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.
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