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Return of the PAC
14 Plays1 year ago
In this episode Dr. Zanotti discusses the current role of pulmonary artery catheters in critical care medicine. He is joined by Dr. Steven Hollenberg a critical care and cardiology physician. Dr. Hollenberg is a professor of medicine at Emory University School of Medicine and director of cardiac intensive care at the Emory Heart & Vascular Center.
Additional resources:
Pulmonary Artery Catheter Use and Risk of In-hospital Death in Heart Failure Cardiogenic Shock.
Kanwar MK, et al. J Card Fail. 2023 Sep;29(9):1234-1244: https://pubmed.ncbi.nlm.nih.gov/37187230/
Pulmonary Artery Catheter Use and Mortality in the Cardiac Intensive Care Unit. Bernard S Kadosh, et al. JACC Heart Failure 2023: https://pubmed.ncbi.nlm.nih.gov/37318422/
Complete Hemodynamic Profiling With Pulmonary Artery Catheters in Cardiogenic Shock Is Associated With Lower In-Hospital Mortality. A Reshad Garan, et al. JACC Heart Failure 2020: https://pubmed.ncbi.nlm.nih.gov/33121702/
Right Heart Catheterization in Cardiogenic Shock Is Associated With Improved Outcomes: Insights From the Nationwide Readmissions Database. Sagar Ranka, et al. J Am Heart Assoc 2021: https://pubmed.ncbi.nlm.nih.gov/34423652/
Books mentioned in this episode:
I Contain Multitudes: The Microbes Within Us and a Grander View of Life. By Ed Yong: https://www.amazon.com/Contain-Multitudes-Microbes-Within-Grander/dp/0062368605/ref=sr_1_1?crid=1EVOY6OVQZ437&dib=eyJ2IjoiMSJ9.Na-UJShWq7ngsH9dxvSV2Q.Ob-k26_k01p5WzKzo4CWnsvD4Jjq9RU1krhQhmUi9u4&dib_tag=se&keywords=I+contain+platitudes&qid=1732299607&sprefix=i+contain+platitudes%2Caps%2C132&sr=8-1
Kind of Blue. Miles Davis: https://www.amazon.com/Kind-Blue-Vinyl-Miles-Davis/dp/B0041TM5OU/ref=sr_1_2?crid=E6F0PBPV33BG&dib=eyJ2IjoiMSJ9.4Kk2sCHn8DAOl9j_qadqsZPMVZPlOuKNXg9vv_NTPEYrl10vHYNIC5-wrGJeFpn9K8rSS8aspG9zhJHjAyDqiIUiC9VKvvHjzQsAGmr4wP9VWUPWumInjcS72CDmoaEYr3h2Uoiy8yt-YfYFHm7Y-6XoPecnwju8_zumwohrrhYWC0X6rR8Ui3Xhp6ILDU3sBNb50TJ6iq_fjataiHX7X6fBL1YnUo3X-uBcnQVfKtc.v-zGaYaLVvE7BGxS1c-2_Brbwsq1kAxVKEuxqsaBci8&dib_tag=se&keywords=Miles+Davis+Kind+of+Blue&qid=1732299762&sprefix=miles+davis+kind+of+blue%2Caps%2C139&sr=8-2
Brahms: Ein Deutsches Requiem. Sir Simon Rattle: https://www.amazon.com/Brahms-Ein-Deutsches-Requiem-German/dp/B000MTEDIE/ref=sr_1_5?crid=2UCHLINLHSETV&dib=eyJ2IjoiMSJ9.aDG2ZKyB5OnEgO3Z6_VOsNplIVSXmtXffLy2Jrylq4vgaRHEYDyBsz_4YG1fE_88IJxJ2ScnxhBvvDkVZjauoazwhTEMef0o_nJN25zUb_7oXFNkPMo_U4WBLhgK5njVOkm2ae67weI5roWsx-KbokunvjgAf-tXngA30o2xDQxh0-9y0kJbJRdKtVY63PcPv3yp9YdOrpgo2PO-gpspQsio7uJ-dgz5SY1vX1je3U4.aMm-IxbuxnZSIacaIBGZWc36GYliQP4r-9f9-SBq5tQ&dib_tag=se&keywords=Brahms+requiem&qid=1732299866&sprefix=brahms+requiem%2Caps%2C142&sr=8-5e
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Transcript
Podcast Introduction
00:00:06
Speaker
Welcome to Critical Matters, a sound podcast covering a broad range of topics related to the practice of intensive care medicine.
00:00:14
Speaker
Sound provides comprehensive critical care programs to hospitals across the country.
00:00:19
Speaker
To learn more about our programs and career opportunities, visit www.soundphysicians.com.
00:00:26
Speaker
And now your host, Dr. Sergio Zanotti.
Pulmonary Artery Catheter: Historical Context
00:00:32
Speaker
The Fongans catheter or pulmonary artery catheter was commonplace in intensive care units and closely linked to the growth of critical care as a specialty.
00:00:40
Speaker
Over time, it fell in disfavor and its use became very rare in most ICUs.
00:00:45
Speaker
In today's podcast, we will revisit the role of the pulmonary artery catheter in our critical care practice.
Guest Introduction: Dr. Steven Hollenberg
00:00:50
Speaker
Our guest is Dr. Steven Hollenberg, a critical care and cardiology physician.
00:00:54
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Dr. Hollenberg is a professor of medicine at Emory University School of Medicine and director of the cardiac intensive care unit at the Emory Heart and Vascular Center.
00:01:03
Speaker
He has participated in guideline development in both critical care and cardiology,
00:01:07
Speaker
including the Surviving Sepsis Campaign, the AHA-ACC Guidelines on Percutaneous Coronary Intervention, Heart Failure and Chest Pain, as well as chairing an expert consensus decision pathway on assessment of trajectory and risk in hospitalized heart failure patients.
00:01:21
Speaker
His research interests relate to microvascular myocardial function with emphasis on the pathophysiology of shock.
00:01:27
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Clinical interests include septic and cardiogenic shock, acute heart failure, and acute coronary syndromes.
00:01:33
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A mentor and a true friend.
Current Relevance of PA Catheters
00:01:35
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Steve, welcome back to Critical Matters.
00:01:38
Speaker
Thank you.
00:01:38
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It's a pleasure to be here.
00:01:40
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Well, I think that we have definitely seen the arc of this topic over the years, and I probably, without aging any of us, put my first PA catheters with you.
00:01:49
Speaker
So we'll see where we stand today in 2024 and moving forward.
00:01:55
Speaker
But as an introduction, maybe you could give us your thoughts on why is the pulmonary artery catheter an important topic for today's practicing intensivist?
Swan-Ganz Catheter: Origins and Early Use
00:02:05
Speaker
So I think that it's a look into hemodynamics and in particular a way of measuring serial hemodynamics.
00:02:14
Speaker
And I think throughout this conversation, I'm going to try to make the case that there are at least some clinical situations in which that's useful.
00:02:22
Speaker
for diagnostic purposes, but also to guide therapy.
00:02:26
Speaker
So I think there is still a role for a PA catheter.
00:02:29
Speaker
And I sometimes like to say that the position that you're never going to need a PA catheter makes no sense.
00:02:38
Speaker
The position that you'll always need a PA catheter makes no sense.
00:02:42
Speaker
So that somewhere in between is that once in a while you might find the PA catheter useful.
00:02:48
Speaker
And then the question is when?
00:02:50
Speaker
Excellent.
00:02:51
Speaker
Could we start maybe with giving some of our listeners who might not be as aware a little bit of the historical context?
00:02:57
Speaker
I mean, why is it called Swan Gantz?
00:02:59
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Where did this start and how it was related to really the growth of critical care as a specialty in the early 70s?
00:03:07
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Yes, so the legend starts with Jeremy Swan in Santa Monica, who says that he was looking out at the water and he saw the sailboats and the idea came to him that if he attached a balloon to a catheter,
00:03:25
Speaker
it would sail along with the blood flow and go into the right ventricle and pulmonary artery.
00:03:31
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He was working with Willy Gantz, who had come over from Poland with, you know, a dollar in his pocket maybe, but had done some work with actually thermodilution and putting things on catheters.
00:03:47
Speaker
And so Swan came up with the idea, and Gantz did most of the rest of the work.
00:03:52
Speaker
And so they developed this catheter.
00:03:54
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They did show that they could float it into the right ventricle and the pulmonary
Evolution of Coronary Care Units and PA Catheters
00:03:59
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artery.
00:03:59
Speaker
And over at Cedars-Sinai, along with James Forrester, they began to use it in patients in their intensive care units, which at the time were pretty much exclusively patients with acute myocardial infarction.
00:04:14
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And so they
00:04:16
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So they floated these catheters and they defined the sort of four subsets in myocardial infarction.
00:04:23
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They looked at wedge pressures and cardiac output, and you could either have low filling pressures and a normal cardiac output, which was normal, or you could have
00:04:36
Speaker
high filling pressures and a normal cardiac output, which is pulmonary edema.
00:04:39
Speaker
And then there were groups with a low cardiac output.
00:04:41
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And if you had a low cardiac output and a high filling pressure, you had cardiogenic shock.
00:04:46
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So they defined these subsets.
00:04:48
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They showed that the patients with cardiogenic shock had the worst outcomes.
00:04:52
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And they began to treat patients on the basis of these hemodynamic subsets.
00:04:58
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So part of the other context is that at the time,
00:05:04
Speaker
The CCU had the best physiology in the hospital.
00:05:09
Speaker
So the CCUs evolved from places where they shocked people out of ventricular tachycardia and saved their lives to places where not only did they do that, but they treated patients with heart failure after myocardial infarction.
00:05:23
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And so you could actually see the physiology and treat the physiology and watch it get better.
00:05:28
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And so
00:05:29
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That was, in a biased sense, the best place, the most fun you could have in the hospital.
00:05:35
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I guess the surgeons would argue differently, but at least for the medicine people, the CCU was the place.
00:05:39
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So that's where it started.
00:05:41
Speaker
And people began putting in PA catheters, and they spread out of the CCU into operating rooms and intensive care units and such, and it went from there.
00:05:53
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Excellent.
00:05:53
Speaker
And I think that obviously there was a proliferation, like you said, of PA catheters.
00:05:58
Speaker
And if you were an internal medicine resident, I mean, it would be a badge of honor when you got to put your first PA catheter.
00:06:05
Speaker
And eventually a lot of people went into critical care or pulmonary critical care or cardiology critical care.
Skepticism and Studies on PA Catheters
00:06:10
Speaker
And PA catheters were really not uncommon when you were on call.
00:06:13
Speaker
Putting in PA catheters for patients was something that I think was routinely, routinely done.
00:06:19
Speaker
However, like everything in medicine, we get very enthusiastic.
00:06:22
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We start doing a lot of things and then people start doing studies.
00:06:25
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And there is a very famous paper I remember, I think came out in the mid-1990s, 1996.
00:06:31
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by Connor and JAMA that raised some questions.
00:06:35
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Can you start talking maybe a little bit about the literature or the evidence that started pushing us away from PA catheters?
00:06:43
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Yeah.
00:06:43
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So Albert Connors, who turned out to be a cardiologist, did something called a support trial, which I believe was about psychosocial aspects as well.
00:06:52
Speaker
But in any case, they looked at patients with and without a PA catheter, and they did something which was
00:06:59
Speaker
as far as I know, more or less unknown in the literature at the time, called propensity matching.
00:07:04
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So they took the patients who had a PA catheter and they did this propensity matching, which at least I didn't understand it all of the time, but somehow when you compared the odds ratio of patients with the PA catheter and without the PA catheter, you looked at mortality, it found a 25% increase in mortality in the
00:07:23
Speaker
patients with PA catheters compared to the propensity match patients.
00:07:28
Speaker
And the paper itself by Connor was reasonably judicious, but some other people started to run with this paper, most famously an editorial by Dr. Eugene Robin titled, Death by Pulmonary Artery Catheter.
00:07:46
Speaker
And there were calls for banning the use of PA catheters by some very prominent people.
00:07:53
Speaker
And that sort of started an era of skepticism about the PA catheter.
00:07:58
Speaker
And then people said, well, maybe we should put this to randomized controlled trials.
00:08:05
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So there were randomized controlled trials of, and importantly, routine use of PA catheters.
00:08:12
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And the first thing these trials did is actually failed to show an increase in mortality with the PA catheter.
00:08:18
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But they also failed to show a decrease in mortality with those catheters too.
ESCAPE Trial and PA Catheter Alternatives
00:08:23
Speaker
And so there was the, in the perioperative setting, there was a trial by Sandum, there was an ARDS trial by Michard, and there was a Pac-Man trial out in England in ICUs.
00:08:36
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And none of them showed any effect of the PA catheter
00:08:41
Speaker
on mortality.
00:08:43
Speaker
And then came the ESCAPE trial.
00:08:45
Speaker
So the ESCAPE trial was a similar trial in patients with heart failure, and they looked at patients who were treated with PA catheters and patients who weren't, and what they showed is that the PA catheter didn't change mortality.
00:08:59
Speaker
So that study has been widely quoted as showing that even in patients with heart failure, the PA catheter doesn't make any difference.
00:09:09
Speaker
And it's not uncommon, I think, in our field and in medicine in general to quote studies without really reading them in detail and understanding some of the issues and what they really represented.
00:09:21
Speaker
And I know that offline we were talking about escape and there were exclusions in escape that I think will be quite relevant to our discussion in 2024.
00:09:30
Speaker
Can you talk a little bit about that?
00:09:32
Speaker
Sure.
00:09:33
Speaker
So if you look at the trial, if you had been on inotropes recently, you were excluded.
00:09:40
Speaker
If your creatinine was greater than three and a half, you were excluded.
00:09:45
Speaker
And at the time, if your physician thought you needed a PA catheter, there was no ankle poise and you were excluded.
00:09:52
Speaker
And if you had cardiogenic shock, you were excluded.
00:09:55
Speaker
So at least in terms of the patient population with cardiogenic shock,
00:10:01
Speaker
that is not spoken to by the ESCAPE trial.
00:10:04
Speaker
There's really not much controversy about that.
00:10:07
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And so there's a lot of, now that most of the PA catheter is coming back to cardiogenic shock, most people believe that the ESCAPE trial really isn't pertinent for that.
00:10:19
Speaker
So, you know, as you know, after the PA catheter use plummeted, but the ICU decided that there were some new toys that could do with the PA catheter.
00:10:32
Speaker
And so there's a whole set of technologies of measuring cardiac output and using pulse volume analysis and PICCO catheters and lithium dilution catheters and such, essentially new toys that
00:10:47
Speaker
We're going to replace the PA catheter.
00:10:50
Speaker
And this podcast isn't really about those new toys, but I would argue that very few of them have been subjected to rigorous analysis either.
00:11:01
Speaker
I was going to mention, and you're right, we're probably not going to dive into all these new hemodynamic monitoring devices, but none of them pass the higher standard than the PAC, right?
00:11:13
Speaker
Actually, the PAC has been studied in more situations than any of those,
00:11:17
Speaker
And if anything has been shown to be safe.
00:11:20
Speaker
So that is true how we are very selective in the requirement of data based on, I guess, on just whatever intuition or bias we have for one device or the other.
Training Impacts of Declining PA Catheter Use
00:11:33
Speaker
Right.
00:11:33
Speaker
And I'm not trying to say those new devices don't have utility.
00:11:37
Speaker
It's just that they haven't been proven to be better than the PA catheter.
00:11:42
Speaker
That I'm willing to say.
00:11:43
Speaker
Yeah.
00:11:44
Speaker
And again, the fact that there's so many tells you that nobody solved the problem finally, right?
00:11:49
Speaker
So I think it's an important...
00:11:52
Speaker
Like you mentioned, I think that with all this data, and to give people perspective, ESCAPE is 20 years old, came out in 2005.
00:11:59
Speaker
So over that span, the use of PA catheters, based on the literature, based on, let's say, based on interpretation of the literature, and based on the fact that there was a proliferation and a push for so many other hemodynamic devices, some of them billed as
00:12:16
Speaker
non-invasive or less invasive, although a lot of them required, I mean, similar levels of invasiveness, right?
00:12:23
Speaker
And the reality is that residents and fellows stopped putting PA catheters, right?
00:12:30
Speaker
And it's almost like it slowly became a skill that was more rare in very specialized units, I would say, and even in areas where it would still be utilized, was utilized less and less.
00:12:46
Speaker
And I should say that the cardiologists have been doing right heart catheterizations in the cath lab for a long time, and they're still doing that.
00:12:56
Speaker
So it's not like the cardiology world has gone back on right heart catheterization, but cardiologists in the cath lab may or may not be comfortable with the idea of internal jugular access and floating a leave-in SWAN catheter in through a neckline.
00:13:15
Speaker
So it's somewhat interesting, but the cardiology world hasn't quite given up on right heart catheterization.
00:13:21
Speaker
It's just that the ICU stopped doing it.
00:13:23
Speaker
And it's also very interesting just from the perspective of if you're not a cardiologist or not interventional cardiologist, if you say right heart catheterization in the cath lab, the mental model of that is much more complex than putting a PA catheter at the bedside in the ICU, but essentially you're measuring the same things, right?
00:13:43
Speaker
Yeah, although often you're doing them in the cath lab, you're often doing them
Mechanical Support Growth and PA Catheter Use
00:13:47
Speaker
from the leg.
00:13:47
Speaker
Okay, and on the floor.
00:13:48
Speaker
So that's commonly an in-out PA catheter.
00:13:51
Speaker
If you want the cath lab to do a leave-in PA catheter, you're asking them to go away from the leg and go to the neck.
00:13:58
Speaker
And they know where the neck veins are.
00:14:00
Speaker
They can do this, but it takes them a little bit longer.
00:14:04
Speaker
And I remember once in a while we had to put a...
00:14:09
Speaker
a PA catheter through the leg in the ICU.
00:14:12
Speaker
And that was really just an endeavor of hope.
00:14:16
Speaker
Right.
00:14:16
Speaker
And if you got lucky, it got in.
00:14:18
Speaker
And if you didn't get lucky, there's nothing you could do.
00:14:21
Speaker
That's about right.
00:14:22
Speaker
And every once in a while you can, you know, you can go to the cath lab, put a wire in the catheter and do it under fluoro.
00:14:28
Speaker
But, you know, that's a road trip and all that.
00:14:31
Speaker
Awesome.
00:14:31
Speaker
So let's talk about the the the.
00:14:34
Speaker
So first, I guess I'll throw a piece of trivia that I found out as I was preparing for this podcast.
00:14:43
Speaker
The original intent was to call it revenge of the PAC.
00:14:47
Speaker
kind of thinking of my Star Wars original trilogy.
00:14:51
Speaker
And then I did a little bit of reading, and the original name of the third movie was Revenge of the Sith, but it was changed to Return of the Sith... I'm sorry, Return of the Jedi, because George Lucas thought that a Jedi couldn't want revenge.
00:15:04
Speaker
And I said, well, maybe...
00:15:05
Speaker
A diagnostic tool that is intended to save lives wouldn't want revenge either.
00:15:10
Speaker
So we went to return to the PAC.
00:15:12
Speaker
So in terms of the return of the PAC, something that's quite interesting, I think, has also fueled this discussion today, Steve, is that CCUs have changed.
00:15:25
Speaker
What we see in CCUs have changed.
00:15:27
Speaker
And actually, I would say that we are on the verge of a rapid increase of a new type of patient in critical care, right, with MCS and other types of support.
00:15:38
Speaker
Could you talk a little bit about that?
00:15:41
Speaker
Yeah.
00:15:42
Speaker
So I think that's absolutely right.
00:15:45
Speaker
So, you know, it used to be that CCUs were places where there were MIs, right?
00:15:50
Speaker
And so they were the province of cardiology.
00:15:53
Speaker
And then in a paper by Jason Katz that published in Critical Care Medicine, they looked at the evolution of CCUs and began to realize that the patients were getting more complicated in terms of multi-system disease.
00:16:08
Speaker
There were more patients on mechanical ventilation, more patients with
00:16:11
Speaker
renal failure, some patients immunosuppressed and you had to worry about infection.
00:16:15
Speaker
So there's a much greater role for critical care in in ICUs and CCUs.
00:16:22
Speaker
And then with mechanical support, the cardiology aspects became much more prominent.
00:16:28
Speaker
So the selection of mechanical support, weaning mechanical support, thinking about the goals, whether you are going, what your escape strategies are, and the use of hemodynamics to titrate mechanical support and figure out what you needed has sort of made the ICUs much more hemodynamic and much more places where cardiogenic shock is involved.
00:16:51
Speaker
And as you're going to hear, I mean, once you get some mechanical support,
00:16:55
Speaker
you have to have a hemodynamic assessment.
New Studies on PA Catheter Mortality Impact
00:16:58
Speaker
If you're going to do a transplant evaluation, you have to have a hemodynamic assessment.
00:17:03
Speaker
And you know, in theory, you could do that as an in-out catheterization laboratory, and sometimes you do in healthier patients.
00:17:09
Speaker
But in your patients in the CCU, in whom you either have mechanical support or are considering mechanical support, you just have to have a PA catheter.
00:17:19
Speaker
And so
00:17:20
Speaker
ICUs that don't necessarily see mechanical support may not have a need for PA catheters, but CCUs that do have to have familiarity with the PA catheter.
00:17:31
Speaker
And this has sort of made a little bit of divide between, say, the cardiology critical care types that take care of patients with mechanical support, who sort of say, you have to have PA catheter, and ones who don't who say, well, we don't really see much need for it.
00:17:47
Speaker
And I do think it's also important to mention that the use of mechanical secretory support is really growing everywhere, right?
00:17:55
Speaker
So clearly there are certain ICUs, like you said, cardiac ICUs, who might be very heavily invested and have...
00:18:02
Speaker
a whole bunch of ECMO, of Impella's 5.5s and other devices.
00:18:07
Speaker
But I do think that these are proliferating everywhere now because they're easier and easier to put, right?
00:18:12
Speaker
I mean, and I think interventional cardiologists and communities now are starting to put them.
00:18:17
Speaker
And I think that my anticipation is that it is more likely that more intensivists will be exposed to these types of patients.
00:18:26
Speaker
And hence, I mean, the topic that we're talking about today.
00:18:30
Speaker
Yeah, and you know, I mean, if you're in a hospital, if you're in an outside hospital and you think your patient might be a candidate for hemodynamic support, the criteria are largely hemodynamic.
00:18:41
Speaker
So you might find some utility in actually measuring hemodynamics and calling your referral hospital with hemodynamic data in hand, saying, here are the hemodynamics, this is why I think we need mechanical circulatory support.
00:18:54
Speaker
Absolutely.
PA Catheter Benefits: Device or Environment?
00:18:55
Speaker
What has changed in the literature?
00:18:56
Speaker
I mean, have there been other studies, I mean, maybe more focused on particular populations?
00:19:02
Speaker
So yes, with mechanical support came a host of, maybe not a host, but at least some observational studies.
00:19:13
Speaker
And so the Cardiogenic Shock Working Group, which is a multi-institutional group, put out a paper in 2020 in Jack Hart failure in which they looked at patients with mechanical circulatory support.
00:19:31
Speaker
and they looked at patients who got PA catheters before mechanical circulatory support, and then they compared them to patients who didn't.
00:19:40
Speaker
And that observational study showed decreased mortality in that group.
00:19:44
Speaker
And they also looked in that study at what they called complete hemodynamics, right atrial pressure, pulmonary artery, systolic and diastolic pressures, wedge pressures, mixed venous oxygen saturation, and cardiac output.
00:19:59
Speaker
And the patients with complete data with a PA catheter did better than patients who didn't quite have all those data with PA catheter.
00:20:07
Speaker
So that started in mechanical support.
00:20:11
Speaker
And then the Cardiogenic Working Group, some years later in 2023, published a paper in the Journal of Cardiac Failure looking at just patients with cardiogenic shock
00:20:24
Speaker
and also found, it's a thousand patients or so, found an odds ratio of 0.68 with the PA catheter compared to patients without.
00:20:33
Speaker
And then a different group, the Cardiac Critical Care Trials Network, which is another large group, it has about 5.
00:20:41
Speaker
35 institutions.
00:20:42
Speaker
We actually participate in that.
00:20:44
Speaker
Did an observational study, and they also showed that the PA catheter was associated with decreased mortality and shock with an odds ratio of 0.79, or about a 20% decrease.
00:21:00
Speaker
And the last piece of data is there's something called the
00:21:04
Speaker
National Readmissions Database, and this is a big administrative database with all the challenges of using coding to make a diagnosis.
00:21:13
Speaker
But suffice it to say, that observational study also showed an odds ratio of 0.69.
00:21:19
Speaker
So there are a bunch of observational studies that suggest that use of a PA catheter is associated with decreased mortality.
PA Catheter Use in Specialized Conditions
00:21:28
Speaker
Of course, you could argue about whether that really means it's the PA catheter or whether it's associated with the sort of people and the sort of environments where they're putting in PA catheters.
00:21:39
Speaker
That's probably at least part of it.
00:21:41
Speaker
But at least there's a set of observational data now that suggests benefits.
00:21:46
Speaker
And I think that, like you mentioned, I mean, is it causal or correlation with something else?
00:21:52
Speaker
But I think that the point there would be that the familiarity with managing and utilizing the hemodynamic data that the PA catheter provides probably improves the team caring for that patient in other ways, right?
00:22:06
Speaker
So one way or the other, it would seem that now when we're going to more of a focused approach, which I think is always important,
00:22:14
Speaker
the key in medicine, right, is choosing the right patient.
00:22:17
Speaker
I mean, same argument we could have with TPA for pulmonary embolism, for ECMO, for ARDS, right?
00:22:24
Speaker
It's about patient selection.
00:22:26
Speaker
So in 2024, like you said at the onset of our podcast, Steve, you wouldn't say everybody or nobody, but you would say if you have cardiogenic shock,
00:22:38
Speaker
If you are thinking of MCS, a PA catheter probably would help, right?
00:22:43
Speaker
And it's probably best practice.
00:22:45
Speaker
Are there any patient populations that you think, I mean, benefit today of a PA catheter as well?
00:22:51
Speaker
Yeah, well, so, I mean, I think, so we start with cardiogenic shock, and not just every cardiogenic shock, but when you start talking about pressors and potential mechanical circulatory support, they have been used in pulmonary hypertension, right?
00:23:08
Speaker
right, you know, the standard of care for pulmonary hypertension is right heart catheterization.
00:23:13
Speaker
If you're going to be treating pulmonary hypertension in a unit with pulmonary vasodilators and such, it makes sense to measure those pulmonary pressures and the cardiac output.
00:23:22
Speaker
So that's a population.
00:23:24
Speaker
And the other use that I think a lot of us have done in the past, and maybe the critical care people have gotten away, but, you know, if you have uncertain hemodynamic status,
00:23:38
Speaker
and you aren't responding to empiric therapy.
00:23:41
Speaker
So if you have, if your patient is getting better, you're giving some therapy and they're getting better, fine.
00:23:47
Speaker
But if the patient isn't getting better and you don't really know what their hemodynamics are, then measuring hemodynamics makes a certain amount of sense.
00:23:57
Speaker
And there are those of us who will at least consider a PA catheter and have experience of sometimes being surprised.
00:24:04
Speaker
Wow, the pressures are really much lower than I thought they were.
00:24:07
Speaker
Or alternatively, the cardiac output is different or something like that.
00:24:11
Speaker
So I think that's still a population.
00:24:13
Speaker
And sort of a subset of that is the concept of the in-out swan in somebody who has renal failure.
00:24:20
Speaker
You don't know whether they're wet or dry.
00:24:22
Speaker
You really don't.
00:24:22
Speaker
You can't figure it out.
00:24:24
Speaker
You put in a PA catheter and settle the issue, and then you just take it out.
00:24:28
Speaker
because now you know, and now you know what
Techniques and Challenges in PA Catheter Placement
00:24:30
Speaker
to do.
00:24:30
Speaker
You don't necessarily need to leave that catheter in, but it is a reasonable diagnostic procedure in that setting, at least in my opinion.
00:24:38
Speaker
And, you know, I think you get
00:24:42
Speaker
The other thing to say is I think you get some data from PA catheter that you can't get from other things.
00:24:49
Speaker
So you could argue about the hemodynamics and the ability to obtain hemodynamic parameters with a good echo, with a Doppler, etc., etc.
00:24:58
Speaker
But I think the mixed venous oxygen saturation is something that you have to measure.
00:25:04
Speaker
I personally think a mixed venous oxygen saturation that is from the right ventricle or pulmonary artery is better than the central venous oxygen saturation, but that's my opinion.
00:25:15
Speaker
But that's an index of the adequacy of cardiac output.
00:25:19
Speaker
Cardiac output is just a number, but if you take that along with the mixed venous oxygen saturation, you can get a sense of the adequacy of cardiac output.
00:25:27
Speaker
And I think that's something that you don't get with other techniques.
00:25:31
Speaker
Excellent.
00:25:32
Speaker
So a lot of our listeners either need a refresher on the basics or maybe did not get exposed to this sufficiently during training.
00:25:41
Speaker
And as we said, we're seeing in more and more environments that all of a sudden we were asking, we put a PA catheter, and I've heard intensivists say, well, I haven't put one in X amount of years, or I haven't put one in training.
00:25:53
Speaker
And I think that obviously that depends on
00:25:58
Speaker
the pattern of your practice and types of patients, but it is a growing, I think, trend.
00:26:02
Speaker
So why don't we do a little bit of a pulmonary catheters one-on-one 2024 edition or 2025 edition as we're ending the year and start with some very basic refresher of indications and contraindications.
00:26:16
Speaker
Right.
00:26:17
Speaker
So, you know, I think you, you know, the indications, the indications are when you think it will help cardiogenic shock,
00:26:25
Speaker
Pulmonary hypertension in some settings, although with severe pulmonary hypertension, you have to be a little careful with the catheter.
00:26:32
Speaker
Those are the ones with very high pulmonary pressure.
00:26:34
Speaker
Those are the ones that you might get in trouble with.
00:26:37
Speaker
And as I said, uncertain hemodynamic status.
00:26:43
Speaker
You are putting the catheter into the right ventricle.
00:26:47
Speaker
And it used to be said that if you had left bundle branch block, you could induce right bundle branch block and thus have complete heart block when you were putting in the PA catheter.
00:26:57
Speaker
And actually they built some of the PA catheters, they built something called a pace port swan, where you could actually pace through the catheter.
00:27:05
Speaker
There was a port where you could drop a pacing wire through the port
00:27:10
Speaker
And then there were pacing swans where the pacer was actually on the swan GANS catheter.
00:27:15
Speaker
I have to say, I've put in a lot of PA catheters, including in patients with left bundle branch block, and I have not induced a complete heart block.
00:27:25
Speaker
And if you do, you just pull the catheter out.
00:27:27
Speaker
So that's probably not a contraindication.
00:27:31
Speaker
I think that the patients to be careful about are people with other sorts of lines, people with
00:27:38
Speaker
a bunch of complicated pacemaker leads.
00:27:40
Speaker
You ought to at least think twice about trying to do this blind, because if you wrap a PA catheter around an indwelling catheter, you have to make an embarrassing call to your interventional radiologist to help you out.
00:27:52
Speaker
So you can do it, but you at least in that setting, you at least ought to think about whether that might best be done under fluoroscopic guidance rather than blind at the bedside.
00:28:03
Speaker
Could you tell us a little bit, Steve, of some placement techniques, maybe some pearls and pitfalls to avoid and maybe some troubleshooting tips?
00:28:13
Speaker
Sure.
00:28:13
Speaker
So, you know, I think you have to remember that.
00:28:17
Speaker
And even I, you know, so I put in a lot of PA catheters, but I'm not an expert with the actual setup as how you plug the transducers in and this and that.
00:28:26
Speaker
So you want to know that that setup is working.
00:28:29
Speaker
So the first principle is that,
00:28:32
Speaker
you need to know where the tip of the catheter is at all times, and it's guided by the waveform.
00:28:37
Speaker
So you have to have a waveform that you can believe, you have to be able to see that waveform, and you have to be confident on the basis of the waveform that you know where the catheter is.
PA Catheter Data in Managing Cardiogenic Shock
00:28:49
Speaker
So before you put the catheter in, so you set up the catheter, you flush the catheter,
00:28:54
Speaker
before you put the catheter in, you take the catheter, you look at your bedside monitor, and you move the tip of the catheter up.
00:29:00
Speaker
You move it up, you know, 10 or 20 centimeters.
00:29:03
Speaker
When you do that, your pressure that your transducer is measuring ought to go up by 20 centimeters.
00:29:08
Speaker
So when you move that thing up and down, you ought to see a tracing go up and down.
00:29:12
Speaker
If you do that, you have reasonable confidence that your
00:29:15
Speaker
monitoring system is picking up changes in pressure at the tip of the catheter.
00:29:20
Speaker
If that doesn't happen, you should sit and troubleshoot until that does happen.
00:29:24
Speaker
You should ask your nurses or technicians to look at that, make sure the stopcocks are all in the right direction, et cetera, et cetera, et cetera.
00:29:34
Speaker
So I think that that's, and you should also, that's another chance to look at the scale.
00:29:41
Speaker
So if you're trying to put a PA catheter in with a pressure of 40 and your scale goes from one to 10, you aren't going to be able to see the top of the of the waveform.
00:29:48
Speaker
So I think before you start, you want to be confident that your monitoring system is measuring the pressures that the other the other tip is is.
00:29:59
Speaker
that I think you'd like to, after you put in the PA catheter and you'd like to write a note that says a couple of things.
00:30:06
Speaker
It's useful to write the initial hemodynamics and not make somebody go hunting through the chart to figure out when you put in your PA catheter and what the numbers were when you put it in your daily note.
00:30:17
Speaker
Write a procedure note.
00:30:18
Speaker
And that includes two things.
00:30:20
Speaker
How far is the PA catheter in when it wedges?
00:30:23
Speaker
That's a useful piece of information because if it stops wedging, it's nice to know where it was wedging in the first place.
00:30:29
Speaker
And what were the initial hemodynamics when you put it in?
00:30:32
Speaker
I think that's useful.
00:30:34
Speaker
sort of the last tip is to look at the correlation between the PA diastolic pressure and the wedge pressure and look at it for the first couple of measurements because it's usual.
00:30:47
Speaker
There are some situations where there's a big gap or something, but usually the wedge pressure is pretty close to the PA diastolic pressure.
00:30:55
Speaker
So if you're leaving that catheter in for a while and the catheter stops wedging,
00:31:01
Speaker
then I think the part you don't necessarily have to gyrate to measure a wedge pressure.
00:31:09
Speaker
You can sometimes just look at the correlation between the PA catheter and the wedge pressure and use the PAD diastolic instead.
00:31:20
Speaker
Excellent.
00:31:21
Speaker
And in terms of access, obviously, you mentioned earlier, Steve, that in the cath lab on the floral, most access is usually through the femoral.
00:31:32
Speaker
In terms of putting in the ICU, if everything else is equal, is there a preference?
00:31:38
Speaker
Is there an access that gives you a straighter path?
00:31:41
Speaker
Yeah, so the other thing I didn't mention is that you want the curve of the catheter to follow the path that you want to go.
00:31:50
Speaker
So sometimes you might even coil the catheter.
00:31:52
Speaker
So you want the catheter to point toward the left side.
00:31:55
Speaker
The internal juggler is really a straighter shot.
00:31:59
Speaker
And it's the straightest shot and probably the preferred access.
00:32:05
Speaker
You can use the right internal juggler.
00:32:08
Speaker
You can use the left internal juggler.
00:32:10
Speaker
It'll go that way.
00:32:11
Speaker
You can use a subplavian artery and assuming those will float.
00:32:15
Speaker
But the right IJ is probably the easiest way to get your catheter where it needs to go.
00:32:21
Speaker
And so you sort of check the orientation of your catheter as you put it in to try to make sure that it's going in the right direction.
00:32:29
Speaker
Perfect.
00:32:31
Speaker
Could you tell us a little bit before we talk about actual management, any potential complications, real complications?
00:32:37
Speaker
I know that there's been reported.
00:32:39
Speaker
Like you said, I have not seen a ton of complications with PA catheters, but they are reported.
00:32:45
Speaker
And I think it's always important for people to be aware so they can recognize them when they do happen.
00:32:50
Speaker
Sure.
00:32:50
Speaker
I mean, it's a central line with a bigger introducer.
00:32:54
Speaker
There's an infection risk.
00:32:57
Speaker
You can get arrhythmias, not so much heart block, but when you bang around the right ventricle, you can have ventricular tachyarrhythmias.
00:33:06
Speaker
Occasionally, you'll put somebody in atrial fibrillation, although that's not very common.
00:33:11
Speaker
The real worry is pulmonary artery rupture and a PA bleed.
00:33:15
Speaker
And that happens.
00:33:16
Speaker
That's why you want to check the position of the catheter.
00:33:19
Speaker
You don't want it to be too far out.
00:33:21
Speaker
You want to make sure that after you blow up the balloon to wedge the catheter, when the balloon goes down, that the tracing changes to a PA catheter tracing because you don't want it in permanent wedge.
00:33:34
Speaker
That's when the trouble happens.
00:33:35
Speaker
As I mentioned, people with pulmonary hypertension are at
00:33:38
Speaker
somewhat higher risk and you might actually decide that maybe you don't really need to wedge the catheter often in those patients.
00:33:45
Speaker
I should mention that you put the catheter in, it's room temperature.
00:33:49
Speaker
And when it sits in the body, it then goes to body temperature, it softens up.
00:33:53
Speaker
So in general, the PA catheter might migrate out a little further from where you put it in.
00:33:58
Speaker
And you can tell that sometimes by x-ray and sometimes you have to pull it back to keep it out, to keep it from being too distal and increasing the risk for pulmonary artery rupture.
00:34:08
Speaker
It's a rare complication, but it can be dangerous when it happens.
00:34:13
Speaker
You mentioned earlier that, for example, a mixed venous from the right ventricle or from the pulmonary artery is a unique feature of the PA catheter compared to other hemodynamic monitoring devices.
00:34:25
Speaker
Are there other things that the PA catheter does better than other devices?
00:34:31
Speaker
Well, I think, you know, at least in my world, I mean, so you can get those data.
00:34:36
Speaker
One of the things that the PA catheter naturally does is allow you to do serial hemodynamic measurements.
00:34:43
Speaker
And there are other devices that do serial hemodynamic measurements.
00:34:46
Speaker
But, you know, people talk about echocardiography as an alternative to the PA catheter.
00:34:51
Speaker
And you can get hemodynamics from a good echo with Doppler and all that.
00:34:56
Speaker
But serial measurements require you to do another good echo with Doppler and all that.
00:35:01
Speaker
And another one and another one.
00:35:03
Speaker
So it's a convenient way to get serial measurements.
00:35:07
Speaker
Not the only way to get serial measurements, but it's more convenient than many of the other techniques.
Educational Value of PA Catheter Data
00:35:13
Speaker
Perfect.
00:35:13
Speaker
How do you use PA catheter data, hemodynamics in your actual management of patients?
00:35:21
Speaker
And I think that we could maybe think about it, Steve, from figuring out what to do with the patient as their cardiogenic shock gets worse, how to manage hemodynamic support, and maybe even how to wean them eventually from some types of support.
00:35:36
Speaker
Yeah, so I think that, you know, you're getting two, maybe two, maybe three main pieces of data.
00:35:45
Speaker
You're getting filling pressures on the right side and the left side.
00:35:51
Speaker
You're getting cardiac outputs, whether that's an assumed fit cardiac output or a thermodilution cardiac output.
00:35:57
Speaker
And I think that helps you with management of the patients.
00:36:01
Speaker
If you're dealing with elevated filling pressures, then filling pressures are what you want to look at.
00:36:08
Speaker
And if you're dealing with low cardiac output, then you want serial measurement of cardiac output.
00:36:12
Speaker
with manipulation of hemodynamics and support devices and such.
00:36:17
Speaker
And you also, the other thing that has become clear in the cardiogenic shock world is that biventricular failure is not uncommon.
00:36:27
Speaker
And the way to diagnose right heart failure is hemodynamically.
00:36:31
Speaker
And there's a
00:36:33
Speaker
There's something called a PAPI, which is basically an index of the pulmonary artery pulse pressure, that is the PA systolic minus the PA diastolic divided by the right atrial pressure.
00:36:48
Speaker
So if you think about it, what you'd like is aโand the pulse pressure on both sides actually is an index of stroke volume.
00:36:54
Speaker
So what you'd like is a high pulse pressure and a low right atrial filling pressure.
00:36:59
Speaker
If the pulse pressure is low and the right atrial pressure is high, then the PAPI is low.
00:37:03
Speaker
And that's something that particularly in mechanical circulatory support, you can use as an index of right ventricular contractility and right ventricular function.
00:37:13
Speaker
So I think that it's a little hard to be to to.
00:37:18
Speaker
you're going to use it differently in all sorts of different clinical situations, but I think that's really what you're thinking about.
00:37:24
Speaker
What parameter am I titrating to?
00:37:27
Speaker
And it goes to the same thing when you wean the catheters.
00:37:31
Speaker
So when you're ready to wean mechanical circulatory support,
00:37:36
Speaker
You want to say that the filling pressures are low, that the indices of right ventricular performance are good, and then if you put it in to support cardiac output, then you're going to measure cardiac output.
00:37:48
Speaker
You can often turn down the support and measure hemodynamics again to see what happens when you give less support.
00:37:55
Speaker
And if the patient maintains his or her hemodynamics, then you have some confidence that it's a good time to wean the support.
00:38:02
Speaker
Perfect.
00:38:03
Speaker
So I think as a general principle, probably, like you mentioned, is the serial measurement in response to therapies and the changes to that therapy is what really helps us.
00:38:14
Speaker
I think that many years ago, residents would have this conception that a high wedge equals pulmonary edema, and that was really kind of a summary of what the PA catheter gave you.
00:38:23
Speaker
But really what we're looking today is
00:38:27
Speaker
new measurements like the poppy, trying to see what the response is on that wedge pressure, filling pressures, but also on the cardiac output to the things that we're implementing over time.
00:38:38
Speaker
Excellent.
00:38:39
Speaker
The other question I was going to ask you is for diagnostics,
00:38:44
Speaker
So you wrote a lot of board type questions for reviews and for the actual boards.
00:38:50
Speaker
At one point, I used to joke that there were certain things related to the PAC that you only saw when you took tests.
00:38:57
Speaker
But from a physiological standpoint, I think there's always some interesting little nuggets to learn there.
00:39:04
Speaker
Are there any patterns in particular that are kind of classical or very instructive?
00:39:11
Speaker
Well, you know, I think that there are a lot of sort of hemodynamic patterns in the cath lab.
00:39:18
Speaker
So there's all this.
00:39:20
Speaker
You can look at the X descent and the Y descent and a blunted Y descent suggests tamponade.
00:39:26
Speaker
at preserved X and Y descent suggests pericardial constriction, and those are right heart findings.
00:39:35
Speaker
The thing about testing is it's classic cardiovascular physiology.
00:39:39
Speaker
It's something that critical care people are supposed to know that other people don't know.
00:39:44
Speaker
So it's, if you will, unique to critical care, and it's testable.
00:39:49
Speaker
And the other thing that you want to think about is you want, it depends a little bit, you want to know when to measure the
Future of PA Catheter Technology and Trials
00:39:57
Speaker
PA catheter.
00:39:57
Speaker
So you really want to measure it at end expiration when the pressures equilibrate between the left atrium and the pulmonary capillary, the wedge.
00:40:14
Speaker
the pulmonary artery, and there's no flow at end expiration.
00:40:18
Speaker
So there's classically the question of when should you measure the wedge, and of course the respiratory pattern changes whether you're in spontaneous ventilation or whether you're on a ventilator, but you do want to go to end expiration to measure the pressures.
00:40:33
Speaker
So those are sorts of things that are kind of testable, and then
00:40:37
Speaker
The waveforms and whether the catheter has too much whip, whether the catheter is appropriately transduce and whether it has too much whip is sort of one of these cute questions that people ask.
00:40:50
Speaker
Even I can't remember how to do it.
00:40:53
Speaker
But there are a bunch of questions.
00:40:54
Speaker
I will say that some of those questions have been left over from when Dr. Perillo was writing questions, and they still perform well on the test.
00:41:03
Speaker
That is, they discriminate the people who are passing from the people who are not passing.
00:41:08
Speaker
And so I don't take the blame for all the PA catheter questions.
00:41:13
Speaker
Fair.
00:41:14
Speaker
Awesome.
00:41:15
Speaker
So as we move forward and looking ahead, are there any upcoming trials or new technology that might be associated with PA catheters that you're excited about?
00:41:24
Speaker
Well, so there is a trial ongoing called the PAX trial.
00:41:33
Speaker
Pulmonary artery and critical care, something like that.
00:41:37
Speaker
But that's a trial looking at the PA catheter and cardiogenic shock.
00:41:43
Speaker
And it randomizes people between early PA catheter placement, that is less than six hours versus delayed PA catheter placement, that is
00:41:53
Speaker
either no PA catheter at all or delayed past 48 hours.
00:41:56
Speaker
And you have to have cardiogenic shock, low ejection fraction, elevated lactate, hypotension or vasopressors, or clinical evidence of heart failure or mechanical support with a balloon pump.
00:42:09
Speaker
So mechanical support with other devices is excluded.
00:42:13
Speaker
It's an adaptive trial.
00:42:15
Speaker
That is, they're looking for outcomes, and it will be somewhere in between 200 and 800 patients, and the primary outcome is in-hospital mortality.
00:42:26
Speaker
So that trial is ongoing.
00:42:27
Speaker
You can imagine that that may not be the easiest trial to recruit for, so we'll see how long it takes, but there is a randomized trial of PA catheterization ongoing, and I think everybody is looking forward to those results, although
00:42:43
Speaker
one wonders exactly how many mines that's going to change no matter which way it
Dr. Hollenberg on Judgment and Evidence-Based Practice
00:42:47
Speaker
turns out.
00:42:47
Speaker
Because I've already said you have to have PA catheter for mechanical circulatory support no matter what.
00:42:53
Speaker
But nonetheless, I think randomized data is always good and we're looking forward to the results of that trial.
00:43:00
Speaker
Perfect.
00:43:02
Speaker
As we close, I always...
00:43:05
Speaker
I'd like to say that the main goal of education is not knowledge but action.
00:43:10
Speaker
And part of the discussion today was to help colleagues who are all of a sudden faced with perhaps there's patients in my practice in whom a PAC, a pulmonary catheter would be very helpful and there's evidence to support that as opposed to where some people were for many years is that we don't use those things anymore.
00:43:29
Speaker
So any recommendations for critical care clinicians at the bedside to develop or regain that expertise with PACs?
00:43:37
Speaker
Yeah, I think that if you're going to put in a PA catheter, you don't want to put it in once a year in a very sick patient.
00:43:47
Speaker
If only for your entire operation of the unit, your nursing staff, your technical staff, your trainees, everybody, you want your unit as a whole to have some familiarity with PA catheters, which I think means that you're going to have to put some of them in.
00:44:03
Speaker
So I think in virtually all, except for mechanical circulatory support, but in any individual case, you can make an argument that you can get away without a pulmonary artery catheter.
00:44:13
Speaker
It's not like there's somebody who absolutely has to have a pulmonary artery catheter, but I do think they're helpful, and I think it's worthwhile to sort of dip your toe in the water, try to find a patient in whom you might get some data with a pulmonary artery catheter, and put a couple in, make sure you have...
00:44:32
Speaker
have a chat with your nurses, say you're going to want to do it, get used to the protocol and how to do it and then do it.
00:44:38
Speaker
And you might want to start just putting them in and this isn't the only place to start, but you could essentially say, if you have a patient with renal failure and you don't know whether they're wet or dry,
00:44:50
Speaker
There are other ways to do this, but if you're not putting a PA catheter, the usual technique is to give a bunch of fluid, and if that doesn't work, give a bunch of diuretics.
00:45:01
Speaker
So you might argue that it may actually have lower morbidity to measure filling pressures and then decide whether what you need is fluids or diuretics.
00:45:10
Speaker
So that might be one situation in which...
00:45:12
Speaker
You don't necessarily need a PA catheter, but you could imagine that it might be useful.
00:45:17
Speaker
And those patients tend to be relatively stable.
00:45:19
Speaker
So that might be one place to start.
00:45:22
Speaker
And, you know, the other thing is that you can get some help.
00:45:24
Speaker
Call your interventional cardiologist and say, look, I want to do this at the bedside.
00:45:29
Speaker
Would you mind coming and talking me through it?
00:45:31
Speaker
I think that would be a good way to start.
00:45:34
Speaker
Excellent.
00:45:35
Speaker
So you've been on the podcast before, Steve, and you know, we like to close with a couple of questions unrelated to the clinical topic.
00:45:42
Speaker
Last time we spoke about books, but are there any books that you've read since we last spoke that really impressed you?
00:45:49
Speaker
So there's one book that I like and I really like to recommend.
00:45:52
Speaker
I don't know if you've read it.
00:45:54
Speaker
It's a book called I Contain Multitudes.
00:45:56
Speaker
It's by a guy named Ed Young, who's a science writer for The Atlantic magazine.
00:46:02
Speaker
And it's about the microflora.
00:46:04
Speaker
It's about bacteria and the microbiota.
00:46:07
Speaker
And as you probably know, we have more bacterial DNA in our bodies than human DNA.
00:46:13
Speaker
And it talks about not only our microbiota, but the way that microbiota finds ecologic niches and the way in which those niches work often in synergistic ways.
00:46:25
Speaker
fashions and help not only host for the microbiota, but help the host organism in a number of ways.
00:46:32
Speaker
And you could argue that our microbiota do that for us.
00:46:36
Speaker
It's an ongoing area of investigation.
00:46:40
Speaker
I think that's, it's a really fascinating book.
00:46:43
Speaker
I have not, the only multitudes I read about was in Leaves of Grass.
00:46:46
Speaker
So I would definitely will, will, will read this book.
00:46:49
Speaker
Sounds very interesting.
00:46:50
Speaker
And I think it's always one of those things that I tell people is reading about things that you have no expertise over or that, that doesn't come in your daily work is usually very enlightening and opens your mind to new ideas.
00:47:03
Speaker
So yeah, definitely.
00:47:05
Speaker
What I did want to ask you though, is I used to ask if you were stuck on an island, but now I've added or isolated with a new pandemic, where there'd be any, what are two musical albums and I'm old school vinyl.
00:47:18
Speaker
So I say albums, although I hear CDs are also coming up, making a comeback these days that you would want to have with you.
00:47:26
Speaker
Yeah.
00:47:26
Speaker
So I, I, I thought about this.
00:47:30
Speaker
I think, I think I might go with a Miles Davis kind of blue.
00:47:34
Speaker
It's a, you know, as you know, it's a classic jazz album, but it's one of those albums that you hear a different thing every time you listen, and you recognize a little more of the genius every time you listen.
00:47:49
Speaker
It's really a great album, and I think I could spend a while listening to that one, too.
00:47:56
Speaker
And then, you know, maybe a classical album.
00:48:00
Speaker
My favorite classical piece is actually the Brahms Requiem.
00:48:06
Speaker
Perfect.
00:48:07
Speaker
And we'll add links to all these in the show notes.
00:48:11
Speaker
So the next question, Steve, is could you share with us something you changed your mind about over in the last couple of years?
00:48:19
Speaker
Yeah, so I think I've, I'm thinking about this.
00:48:25
Speaker
I've sort of changed, I don't know that I've changed completely, but I've kind of changed my attitude about the concept of, of why not try an unproven therapy when you don't know what to do, particularly if you think that unproven therapy is relatively safe.
00:48:43
Speaker
And sort of, you know, what could it hurt?
00:48:46
Speaker
And I think we saw a lot of this in the COVID pandemic.
00:48:50
Speaker
And we saw a lot of people trying a lot of things.
00:48:53
Speaker
They tried vitamin C, they tried ivermectin, they tried hydroxychloroquine, and the argument was, well, they're probably not harmful.
00:49:01
Speaker
And
00:49:02
Speaker
They probably weren't harmful, but they weren't helpful.
00:49:06
Speaker
And to me, that really hindered the effort to figure out what works because it just complicated things.
00:49:13
Speaker
So to me, when you don't know what to do, you should at least have some plan to study what you're doing.
00:49:21
Speaker
And that doesn't mean that you have to only do things that are proven in randomized clinical trials.
00:49:26
Speaker
But if you're going to try something, then you want to know, you want to at least have some sense of,
00:49:32
Speaker
what would say that that particular therapy was working and sort of measure it, try to figure out whether that particular therapy is doing what you think it is doing, whether that's an observational thing or whether that's a...
00:49:46
Speaker
participation in a controlled trial is sort of up to you.
00:49:50
Speaker
Controlled trials are preferable, but there may not be there.
00:49:52
Speaker
So I've kind of gotten a little harder on, you know, don't just do something, stand there.
00:50:00
Speaker
And I also think along those lines that we in the scientific and the medical world need to be advocates for that approach.
00:50:10
Speaker
We need to say that science works and that we need to study things and try to
00:50:16
Speaker
figure out what works in a scientific fashion rather than letting everybody choose an empiric therapy that makes sense to them.
00:50:23
Speaker
I agree.
00:50:24
Speaker
And I think that on that note, obviously, two things that come to mind immediately, Steve, are our best to action.
00:50:31
Speaker
Right.
00:50:32
Speaker
We always think that doing is better than not doing.
00:50:34
Speaker
And I think that gets us into trouble many times.
00:50:37
Speaker
But the other mental model idea or concept that that I think applies and I've been thinking a lot, a lot about a lot lately is opportunity cost.
00:50:48
Speaker
Every time we do something, we are paying an opportunity cost to maybe do something that was more valuable
Closing Remarks and Future Expectations
00:50:54
Speaker
or better.
00:50:54
Speaker
And I think it's worth thinking, right?
00:50:56
Speaker
I mean, I think that all the energy, time and money spent on all these trials and all these to try to prove or disprove these worthless therapies were wasted because there probably was better scientific arguments to go in other directions.
00:51:11
Speaker
Right.
00:51:11
Speaker
And, you know, the other thing is that what you give may be safe, but what you don't know is whether that safe therapy is making something else stop working.
00:51:23
Speaker
And you don't know that unless you test it.
00:51:26
Speaker
So, you know, imagine doing a trial in COVID where half the patients are on hydroxychloroquine and half of them aren't.
00:51:32
Speaker
That just introduces unnecessary complexity into the interpretation of a trial.
00:51:37
Speaker
For sure.
00:51:38
Speaker
So the last closing question is, what would you want every listener to know?
00:51:43
Speaker
Could be a parting thought, a quote, or something else.
00:51:48
Speaker
So I thought about this.
00:51:50
Speaker
I've decided this is my new favorite quote about medicine.
00:51:54
Speaker
And the quote is, and I didn't invent it, but I heard it once.
00:51:56
Speaker
I can't even remember who said it.
00:51:58
Speaker
But the quote is, good judgment comes from experience, and experience comes from bad judgments.
00:52:05
Speaker
So this is not, I don't read this as a call to have bad judgment, but I think it really stresses the concept of continuous learning.
00:52:18
Speaker
Try to figure out when something doesn't work,
00:52:22
Speaker
try to figure out what you could have done differently, how that could have gone differently.
00:52:28
Speaker
And there are processes within the hospital, but even in your own practice, when things don't work.
00:52:34
Speaker
And even when you do something and get in trouble, why did you get in trouble?
00:52:38
Speaker
What were you seeing that was deceiving you?
00:52:41
Speaker
Or what did you not see?
00:52:43
Speaker
And sort of how can you try not to have that happen the next time?
00:52:48
Speaker
So that's my new quote.
00:52:50
Speaker
I think that's a perfect place to stop.
00:52:52
Speaker
Steve, thank you for sharing your time and your expertise with us once again.
00:52:56
Speaker
Look forward to have you back and to talk about other topics.
00:53:00
Speaker
And always good to learn from you.
00:53:03
Speaker
Great.
00:53:03
Speaker
It's been a pleasure.
00:53:04
Speaker
And thank you for having me on.
00:53:08
Speaker
Thank you for listening to Critical Matters, a sound podcast.
00:53:11
Speaker
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00:53:17
Speaker
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00:53:22
Speaker
To learn more, visit www.soundphysicians.com.