Coagulation Guideline for Interventions - HD

Introduction

My name's Tom Winter.

I'm a professor of radiology at the University of Utah in chief of abdominal imaging.

And we're gonna be talking about controversies and coagulation techniques.

I could talk for 15 hours versus 15 minutes, and we still wouldn't resolve many of these issues because there's very little science there.

I was privileged to work with a old fashioned hematologist, Elliot Williams several years ago when we investigated this.

He was old fashioned in the sense that he practiced just hematology, not oncology.

And he taught me that many of the practices that we follow were following based upon, we've always done it this way rather than any scientific concepts.

But what I'll try to do is give you some of the more recent data in the last couple years, and there's several areas where the literature is starting to converge and we can reach reasonable agreement on it.

After this introduction, we'll go through the talk.

We'll be talking about pre-procedure laboratory testing, and should we distinguish between easy procedures like paracentesis and riskier procedures like deep image guided percutaneous biopsy.

Then we'll move on to periprocedural anticoagulation and we'll make a particular example of aspirin.

A major theme of this talk is that how you do the procedure is much more important than the underlying hematology.

And then we'll sum up, and one point just to make here is that we're not talking about embolizing the artery of a a ditz and a patient in DDIC we're talking about standard biopsies and, needle procedures under ultrasound guidance.

Pre-Procedure Laboratory Testing

Now any vascular bed may bleed.

This is courtesy of one of our hematologists who gave a great hour long lecture on this topic at surgery grand rounds earlier this year, and her talk was filled with slides like this that were basically uninterpretable to us non hematologists.

This is really, really complex stuff.

One thing though that's not complex is that if you read the literature, the history and physical exam, trump testing, if you say, ma'am, when you're working in your gardening, you get cut by one of your roses.

Do you stop bleeding in a normal fashion?

That's a lot more predictive of outcomes than all of our fancy expensive tests.

Do you need to test?

The literature describes ordering tests, certainly for medical-legal issues, and there's even an old JAMA article talking about pecuniary reasons in our paper.

Stacey came up with a quote, physicians often fail to act on abnormal results from the ordered laboratory tests ignoring up to 96% of abnormalities in the study in which 96% of abnormal results were ignored.

There were very few complications.

This was a great article by Matre who was sitting in the audience here, and he looked at, do we need to check, INR and platelet prior to para thora and thyroid?

And do you need to proceed with, blood products in patients who have an elevated INR or a thrombocytopenic?

And the answer is no to both of those.

This is more conventional study.

There are a bunch of papers primarily from the Mayo Clinic this year talking about, kind of high value target biopsies.

This was 61 hepatic adenomas and they said if the platelet count is over 50 and the INR less than one and a half, go ahead.

Here's another one on spleen biopsies.

Again, platelet count over 50 in INR less than about one and a half.

Go ahead.

In our paper, Elliot, looking at the data actually recommended, and this is an A JR saying that you can change parameters for interventions to an INR of less than two and platelets of over 25,000 instead of the one and a half and 50.

But even for simple things like para, many patients insist on or many providers still insist on INR and platelet assessment.

But remember that the INR is often abnormal in liver patients and platelet number often has no relationship to function.

Think renal failure, you have a million platelets, none of 'em work, but you've got an awful lot of 'em.

Paracentesis

The hepatology literature is filled with statements like this.

There is no data supported cutoff of coagulation parameters beyond which paracentesis should be avoided.

They talk about doing paras up to an IR of eight since bleeding is really rare using FFP or platelets before para is not recommended, what do I do?

No data on this, but if the IR is under three and the platelets are over 25,000, I'll do a para without even thinking about it.

If the INR is over that value, I'll do it without transfusion, but I'll touch base with the doc and counsel the patient, just to make sure it's a legitimate request there.

This is more medical-legal rather than scientific driven.

Thoracentesis

Thoracentesis is a step up in terms of risk, I think for most of us.

And here's two papers.

One said abnormal pre-procedural INR and platelet counts are not associated with increased bleeding after an ultrasound guided thora.

Another said that bleeding is really rare after ultrasound guided thora In attempting to correct an abnormal INR or platelet level is unlikely to confer any benefit.

We consider the patient safe, the procedure safe in patients with abnormal parameters if done by somebody that knows what they're doing.

Deep Image-Guided Percutaneous Biopsy

Now, moving up to deep image guided percutaneous biopsy, kind of the classic teaching is that you should correct if the INR is over one and a half and the platelets are under 50,000.

There are some very, publicized guidelines from the Society of Interventional Radiology in 2012.

A lot of smart people on there, I don't mean any disrespect, but I think a lot of these were driven by what's been done in the past rather than true, scientific data there.

But they said that you should correct a para and ahora if the INR is over two and you should correct a liver biopsy until the INR is under one and a half and the platelets are over 50.

We'll talk a little bit more about why that probably doesn't work.

Remember that we le live in a very fluid time.

A million years ago when I actually gave FFP I never do anymore.

We gave FFP, but that's been replaced by three or four factor prothombin complex concentrate.

I can't even pronounce it, but this is two, papers from the neuro ICU literature in the last year or two.

So get the experts involved if you have something weird there.

This was a great paper where they looked at, they went into the operating room, the liver got cut, and then they timed until it stopped bleeding and they found that the time to stop bleeding didn't correlate with abnormalities in the PT platelet count or whole blood clotting time.

Evidence-based the strongest randomized controlled trial indicates that prophylactic plasma for transfusion is not effective across a range of different clinical settings.

And this is supported by data from non-randomized studies.

Just as an aside, there's some pretty cool literature showing that if it takes X units of FFP to drop your INR from eight to seven and a half, it takes a hundred x to go from two to one and a half.

I'm obviously making up the numbers, but we're giving homeopathic doses most of the time and remember that there's potential real harm in transfusions.

We all think of a, B and C, but the last I checked, they were up to hepatitis G.

And then there's something called trolley or transfusion related acute lung injury.

You can hurt people, giving transfusions, particularly if you're not helping them, and there's no benefit.

So the take home message is that deep image guided percutaneous biopsy is safe.

15,000 percutaneous biopsies from the Mayo Clinic.

Very, very rare serious complications.

Periprocedural Anticoagulation

Now let's move on to periprocedural anticoagulation and to paraphrase, paraphrase Shakespeare, should we interrupt or not interrupt?

Should we bridge or not to bridge?

Here's a couple quotes.

This is from earlier this year from our literature, and here's from New England Journal basically saying that a lot of people are running around on anticoagulants and nobody knows whether to stop or not for procedures, we would all like to stop, but remember that the surgeons will perform surgery in patients on heparin and that, you're anticoagulated for a reason and clotting off your coronary or cerebral stent is a really bad thing.

So it's all a risk benefit analysis.

Great quote from one of I think the Mayo papers this year.

If it's, anything at all complicated, go to somebody who does this for a living, our hospital, and I'm sure your hospital have a thrombosis service, so get them involved in anything that's really weird.

Aspirin

Let's talk about discontinuing aspirin right here.

And the rationale is that, what I was taught years ago is it takes about a week and a half for platelets to recover after you nuke them with aspirin there.

But remember, everything's a risk benefit analysis as we talked about.

So here's Tommy Atwell's paper saying that aspirin therapy doesn't appear to increase the risk of bleeding complications.

This is 15,000 percutaneous biopsies, big numbers.

Here's lung biopsies.

1200 numbers, 1200 patients continuation of aspirin before transthoracic lung biopsy is not significantly associated with an increased risk of hemorrhage.

This is from our own mon uh, talking about safety of ultrasound guided FNA in patients taking antithrombotic or anticoagulant medications including aspirin, tid, heparin and warfarin.

And there is no difference in the incidence of hematoma formation.

So why bother checking a platelet or a nine R for these procedures in our paper?

Most interventional procedures can probably be performed safely without stopping aspirin treatment.

So my recommendations, and more and more, I'm not even worrying about it.

If I happen to hear 10 days ahead of time, which I usually don't do the logistics of our setup, I'll call up the doc and ask him if it's okay to stop the aspirin there.

But in general, I'll always do a deep biopsy on aspirin.

I won't cancel, I won't reschedule.

And the SIR guidelines do back up this practice.

New Anticoagulants

Now, there's some new anticoagulate out there that are very, very confusing.

The surgeons are up in arms until very recently when there were no reversal agents, but just four weeks ago in New England Journal they're talking about there are some antidotes that will come on the market right now, but this is confusing.

The surgeons are confused.

Get your anticoagulation service involved.

This is a really nice paper by Tracy Jaffe from Duke, and they divide, procedures up into a risk of low, low risk of bleeding, medium risk of bleeding, et cetera.

And then you're on all these polysyllabic agents there and you start stop them x days ahead of time and you start them up y days or y hours after the procedure there.

And she has a similar table for the new platelet agents as well.

Importance of Technique

Put in a plea for old fashioned medicine.

Use your finger and push hard on the biopsy site for two minutes.

This is probably one of the most important points in this talk.

The surgeons say that applying pressure with your finger to a bleeding thing is the second most important rule of all of a surgery residency.

Right there, we guide for political reasons for the nephrologists when they do biopsies, and we have several nephrologists who will biopsy the kidney, the probably the most risky target in the abdomen and then just walk away without putting any pressure.

Some of our nephrologists and clinicians will put a sandbag on, which I think is completely ridiculous.

It's low mass, it's a wide surface area.

There's low pressure.

All it does is hide the bleed.

Now, do I have any data to support pushing with your finger or not using sandbags?

No, but not everything can be evidence-based medicine.

This is a trial from one of the most prestigious gynecologists in the world at Cambridge University in the uk and he published it in the prestigious British Medical Journal.

Parachute used to prevent death and major trauma related to gravitational challenge, a systematic review of randomized controlled trials.

And in that, he concludes that we think that everyone might benefit if the most radical protagonists of evidence-based medicine organized and participated in a double-blind, randomized, placebo controlled crossover trial of the parachute take home message, obviously is have common sense.

Remember that you are gonna have complications.

Here's one of our surgeons who did a, paracentesis on the floor, managed to hit the inferior epigastric artery.

The patient was miserable for a while, but eventually did okay, fortunately.

And here again from New England Journal, there's no evidence that a prolonged PT is associated with the risk of bleeding, nor that there is a need for plasma prophylaxis.

Take Home Points

So take home points.

Number one, technique is more important than testing.

Push with two fingers for two minutes.

Push hard, don't use a sandbag.

Number two, one can make a very good case for not testing nor correcting thyroid, FNAs, paras and thora, but have common sense.

Obviously, this doesn't apply to patients in DIC and be aware of the legal issues.

There's some contradictory, guidelines out there.

The most prominent of which is from the Society of Interventional Radiology.

Transfusion carries real risks.

Probably doesn't work given the randomized controlled trials.

And even if it did work, we're not giving enough.

Remember that exponential nerve, curve for replacement.

Get the experts involved regarding stopping anticoagulation and with all the new agents.

But you probably don't have to worry about aspirin.

I think there's a lot of data saying that you can do deep image guided percutaneous biopsies in the ab abdomen, in patients on aspirin.

Remember that you're gonna have complications if you do procedures.

Everything's a risk benefit analysis.

There are no absolute contraindications to any of our procedures.

Talk to the clinical team and weigh it out.

And I just wanted to put in a brief shout out for Bill Sau for lots of wise advice over the years.

One of the smartest and most practical people I've ever met really help me with my interventional procedures.

But obviously any mistakes in this talk are mine.

They're not bills.

Thank you very much.