Central Line
Episode Number: 161
Episode Title: Advances in
Transfusion Medicine and Patient Blood Management
Recorded: April 2025
(SOUNDBITE OF MUSIC)
VOICE OVER:
Welcome to ASA’s Central
Line, the official podcast series of the American Society of Anesthesiologists,
edited by Dr. Adam Striker.
DR. ZACH DEUTCH:
Hello, everyone, and
welcome to the Central Line Podcast. I'm your host, Dr. Zach Deutch, and for
this edition, we have two experts on the topic of transfusion medicine and
blood management. Dr. Nicole Guinn, who's a guest editor of June's ASA Monitor,
and Dr. Steven Frank who is a contributor to that issue. We'll learn about this
important topic, which is highly relevant to all aspects of medical care and of
course certainly highly relevant to perioperative medicine. We'll start off by
getting some introductions and background information from our two guests
today. We'll being with Dr. Frank. Tell us a little bit about yourself, your
professional journey and your interest in this specific topic.
DR. STEVEN FRANK:
Sure. Thanks, Zach. I'm
privileged to be here, and I'm on the faculty at Johns Hopkins in the
Department of Anesthesiology. I'm a professor, and I've been running the
patient blood management program here at Johns Hopkins for over a decade, uh,
which aims to improve blood utilization. And I also run the Bloodless Medicine
program that aims to avoid transfusions for patients who don't accept them,
primarily Jehovah's Witnesses. And my interest in blood really started back
when I was a resident, when I personally had a lifesaving transfusion. It was a
bicycle versus car accident, and I needed a splenectomy, so I was bleeding
internally. And if it weren't for blood, I wouldn't be here today. Uh, so my
favorite cases are traumas and transplants, uh, that often end up with massive
transfusions. But I also specialize in Jehovah's Witness patients who wish to
avoid transfusions altogether.
DR. DEUTCH:
Thank you, Dr. Frank.
And welcome, Dr. Guinn, can you please give a little introduction to our
listeners and also talk about your interest in the topic?
DR. NICOLE GUINN:
Yes. Happy to be here as
well. My name is Nicole Guinn. I am a professor of anesthesiology at Duke
University, where I've been on faculty for about 13 years. Like Steve, I ran
our blood conservation program, which was really designed to serve patients for
whom blood is not an option. So many of the Jehovah's Witness faith or patients
who would decline blood for other reasons. While running that program, we also
realized that there was an opportunity to help other patients to avoid
transfusion. And so I founded our preoperative anemia clinic and have focused a
lot of my research efforts in managing perioperative anemia. I'm the immediate
past chair of the ASA Patient Blood Management Committee, and I'm currently the
chief of neuro anesthesia at Duke.
DR. DEUTCH:
Thank you and welcome, Dr,
Guinn, we will stick with you for an important clarification. And just getting
our language and our understanding correct for our listeners and for myself as
well. Please define for us blood management and transfusion medicine and talk
about the difference between the two.
DR. GUINN:
Thank you for asking
about that, Zach. Uh, our special issue really covers both, but they are
different. I think of patient blood management and transfusion medicine as two
ends of the spectrum that really go all the way from bloodless care to massive
transfusion. Uh, patient blood management is defined as an evidence based,
patient centered approach to a patient's blood health, really supporting their
own hematopoietic system, whereas transfusion medicine encompasses more of the
appropriate use of blood products and pharmacologic adjuvants, and includes
optimal blood use and treatment of coagulopathy. So they really cover
everything from not giving any blood products, avoiding them at all costs to
the massive transfusion and everything in the middle. And just about all of our
patients can benefit from some of these techniques.
DR. DEUTCH:
Okay. That's helpful. So
we know what we're dealing with. Dr, Frank, let's take a step back. Let's talk
about our historical perspective in this clinical area. Where have we come
from? Where have we progressed to, and what events insociety,
culture, whether it be specifically medical culture, or generally American
culture, have driven us to where we are.
DR. FRANK:
Sure. Yeah. When we talk
about history, We have to go back about 40 years because in the early 1980s,
specifically 1984, that was the worst year ever to have a blood transfusion
because there were people dying from HIV, contracted from blood transfusions,
because it wasn't until 1985 when they discovered the virus and could actually
test the blood for HIV. And by the way, it wasn't until 1990 when the hepatitis
C test was developed. So the blood was very unsafe in the 1980s and people were
really afraid of transfusions. So that's part of the story where patient blood
management really started. And then along came the Jehovah's Witness patients,
who suddenly looked pretty darn smart for trying to avoid transfusions while
the risk of viral infection was so high. And then historically, we have to go
to 1999 when the Trick Trial came out. That was a Canadian study with ICU
patients showing that they did just as well when you give them less blood. They
looked at hemoglobin triggers and found that. Even in critically ill ICU
patients, a hemoglobin trigger of seven was just as good as a hemoglobin
trigger of ten. So now we have 14 randomized trials since the trial that have
come out that all basically show that less is more for transfusion. And that's
why blood use is down over the last decade in the United States by about 30%.
So that's the history behind patient blood management.
DR. DEUTCH:
Okay, well, you've
raised a number of questions, but I'm going to try to stay on track and not get
us all over the place. I'm going to go to Dr. Guinn for this to kind of focus
in on one thing you talked about, which is risks. And you obviously covered the
early days at the high level of infectious risks. So today let's talk about our
situation that we have in what we call for ourselves modern medicine. What are
the risks of blood transfusions right now, and what options are available for
people who can't be transfused? For whatever reason? It would be nice to kind
of explain to listeners what bloodless care actually looks like in the
perioperative setting for those groups of patients that were not able to
transfuse.
DR. GUINN:
Sure. So, you know, like
Steve said earlier, blood transfusion can really be life
saving in the setting of acute hemorrhage. But it does have significant
risks. And not just that risk of viral infection, but also infection from
immune suppression. Taco and trali are some of the
more common risks, and we have many, many studies showing that transfusion,
whether it's causing it or just correlating, is associated with higher
morbidity and mortality, everything from stroke and kidney injury to MI. So a
lot of risks, including death, have been associated with transfusion. And the
more you transfuse, the more you increase those risks. So they used to say, if
you're going to give one unit of blood, you might as well give two. Bring the
patient up, kind of the two scoops theory. And now instead we say why give two
when one will do. We should really give the minimum amount of blood necessary
to minimize these risks.
Now, for the patients
for whom transfusion is not an option, we really have a variety of strategies
for bloodless care throughout the entire perioperative period that have
developed, and it starts early, so it starts before the patient even gets to
the O.R.. You need to identify these patients, check their laboratory studies,
make sure if they have anemia, you determine the etiology and you treat it,
really optimize their hemoglobin. And Steve and I actually worked together on a
paper and a project where you could figure out how much you needed to do that.
We used the allowable blood loss formula and rearrange it to figure out, okay,
if a patient's starting at this hemoglobin and you expect this much blood loss,
what do you really need them to be at preoperatively to minimize transfusion or
to avoid it entirely in these cases. So it starts early with identifying the
patients, treating their anemia. And also for the patients who decline
transfusion, really having the conversation of what is and is not acceptable to
them, because in the Jehovah's Witness faith, what they consider to be minor
fractions or things that come from blood like albumin cryoprecipitate may or
may not be acceptable. Once we get into the interop period, then there are a
whole bunch of other techniques that are available, including use of cell
salvage, acute normal volumic hemodilution, certainly
antifibrinolytics like Txa have been really effective
at reducing blood loss and transfusion. And then as we move into the post-op
period, still thinking about treating anemia, tolerating anemia when
appropriate, and minimizing all those blood draws so that we really try to keep
the patient's blood in their body. So it really goes across the entire
perioperative spectrum.
DR. DEUTCH:
Okay. Understood. I
think most listeners understand these terms. But just in case there's some out
there that aren't as clear, could you define taco and trali
as it's currently understood?
DR. GUINN:
So taco is transfusion
associated circulatory overload and trali is
transfusion related acute lung injury.
DR. DEUTCH:
Okay. Very good. Dr. Frank, we talked about
some patients that are critical here in the sense that they cannot be
transfused. Can you explain to our listeners who are these patients? What are
these populations and how are we dealing with this?
DR. FRANK:
Sure thing. I think,
really, all our patients are candidates for patient blood management and that
includes both medical and surgical patients. We always talk about surgery
patients, especially the ones having bigger surgeries that have substantial
bleeding risk. And for those, like Nicole said, we pull out all the stops -- the
anemia cell savers, tranexamic acid. Simply keeping patients warm during
surgery is helpful so they bleed less. Controlled hypertension, minimizing
phlebotomy blood loss, and even tolerating lower hemoglobin than we used to
tolerate. Uh, all those are helpful. But we also manage medical patients such
as GI bleeding patients. There's so many people now on blood thinners that a
simple GI bleed can be life threatening, especially in patients who don't
accept transfusions. And a few other patient candidates… Pediatric patients,
since they're smaller, they have lower allowable blood loss. And we have now
several randomized trials showing that even children tolerate lower hemoglobins than we used to target. And then in countries
where malaria is a problem or HIV is still a problem, or there simply no blood
available in some rural areas, all those locations are appropriate for patient
blood management. So I'd say a broad spectrum of patients are all candidates.
DR. DEUTCH:
And it sounds like we
should bring a degree of sophistication and conscious stewardship to all of the
care that we give in medicine regarding this and your your
answer really speaks well to that. I would like to ask a question that came up
when both of you were answering these past two questions. We talked about what
was acceptable for patients based on their beliefs. And I've also seen in
medicine some ethical and philosophical concerns raised by practitioners who
felt that doing a certain procedure on a patient who refused to accept blood
and these type of circumstances was not acceptable to them, and they felt it
was a violation of their ethics. I would like both of you to comment on that. Dr.
Guinn, we'll start with you, please.
DR. GUINN:
I've heard of this, and
I've run in to people who would not agree to care for patients who would
decline blood for this reason. And and I've often
kind of thought of it similar to a patient who chooses to be a do not
resuscitate. And they may choose that for a variety of reasons. I think if we
think that we can't care for the patient, if it's not feasible, it's not
possible, that's one thing. If a patient needs a surgery that cannot be done
without transfusion, then I think you have that conversation with the patient
and say, if you do not accept transfusion, which is their right to decide what
medical treatments they do and do not want, then we can't offer you this
surgery. But if it's something that can be done, and we have a lot of tools
that have helped us to be able to do more and more, then I do think it's
patient's right to decide what happens to their body and what they accept and
what they do not accept.
DR. DEUTCH:
Have you ever been faced
with a situation that you thought was was absurd in
this regard, in terms of the risk benefit or the demands of the surgery or
whatever the clinical circumstances were, and it was a patient that couldn't be
transfused, and it looked like there was going to be significant risk to the
patient? I'm curious what your thoughts have been when personally faced with
that or any scenario that you faced.
DR. FRANK:
I can take that first,
Zach. We've been running a program for patients who don't accept blood for 12
years now, and there's only really two types of cases that we thought might be
too high risk to attempt without transfusion. One is a liver transplant, which
some places do and some places don't, but it's still very high risk. And the
other is a thoraco abdominal aortic aneurysm. And we
all know those are like a scheduled exsanguination event. So there are some
cases that we think are too big, but those are few and far between.
DR. GUINN:
I would agree with
Steve. I mean, we've even we've done heart transplants, numerous heart
transplants without blood. Uh, liver transplants, I think are more challenging
cases. And, uh, another case that I recall that we agreed as a team, after a
lot of discussion, that we didn't think we could perform without transfusion
safely, was a patient with an acute aortic dissection that would need a massive
aortic surgery. And we had really no time to to
optimize them.
DR. FRANK:
From the ethical
standpoint, the patients that were most concerned about are pediatric patients
with Jehovah's Witness parents. They fall in a special category because, at
least in the United States, parents are not legally allowed to refuse
lifesaving therapy for their children. So we have to handle pediatric patients
with Jehovah's Witness parents with special care. And what we do is we tell the
parents all the things we're going to do to try to reduce or avoid the need for
transfusion. And we tell them about cell savers and tranexamic acid and keeping
your child warm and minimizing phlebotomy blood loss. So they like to hear all
these things we're going to do to try to avoid transfusion. But we also tell
them if their child's life is threatened, that we're legally obligated to give
them blood. And I think the parents like to hear that sometimes as well,
because it takes the weight off of their shoulders. And we tell them that, hey,
we're going to save your kid's life. And we've shown that that only 6% of
pediatric patients actually get transfused under those circumstances.
DR. DEUTCH:
Dr. Guinn, do you have
anything to add?
DR. GUINN:
We've had similar
experience at Duke. We have parents who would not want their children to be
transfused, to sign a form, our acknowledgement form, where we acknowledge that
we will do everything we can to avoid transfusion, and they acknowledge that
both hospital policy and law requires us to transfuse, should it be a life
threatening emergency. And I think it does take some weight off. They’re not
consenting to transfusion, but they are acknowledging that this is the law,
this is the policy, and we're acknowledging that we're going to do everything
we can to avoid it.
DR. DEUTCH:
Okay. And I think that
based on what you all have said already in this, in this podcast, the
sophistication with which we approach this clinical issue has allowed us to obviate
a lot of these problems, because we just are not transfusing as much, and we're
able to manage patients with low levels of hemoglobin we wouldn't have even
dreamed of in the past. So that's kind of a big help in this regard, which
brings me to my next question for you, Dr. Guinn. Talk to us about advances in
transfusion medicine that we've seen recently, and which of those you think are
the most important and noteworthy?
DR. GUINN:
Well, I really think the
biggest game changer that we've seen in the last decade or so has been with
Antifibrinolytics, especially TXA. There are just numerous studies showing in
all kinds of different patient populations that it's effective at decreasing
blood loss and transfusion. And it is inexpensive, easy to give, readily
available. So I think that's something that globally has made the biggest
difference in managing patients without transfusion and decreasing transfusion
needs.
DR. DEUTCH:
Okay. So let's talk
about the future, the path forward. What advancements are coming. And I'm going
to address to both of you this question. Talk to our listeners about what you
see coming down for the future of transfusion medicine. And also talk to them
about what you see are problems that could arise to delay or hinder
advancements. Dr. Frank, I'll start with you, please.
DR. FRANK:
Yeah, sure. I'm trying
to predict the future is never easy. But I know that we're all hoping and
wishing for a viable blood substitute. For literally 100 years, we've been
looking for a safe and effective blood substitute, and a few have tried to come
to market. Primarily what we call hemoglobin based oxygen carriers. And it was
about 25 years ago when these were all the rage, and most of them were bovine
hemoglobin derived large molecules that are polymerized and they carry oxygen,
but they also have side effects like nitric oxide scavenging and some renal
toxicity. There's even a meta analysis showing
increased ischemic cardiac events that put the brakes on artificial blood or
blood substitutes back in 2008. But there's a resurgence of interest and
funding right here in Baltimore at University of Maryland. And there is some
hope that we might see a blood substitute in the near future.
DR. DEUTCH:
Okay, Dr. Guinn it's
your turn. Look in the crystal ball. Tell us what's good that's coming. And
tell us what bumps in the road we might see as well.
DR. GUINN:
So I, you know, I think
we can't, uh, look at the future and not think about large data and AI and
predictive modeling and what that's going to do in all different fields. Um,
and I think there's really opportunity in medicine and patient blood management
for this to happen. As Steve mentioned, way at the beginning of the podcast,
ever since the trick trial, we've been going off transfusion triggers, which
are the opposite of individualized patient care. They're just a random number when
so many other things play into whether a patient has adequate oxygen carrying
capacity. So I hope that AI, predictive modeling, large data sets will help us
to really individualize transfusion medicine and patient blood management and
think about really which patient needs which products and how much. And I'm
hoping that that data will come and help us to have more targeted therapies so
that we have the benefit without the risk.
DR. DEUTCH:
Okay. Uh, we're coming
to the end here. So I'm going to have a question for both of you. After having
participated in this podcast and having been contributors to the issue of the ASA
Monitor, talk to us about what you really want as a take home message for our
ASA members regarding transfusion medicine and blood management. And Dr. Frank,
I'll start with you.
DR. FRANK:
Sure thing. Uh, take
home message is now we have 14 huge randomized trials, all showing what I call
less is more for transfusion, most of which have come out in the last ten
years. So people are still trying to adjust their transfusion practice to this
less is more approach. But the other take home is there's many ways to benefit
our patients without giving blood. For example, Nicole mentioned pre-op anemia
treatment. But there's other methods of what I call keeping the blood in the
patient that it's much better to prevent severe anemia than it is to treat it
with either transfusions or either iron or erythropoietin. So keeping the blood
in the patient is very important. And like Nicole said before, blood saves
lives when you need it, but only increases risk and cost when you don't.
DR. DEUTCH:
And also a cautionary
tale for our listeners. Be careful when you're on your bike. Correct?
DR. FRANK:
Unless you want to
donate your spleen to a trauma center, that's good advice.
DR. DEUTCH:
And I suppose it depends
on where you live, because here, where I live in Florida, people love to bike
because the weather's nice. But there are no good bike trails. And
unfortunately, you see a fair amount of bike accidents. So we'll try to think
happier thoughts about that. Um, and if you do get into an accident with
experts like you at the helm, maybe you won't even need blood anyways. Um, Dr,
Guinn, share with us your take home messages and final thoughts for listeners,
please.
DR. GUINN:
So Steve said, two of my
favorite things keep blood in the patient and blood saves lives when you need
it, but increases costs and risks when you don't. I'll add one more, which is
try to get to the patients early to make the biggest impact. To really optimize
hemoglobin and treat anemia, we really ideally want to see them four weeks
ahead of time. But that being said, it's never too late to make a difference.
We can even treat anemia, post-operatively and decrease transfusion and help
the patient feel better when they go home. So really, don't forget to think of
anemia as a modifiable risk factor and not just default to transfusion.
DR. DEUTCH:
Thank you both for
joining us. I've learned a lot. It's been an interesting topic to reflect on,
given that if you've been in this field of anesthesia and perioperative
medicine for a while, many of the things, as you all pointed out earlier, that
we've been taught about physiology, blood management, oxygen delivery are
really outdated, and we've seen just how far we can take our frontiers in terms
of protecting patients from other risks while still maintaining their health.
And that's excellent.
So for listeners, I hope
you enjoyed this edition. I want to thank both of our experts for being here
and you can always go to asamonitor.org for more information about this topic
or any others. And we look forward to seeing you on the next Central Line
podcast. Take care.
(SOUNDBITE OF MUSIC)
DR. DEBORAH SCHWENGEL:
Hi. This is Doctor
Deborah Schwengel. With the ASA Patient Safety Editorial Board. Cognitive
biases are a significant problem in medical decision making. Laws and judgment,
rather than lack of knowledge are central to diagnostic error. The most common
types of bias are overconfidence, anchoring, and confirmation bias. Steps to
mitigate errors due to cognitive bias could include raising awareness by
defining and discussing the terms heuristics and bias. Reflective practice and
cognitive bias awareness. Challenging your own biases. Becoming a more critical
thinker, and acknowledging that some unknowns are unknown. We must acknowledge
the contributions of bias to our medical decision making. Embrace the
opportunity to use metacognition techniques to think critically. Be open to
alternate analyses and be reflective in your practice of medical decision
making.
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