A deep dive into CRT

The Comprehensive CRRT Explained Series!

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Summary

Eddie Watson from ICU Advantage, known for simplifying complex critical care topics, presents a comprehensive video covering the entire Continuous Renal Replacement Therapy (CRRT) series. The video compiles six lessons, delivering a foundational understanding starting from renal system anatomy and physiology, and moving through basic CRRT principles, modes, setups, and related anti-coagulation strategies. It also includes practical insights absorbed over years of field experience, making it indispensable for ICU professionals aiming to thrive in critical care environments. The video also highlights how CRT differs from other forms of dialysis and offers practical advice for hands-on application and troubleshooting during therapy. Membership benefits like continuing education credits and access to detailed notes enhance the learning experience.

Highlights

Eddie Watson offers unmatched clarity in explaining CRRT's intricate details and practical application in ICU settings. 🧠
Experience the full gamut of CRRT, including key operational principles, through engaging, detailed lessons. 🎥
Explore machine setups with a practical lens towards CRRT's applications and importance in maintaining patient stability. 💡
Differentiate between various dialysis therapies, with a strong focus on CRRT's continuous mode for critical care patients. 🔄
Tackle common challenges and boost efficiency with Eddie's expert insights and troubleshooting tips. 🌟

Key Takeaways

CRRT is a continuous process aiming to simulate kidney functions 24/7, ideal for unstable ICU patients who can't endure traditional dialysis. 🏥
Understand core principles like diffusion, convection, ultrafiltration, and adsorption which underpin CRRT's effectiveness. 📚
Master the setup and circuit design of CRRT machines like PrismaFlex and learn practical application strategies. 🔧
Choose appropriate CRRT modes—like SCUF, CVVH, CVVHD, and CVVHDF—tailored to patient needs. 🚑
Anti-coagulation strategies (regional and systemic) are crucial for extending filter life and reducing bleeding risk during CRRT. 💉
Membership offers avenues for continued education credits and access to premium educational content. 🎓

Overview

Welcome to the extensive CRRT Explained series by ICU Advantage, crafted to imbue confidence in ICU professionals facing critical patient care! Eddie Watson demystifies the sophisticated processes of continuous renal replacement therapy, ensuring caregivers can leverage CRRT effectively for patients requiring stable, gentle hemodynamic management.

The series navigates through the essential knowledge required for CRRT—starting from basics like renal anatomy and filtering mechanisms, to a full exploration of CRT modes, such as SCUF, CVVH, CVVHD, and CVVHDF. Eddie’s practical breakdown of machine setup and maintenance ensures that even those new to CRRT can follow along and implement their knowledge confidently.

Conclude your deep dive with an understanding of anti-coagulation strategies vital for efficient CRRT filter utilization and patient safety. With real-world tips shared in Eddie's signature, engaging manner, you’re on a path to mastering CRRT like a seasoned pro while claiming membership benefits that prolong your professional learning journey.

Chapters

00:00 - 01:30: Introduction The chapter is an introductory video lesson by Eddie Watson, aimed at boosting confidence in handling ICU tasks. It promises to simplify complex Critical Care subjects to aid understanding, specifically focusing on a complete CRT Explain series.
01:30 - 10:00: Renal System Review This chapter provides a comprehensive review of the Renal System with a focus on Continuous Renal Replacement Therapy (CRT). It includes six lessons aimed at building a solid foundation in CRT, starting from renal system anatomy and physiology. The chapter also explores different principles and operational modes of CRT, discusses anti-coagulation, and presents a collection of practical insights gained over the years. Additionally, it offers an option to earn Continuing Education (CE) credits for this series by becoming a member of the ICU.
10:00 - 18:30: Introduction to CRRT The chapter introduces the Continuous Renal Replacement Therapy (CRRT) and features offerings from Advantage Academy. The academy provides access to redesigned premium notes on CRRT for its members, which can be obtained by following a link. Additionally, even if one doesn't require credits, original style notes and audio versions of lessons are available.
18:30 - 25:00: CRRT Machine Basics The chapter introduces the start of a lesson series on Continuous Renal Replacement Therapy (CRRT). It mentions the availability of additional resources through YouTube or Patreon memberships, including notes and audio versions. The chapter serves as an introduction to the foundational and important aspects of CRRT.
25:00 - 40:00: Principles of CRRT The chapter titled 'Principles of CRRT' focuses on providing a review of the renal system to support understanding Continuous Renal Replacement Therapy (CRRT). Although it assumes prior knowledge from anatomy and physiology classes, it revisits essential information about renal anatomy. The objective is to establish a foundational understanding of renal anatomy and physiology necessary for comprehending the goals of CRRT.
40:00 - 49:00: CRRT Modes and Therapies The chapter 'CRRT Modes and Therapies' begins with an introduction to the anatomy of the human kidneys. It explains their location in the retroperitoneal cavity on each side of the spine between the 12th thoracic and 3rd lumbar vertebrae, with the note that the right kidney is lower due to the liver's placement. The chapter goes on to describe the three layers of the kidney: the cortex (outer layer), the medulla (inner section), and transitions to discussing various continuous renal replacement therapy (CRRT) modes and therapies.
49:00 - 60:00: Anticoagulation in CRRT This chapter explores the anatomical structure and function of the nephron, the functional unit of the kidney. It outlines the role of nephrons in maintaining water balance, with an introduction to the renal pelvis where urine is collected and sent to the urethra. The chapter emphasizes the vast number of nephrons present in the kidney, highlighting their collective function.
60:00 - 75:00: Summary and CRRT Pearls This chapter delves into the complex structure and functions of the nephron, a critical component in maintaining electrolyte balance and acid-base equilibrium in the body. It begins with explaining the structure of the glomerulus, which is housed within the Bowman's capsule. The summary highlights the significance of understanding the nephron's anatomy for grasping its role in bodily homeostasis. The chapter provides insights into each part of the nephron, laying the foundation for understanding renal physiology and filtration mechanisms.

The Comprehensive CRRT Explained Series! Transcription

00:00 - 00:30 [Music] all right you guys welcome back to another video Lesson from ICU Advantage my name is Eddie Watson and my goal is to give you guys the confidence to succeed in the ICU by making these complex Critical Care subjects easy to understand all right everyone this lesson here is going to be the complete CRT Explain series all in one video all
00:30 - 01:00 six lessons from that series are here back to back and we'll cover everything you need to know for a good solid foundation in CRT from our renal system anatomy and physiology through the different principles of CRT the different modes that we can operate in uh as well as a discussion of anti-coagulation and a fairly comprehensive collection of pearls that have just been learned over the years now if you'd also like to earn C credits for watching this series then you can simply become a member of of ICU
01:00 - 01:30 Advantage Academy at IC advantage.com Academy or follow the link down below and joining there now as an academy member you're also going to have access to the brand new and beautifully designed premium notes that I'm working on redesigning that said you can also pick up a copy of these CRT premium notes by following the link down below now if you don't want or need c credits but still would like access to the original style notes as well as audio only versions of of my lessons you can
01:30 - 02:00 also become a YouTube or patreon member and access all the notes as well as all those audio versions of the lessons for the entire Channel you'll find links to both of those down below as well I hope you guys enjoy this master cut on many aspects of CRT that are foundational and important for you to know all right so in this lesson here today this is going to be the first lesson in a series of lessons talking about continuous renal replacement therapy or crrt now before we get into talk about this therapy
02:00 - 02:30 though it helps to have a good understanding of the normal anatomy and physiology of the renal system to really better understand what it is that we're trying to accomplish with this and that's the point of this lesson here is to go over this renal System review now this lesson is not going to go too in depth as I know most of you have already had the anatomy and physiology class but I am going to review through some of the helpful information and so to start let's begin talking about some of our renal Anatomy now as we know the organ of the renal
02:30 - 03:00 system is the kidney which we have two of they sit in our retrop paratenial cavity on each side of the spine between the 12th thoracic and third lumbar vertebrae and just interesting to note the right kidney is actually lower than the left due to the placement of the liver now we can divide the kidney up into three layers we have the cortex which is this outer layer here next we have the Mulla which is going to be this inner sort of open section here and then
03:00 - 03:30 finally we have the renal pelvis which is going to be this area here and this is where the urine is collected and sent to the urethra now the cortex and the medulla they contain various parts of the Nephron which is actually what we're going to talk about here next and so the the nephron this is our functional unit of our kidney and so what's really interesting is that each kidney contains more than 1 million of these nefron units in it and collectively together that they work to maintain the water
03:30 - 04:00 electrolyte waste and acid base balance in our body and the way that they do that is through this pretty complex structure that you see that I have the picture of here and so let's go through and talk about some of the different parts of this pretty complex nephron structure so the first is going to be this big capsule like structure here and this is going to be something that we call the Glarus and as you can see it's surrounded by this membrane something that we call the Bowman's capsule now the first section coming out of the GL marless is going to be our proximal
04:00 - 04:30 tubule and then continuing on from here this is actually still technically part of the proximal tubule but this is something that we call the loop of Henley and the loop of Henley is composed of three sections we have the thin descending Loop the thin ascending Loop and then the thick ascending Loop and then from here we go on to the distal convoluted tubule before finally going into the collecting tubule and the collecting duck now important to go along with the tubules of the nefron is also going to be the renal blood supply
04:30 - 05:00 that we have going through here and interestingly 20 to 25% of cardiac output is going specifically to the kidneys and so everything really begins with the renal artery branching off the aorta and so we can see that coming in on the image here on the right and then from there it's going to Branch down until we have something that we call the aparant arterials and this aeren arterial is going to be what enters the Bowman capsule and really helps to form that glomerulus now from there the blood is it's going to exit the glomerulus via
05:00 - 05:30 what we call the eer arterial and then the eperen arterial is going to become this pretty big complex something that we call the peritubular capillaries and really these peritubular capillaries are going to interface with all the different parts of the tubules to continue to perform functions that need to happen within the nefron all right so now that we have the basic structures out of the way let's talk about the actual renal physiology that's taking place here and so the main goal of the kidney here is to filter the
05:30 - 06:00 blood and form urine again like I said in this process the nefron is going to be regulating water electrolytes waste and the acid base inbalance so like I just talked about the aarant arterial is what goes in and forms the glomerulus which is actually a high press capillary bed to which then the blood exits via that eperen arterial now here the aeren arterial is actually a larger diameter than the eperen arterial and this is what allows a greater volume of blood to to enter the Glarus than what's actually
06:00 - 06:30 exiting and this is going to create a high pressure and it's specifically this high pressure that creates the hydrostatic pressure allowing water to be filtered across the basement membrane and so then the basement membrane of the Glarus is actually a semi-permeable membrane and it's going to allow all but the larger molecules to pass through it so think here we're excluding things like protein albumin red blood cells and so here we're going to have particles that are small enough to pass across the basement membrane which are going to be
06:30 - 07:00 moving from areas of higher concentration to lower concentration and this is also something that we call diffusion now on top of that if we have enough water that's being forced across that membrane via that hydrostatic pressure that we just talked about additional particles or solutes are also going to be dragged along with it something that we call convection and so typically with our kidneys large volumes of water are going to be filtered allowing for this additional waste clearance that we see so now we have blood that's left with these large
07:00 - 07:30 molecules and proteins and it's going to be leaving via that eperen arterial now having these large molecules and proteins in there is actually going to provide oncotic pressure for water and solutes to be reabsorbed in those peritubular capillaries and so as you can see the blood that's exiting via the eperen arterial is still oxygenated blood and so in addition to also going into those peritubular capillaries another responsibility that it has is to actually peruse the kid itself and
07:30 - 08:00 that's why finally at the end here we do see the blood becoming deoxygenated as it goes out into a vein all right so like we talked about we have that high volume of of water filtrate that has left out of the glomerulus and first we're going to enter into the proximal tubule and this is going to be responsible for the reabsorption of water and important solutes and electrolytes and here we're talking about things like potassium sodium chloride glucose and bicarbonate now on top of this reabsorption we also have
08:00 - 08:30 hydrogen ions that are going to be passively secreted here now continuing on we actually have different nephrons that have different responsibilities for what actually takes place in the loop of Henley so we have shorter cortical nephrons which are going to focus on the excretion and Regulatory functions while we have longer jux to medular nephrons which either dilute or concentrate the urine depending on what needs to happen now if you remember looking at the Loop of Henley there's a big distinction between Parts one and two and part three
08:30 - 09:00 in terms of the thickness and it's this thickness of the loop of Henley that actually impacts the permeability of the membrane allowing it to do different things so then moving on we have the distal convoluted tubule which plays an important role in the regulation of blood pressure while also regulating solutes by absorbing or excreting them in this section and in this section we also have the antidiuretic hormone or ADH which AIDS in water reabsorption towards the end of this distal convoluted tubule now we do see some
09:00 - 09:30 bicarb being reabsorbed here as well as hydrogen ions being actively secreted and then the main waste products that we're looking to excrete through this active filtration by the nefron are going to be our bu uric acid and creatin and so as you can see the the kidney and their functional units the nephrons really play that vital role in the homeostasis of our bodies they're regulating the fluent balance by controlling how much water is reabsorbed waste electrolytes and solutes are going
09:30 - 10:00 to be filtered out but then the regulation of the electrolyte solute reabsorption is going to take place to ensure that our body has proper levels and then also through the reabsorption of bicarb and the secretion of those hydrogen ions they're going to be working to regulate the body's acid base imbalance and so when our patients go into acute kidney injury and ultimately renal failure this important regulation really becomes ineffective or non-existent and in order for us to be a to support these patients we really need
10:00 - 10:30 to recreate the work of what's Happening inside this nephron and so much of what we attempt to do with the therapies that we offer is based on what the natural nefron is doing and therefore having an understanding of what normally happens in here is going to be important to understand the how and why the therapy that we provide does what it does and so that's why I wanted to do this renal System review for you guys so that you had this understanding of what was going on here because as we move move forward and begin to talk about CRT and how that
10:30 - 11:00 works much of what's going on there is really driven with the purpose of trying to recreate what happens here so that we can effectively filter the body's waist as well as controlling the the fluid balance as well as the electrolyte and solute balance of the body as well as having an impact on our patients's acid base balance so I hope this was a good quick review of what's going on here in the renal system like I said we're going to apply this information moving forward
11:00 - 11:30 continuing on the CRT lessons all right so this is going to be a continuation on the series here talking about CRT and really explaining what this therapy is in the second lesson here what we're going to talk about is what exactly CRT is I'm going to explain what the therapy is why it is that we use it and give you some basic info really about the therapy and the setup of everything over the next few lessons we're going to dive deeper into the principles and the type of therapy that we really can offer these patients so make sure and follow
11:30 - 12:00 along and stay tuned all right and so let's go ahead and get started here and let's start off talking about what exactly is CRT so CRT stands for continuous renal replacement therapy and so CRT is a therapy that really is in the same class as our intermittent hemodialysis ihd or our peronal dialysis PD and so what CRT is designed for is for the critically ill patient who often times is unable to tolerate the rapid short iterations and and the accompanying fluid and electrolyte
12:00 - 12:30 shifts that we typically will see with intermittent hemodialysis and so as its name suggests instead of the typical 3 to 4 Hour run times that we see with normal dialysis CRT is running continuously 24 hours a day and so this is going to be better tolerated by our unstable patients and so just as with regular dialysis the goal of CRT is to remove toxins excess fluid and really balance our electrolytes and our goal is to mimic the job of the fail kidneys it
12:30 - 13:00 does this by reproducing the the various functions that we saw on the nefron that I talked about in that first lesson now it is important to know though that not all facilities offer CRT often times in these cases when we have these critically ill unstable patients is we're going to offer them a different type of therapy that we call sled which stands for slow low efficient dialysis and these are runs that last anywhere from six to 8 hours and are often times done every single day for these patients so as you can see that'd be a pretty resource time heavy commitment for these
13:00 - 13:30 patients but in facilities where you just don't have a CRT available to you this is a really good option for these unstable patients now in order to operate the CRT machine as well as to take care of the the patient that's receiving the therapy it really requires specialized nurses who have been trained in this therapy uh as well as the physiological impact that this therapy is going to have on the patient now these patients are often very sick and to be honest quite timec consuming and in many facilities these patients who are on CRT are staffed as one to ones
13:30 - 14:00 and so the next question we want to ask is why is it that we use CRT and so I really hit on some of this already but we're going to use CRT in the critically ill unstable patient who have Aki or acute kidney injury and are in acute kidney failure or in patients who are endstage renal patients who receive dialysis who are also too unstable to receive normal ihd and then just to list out some of the main indications for renal replacement therapy which would also include CRT and those critically
14:00 - 14:30 ill unstable patients are going to be things like elevated toxins so are creatinin and bu fluid volume overload severe electrolyte imbalances and some acid base imbalances now those are the primary indications but we also find that we can use CRT for patients in sepsis to Aid with the cytokine clearance patients who have rabdomiolisis CHF and even postop heart surgery and then given that these patients are pretty sick typically these patient are going to be hemodynamically
14:30 - 15:00 unstable and they're going to be requiring pressors to maintain an adequate blood pressure and one of the really nice things about CRT is that because it's continuously running we can make changes to the therapy at any time and so we can adapt to really rapidly changing situations that are being presented with these critically ill patients so that's kind of the quick down and dirty on what really CRT is and why it is that we're going to use it and so then let's move on and talk about really the basics of the machine and the circuit setup for running these patients on CRT so what we're going to do is
15:00 - 15:30 we're going to talk about the arrangement of the machine in the circuit and really how it is that we run the therapy through here there are different types of therapy which use some are all the parts that I'm going to talk about here and I am going to discuss those in the next lesson but for now let's just review the entire setup now there's really three main machines that are used most often four if you want to count the the most recent upgrade to one of them and honestly there there may be others but these are the three that I've seen now the first and most popular of these is actually going to be by a company called Baxter
15:30 - 16:00 and this is going to be the more common and and older machine which is the prismaflex as well as their new prismax then we have the Edwards life science Aquarius and I believe this machine and its business was actually purchased by backer some years ago so these might be just eventually working their way out into the newer backer machines and then the other one is going to be something called next stage now each facility that I've worked at is used the backer pris flex and then now we're starting to get in some of the new prismax machines the
16:00 - 16:30 Aquarius is actually very similar in the machine configuration to the Prisma flx prismax now I did spend a little bit of time Moonlighting at a facility that used next stage I didn't get to the point to where I was actually doing this therapy on those patients there but this machine seemed simpler to use and required less work from the ICU nurse from what I saw now the operation of the next stage was slightly different than what I was used to with the pris flex but really the basics I'm going to talk about here and the principles discussed in this lesson as well as next couple lessons are still going to apply to
16:30 - 17:00 nurses who are are running therapy through that machine now with all that said I'm going to base my example here on the Baxter machine and honestly part of this is because of the Simplicity and really just the the availability and the wide use of this machine as well as just my personal experience and and knowing this machine much better now again each of these machines essentially has the same parts so really functions in much the same way all right so when we talk about CRT therapy the first thing that we have to talk about is our access in
17:00 - 17:30 order to operate we need to be able to remove blood from the patient run it through our CRT machine and then return that filtered blood back to the patient now most patients that are going to be running with this are going to be newly placed temporary catheters and these are typically 12 or 14 gauge double Lumin catheters and these catheters are going to be placed in a vein most commonly in either the internal jugular subclavian or femoral veins now these can be either tunneled or non- tunn but again typically most are not going to be and
17:30 - 18:00 so for our example here I'm going to have a Right igj double Lumin HD line now on this catheter there is going to be an access and a return line on the catheter and typically these are going to be colorcoded red for Access and blue for return and so for this catheter we really want to make sure that we're using the proper ports that are going to our circuit and to really help better illustrate this let me draw a quick example of what the catheter is like internally and so what happens is we have the return Lumen that's exiting at the distal part of this catheter and then the access line is going to draw
18:00 - 18:30 from more proximal ports and the reason that this is is that we're trying to minimize drawing any already filtered blood back into the system which if we do that is really just going to reduce the efficiency of what our run is able to do all right so now that we have the talk about access out of the way the first part of the machine that I actually want to talk about is going to be the blood pump and so this pump here is a roller pump and this is going to create negative pressure on the patient side to draw blood from the patient and
18:30 - 19:00 then positive pressure on the machine side to drive that blood through the filter and then return it to the patient now for the blood pump typically we're going to see blood flow rates that are anywhere from 150 to 300 ml per minute but we can actually have much higher flow rates that that can be achieved with this although we typically aren't going to run the therapy this way all right so next thing along on the machine that I want to talk about is going to be our actual filter and this filter is actually going to be very similar to a typical dialysis filter and for these there are different types
19:00 - 19:30 that have slightly different purposes but the one thing that they have in common is they're actually filled with thousands of hollow fiber membrane tubes and I'm going to put up a picture here to to hopefully show you kind of what that actually looks like and if you really look at it up close it really looks like thousands of tiny hairs and so what we get is the the blood flows up from the the bottom to top inside of those tiny fibers and it's here in this filter where all the magic is going to be taking in place all right and so now
19:30 - 20:00 we're going to have filtered blood that's now coming out of our filter here and the next stop is to go through some sort of air removal or in the case of the backer this deoration chamber it's going to continue on from there and then it's going to reach the safety clamp and the safety clamp is really going to be the the last stop if it detects air or some other critical issue that's really going to stop the machine and stop the blood flowing to the patient now one thing to note real quick is I did draw this with red and blue which typically we see when we're talking about circulation in the body denoting
20:00 - 20:30 oxygenated and deoxygenated blood but that's not the case here we're going to have the same oxygen content of the blood that's coming out of the filter as what first went into it but these are the the color schemes that these machines use to really identify which is your access line and which is your return line so like I said the access is going to be red and that return is going to be blue so now let's actually talk about some of the different fluids that we use and the pumps that help to to drive all this now on this system there's three different types of fluids
20:30 - 21:00 that we can use and each is going to have its own dedicated pump and I'm going to color coordinate these with the same colors that we see again on the the pris flex machine first we have our pre-blood pump which is our pre- replacement solution then we have our dialysate and then we have our post filter replacement fluid so first let's talk about the dialysate here so this is going to flow with the help of our pump to the top of the filter and this is going to float top to bottom in the filter on the out outside of those Hollow fibers carrying the blood and
21:00 - 21:30 then this now filter dialysate is going to exit the bottom of the filter in what we call the affluent line now this affluent drainage is actually going to be controlled by another pump what we call the affluent pump and it's really this pump that is going to be responsible for pulling the plasma water out of the patient's blood across that filter membrane again this is going to be something I'm going to talk more in depth into the next coming lessons here but so the affluent is going to move past the affluent pum and then make its way to the affluent drainage bag all
21:30 - 22:00 right so now let's go on and talk about the pre-blood pump or the pre-re repacement fluid and this one's actually going to travel a long way the pump is going to move it along and it's going to connect with the access line just after we draw the blood from the patient and therefore we're going to be infusing this fluid before it gets to the filter and then finally we have our post filter replacement and so again we're going to have the pump that's going to move this fluid along and it's going to meet up in the case here right at the the point which the blood is going into the deoration chamber and so then this means
22:00 - 22:30 that this fluid is being mixed with the blood after the filter and just prior to going to the patient now when we talk about these different replacement fluids and the dialysate there's many different types of solution that we can use for these fluids now we do have pre-made solutions for this that actually have like particular balances of electrolytes and bicarb or your Pharmacy can mix up special bags or even you can use some various standard fluids in certain cases so again I'm going to discuss some of those differences on when and why you
22:30 - 23:00 would use them in the later lessons in this series now one last bit of solution or fluid that we really could include in the system is going to be our anti-coagulation and this is actually going to be a topic that I'm going to dedicate an entire lesson to but know that there is an option to use a heprin syringe or some other form of anti-coagulation to be given to the blood prior to entering the filter and typically this is if we're using the syringe pump it's going to be just prior
23:00 - 23:30 to the filter or in other cases uh we actually put a Y connector up on the access line and Infuse it way back there all right the next important part of this whole circuit in this setup is actually going to be our pressure monitoring so we monitor the pressure at various points in this system and there's really four main pressures that we're monitoring first we have our acccess pressure and this is going to be the pressure required to pull the blood from the patient and this one's always is going to be negative next we have our
23:30 - 24:00 pre-filter pressure and this is going to be the pressure required to move the blood up through those Hollow membrane fibers this one's always going to be positive and then we have our return pressure and then this one's monitoring the pressure required to return the blood back to the patient and again this one's always going to be positive and then finally we have our affluent pressure and this is going to be the pressure required to pull the plasma water from the blood typically this one is going to be negative but from time to time it can be slightly positive not
24:00 - 24:30 usually though and in most cases you're going to have a negative value here and so this here is the the basic overall setup of our CRT machine and our circuit what different parts and fluids we have coming in and where they're going in and kind of what's happening at various points uh along the way within this machine now I know it looks kind of crazy on here a lot of things going on uh but as we go through the next few lessons here I'm really going to be talking about the different types of Therapies and the way that we run the machine you'll have a good understanding
24:30 - 25:00 of why it is we would do certain things at certain points to really help and Aid in the process of filtering our patients blood so hopefully this lesson though at least gave you a good understanding of again what exactly CRT is the indications and why we're using it and then give you a good overview of how this circuit is set up so that as we talk through some of these next steps you'll have an understanding of where this stuff is taking place all right so in this lesson we're going to be discussing the basic principles that
25:00 - 25:30 apply to CRT these principles are going to help us to better understand how it is that we're able to filter the blood and essentially mimic the job of the nefron understanding these principles is fundamental to understanding how CRT does its job as well as the various impacts of the different solutions that we use for this machine now these principles will also help you understand the different types of therapy that we can offer which I am going to talk about in in the next lesson now if you
25:30 - 26:00 remember from the first lesson what the main job of the kidney and the nefron is to maintain fluid electrolyte waste and acid base balance and we can mimic these functions through four primary methods which I'm going to talk about here and they are diffusion ultra filtration convection and adsorption and so first let's start talking about defusion all right so this is the movement of particles something we also call solutes from an area of higher concentration to an area of lower concentration across a
26:00 - 26:30 semi-permeable membrane and so this is an example of a semi-permeable membrane that we're dealing with when we have CRT so over here on the left side this is where we have our patient's blood and if you remember from the last lesson where we talked about the basic setup of the CRT circuit that the blood is going to flow through the filter from bottom to top and on the right side this is where we're going to have our dialysate and if you remember we have this flowing top to bottom now remember that the blood is flowing in those Hollow fiber
26:30 - 27:00 semi-permeable membrane tubes but essentially the material that makes up that tube is actually a semi-permeable membrane which is what we have here and it's this semi-permeable membrane that's going to allow for Selective diffusion and then really it's the concentration of solutes that are in the dialysate that is what drives the concentration gradient so as you can see from the picture here we have less solute in the dialysate and more in the patient's blood so because of that change that difference in the concentration gradient
27:00 - 27:30 those solutes are going to diffuse across that semi-permeable membrane to reach a state of equilibrium now as I just mentioned we have the blood and the dialysate flowing in countercurrent directions so the reason that we have this is that by having these flows going countercurrent is it's actually going to promote the continual clearance and it does this by ensuring an adequate diffusion gradient is maintained the whole way through so I know that sounds a little complicated so let me kind of illustrate that to help make the point
27:30 - 28:00 so let's say here we have a semi-permeable membrane and we've got again our blood on the left side and the dialysate on the right side and we know that starting out that the blood is going to have higher concentrations of solute compared to the dialysate so now if we had both of these flows going in the same direction as that diffusion is taking place we'd see the concentration of solutes in the dialysate increasing and then the blood which is moving along in the same direction as it works its way towards the end because of the high concentration of solutes in the
28:00 - 28:30 dialysate we're going to have less of a concentration gradient going on and therefore we're going to see less clearance out of the blood towards the end of the filter and so as we go along those concentrations are decreasing in the blood but they're also increasing in the dialysate and this is going to make it harder to get that last little bit of diffusion to take place whereas if we have the dialate flowing in the opposite direction of the blood when that blood reaches the end of the filter and it has a lower amount of solute concentration
28:30 - 29:00 instead of having a dialysate with a high concentration of solutes that we see in the example here instead we're going to have it interacting with diolate with a very low concentration still giving us that concentration gradient and as it continues to move down we still remain with a lower concentration than what's in the blood and so thus by having this countercurrent flow we can get the maximum amount of solute clearance through diffusion so hopefully that Mak sense for you guys so as you can see
29:00 - 29:30 from the drawing here in the blood we have things like blood cells and large molecules such as proteins that are going to be too big to cross the membrane therefore only the desired solutes are going to be able to cross so diffusion is going to be effective at clearing small molecules but not large ones and really the size and type of membrane is going to impact this clearance essentially the filter's permeability is going to be affected by things like our filter por size the
29:30 - 30:00 number of pores that we find in that membrane as well as just the general membrane thickness and this all does vary based on the type of filter that you're using now like I said the concentration of solutes in the dialysate is what's going to drive that concentration gradient and for our dialysate solution uh this is typically going to contain concentrations of sodium chloride and magnesium that are going to be in amounts equal to that of normal serum levels and so we're only going to see these solutes to fuse in cases where the patient either has high
30:00 - 30:30 or low concentrations in the blood now the next solute that's probably one of the most important ones that we have in here is actually going to be our potassium and often times when we're starting patients on CRT we're going to see very high levels of potassium and so what we might actually do is start the patient on a therapy delivering a very low level of potassium in our dialysate and example of this would be one of our 2K baths but since the potassium is going to clear pretty quickly we need to make sure that we're closely monitoring
30:30 - 31:00 and make that transition to a more normal level such as one of our 4K baths as our patients begin to normalize their pottassium level now serum bicarb levels are typically going to be low in patients with renal failure so typically we use a dialysate solution that contains bicarb to Aid in the diffusion into the blood and then finally waste products such as our Uria and our creatinin they're not going to be present in our dialysate therefore these are going to diffuse and be filtered out of the blood now when we're talking
31:00 - 31:30 about diffusion that's taking place from blood to dialysate in a filter this is something that we actually refer to as hemodialysis all right so that's the principle of diffusion and hemodialysis uh hopefully that makes sense for you guys cuz let's go ahead and move on and let's talk about the next principle something that we call ultra filtration so one of the keys to this principle is knowing that fluid is able to cross a semi-permeable membrane brain in response to a pressure gradient
31:30 - 32:00 and this pressure gradient can be the result of one of three things it can be either osmotic pressure oncotic pressure or hydrostatic pressure so now if you remember back to that first lesson when we were talking about the nefron and specifically the function of the glomerulus we have those epher arterials which is carrying that blood away from the glomerulus that those were of a smaller size than the aparent arterials bringing the blood in as well as they were able to constrict and relax working to regulate pressure basically creating
32:00 - 32:30 hydrostatic pressure in the Glarus and this is what would help Force water out of the blood ultra filtration is essentially that same process we're going to be moving fluid through the semi permeable membrane across a pressure gradient now when talking about our circuit we can actually create this pressure gradient in a couple different ways we can either create positive pressure on the blood side pushing the blood through the filter or we can create negative pressure via the
32:30 - 33:00 affluent pump but either way creating this pressure gradient from one side to the other and we can adjust both of these pressures to impact the amount of the pressure gradient and the difference in pressure across this membrane is something that we call our transmembrane pressure or our TMP and it's ultimately this TMP that determines the ultra filtrate production by adjusting this pressure gradient either increasing the positive pressure on one side or the negative ative pressure on the other side or a combination of the both we can
33:00 - 33:30 control the amount of fluid that's removed from the blood and ultimately from the patient now when we have this process of ultra filtration again within our circuit and a filter this is something that we call hemo filtration so the big takeaway here with ultra filtration and hemo filtration is that it's removing fluid from the blood and ultimately the patient all right so let's go ahead and move on and now let's talk about the principle of convection and convection is actually tied to hemofiltration as it is a principle of
33:30 - 34:00 such so here with convection we have a one-way movement of solutes through a semi-permeable membrane with the flow of water so again as you can remember with ultra filtration we have our water that's moving across our semi-permeable membrane but if we have enough flow of this water we're also going to see some of these solutes that move across the membrane with it and this is something that we refer to as solute drag as the solutes are being dragged across that
34:00 - 34:30 membrane with the flow of fluid now when we start talking convection here this is actually going to be effective at clearing small medium and large siiz molecules that are able to fit through that semi-permeable membrane pore now the greater and faster the flow that we have the more clearance that we can achieve and ultimately the molecule size as well as the membrane type are going to impact the flow of these solutes now because it often requires re Ires a large removal of fluid to achieve these
34:30 - 35:00 flows this means we're also going to be removing a large volume of fluid from the patient so then we have to replace this volume back to the patient via the replacement solution and typically the solution that we're going to use for this replacement solution is going to have the same level of electrolytes and bicarb that we normally find in normal physiology and if you remember from the last lesson where we were talking about that circuit we actually have two different spots that we can give this replacement solution to to the patient we can either give it before the filter
35:00 - 35:30 or after the filter as the blood is returning to the patient and interestingly one of the things when I first started doing CRT that really kind of tripped me up was that how adding solution after the filter would have any kind of impact on our solute clearance as it was just basically going straight to the patient and I'm going to explain that more here in just a minute but eventually it was explained properly to me that by adding this fluid it allowed us to pull more fluid via the hemofiltration and this resulted in seeing additional convection and
35:30 - 36:00 ultimately more solute clearance but at first it seemed quite backwards that by giving them this solution as it was going to the patient how is this impacting any sort of clearance of solutes now speaking of this replacement solution we need to talk about something that we refer to as pre-dilution versus postdilution so like I said we can return replacement fluids to the patient's blood either before the filter or after the filter before the filter is what we call pre-dilution and after after the filter is what would be our post delution and there are advantages
36:00 - 36:30 and disadvantages to doing both now if we give this solution pre-elution via our pre-blood pump or our PBP that this is going to dilute the blood going into the filter and leads to less solute clearance but by having dilute blood in the filter that this is going to help reduce the clotting of the filter and really preserve the life of the circuit now on the flip side if we give this replacement solution post dilution via our post filter replacement then this is going to lead to more concentrated blood
36:30 - 37:00 in the filter and ultimately it clotting sooner but having more concentrated blood leads to better solute clearance so typically when we're starting out what we actually do is a mix of both and often times I find that we're going to run at least starting out equal amounts of pre and post solution and ultimately the belief tends to be that we actually want a little bit of both we don't want to give all the solution either pre or post because of some of those negative consequences now one thing to remember
37:00 - 37:30 though is we're giving the patients a lot of fluid into their blood via this replacement solution but all of the volume that we give them is actually going to be pulled off via hemo filtration so it doesn't have any impact on the patient's fluid volume balance our patient's fluid volume is only going to be adjusted by the balance of the overall fluid that we pull off something that we refer to as the patient fluid removal rate and this can lead to either positive negative or for really an equal balance of fluids although more than
37:30 - 38:00 often we're running them either equal or negative so essentially we're usually either keeping them balanced with their fluid state or we're slowly working to remove some fluid all right so hopefully that made sense with convection and you can see how it's actually tied to the other principle of ultra filtration and then finally the last principle I want to talk about here is something that we call absorption now absorption is one of the unique properties of CRT that we don't fully get with intermittent
38:00 - 38:30 hemodialysis essentially what this is is it's the adherence of solutes and other biological matter to the surface of the membrane so you can imagine that as time goes on we begin to see things basically adhering or really sticking to our semi-permeable membrane here and as time goes on we see this begin to to build up and as we see higher and higher levels of this absorption taking place that this actually lead to something that we call the filter as clogging basically
38:30 - 39:00 this means it becomes less effective now the membrane type is going to affect these absorptive properties and really the efficiency of a particular filter to absorb this material one really good example of this is something like the cytosorb filter that's specifically designed to absorb higher levels of cytokine to Aid in patients with cyto storm so essentially some filters are going to have more adsorptive proper properties than other filters and this adsorption may have a small effect on
39:00 - 39:30 the clearance of some solutes from the patient's blood all right so those are the four principles of CRT it's these four foundational principles that really guide the different modes of therapy that we run for our patients and really help to mimic the functioning of the nefron and the kidney to ultimately work to filter waste from our patients control the fluid volume balance the electrolyte and acid base imbalance in our patients now there are some things
39:30 - 40:00 that we do in addition to just these principles that kind of work to ensure that we're achieving the proper levels of electrolytes and acidbase balance but the core of what CRT is doing is based on these four principles here in the next lesson I'm going to be talking about the different modes and therapies that we can offer for CRT and you have to have an understanding of these principles to understand how these modes are different from one another all right so in this next lesson this is going to be the fourth lesson in this series on
40:00 - 40:30 CRT explained and in this lesson we're going to be discussing the different modes or types of therapy that we can offer with CRT this should be a relatively short lesson now in the last lesson in the series we talked about the principles of CRT that really guide our therapy and our solute clearance if you haven't watched that already please watch that lesson first as understanding those basic principles is really going to help you to understand how these types of therapy really work and differ
40:30 - 41:00 from one another there are several different types of therapy that we can offer with CRT and much of it's going to depend on what the patient needs as well as really the provider preference on how they want to run it and so let's go ahead and get into talking about these different modes that we have and it's important to know that the therapy that we can offer people really consists of various applications of either hemo filtration hemo dialysis or a combination of both principles which were discussed in great detail in that last lesson so as we talk about these
41:00 - 41:30 different modes I'm going to add them to this chart here so you can really see where they fall in this alignment of either hemo filtration or hemo dialysis or some combination of both now as well as when we go through and talk about these different modes I have the basic circuit set up here with a patient and again as you remember from that second lesson we have our dialysis line with our acccess line coming off in red the blood is going through our blood pump pushing it through through the filter and then from there we have the blood exiting the filter via the return line
41:30 - 42:00 and going back to the patient now in addition to that we also have our affluent line coming off of the filter and this is to collect the filtrate or a fluent that we pull off in therapy so regardless of the different mode that we're going to talk about all of them are going to have these basic components to them and then from there we're going to either add or takeway or do some different combination of other things in order to achieve the different principles that we talked about about from that last lesson so as I go through and talk about those I'm going to
42:00 - 42:30 include those on here so you can really see how that fits into our CRT circuit so the first of these modes that we're going to talk about here is going to be our slow continuous ultra filtration or scuff now essentially this is the process of removing fluid so Ultra filtrate or a fluent at slow rates and without using any replacement fluid now this mode uses the principle of ultra filtration but because of the slow rate of it we have little to no solute clearance AKA convection and so let's go
42:30 - 43:00 ahead and place this one on our chart here under the Hemo filtration and the main goal of scuff is going to be the safe removal of fluid from the patient who has fluid overload now when we talk about the setup of our CRT circuit we're not going to be using any dialysate nor replacement fluid so essentially the circuit that I have shown here as an example is exactly what we're going to have we're just going to pull blood from the patient and we're going to pull a small amount of fluid off as a fluent so pretty
43:00 - 43:30 straightforward all right so the next mode that we're going to talk about is going to be our continuous venovo hemo filtration or cvvh and so here we're going to have the process of both fluid removal as well as solute clearance the principles that we're going to be using here are both ultra filtration and convection and so now because of the volume of fluid that's going to be removed in order to drive that convection we must use replace fluid and this can be either pre post or both now
43:30 - 44:00 again this is going to remove both small and large molecules and we will see the the pH will be impacted by the buffer that's being contained in our replacement solution now this therapy is going to be indicated in ureia in severe acid base or electrolyte disorders or if the removal of large molecules is needed and for this mode we're not going to have any dialate that's used but we are going to be using replacement fluid so let's go ahead and add this mode to chart that we have here uh and again this one's going to be listed under our
44:00 - 44:30 hemo filtration side and then if we look at our circuit setup here we're still going to have the same setup that we have drawn out here in addition to that we're going to be adding in some sort of replacement fluid and there's two different spots that we can be adding this fluid we can either be adding it pre- dilution so essentially into the blood before it gets to the filter or we can be adding it post delution to the blood after it's gone through the filter or like I said some combin of the both all right so let's go ahead and move on and we'll talk about the next mode that
44:30 - 45:00 we have here the continuous venovo hemo dialysis or cvvhd now this is going to be the process of removing waste products and solutes and for this mode we're going to be using the principle of diffusion also known as hemodialysis and so let's go ahead and add that one into the chart here under the hemodialysis column and so here in this mode we're only going to be removing the small and mediumsized waste products and Sol as well as our patient pH is going to be impacted by the buffer that's contained
45:00 - 45:30 in the solution that we use now we can also use this mode to safely remove fluid volume from the patient so here though we're going to primarily be using this for patients with ureia and either severe acid base or electrolyte imbalances and for this setup here we're going to be using dialysate but not replacement fluid so here we're going to have our dialysate solution which we're going to infuse into the filter on the outside of those Hollow fiber semi-permeable membrane tubes that are carrying the blood and then that dials
45:30 - 46:00 is going to come out of the filter in the form of the affluent so you can think here because we have this dialysate fluid flowing through the filter on the outside of that semi-permeable membrane we're creating that concentration gradient thus giving us the diffusion or the hemodialysis which makes up its name all right and so moving on we'll talk about the last mode of therapy that we have something that we call continuous venovo hemo diala filtration or cbv hdf so here again this is going to be the process uh using a
46:00 - 46:30 combination of principles to remove waste products solutes as well as fluid and so here the principles that we're going to be using are going to be diffusion ultra filtration as well as convection now one thing I didn't specifically mention in any of these modes here is the principle of absorption and that is actually going to be present for all of the modes that we do again really just kind of dependent on the filter type that you're using if it has more adsorptive properties then
46:30 - 47:00 we're going to see those benefits in the therapy so now let's go ahead and add this mode to our chart here and as you can see this one actually uses both hemo filtration as well as hemo dialysis so we're going to have this one straddling the middle of our chart now in my experience though most patients are typically just ran on this type of therapy part of the reason is because it's going to be the most efficient and can contribute both to removing fluid controlling our patient's fluid balance as well as that waste and solute clearance but in addition to that if we
47:00 - 47:30 want to change modes for our patient you can't on some machines add the therapy as you go you'd have to stop take down the filter and reset it up with the new therapy that you want to do as opposed to if you have the patient running in cvvhdf you can just turn down the flows to either replacement or dialysate which would essentially be doing the same thing so speaking of that this therapy is going to require both the use of dialysis and replacement fluid and this therapy is going to be effective at
47:30 - 48:00 clearing small medium and large siiz molecules our patient's pH is going to be impacted by the buffer and the solutions and we can safely remove fluid from our patients in this mode and our indications to use this one here is going to be for ureia severe acid base and electrolyte imbalances uh fluid removal or when large molecule clearance is necessary so again looking back at our circuit setup we're going to have the use of both the dialysis as well as the replacement solution and again we'll
48:00 - 48:30 have our dilate going in top to bottom in the filter and coming out as a fluent and then we'll have our replacement solution either going in pre-dilution into the blood before the filter or running as post dilution going into the blood after the filter and so in this mode we're going to be using all of the different parts and all of the different fluids that we talked about in that second lesson as we went through the full setup of the CRT circuit so again cvvhdf is going to be our most included Ive it's going to be hitting both the Hemo filtration and the Hemo dialysis
48:30 - 49:00 and really providing the most amount of clearance and support for our patients all right so I hope this lesson really kind of clearly explained the differences between the different modes that we have for CT and really also to help you kind of understand which basic principles of CRT are being used for each mode and really how that's benefiting our patient so we've really kind of stepped our way through these first few lessons and kind of talked about you know things that built upon one another to get us to the point to
49:00 - 49:30 where when we talk about these different modes that you'd have a good understanding of what's happening in each one there are going to be a few more lessons after this one which are going to cover different aspects of CRT therapy which are going to be certainly beneficial if you're taking care of these patients so make sure you guys stay tuned in order to catch those future lessons all right so let's go ahead and jump into our lesson here this is going to be the fifth lesson in the CRT Explain series and in this lesson we're going to be talking about anti-coagulation there are a couple
49:30 - 50:00 guiding principles as well as a couple main anti-coagulants that we might use and so my goal in this lesson is to try and break them down so you guys have a good understanding of what we're doing with them and so let's start off and talk about why it is that we anti coagulate the whole purpose for using anti-coagulation is going to be to maintain longer filter run times it's that simple so if our filter is clotting we're losing efficiency as well as when it actually clots off there's a period of time in which the therapy is just not going to be running now typically the
50:00 - 50:30 provider is going to build in a buffer to our flow rates and really the targeted therapy rates to try and account for this downtime But ultimately the less it's down the lighter that we can really run the therapy and at its core the problem is related to clotting which is typically going to be the result of platelet activation uh as well as activation of the clotting Cascade and then ultimately the obstruction of those Hollow membrane fibers in the CRT filter as a result of this our anti-coagulation therapies are going to be aimed at interfering with this
50:30 - 51:00 clotting Cascade there are obviously risks to using anti-coagulation and the risk must be weighed against the possible benefits and then we have to monitor closely in our patients so with the ywe anti- coagulate out of the way let's talk about some of our strategies for anti-coagulation and when we talk about these strategies there's three main strategies that we can use the first strategy is going to be no anti-coagulation the second strategy is going to be our systemic anti-coagulation and then the last of these strategies is our regional
51:00 - 51:30 anti-coagulation now the main benefit of our no anti-coagulation strategy is that it's going to be useful in situations where anti-coagulation might be contraindicated some examples of these contraindications although not in an exhaustive list are going to be things like our trauma or postsurgical patients patients who have head beds and patients who have known bleeding although this one sometimes is not always a contraindication patients who have liver failure as well as sepsis with
51:30 - 52:00 coagulopathy now the major downside to a no anti-coagulation strategy is really going to be the life of the filter which is often pretty poor and as discussed the less downtime we have the better this is this may also require greater pre-dilution replacement rates which is also going to decrease our efficiency and the other potential Dum side is if the filter completely clots off and we're not able to return the blood while it's still safe then almost a half a unit of blood is going to be lost now if this this is happening frequently obviously this can lead to need for transfusion for patients now for our
52:00 - 52:30 systemic anti-coagulation strategy we're either going to want to anti- coagulate our patient through the syringe pump on the CRT machine with heprin or systemically given to the patient with Hein or other drug options now this strategy is often going to be useful in patients who require systemic anti-coagulation already and examples of this would be patients with mechanical heart valves or if they have a DVT or a PE where we're going to need to give them systemic anti-coagulation anyways
52:30 - 53:00 and our CRT is just going to benefit from that this strategy though has the highest risk of bleeding and is also going to be impacted by the patient's own coagulation status now if we are using a drug that has a reversal agent the doses of those reversal drugs may be impacted by the filtering of that drug from the CRT filter main takeaway here though is the filter life is going to be extended but with the increased risk of bleeding for our patient now as far as the drugs that you might give to your Pati systemically there's really two main groups that you might give the
53:00 - 53:30 first is going to be either Hein or low molecular weight Hein although Lenox really is not often used for this and the other is going to be our direct thrombin Inhibitors and this is going to be either our Bal Rudin or our gatan or other medications of that class now of these heprin is going to be the most commonly used one and this one has the ease of monitoring and dosage adjustments it is easy to reverse with protamine but we do need to monitor these patients for hit and if their platelets start falling then we're going to need to stop it now for our direct thrombin Inhibitors we don't have
53:30 - 54:00 reversal agents for these so ffp can be helpful as well as cryo and other clotting factors but there is no risk for hit now for our regional anti-coagulation this one is probably the most common one that you're going to come across and there are several studies out there to show that this one is safe and effective now with this strategy there's actually going to be less risk for bleeding and we can use it in some patients who have known bleeding or bleading risk factors ultimately our filter life is going to be extended with
54:00 - 54:30 a lower risk now this strategy though is going to require closer monitoring of our patients now when it comes to using this strategy there's actually going to be three main drugs that we do the first one is going to be Hein and combination of protamine now in order to understand this one a little bit better I'm going to bring up the diagram that we had of our CRT circuit and blood flow again this is just the real basic minimal setup here so in order to use Hein protamine in this Regional anti-coagulation strategy heprin is
54:30 - 55:00 given prefilter and then protamine is going to be given post filter to reverse the anti-coagulation so looking down at our diagram we're going to have our heprin that is going to be infused into the blood after it's drawn from the patient but before it gets to the filter and then the protamine is going to be going post filter back into the blood just before it returns to the patient and then the goal is that the dose of protamine is going to be enough of a dose to be able to reverse the effects of however much heprin you've given and essentially the way it works is for
55:00 - 55:30 every 100 units of heprin that you give you're going to be giving 1 gr of protamine the next drug to use here is actually going to be our citrate calcium combo and tri sodium citrate is becoming more and more popular now in order to understand how this combination is actually beneficial here is the citrate actually binds with calcium which is a key player in almost all parts of the clotting Cascade now once the calcium is bound the citrate is no no longer activated and so what we do here is again looking at our diagram we're going
55:30 - 56:00 to be giving the citrate prefilter just like we did with the Heen protamine combo and then most of the Unbound citrate is actually going to be removed via the filtering process but what we do then is we then Infuse calcium post filter and this can either be in the return line going back to the patient or just giving it to the patient systemically in order to ensure that they have adequate systemic levels of calcium and so here we're not going to be reversing the effects of the citrate it's just we've now depleted the calcium
56:00 - 56:30 from the blood being bound with that citrate that's no longer active so we have to replenish that calcium back to the patient so that it's available for many different things one of those being used in the clotting Cascade so this is actually very similar to how blood products work they actually put citrate in red blood cells in order to be able to store them without clotting and so that's why if you've ever had a patient who's been bleeding out from GI bleed surgery gone bad maybe a trauma patient that's not doing well and you've given
56:30 - 57:00 them lots and lots of blood after so many units of blood you have to give them that amp of calcium because there's that citrate in the blood which is going to be binding up all that calcium that the patient normally has and you're going to be working against yourself cuz you're just going to continue to bleed because now you're anti- coagulating the patient now sodium citrate is actually going to be metabolized into sodium bicarbonate we can which can actually benefit our patients who have metabolic acidosis the great thing here with sodium citrate is it has equal efficacy to heprin with much less risk and the
57:00 - 57:30 way that we monitor patients when using this strategy is that we're going to evaluate both a post filter as well as a patient ionized calcium and so here what I'm talking about is we're going to draw blood just after it goes through the filter and then check an ionized calcium level and we should see it be critically low at this point because hopefully that calcium has been all bound up by the citrate so here on this post filter if our ionized calcium is too high this means we're not binding enough of that calcium we're going to have to increase
57:30 - 58:00 our citrate infusion rate and vice versa if it's too low then we're going to go over here to our patient and then draw a patient ionized calcium and here we're targeting for normal calcium level so if it's too low the patient doesn't have enough calcium so we're going to have to increase the rate of our calcium refusion and then again vice versa if it's too high so again really important that you have close monitoring of the patients when you're using this strategy because we want to ensure one that we have enough anti-coagulation in order to
58:00 - 58:30 get that increased longevity out of the filter but we also really need to be monitoring our patient to ensure that they have the proper calcium level because that's really going to be important to them and their body processes as well as reducing that risk of bleeding and then finally the last drug group that I want to talk about real quickly is going to be our prosta cyclin so this is going to be like our EO now I can say I personally have never seen these ones given but I have seen them mentioned in some literature so I did want to make quick mention of them
58:30 - 59:00 here and our prostacyclin are actually platelet Inhibitors and anti-thrombotic they have a very short halflife of only about 30 minutes but they are potent vasodilators and if they're not dosed properly it can lead to worsening hypotension in shock patients which is going to be pretty common in patients who are on CRT as well as it can lead to cerebral edema and with this there does come the risk for thrombocytopenia like I said though i' I've never personally seen this one so I really don't have much experience in
59:00 - 59:30 being able to speak much more to it than that all right so those were our strategies for anti-coagulation as you can see there's three really different strategies either we're not going to anti- coagulate them or we're going to give them systemic anti-coagulation so we're going to get the the benefit of the preserved filter life but also the risk for bleeding because our patient is also anti-coagulated and then we have this beauty of the regional anti-coagulation where we can will provide anti-coagulation as it's going through the filter but then give them
59:30 - 60:00 either protamine if we're giving heprin or give them calcium to replace the calcium that's bound up by the citrate and still get that preserved filter life without the risk of bleeding all right so for this lesson this is a sixth lesson in the CRT Explain series and in this lesson we're going to be talking about the pearls of therapy I'm basically just going to be rambling through some pearls that I've learned over the years or just some common things that that come up when running CRT therapy now this isn't going to be an exhaustive troubleshooting list
60:00 - 60:30 and I'm sure I'm going to miss some things later that I wish I included but hopefully this contains some good information for you guys so first let's talk about our access and return issues and this is probably the biggest headache of running CRT if you're having access or return line issues it's really going to make for a really annoying and sometimes awful shift now unfortunately this is probably something that you guys are going to come across I definitely can recall many nightmares of just having constant issues on getting CRT to run on patients and really what I'm
60:30 - 61:00 talking about here is when we have our access which is going to be too negative or our return which is going to be too positive now if these are too high then these are going to Red Alarm on the machine and the system is going to stop not only just the therapy but also the blood flow so it's going to be really important that you guys fix this quickly now with this we do want to avoid flipping lines so typically we have the red to the red and the blue to the blue on the catheter and the flipping is where you basically switch that you have red to blue and blue to red and the
61:00 - 61:30 reason for this is this is actually going to decrease the effectiveness of the therapy if you remember in that second lesson where I talked about where those ports are on the dialysis catheter we would to ideally be pulling the blood from the the proximal port and then returning the blood to the distal Port now if it certainly comes to a matter of running or not running then absolutely will flip those lines in order to keep the therapy going but just remember that we're losing efficiency Now by having having those lines flipped patient positioning can sometimes be the cause of the issues that we have here so if
61:30 - 62:00 you have your line in the patient's i j make sure you're checking their upper body position position of the limb uh as well as their head and neck if we have femoral access then make sure we're checking lower body position making sure that the leg is Not Bent and there's really nothing pressing on the line when having these issues sometimes a good couple flushes can do the trick and really speaking of flushes also make sure that you guys are flushing the lines good when you're disconnecting or doing filter change our goal is to really keep that line functioning good
62:00 - 62:30 now some places still pack these lines with Hein or citrate so make sure that you guys know what your facility process is if you do pack or you're unsure if you do then you really need to make sure that you're withdrawing this and that you're not flushing this into the patient and really at the end of the day if all else has failed it's really vital that our patient is getting this therapy if you need to advocate for a new line and perhaps a new location of that line make sure guys do so all right so now let's talk about clotting versus clogging and really when we're talking
62:30 - 63:00 about this terminology we're talking about two primarily different things we have our transmembrane pressure or our TMP and our pressure drop now our TMP is basically the hydrostatic pressure across the membrane now this is a difference in pressure between the blood and the dialysate compartment to really simply think about this this is the amount of pressure required that hydrostatic pressure to move fluid from the blood across that membrane into the dialysate this is the driving factor for
63:00 - 63:30 our convection and some of the settings on the machine are actually going to change this TMP value so if we're adjusting blood flow rate the patient fluid removal rate as well as the replacement solution rate these are all going to impact our TMP now if we hit a positive pressure 350 this is going to trigger an alert and if we go above a positive pressure of 450 this is typically going to trigger the alarm and this increasing TMP is what's going to be measuring that our filter is clogging
63:30 - 64:00 so you can really think about it as the filter begins to clog those pores that are in the membrane that allow the water and solutes to cross are going to begin to get filled up with junk the more of these that are filled up or the more restrictive that they become it's going to require more and more pressure in order to move that fluid across there hence as the filter is clogging you're going to see this going up and up and up now our pressure drop is a measure of the pressure required to go through the filter so you can really think of this
64:00 - 64:30 as the change in pressure of blood entering and then leaving the filter and here as we adjust the blood flow rate that this is going to impact the pressure drop the higher the blood flow rate the higher the pressure is going to be initially going into that filter once this value reaches 200 or higher that this is what's going to trigger the alarm and then this is going to be our indicator for the filter is clotting so again you can think about remember in the filter we have those really tiny hairlike holiber membranes and the blood
64:30 - 65:00 is Flowing inside of those tiny fibers as they eventually begin to clot off it's going to be harder and harder in order to move the blood through there leading to a higher and higher pressure drop all right now let's talk about our prescribed versus our delivered therapy dosing now while we as nurses do not directly control the rates of therapy we can and do have sign significant impact on what is actually delivered versus what is prescribed according to many different studies that have taken place
65:00 - 65:30 the generally accepted delivered dose goal is going to be 20 to 25 milliliters per kog per hour and really our surrogate for this deliver dose is going to be our affluent rate now this dose along with the prescribed dose is going to be shown on the machine and this is really why we enter the patient's weight in here and stoppages in therapy happen frequently and are often times unavoidable things like simple bag changes will stop the therapy until that bag is changed the quicker we can detect this and complete these tasks the less
65:30 - 66:00 downtime that we're going to have also a multitude of alarms will either stop therapy or even stop blood flow completely so it's really important to be on the listen for these alarms and work to correct them quickly now access and return line issues like we just talked about can really lead to significant reduction in the therapy that's being delivered depending on how much trouble your line is giving you and so we can really do our part to minimize these disruptions in therapy interventions we do directly impact this if you notice that your deliver dose is
66:00 - 66:30 below the 20 to 25 Ms per kig per hour then you should really be alerting the provider to see if they need to increase the prescribed dose to make up for any of the issues that we're having so that at the end of the day we end up back within that actual delivered dose goal of 20 to 25 next we have our blood return and there's generally around 150 to 165 mL of blood in in the CRT filter set depending which filter set you're using and which machine so it's really
66:30 - 67:00 important that we're able to get this Blood returned to the patient before our filter completely clots and we're not we're unable to do so and if it's not returned this is really equivalent to about a quarter of a unit of whole blood if we're having frequent filter changes that are happening and the blood is not being returned this can obviously lead to the patient having pretty significant blood loss and ultimately requiring transfusion so in order to return this blood to the patient before the filter either clots or clogs off what we do is
67:00 - 67:30 we stop the therapy we disconnect the access line from the patient making sure that we flush the access line of the dialysis catheter good and then we're going to attach that access line to a bag of fluids then as we go through the process of returning the blood basically we're going to be filtering this fluid from the access all the way up in through the filter and then back through the return line to the patient really returning a majority of the blood to the patient of course it's important that we're closely monitoring during this time for any clots or how the patient is
67:30 - 68:00 really tolerating this another important thing to talk about is pre- priming a filter set so this is essentially when you get the machine and the filter all primed ready to go but your patient's not there in order to hook right up to in these cases it's really important that you don't pre-prime this filter set and leave it sitting for too long doing this can actually lead to a reaction in your patient potentially when hooking them up and starting the therapy so really our best practice is to Prime when you're ready to hook up to the
68:00 - 68:30 patient now a crucial part of CRT therapy is going to be the precise management of our patient fluid balance and this is going to be through managing our patients ins and outs or eyes and no every hour we're going to be meticulously adding and subtracting and figuring out what our balance is and often times we're chasing the hour that just happened and what I mean by that is we're figuring out where our fluid balance was for the past hour and then adjusting the patient fluid removal rate on the machine to ensure that we're
68:30 - 69:00 having the proper balance that's being ordered by the provider and so it's really important that you don't miss anything you've got to make sure that you're thinking of all the flushes that you do any drains that they might have make sure you include all of those now in order to get the most accurate volume that's infused through the pumps if you have the ability to do so make sure you pull that exact volume that's infused a lot of the pumps are able to go in there and look at how much volume has actually been given and then reset that number so that way when you do your next check in
69:00 - 69:30 an hour you'll have the exact volume that was given now some caveats to this are going to be if you're giving someone fluid or albumin for hypotension please don't pull that fluid back off the whole point of giving them that fluid is to give them the volume that they might need and if you pull it right back off through the CRT you're basically nullifying what you just did and the same goes for blood or ffp again if you're giving it to your patient because hypotensive as a result of that if you're just giving them a standard transfusion because they're having
69:30 - 70:00 hemoglobin drift then it's okay to pull that volume off for the the blood that you've given at that point now if you're having to change your filter it's really important that you get the actual volume of fluid that was removed from your patient before you begin the process this way you can accurately calculate how much fluid your patient was positive during the time that the filter was down now if the therapy is going to be down for an extended time don't try and make up all that fluid in 1 hour try to spread that out over a couple hours and then probably most importantly is every
70:00 - 70:30 hour you want to figure out whether you were over or under your set fluid removal rate so did you pull more or less fluid than you were supposed to you want to then figure out what that difference is and either add or subtract that to the next hour this is really important because if you're short pulling fluid 10 to 20 milliters an hour for an entire day that that's really going to add up now what if you have a crashing patient now if your patient Pati's going down and your therapy's order to be pulling fluid and running your patient negative stop pulling that
70:30 - 71:00 additional fluid now if things are continuing to deteriorate and your patient is near cating then at this point you might want to just stop all the fluid removal until you say see which way things are going to go now often times these very sick patients are getting large volumes of fluid with the drips that they're getting so obviously we don't want to do this for very long but doing this can be a quick code prevention in the moment now speaking of codes if your patient does actually code then you want to turn your blood flow down as low as it goes and really as
71:00 - 71:30 soon as you get the chance you want to return that blood because really compressions and CRT running smoothly do not go together the last thing you want while your patient is coding is to be constantly dealing with the CRT alarming now in the last lesson we talked about the anti-coagulation strategies for CRT so I do want to talk a little bit more here just about some pearls for our citrate anti-coagulation so it's going to be important that you ensure that you're using dialysate and replacement solution with no calcium in
71:30 - 72:00 there the calcium that's in the normal premixed bags can bind the citrate basically making it less effective now if you're using a hypertonic citrate solution such as Tri sodium citrate close monitoring of our patient's sodium level is also going to be important these Solutions can actually lead to hyper netr in our patient and if they do become hypernut you're going to need to reduce the sodium that's in either the dialysate or the replacement fluid now in my facility when this becomes necessary we have a protocol to basically switch between normal saline
72:00 - 72:30 half normal saline and D5W as our replacement fluid based on where our patient sodium level is now the other important thing here is when you're starting or stopping your therapy it's absolutely vital that the citrate and the calcium infusion are stopped and started together don't ever run one without the other even just for a little bit now always make sure that you have a hand hand crank with your machine the last thing you want is the machine to die and you have no way to return the
72:30 - 73:00 blood that's in there now because we're extraorally filtering the blood hypothermia is a common concern both blood and fluid warmers are often used and sometimes though this is not enough and a warming blanket or some sort of warming machine is also going to be needed now knowing this though it's important to know that CRT has a way of actually masking fevers if you're finding that your patient is normothermic without any sort of warming device I'd be worried that your patient is actually febr underneath also don't
73:00 - 73:30 sit on bag changes or a fluent bag empties in this state here the blood pump is still running but the therapy is not and the same goes for clearing alarms the yellow alarm could mean that therapy is not running for your patient now let's talk about the blood leak detector or the BL now this part can be finicky especially when it's not cleaned properly you want to take an alcohol swab to this between runs the affluent coming from your patient should be either clear or yellow if you do get the BL alarm on your machine or you think
73:30 - 74:00 that you see pink in the affluent bag that this could mean that you have a ruptured membrane send a sample of the affluent to the lab to check for blood and change the set if it is detected now word to the wise don't forget to clamp the syringe tube line if you're not using it for the CRT machine and along those lines always check the connectors especially on a new set I've personally had the Y connector come off during priming also really important never use an old affluent bag when you're priming
74:00 - 74:30 a new set remember that we're attaching that return line to this bag for the priming process and then disconnecting from there and attaching to the patient this is a major nogo and then lastly if you're having to put up a new filter set when you've been already running you don't have to use new full bags of replacement and dialysate when you're putting that new setup don't waste those old fluids just make sure and cap off the ends while you're putting the new set in place and then put those same used bags back on the scales with the
74:30 - 75:00 new filter the machine is pretty smart like that and it's going to be able to figure out how much fluid you have all right so those are the main pearls that I wanted to just kind of talk to you guys about that sort of came up while I was making the lessons for the last few lessons here and I really wanted to kind of share some of this information with you guys because again like anything else that we do so much of the experience that we gain is really through just doing doing things over and over and coming across new things or learning from those who came before us
75:00 - 75:30 so my goal here was to sort of share some of the things that I have learned over the years to hopefully give you guys some good information to be able to carry that forward in caring for your own patients