Thank you so much, and thank you to the organizers, and it's really an honor to share this stage with such an accomplished group of speakers and this whole morning with Fluid Fluid in this room all morning. So I do not have any really pertinent relevant disclosures, but it is important to know that I do receive some royalties for the chapter on CRRT prescription from UpToDate, of which I'm a co-author, and I will be discussing CRRT and how to prescribe some CRRT. And so that's just an important thing for me to let you know. I was given this objective, which is to discuss the literature surrounding the mechanisms, i.e. diuretics or dialysis, and the speed of fluid removal in critically ill patients. That's an almost impossibly large topic to cover in 10 minutes. So this is going to be a very high overview, and I'd be happy to talk as long as you want into the lunch hour period if you have questions after this. There is an important lecture starting point that we have to agree with. Because of the time limitations, I can't really go into whether or not it's time to start diuresis or why fluid overload is causative of bad outcomes. So we're just going to have to agree that for purposes of this talk, you have decided that your patient is fluid overloaded and that you have decided you would like to return the patient to uvulemia. And so then the question becomes, how are we going to do that? So it's unfortunately a little bit more complex than we would like it to be. We need to assess the volume. I would suggest that we need to recognize that fluid overload exists. We need to use objective assessments that you've heard from Dr. Connor Schuller and others, Dr. Mayatra earlier this morning. I think gone are the days when we should just be sort of using hyperbole or sort of gestalt as I think my patient's volume depleted or I think my patient is fluid overloaded. We have enough tools now that we should easily be able to objectively assess that. We then need to decide on a fluid removal strategy, and that requires us to establish fluid balance goals. We're going to talk a little bit about that. And then we have to talk about timing, method, mechanism, rate, and any sort of co-interventions that we need to do to help us remove the fluid. And then we need to monitor the clinical impact that this is having on the patient. We need to individualize how we're defining tolerance, how we tolerate what one patient is tolerating. It may not be the same definition of some other patient. So we may be able to tolerate a little bit of pressors in one patient and not in another. And again, we need to use objective tools, and then we need to begin all of this again. So let's just very, very briefly touch base here because other talks have already touched about this. Half the battle is really recognizing that fluid overload has occurred in your patient. Part of that means that we need to, I've lost the ability to move forward there. Part of that means that we need to strictly measure all of our I's and O's. We need to document all of our urine output. We need to be getting daily weights. These are simple things that we need to do. We can't have Foley catheters in patients and throwing away the urine without having documented how much comes out. We need to also recognize that without active management by the team, fluid does just accumulate. The FACT trial was brought up in the earlier session, and this is again, you know, compared two different arms of fluid management. But in the usual care or the liberal sort of fluid arm, when they were not given any protocolized diuretics, they just continued to gain fluid the entire time. So we need to recognize that it does require an intentional act by the ICU team to remove volume. So let's move on to the other sort of topics. So fluid removal strategies. That's the balance of this talk. So the first thing I said is that we need to establish fluid balance targets. And believe it or not, we're really actually quite bad at that. So this is a really important study that as one of their secondary endpoints, they looked at how commonly for patients that are on CRRT, did the team actually decide what the fluid balance should be that day on the patient? And we actually don't do a good job of this. In this study, only 38% of patients on CRRT had a fluid balance goal discussed by the team for that day, 100% of the days that they were on CRRT. Personally, we talk about it every single day on patients. But in general, it's not something that we're doing particularly well across the board. Now there is a little bit of relationship to how sick the patients are here. So as patient SOFA scores are higher, the team may not be prioritizing fluid removal. But I would still argue that they should at least be talking about, is there a peak? You know, do we want this patient to be 10 liters positive? Or maybe does the machine need to keep us down at like four liters, for example, positive? If we're also talking about that I said that this is half of the battle, the other half then becomes the intervention. What are we going to do? Diuretics, nothing, renal replacement therapy. And how are we going to remove the fluid? So there's basically sort of three ways. We can pee it off. Dr. Hawkins likes to say you need to be free of the ICU. And that could be either spontaneous or augmented. We have dialysis or effluent. And then we have a whole group of other things like NG tubes, stool, skin from burns, bleeding. Generally speaking, this category is uncontrollable and I'm not going to necessarily induce diarrhea or cause burns in my patients. And so therefore, you know, we sort of have to discount this and we're just going to sort of not view this as a controlled mechanism of removing fluid. So let's talk about urine first of all. Before we get into diuresis, I do want to sort of bring us back to a couple of very key points about IV fluids and fluid excretion. So I already said that fluid overload is very common in the ICU, but our IV fluids contain salt and water. So 0.9% sodium chloride contains 9,000 milligrams of sodium chloride, which is about 3,540 milligrams of sodium. And just as a dietary example, there's a certain roughly shaped potato chip out there that contains 150 milligrams of sodium per one ounce of potato chips, which means that one liter of normal saline is equivalent to eating 1.5 pounds of this roughly shaped potato chip. So our patients are not just water overloaded, they're salt and water overloaded. And normally, our urine contains varying quantities of sodium, water, and other substances based on our intake that our kidneys decide that they need to excrete. The problem is that sick kidneys can struggle to excrete all of this extra intake, all this extra salt and water. And even kidneys that have no demonstrable dysfunction can struggle with the overwhelming burden of salt and water that had been applied to it and can have trouble getting rid of all of it. And they'll need diuretics in order to do that. So what are the patterns of diuretic use in the ICU? So this actually has not been studied that great. This is sort of the best study that was published in 2019. And they used the MIMIC-3 database, which included about 46,000 patients in this study and looked at the diuretic use. Now it's really important to remember that this included patients in MIMIC-3, which was 2001 to 2012 patients. So it reflects patterns in 2001 to 2012, not necessarily current patterns. And what did they find? They found that about 50% of ICU patients received diuretics. There was a distinct relationship based on the flavor of ICU that the patient was in. LASIK was the most common use. And combination diuretic use was really very uncommon. And also, quite interestingly, they showed that based on admission to the hospital serum creatinine, as the kidneys were sicker, the patients got less diuretics, which doesn't really make a lot of sense because a lot of these patients are going to be diuretic dependent on their best day at home. And then they come in the ICU, get flooded with salt and water, and no diuretics are given. So what are lessons from this? So ICU patient flavor clearly does impact. During this time period, there were a lot of patients that didn't get diuretics despite being very commonly fluid overloaded. And so I would suggest that this probably is a reflection that maybe these providers either accepted fluid overload as sort of being OK, or that there was some discomfort by the providers in using diuretics. Has our approach to fluid management changed since 2012? I would say most definitely, yes. We are more aggressive at returning patients to euvelenia, so I would suspect that there is a higher use of diuretics now than there was during this time period. And it's important for us to remember, and for me to stress to you guys, that patients with CKD and AKI will likely need diuretics in order to excrete what you are giving them. And that diuretics are not nephrotoxins. The fluid overload is actually a nephrotoxin, which is a whole separate conversation that I can have with you. And this study used the same MMIC3 database and looked only at patients with acute kidney injury, and they showed that basically across the board, giving diuretics improved outcomes for all of these different subgroups of patients. Now here in this sort of stage 3 AKI patients with advanced serum creatinine changes, they were probably not very diuretic resistant, which is probably why you're not seeing much. So let's move on to dialysis. So what about the speed of fluid removal? I apologize, I'm going to probably go a couple of minutes over here, because this is a really important concept, is how fast can we remove volume, and is there a sort of safest rate of fluid removal? So there's been a few studies published, three of them by the same group of investigators using different data sets, and then two others by different groups of investigators. In the absence of being able to have the time to go through all of this together, I put this together here in a table, and just to sort of show you that they've used different data sets of patients. The RENAL trial was a randomized controlled trial, but this is a retrospective study of those patients, and then other sort of data sets, either in the U.S. or Australia and New Zealand. There's overlapping sort of tertiles of patients, so in this one study, the highest tertile was greater than, say, one milligram per kilo per hour fluid removal, which is equivalent to the lowest tertile in these two studies, and so it's a little bit difficult to interpret, but when you sort of look at this, it sort of says that too low fluid removal is bad, too high fluid removal is bad, and there may be some sort of like Goldilocks sort of period that's in here. In short, it's really very confusing, and I do want to point out that there are some real problems with these studies, and I really want to caution you against over-interpreting these studies. The first of all is that there may be some location of the study or location of the patient bias, okay? The studies that tended to show that fluid removal was, that high fluid removal was bad, occurred in Australia and New Zealand, which tend to be very fluid-restrictive locations in general, and studies that showed that more fluid removal was good occurred in the United States, where we tend to be actually drowning most of our patients. The other problem is, is I just want to call your attention to that they define this as net ultrafiltration, which is really the very incorrect term if you look at the math behind that definition. How they calculate a net ultrafiltration is actually the ultrafiltration or the patient fluid removal rate on the machine, which was not accounting for the ongoing intakes in the patient. And so these studies say nothing about what the net fluid balance was of those patients, and net fluid balance is much more clinically relevant than how much I'm taking off on a given hour by the machine. And I would also say that there's probably a lot of bias in here, because we know that fluid overload itself causes bad outcomes in our patients. It's not just associated, it causes it. Why would I prescribe, as a prescriber, more fluid removal on the machine? Why would I turn the dial up and take a lot more fluid off if they were not already fluid overloaded or having a high obligate ongoing intake? I'm not going to take a lot of fluid off of Dr. Barreto when she's not necessarily fluid overloaded. So the patients that were getting more fluid off were obviously either fluid overloaded and therefore having a higher risk of death because they were already fluid overloaded, or they had higher obligate intake, lots more infusions or antibiotics, and were likely meaning that they're generally sicker. And so just to finish up, going back to this study that I showed you before, the primary outcome of this study was actually fluid removal and whether or not that improved outcomes. And in this study, greater fluid reduction during CRRT was associated with higher survival. The other important thing was that the number of days in which a patient was fluid over or the number of days in which they established a fluid balance goal was strongly correlated with the ability to achieve a negative fluid balance. So talking about it helps you actually achieve it. And then we're going to obviously move past this. So in summary and conclusions, we have a daily sort of workflow management on our patients. We need to measure everything and document everything. We need to discuss and establish our fluid balance days goal. We need to stop excessive IV fluids, and then we need to ask ourselves, is the patient fluid overloaded and ready for removal? If they're not, then you just go right back to this and just keep going. But if they are, we probably need to have a little bit more liberal use of vasopressors, and then monitor how well the patients are tolerating the removal. We need to give diuretics in an individualized and guided fashion for patients' fluid balance needs and targets. When I prescribe diuretics, I don't just say we're giving it twice today. We're going to give diuretics until we achieve a certain goal. Sick kidneys need diuretics. You can't expect the kidney that's unhealthy to be able to do this on its own. And that combination diuretics enhance sodium excretion and therefore may be useful because our patients are actually salt and water overloaded. And then when they're on CRRT, we need to transition to at least a net even fluid balance by using the CRRT machine to maintain that during the maintenance phase of illness. We need to start de-resuscitation and monitor tolerance closely. And then we need to escalate removal if our patients are tolerating. And remember, it's a race to liberate from the ventilator, not necessarily a race to liberate from vasopressors. And with that, I'm going to thank you. You can reach me here if anybody is actually still using Twitter. I'm also available on that.

fluid removal

critically ill patients

fluid overload

fluid balance goals

diuretics