touched on it. I just want to let that be the, let this be the last question we address. Can people speak about this issue about essentially administration being all about taking catheters out of patients, you know, getting rid of Foley's and this super tension around CAUTI? You know, does any of this make any sense that we would talk about, you know, technology that would be used for Foley catheters when we're just going to get rid of Foley catheters? Can people speak about that? I would be happy to, but I can defer to others, but I would, I mean, you know, we have supposedly, I think, put the, we have thrown the baby out with the bath water here, you know. According to the CDC, supposedly 20,000 people a year die from, you know, I don't know how that happened, but 20,000 people per year die from CAUTIs in the United States. That's not a balloon thing. You know, we have an epidemic of AKI in the ICUs where we have anywhere between three and a half and four million cases of ICU acquired AKI per year. I mean, it's ridiculous to think, and to think that some of our other technologies are not responsible is ridiculous. I've had plenty of patients get CAUTIs from condom catheters because the urine sits there at the tip of the urethraeumatis. I've had people get CAUTIs from the PureWick catheters because the PureWick device, you know, sits there. So, I think it's a misnomer to say that it's purely catheters, but, you know, I'm using hyperbole. I'll defer to the others. I also think it's two separate patient populations, right? There are people who they're right to try to get the catheter out of, right? If you're coming out of your cardiac surgery, you're extubated in the OR, and you're looking good, I don't know that you need a catheter for two days like they used to have, right? I'm not necessarily advocating using devices like this in those people. It's the people who, you don't know which way they're going or you're, you know, it is 24 hours after, and they're still intubated, right? It's two separate patient populations. I'm all for sort of the rapid de-escalation of care when it's appropriate, but it doesn't mean that that's appropriate for everyone, which is what I think. Well, and David, you made the argument that, you know, using this technology sparingly and using Foley catheters sparingly on the patients that deserve it, and simultaneously removing Foley catheters from patients who shouldn't have them, is a way of keeping the overall price tag in a manageable sort of way. In other words, if you really think the patient's sick enough to need a Foley catheter, you probably need an automated system to measure urine output, and if you don't, then maybe you don't need a Foley catheter at all, and maybe that is a way to approach it. So with that, we're right at the top of the hour, and unless anyone has a five-second comment they want to make, we're going to go ahead and conclude this webinar. Thank you very much for participating, and thank you, audience, for coming on. We have quite a large number of people, and I hope you enjoyed this presentation. Thank you for joining us for this webcast titled Urine Output Monitoring in Critically Ill Patients. We hope you found the information valuable and insightful. We extend our gratitude to the American Association of Critical Care Nurses for their collaboration on this project, and to FISE Medical for their educational grant support. Stay tuned for more educational opportunities, and thank you for your dedication to improving patient care.

urine output monitoring

critically ill patients

automated devices

acute kidney injury

Foley catheters

real-time measurements

clinical outcomes

KDIGO guidelines

nursing workload

technological reliability