Welcome to Katie. Go conversations in Nephrology. This episode is titled maximizing filter life. During see our Arty. Best practices on any coagulation and citrate use. Here's your host dr. Ravi meta. How does one go about maximizing food to life during CRT today we discuss best practices on anticoagulation and citrate. Use, hello and welcome to KD. Go conversation Nephrology, I'm dr. Avi Mehta Professor of medicine at the University of California,
San Diego, and on the program. With me today to discuss maximizing filter life during CRT is dr. Ashida to Ronnie in order to Ronnie is a professor of medicine at the University of Alabama, in Birmingham, in the United States, her research interests include acute. Kidney injury, is you Nephrology and CRT, and she's an expert on sitted anticoagulation. So, certainly the perfect guest for our topic today, dr. Tehrani. Welcome to the program. It's an honor to be here.
Thank you so much for inviting me. So she'd have to start. Why is the circuit patency and integrity important for CRT and what are the key issues that we should consider CR T stands for continuous, renewal placement therapy. So to provide effective solute clearance include removal and really needs to run uninterrupted. And we know that decreased
circuit patency results. In significant time off the CRT device, this has adverse consequences, such as decreased, Re of dose decrease, fluid removal goals, increased loss of blood, if you hit return the blood when the filter clots, it also increases the burden for the nurses who need to keep replacing the filter and increases costs, because extra filters are used, you have wastage of CRT solutions to.
So making sure the circuit stays Peyton's very important, and there are several characteristics that you have to consider that affect circuit. Patency, I would say, probably the most important is the vascular Access. Vascular. Access dysfunction is a very common cause of delayed circuit life so it's very important. You have the correct catheter length for the correct position and the tip should be the correct location. The best catheters that work for CRT are a right IJ catheter.
Other things that affect circuit patency are really circuit related factors, adding stopcocks to the system increases resistance, you know, many of the CRT device. Have a deaeration chamber and that are blood interface can cause clotting, if you don't have a proper layering of fluid, nursing delays in addressing alarms.
Also can cause increased circuit clotting because the blood pump continues, while the other pumps do not and that can contribute to filter clotting, especially since the patient, won't be getting an anticoagulant. The mode of therapy also affects circuit. Paint see what convective therapy since you have high ultra, filtration rates in, you're pulling plasma through the filter, you have increased. Viscosity by the end of the filter with increased somatic.
Rip this can prone to clotting. We measure this effect by something called, filtration, fraction. Filtration fractions is the fraction of plasma, that is removed from blood during hemofiltration, and it, ideally should be kept less than 20 to 25% to decrease the chance of circuit. Clotting with convective therapies. The way to do this, is by either using an increased blood flow, right?
Or by using more pre dilutional replacement fluid Only even if you have optimized all these circuit characteristics, you still have increased cloudy in the circuit because exposure to an extra Corporal, circuit activates clotting Cascade. So, insufficient anticoagulation is a big deal. Thank you for bringing out. These really important elements for the circuit, given that anticoagulation techniques are
present and so variable. How do you decide which one to use and is it really necessary to use anticoagulation? There have been Been described in the literature. No anticoagulation, protocols, having effective circuit patency, and you can definitely maintain Circuit patency by optimizing all those circuit factors. We just talked about like the access, the circuit issues, ETC.
But even if you have a circuit Peyton, that doesn't mean that you're actually delivering the proper dose of therapy because we know over time the filter permeability decreases. And this decreases the diffusive or convective loss of solute through that filter essentially it Kris has your solute delivery or I should say dose given that I recommend that anticoagulation should be used for that purpose. The most common anticoagulants used for CRT or unfractionated Heparin and Regional citrate
anticoagulation other options. You may see in the literature are unfractionated Heparin with protamine low, molecular weight Heparin thrombin antagonist, pepper noise or platelet
inhibiting factors. We all are familiar with unfractionated Heparin. It's Easy to use, has a short, half-life we all know how to use it, but we know there's significant disadvantages to it has unpredictable pharmacokinetics, so that results in a dosing variability, there's a risk of Heparin resistance due, to low antithrombin levels, the development of potentially heparin-induced thrombocytopenia.
But I think the biggest drawback of systemic Heparin is that the risk of hemorrhage, systemic Hemorrhage of the patient, and We Know by multiple studies, that it really does increase life-threatening hemorrhage. For these patients. So that's why citrate has become more common because it's a regional anticoagulant. So basically the way citrate works, it chelate, sinai's calcium. And if you look at the clotting Cascade, free calcium is
required at every step. So, if you get the ionized calcium, low enough in the circuit, the filter cannot clot. So the optimal level was an ionized calcium lesson point 4 millimoles per liter and that fact of the anticoagulant is reversed by providing. In a calcium infusion back to the patient and keeping the ionized calcium in normal levels. So that's how citrate works and why it's a little bit better than Heparin because it doesn't
have the systemic effects. Now, when you're really choosing an anticoagulant for the patient, it should be individualized, it should be based on not only the patient's condition but also the availability and expertise at the institution. So in sensually, you really need to focus on safety of the patients. So patients who cannot tolerate anticoagulation because they have a high risk of bleeding. No, we should all sit right. Anticoagulation. If you have the expertise would
be preferred in patients. Who have normal or moderately Disturbed hemostasis. Then using Heparin would be probably appropriate, impatience of Heparin induced
thrombocytopenia. You may consider a gas turbine or Bible route in, but no matter which anticoagulant used you would change it according to your patient's condition and your expertise that was very helpful given that Regional sat/rad anticoagulation is now Increasingly used, and is being recommended as a preferred method for anticoagulation. Is there adequate evidence to support this? There is, there were multiple randomized trials.
Now, comparing Regional citrate anticoagulation to Heparin and most some have suggested that citrate provides increased
filter. Patency, in fact, there was a meta-analysis published several years ago of 11 randomized, trials and nearly 1,000 patients with show that the risk of circuit loss was Or with RCA and that she had decreased bleeding and by the way this was recently confirmed in a large Germans multicenter study of 600 patients and it's for these reasons that que digo has recommended the use of citrate is first line for patients with Aki reading CRT.
I know Ishita you have utilized arcia protocols for citrus safely and effectively for many years. What are the parameters that should be monitored? Third, both for circuit integrity and how frequently should these be done to assure the best performance?
Okay. Well, first of all, want to say that RCA's available for all CRT modalities and even if the patient is systemically anticoagulated, you should still use our CA because you want complete control of the circuit, you don't know what's going to happen with the systemic anticoagulation. When it's going to be stopped excetera. So we use it, even in patients, who are systemically anticoagulated.
When you give RCA, it could be delivered as a fixed ratio between the blood and citrate, infusions, or titrated based on ionized calcium levels. Many of the CRT machines these days have our see a software that allows for safer and easier delivery of the RCA. But, unfortunately, it's not available everywhere including the United States. Given that truly important to know, all the different components you have to think about When developing a citrate
protocol. The first component, of course, is a citrate solution. Citrate Solutions can be classified as either hypertonic. They have a high level of sodium in their concentrated or basically physiological solutions, that have a normal concentration of sodium.
The hypertonic Solutions are administered as a separate citrate solution and is distinct from the replacement or dialysate Solutions. While the isotonic Solutions with a physiological sodium content are dilute and are used as an anticoagulant in a pre delusional. Placement fluid depending on which CRT solution use, you have to choose what type of CRT other solutions to use dependent on
the citrate choice. For instance, if you use some of the hypertonic Solutions, you may have to use hyponatremic solutions for CRT like a replacement fluid or dialysate or even a lower buffer concentration, since citrate is
converted to bicarbonate. The liver for using the isotonic dilute Solutions, you can use a commercially available Solutions. Without any issue, the other thing to be aware of is the potential complications of RCA these include hypernatremia, depending on citrate solution to use a since sit regulates calcium, you can have hypo or hypercalcemia citrate. Also calculates magnesium's you had can have hypomagnesemia and of course since it rate is converted to bicarbonate, liver is working.
There are acid base disorders, you have to be aware of most of the time when you're monitoring for citrate most protocols Archer blood, electrolytes, including the circuit and systemic ionized calcium is at least every six hours or more
frequently. If there are changes made, or if there's concern for accumulation of citrate, the bottom line is that in order to have a proper RCA protocol, you need a comprehensive algorithm of how to adjust the rates of the different components to prevent or correct for any of the acid-base abnormalities. And finally, one last thing I just want to say, Is that patients with severe liver failure or lactic acidosis? May have difficulty in
metabolizing citrate. So you need to be able to recognize citrate accumulation and how to correct for it again. RCA's been used safely in patients with Advanced liver disease and with lactic acidosis and these metabolic complications can be avoided if you use really strict, protocols, appropriate training and of course safer, citrate Solutions. Integrated citrate software to have that availability. Thank you for sharing those.
For those just joining us. This is que digo conversation Nephrology. I'm dr. Ravi meta. And I'm speaking with dr. Ashida to levani on maximizing filter life during CRT best practices on anticoagulation and citrate use so dr. Shivani what have been the challenges you've seen during the pandemic with maintaining the circuit Integrity. As I believe this has been a major issue. Reported in the literature that is correct.
It's been very challenging. There are patient, related, factors and technique factors that make this so challenging the patient related factors of course, are that these patients often are hypercoagulable. And this can be from the cytokine storm or other reasons. During this time, we also wanted to limit nursing exposure and use of ppes. So that related to issues with maintaining CRT circuit patency also, for an instance, this meant Manipulations of the CRT
device. So you know, we had law firms that lasted longer to prevent nurses from having to go infrequently. We ourselves are institution, use extension tubing. So all our CRT machines were outside the ICU rooms and because of that, this led to increase clotting of the circuit. Other challenges, this patient population is use of prone ventilation with issues with the access placement. You had lots of issues of access dysfunction. So how we manage these challenges?
Are all different ways. First of all, it's very important that we ensured, a proper axis in the right IJ. Many places. If they're using conductive therapy made, sure they use higher blood flows to decrease the filtration fraction or even convert it to diffusive therapy. But I think what came out of this pandemics a realization that these patients need anticoagulation there really has not been a single anticoagulant regimen that has been shown to be better for these covid patients.
And people have tried all different things. From Regional citrate anticoagulation to systemic Heparin to thrombin Inhibitors. When we use the extensions, we had to use a combination of citrate and heparin to keep the circuit patent. And this was in predominantly all our patients who had extensions. When we stopped using the extensions, however, we were successful in over 90% of our patients, keeping the circuit
Peyton just with citrate. So this has been great to see how you adapted your anticoagulation and sir, get strategies for the covid pandemic. Finally, what would be your recommendations for clinicians to optimize the effectiveness in their own institutions? Why I think it's always important to take into
consideration. All those circuit factors we talked about you need a well-functioning, vascular access if you're using convective therapies, higher blood, flows, or using a pre dilutional fluid to reduce the filtration fraction, making sure you decrease the blood are contact in the bubble trapped And promptly reacting to alarms.
If you're using an anticoagulant Regional citrate, anticoagulation RCA is recommended if you have the expertise or the availability of the solution regardless of whatever anticoagulant you're using.
It's really important to have standardized protocols in order sets because those are the keys for multidisciplinary management and then you have to have a quality improvement program, you need to monitor the downtime and I periodic measurement of solute clearance to ensure that you're providing good therapy and delivering CRT as it should be delivered with that. Take me in mind, I want to thank my guest.
Dr. Ashida to Ronnie for joining me to discuss best practices on anticoagulation and citrate used during CRT doctor through money. It was great having you on the program. Thank you so much. It was a privilege being here today. I'm dr. Ravi mantha to access this and other episodes in our series visit KD go. Dot org. Slash what Cass? Thanks for listening this episode of que digo conversations in Nephrology was provided by KD go and supported by Baxter Healthcare.