KATE: But, yeah. All right, so let's slowly get it started.
So, hopefully, as you all know, you're here for Lecturio Live.
This is our first session. We are talking with Dr. Stephen Holt.
He is our educator for the physical examination course.
And a couple of our other courses on Lecturio,
but today, we're talking about physical examination.
Before we dive into the actual meat and bones of the presentation,
I just want to get to know you guys.
So, if you can put in where you are in the chat, but I'm sending out a poll right now.
Tell us who you are. Like, where are you in your med studies.
Are you studying medicine?
Maybe you're done, maybe you're already working, maybe you're a nursing student.
And if so, we have nursing events specifically as well,
but of course, you're always welcome here.
So, go ahead and pop your answers to the poll.
If you are on mobile, you might need to just scroll down
or tap the little icon on the bottom right and the poll should pop up.
Otherwise, on a computer, it'll be on the right-hand side which in my screen,
it's showing I'm pointing to the left, but I'm pointing to my right.
So, on your right-hand side.
For those of you who are non-student or other,
can you maybe let us know in the chat, you know, who are you,
what are you - what brings you here today?
All right, we've got a post-doc and epidemiology.
I always say that word wrong, I apologize.
We got an economics major. Interesting.
Some licensed physicians, graduates, thinking of going into IR.
We got a high school student. All right. You're way ahead of the game.
All right. All right. Then, I've got another question for you all, for you all.
We are here hosting you from Lecturio, so how many of you know Lecturio?
Because obviously, you know, if you're a member of ours,
we send you an invite in email of course,
but some of you maybe don't know what Lecturio is
or have used it in the past or watched our videos on YouTube.
So, let us know, you know, how familiar are you with Lecturio.
Just so we can get an idea.
HOLT: You missed the one person in the chat who said that they write medical romance novels
and that's why they're here, so that's awesome.
KATE: Oh, that's fascinating. That is - can I have that job? No?
HOLT: I know, yeah. I will definitely make sure that my talk caters
to that particular audience member somehow.
KATE: Absolutely. I love it.
All right. And a lot of your characters are doctors.
All right. Well, Amy, we're really excited to have you here.
We're excited to have everybody here, of course, but I think that's by far,
the most interesting answer we've gotten in our previous events.
Speaking of previous events, one last question.
This one's for the chat. Have you been to one of our previous events?
From many of you, this might be your first one, but for others, you may have joined us before.
We've been doing a series on learning science, techniques for students,
the most recent was last month.
We were talking about how to hack your memory.
And, yeah, we've talked about other things such as interleaving and spaced repetition and -
or spaced retrieval, and all sorts of fun things.
So, yeah, let us know if you've been at any of our previous events.
It's great to see those of you who are coming back.
That always makes us really happy.
For those of you who are new, welcome.
We're excited to have you here. Yeah, all right.
Well, thank you so much, again, everyone, for joining us.
You probably don't want to hear from me anymore, so without further ado,
today, we've got just a few things on our agenda,
but I want to introduce you to our wonderful guest speaker.
This is Dr. Stephen Holt. He's a professor at the Yale School of Medicine
and he is one of our educators with Lecturio.
So, Dr. Holt, please go ahead. Take the stage. The floor is yours.
HOLT: It's an honor to be here to see folks from such a diverse arrange,
you know, array of places as well.
I'm happy to say I've been to a number of those places.
Peru and Honduras and Singapore, Malaysia, of course, England and Germany.
It's really great to sort of be coming together with folks from such a diversity of places.
So, I'm here today because I want to talk about the physical exam
and it's one of the things that I'm most passionate about within medicine.
And it's one of the things which I found has drawn all of us
in some ways to our interest in medicine.
There's many things that are wonderful about medicine,
but the initial ability to use our hands to actually identify a disease
and hopefully to use that information to come up with a treatment plan
has always been something that's fascinated me.
The problem-solving aspects of it.
It's really what Sherlock Holmes did.
He was, of course, a physician as well and sort of trying to figure out
what was going on with the people he was meeting.
He could learn so much just by observation alone,
so that's some of the things I want to talk about today.
But of course, as we always do, let's start off with a case.
So, this is a 49-year-old man with a medical history of obesity
who presents with left-sided anterior knee pain
that began immediately after twisting his knee during a basketball game.
He is concerned he might have torn his anterior cruciate ligament and asks to get an MRI.
So, our first poll question, what is the purpose of performing a physical exam on this patient?
So, we'll open up the chat here. Like, why do a physical exam at all?
Why not just get an MRI? That's the real question.
Why not just get an MRI and skip the exam altogether?
Resource management, somebody's talking about resource utilization.
You know, you can't just MRI every single person that comes in with knee pain.
That gets pretty expensive. Checking for abnormal movements.
Hopefully, that'll help you further characterize the lesion.
Make a differential diagnosis. Look for other types of injuries.
Just to confirm, if the patient in fact needs an MRI. That's a great answer.
Avoid exposure to radiation, which certainly CT scans can cause.
Looking for other diagnosis.
MRI helps in having a skim but not really with the pain or with the abnormal movement.
Judging the necessity with the neurovascular status.
Great. I love all of those answers, so in many ways,
a lot of your comments there are in some ways,
a contest or a juxtaposition between the role of the physical exam
compared with the role of radiology, right?
The question is whether or not one is better than the other
or is appropriate in certain settings, etc.
And so, let's just throw another quick question out there
as we dive into the difference between them.
I'll have a couple of times, during this talk,
where I throw a little physical exam things at you guys to see if you can identify them.
Can anybody identify this finding and what it might signify?
It's a finding on the physical exam here.
Okay, I see a couple of options.
In terms of claw hand, this patient can actually open their hands,
so there - it's not the hand, it's not the fingers themselves.
Oh, I saw somebody write half and half disease and kidney disease,
and that is in fact, the correct answer.
So, what we're highlighting here is the proximal half of this nail plate is white.
Kate, they can actually see my mouse, right, or no?
Oh, I'm not sure if you guys can see my mouse or not,
but in the - you can't see my mouse.
Okay, well, that's good to know.
Do I have a pointer of some sort, Kate? I don't think so.
Well, on the nail bed itself, you can see that the proximal half is white
and the distal half is kind of pink in color.
And that is actually called half and half nails or Lindsay's nails,
and that is a marker of end stage renal disease.
This is just one example of a finding which you don't need a blood test
to identify if somebody's having Stage 4 or stage 5 kidney disease.
A simple physical exam finding can actually make this diagnosis for you.
And particularly, if you don't have access to blood work immediately
or if you're in a primary care setting where you're not getting blood work
every time somebody walks in your office,
these are the kinds of things that you can detect.
So, in many ways, the distinction between a physical exam
and radiology comes down to this question.
You know, is the physical exam antiquated?
Is it basically just kind of so obscure and outdated,
and you know, you're invoking Rene Laennec from the invention of the stethoscope in the 1800s
and Auenbrugger, you know, using percussion for the first time?
We're talking about ancient history.
Is that stuff still relevant today in the modern era of diagnostic imaging?
Lack of training, you know,
the reality is, is that the physical exam, you know, you'll spend a few months
working on the physical exam during your clinical years in medical school
or whatever health professional school you're in,
but you know, maybe you don't get a lot of exposure to physical exam after that
and attending physicians assume you know what you're doing,
but they don't actually watch you checking deep tendon reflexes
or trying to elicit a Hoffman's maneuver or auscultating the heart.
So, maybe that's one of the barriers for the physical exam.
The third question is whether there's any accuracy to the physical exam.
Is it actually a useful diagnostic test or is it a lot of mumbo jumbo,
a lot of hand waving, and in reality,
we can't really make reliable diagnosis with our hands
and with our stethoscopes and our reflex hammers? And then, the question of time.
Like, do we really have time to go
and be in a room with the patient performing these examination skills
when we could just, you know, with a click on, of a button or a quick written order,
we can order that CT scan, that MRI, that ultrasound,
and not have to worry about whether or not we're examining the patient or not.
So, let's first look at accuracy, which is this last one there.
Or the third one there, just the interest of time.
So, this is an MRI example.
It was actually from a study, which I believe, the citation is down there at the bottom,
which looked at 100 asymptomatic people.
So, people actually have no knee problems whatsoever, a range of ages,
or in this case, all over the age of 45.
And what they found is that these people
who before the study was performed were out maybe jogging
or walking or playing tennis or what have you,
36 out of 100 people had meniscal tears on their MRI.
So, what this highlights is that yes, it's true,
if you look to the figure on the right here, radiology is very precise.
If you get, you know, 50 radiologists in a room,
they will all identify that specific meniscal tear finding on the MRIs of high precision,
but in terms of accuracy, that is how much does that finding correlate
with the source of a person's pain, the accuracy is terrible for an MRI.
The problem is you're going to find all these findings
which may have nothing to do with the patient's actual source of pain.
Because as I said, 36 out of 100 people who have no pain at all have a meniscal injury.
So, if you have somebody who actually does have pain and you get an MRI,
there's a pretty decent chance that the meniscal injury
you find there has nothing to do with their pain.
But now, you found this meniscal tear
and so now, you're going to send them to an orthopedist,
maybe they'll have an arthroscopy, undergo a meniscal repair.
Very expensive, potentially has its own complications,
and lo and behold, maybe their knee pain had nothing to do with the meniscal tear
that you saw in the MRI.
And in fact, they had pes anserine bursitis
or maybe they just had medial compartment osteoarthritis
or any number of other potential causes of knee pain.
So, accuracy is one of the big problems of radiology.
You will find stuff every time you do an MRI, but is that stuff,
does it have anything to do with what's going on with your patient
who's in front of you right now?
Moreover, you'll find incidentaloma - the finding of a meniscal injury
and you can see that stuff with any -
All right. You could find that stuff with any of these MRI studies
where you look at the C spine, you'll find spinal stenosis in people that have no symptoms.
You'll find rotator cuff tears in people with no symptoms.
This is sort of a classic problem with our advances in diagnostic imaging today.
But sometimes, you'll also find a small mass.
A lesion of some sort that is going to prompt people to be concerned
and have anxiety about what they found.
If you look at the rate of thyroid incidentalomas,
that is when somebody gets a carotid Doppler
or just an ultrasound of the neck to follow up over time if you had a CT scan of the neck.
You may find these incidental findings.
So, 10-67% of neck ultrasounds will find the lesion.
4% of CT scans of the abdomen will find completely incidentally found lesion on the adrenal glands.
15% of MRIs have pancreatic incidentalomas,
and 17% of MRIs and CT scans of the head have pituitary incidentalomas.
And that's not a benign finding.
It may have never ever caused a patient have any problems in their lifespan,
but now, you've got this new lesion there, it's causing anxiety for the patient,
it's something that probably now needs to be worked up
because now that you have it, you can't just completely ignore it.
There's, you know, a lot of defensive medicine stuff out there
with people wanting to, you know, cover their tracks.
If you find something, you kind of have to do something about it.
So, radiology is not without complications in that regard.
And radiation itself is dangerous.
We know this is more relevant for the CT scans
since MRIs don't really expose patients to radiation, not a significant amount,
and neither do ultrasounds, but certainly, CT scans do.
In fact, a single CT scan exposes a patient to approximately 10 millisieverts of radiation.
That's how we measure radiation, it's in - with this unit called millisieverts.
And in general, background radiation,
you know, in like, the industrialized world is around 5 millisieverts,
5-6 millisieverts per year of background radiation.
So, you'd basically be adding 10 millisieverts on top of that in,
you know, all at once in a span of an, you know, 30 minutes.
And folks who are in the hospital frequently oftentimes are getting multiple CT scans per year.
And we know from looking at longitudinal data, looking at radiation exposure,
that when patients are exposed to an excess of 50-100 millisieverts,
there is a statistically significant increase in cancer mortality.
So, not just getting cancer, but actually dying from cancer.
And based on that data, there was a report done a few years ago now
that estimated that more than 2% of all future cancers that,
this was based in the United States, that all future cancers that will occur in the United States
are actually exclusively due to CT scanning.
Which is a pretty staggering statistic
when you think about cancer and the burden of cancer for families
and patients and the healthcare system.
To think that more than 2% of all those cancers are actually iatrogenic.
We have caused them by our over reliance on using CT scanners.
It's a pretty staggering statistic.
And as one of my mentors and role models had said many years ago,
Abraham Verghese, out in Stanford,
"And so many clinical signs, such as rebound tenderness, lid lag, tremor, clubbing,
and hemiparesis cannot be discerned by any imaging test."
And he was essentially highlighting here how there are some things
you can't use radiologic imaging or laboratory testing to identify.
So, the physical exam is such an important skill set.
And here's another one for you.
Can any of you identify this finding and what it might signify?
You can put it in the chat if you know what it is.
All right. Clearly, this one was a very easy one.
Strong work, team. It is in fact xanthelasma suggestive of a hereditary dyslipidemia.
Strong work. All right. But having talked about some of the problems
with an over reliance of radiologic imaging,
let's talk about the actual advantages of using the physical exam.
So, first off, there are rarely incidentalomas.
I mean, you could have an incidentaloma.
You could find something on a physical exam that may be,
you know, if you hear a bruit over the carotid and you get an ultrasound
and there was nothing there, maybe that was an incidental finding on your physical exam.
But you're not going to expose anyone to radiation.
You know, unless you just drank some radioactive iodine
right before you performed your physical exam,
you're not going to be, you know, giving radiation to your patients.
So, that's good. And I would argue, it's pretty rewarding.
You know, I don't think anyone on this chat, I doubt that they have gone into this field
because they wanted to be data programmers or computer engineers, you know?
We actually like people. We want to be around human beings.
We want to be in the room with people.
Learning how to communicate with them, learning how to allay their anxieties,
and using our own observation skills, our five senses, to identify and treat disease.
And so, for me, it's just intrinsically rewarding to know that I can do that rather than,
you know, basically going into iGoogle and having a machine do all the work for me.
In particular, as we said, the machine can make a lot of mistakes
and cause a lot of problems down the road. It's free.
Your physical exam costs you nothing and it is available 24/7.
You've got it at 2:00 in the morning when you're on call in the ICU
and you don't have access to an MRI machine,
and you've got it if you're out doing rural medicine
or if you're doing mission work somewhere.
You always have your physical exam,
which brings me to the next bullet, which is the timelessness of proficiency.
There is a lot of things that I learned in medical school
like the side effect profile of using interferon to treat hepatitis C,
the role of Coumadin in terms of the exact mechanism of a factor Coumadin
and the specific epoxides that it affects in terms of the synthesis of pro-coagulants
or factors in our coagulation cascade.
I learned about all of those things, and it turns out that they're largely obsolete,
at least in my healthcare system. We don't use interferon anymore for hepatitis C.
We're moving away from Coumadin
and it's probably going to be obsolete within the next few years.
There's all these things that I learned, a lot of cancer treatments, etc.,
that have no significance anymore because those kinds of things, diagnostic,
I mean, the treatment modalities, medications, even some laboratory tests, they expire.
They kind of have an expiration date on them.
The only thing that you will ever learn in medical school
which has no expiration date is your physical exam.
Every single skill you learn with proficiency on a physical exam that you learned today,
you will have, for the next 40 or 50 years, however long you practice in medicine.
And so, there's a real sense of it's the most important thing to invest your time in.
So many other things are going to not be relevant.
The pathophysiology of course is also something worth learning
because that also is timeless, but a lot of the treatments,
they really don't - they have a lifespan on them.
And then, lastly, connection to patients.
As I said, you know, there's almost a ritual associated with doing a physical exam,
of laying your hands on your patient's, of making that physical bond
and the physical connection with your stethoscope or with touching the patient's hands,
looking at their fingernails, feeling their abdomen
during the musculoskeletal exam with competence.
That builds a rapport with the patient.
You know, so often today, I see medical students with residents,
they spend two minutes at the bed side of the patient,
and the rest of the day is sitting in front of a computer, looking at the chart,
looking at diagnostic imaging test results, etc.
And that's at least, that's not what I went into medicine.
So, which brings me to putting the patient first.
The good physician treats the disease,
but the great physician treats the patient who has the disease.
When you are examining patients with your students
as you become interns soon or whether you're an attending physician
and you're rounding with your team at the bedside,
make sure that you always ask permission to perform the physical exam on patients.
They are not objects, especially if you're doing teaching rounds.
Make sure it's clear that that's what you're doing with patients.
Respect their modesty.
Only really expose the part of their body that needs to be exposed
to perform the particular aspect of the physical exam that you're doing.
Ensure the patient is comfortable throughout.
Whenever I have the patient hold their breath
while I'm performing a cardiac exam or assessing diaphragmatic excursion
or something, I always hold my own breath
so that I don't forget my patient is holding his or her breath,
which can, you know, it can start to become uncomfortable
if you're talking to your students about some finding,
and there, the patient is still holding their breath and turning blue in the face.
So, I always make sure my patient is comfortable throughout.
Introducing everyone who is in the room.
And then, of course, summarizing my findings to the patient rather than just talking,
you know, casually about different findings with my team,
and then just walking out of the room.
You can really put a lot of anxiety in your patient's minds
if you don't tell them what you're doing and what you've done.
With that, I want to transition to the second portion of this presentation and it's a bit shorter,
but I just wanted to focus on how to use likelihood ratios.
I talked before about accuracy and precision and how radiologic imaging is very precise
but not very accurate in terms of identifying the source of a person's pain or dysfunction.
If you know likelihood ratios, you know how to use a physical exam
to have the same kind of sensitivity and specificity
to maximize the precision of your physical exam tests.
So, what do I mean by that?
First off, a quick question to the audience again.
Can anyone name some exam findings that are specific to an ACL tear?
Tell us something in the chat.
Great. Yep, anterior drawer test,
which I see somebody has also called the tibia pull,
which I - that's basically the same thing. Great.
And there's one other important test other than the anterior drawer test.
Lachman's test. Excellent job there, Fra,
and a few other folks who named the Lachman's test as well. Great. Those are the main ones.
Obviously, there could be other findings as well
and effusion would be very common in the setting of an ACL tear.
So, I want to talk a little bit about likelihood ratios here.
So, let's say that we have a 49-year-old male,
oh, we actually already presented the case in the start of this talk,
so this guy came in, he had a left-sided anterior knee pain.
It started right after he twisted his knee and he's concerned about an ACL.
He wants to get an MRI, so the question is, do we really need an MRI,
or will a physical exam be sufficient?
So, we perform the physical exam and you have developed competence in the physical exam.
And so, you're confident in your skills here.
You perform a Lachman and an anterior drawer.
If we look at the Lachman here,
we can see the positive likelihood ratio for a finding of the Lachman is 17
and the negative likelihood ratio is 0.2.
So, what does that actually mean?
So, here's how you interpret a likelihood ratio.
So, the first step is to come up with what your pre-test probability is.
And it's basically your clinical gestalt.
Like, if a person comes in with this story and they're this age
and they have this kind of injury,
before I even lay hands on the patient, before I do any physical exam,
how likely is it that this person actually has an ACL tear?
And some of that comes from your own clinical experience,
from - there's actually in the JAMA Rational Clinical Exam series,
they have a lot of these kinds of questions.
You know, does this patient have ascites?
Does this patient have - is this patient having a coronary syndrome?
And they look at historical features and look at the likelihood, the probability,
based on certain historical features that a person does or does not have ascites.
So, if you use JAMA's Rational Clinical Exam series
and you look at the one for ligamentous tears in the knee,
you'll see that just based on the data I provided, his age, the mechanism of injury,
and the acuity of his pain, the pre-test probability
that this person actually has an ACL tear is 20%.
So, that means there's about a 1 in 5 chance that he has a tear,
and if I were to turn that 1 in 5 chance into a probability,
that would mean that there's a 20% chance he does have an injury, and ACL tear,
there's an 80% chance he does not have an ACL tear,
so the odds is 20 to 80, which is 1 in 4. So, your odds are actually 1 to 4 or 4 to 1.
So, that's your pre-test odds.
What I've done is I've taken a pre-test probability and converted that to a pre-test odds.
You have to do that step because when you're using likelihood ratios,
you're using likelihood ratios to modify an odds, not a probability.
And you know, that's a little semantic.
I'm not a statistician, so why one thing is called probability
and the other is called odds, I'll leave the statisticians in the room to address that.
But this is called odds when you're talking about,
you know, 1 to 4 likelihood of having versus not having a disease.
So, then, you take your odds, and you multiply
that negative likelihood ratio that I was talking about before.
I said the negative likelihood ratio for a Lachman's maneuver is 0.2.
So, that means if you perform the maneuver and it's negative,
you'll take a look at the negative likelihood ratio and it's 0.2,
and multiply that by my pre-test odds, which was 1 to 4,
and now my new post-test odds is 0.05.
Now, you want to convert that post-test odds back to a probability,
because remember, we want to start off - we had a pre-test probability of 20%.
How much is that been modified?
What is my post-test probability of this person having an ACL injury?
So, to convert an odds back to a probability, you take the odds over odds plus one.
So, 0.05/(0.05+1), and my new post-test probability of having an ACL injury
has dropped from 20% all the way down to 5% with a single test,
which really highlights how important a physical exam can be to have immediately,
with a single finding, significantly reduce his likelihood of having an ACL injury.
So, again, there's the pre-test probability derived from history and prevalence,
then there's the likelihood ratios.
In this case, the negative likelihood ratio is 0.2.
Now, that was a complicated series of steps,
and you know, you don't necessarily always want to be doing that on the fly.
It's good to have a ballpark idea of some of the likelihood ratios for certain tests.
But it's also useful to have a couple tricks up your sleeves.
So, one is on the far right, it's this likelihood ratio nomogram
which you can download a copy and put it on your phone or just carry around a copy.
It's very useful and if you look at that first line, I'm talking about the figure on the right,
but the first line on the left of that figure, the vertical line, says pre-test probability.
So, in this case, the pre-test probability was 0.2.
So, you can see the blue and the red line there are originating from 0.2.
And if I go through the likelihood ratio line that's there, so for the negative test,
again, the negative Lachman test had a negative likelihood ratio of 0.2,
the red line is going through 0.2, and it ends up on a post-test probability,
in this case, 0.05, which means a 5% chance that he still has an ACL injury.
So, that's at least one simple thing you carry around in your pocket is that nomogram.
If in contrast this patient have had a positive Lachman,
the positive likelihood ratio for a Lachman is 17, which is ridiculously high.
So, if you go through the blue, follow the blue line from left to right,
the blue line goes through approximately 17, should be between 10 and 20,
and now your post-test probability based on a single test is around 0.75.
So, that's a 75% chance that he has an ACL injury.
So, a single test can help you to distinguish between
there's a 75% chance this person has an ACL injury.
And I would say, if you see that this person has an ACL tear,
he needs to get an MRI and go see an orthopedist or with that same test,
if it's negative, their likelihood of having an ACL injury has dropped to less than 5%.
Another trick though that's even easier than carrying around a nomogram
is this little rule on the left of the figure here,
which is if you know this quick guide, you can sort of quickly memorize this.
So, a positive likelihood ratio of 2, 5, or 10 on the left there,
you can just add 15, 30, or 45% to their pre-test probability.
So, if somebody's pre-test probability of having a disease was 50, let's say 50%,
and you do a test that has a positive likelihood ratio of 5,
I simply add 30% to 50%, and now my likelihood of this person having this disease is 80%.
In contrast, the flip side of that is looking at the negative likelihood ratio tricks
there for a negative likelihood ratio of 0.5, 0.2, or 0.1, I subtract 15, 30, or 45%,
and that can be a quick and dirty way to come up
with a ballpark figure of what somebody's post-test probability is.
So, that's useful way to get this stuff.
There are, by the way, some lists of likelihood ratios.
One of my favorite places is, it's called the nnt.com,
which actually means numberneededtotreat.com,
just in response to the question in the chat there.
I'll come to questions in the chat in a minute.
So, I was highlighting a single exam maneuver,
but of course, I never diagnose a disease based on a single test.
I tend to perform a number of different tests,
and this reminds me of this metaphor of the elephant and the blind men.
You know, three blind men are examining an elephant
and the first blind man is examining the trunk and says,
"Oh, an elephant is a creature that has - is like the trunk of a tree.
It's very thick and snake-like."
Another person was examining just the side of the elephant and said,
"Well, an elephant is like a wall. It's very firm, it's, you know, it can't be moved."
And then, third person just said that an elephant is like a snake
or a rope because it was just examining the tail.
So, with the physical exam, you never want to examine one thing.
You want to combine the input from several tests.
Just like combining the input from three blind men
might yield a better characterization of what an elephant is.
Similarly, I think of the piano metaphor,
which is if I play a single note on a piano,
it doesn't really tell me much of the story of what's going on in a song or in a piece,
but if I play a whole D# minor 7 chord, that has its own ambiance.
It sort of tells a story. It has its own feeling.
So, combining all those individual notes on the piano
is a way to flesh out the story of what's going on with the patient's presentation.
And sometimes, all those notes end up being something really straightforward like,
you know, a C major chord that just everything sort of sounds beautiful and like Bach.
But sometimes, it's more dissonance and you play the chord,
and some pieces of the chord don't actually add up and you've got now,
you know, a C# minor 7 sus or something, and it does sound disordinate.
And so, it's not unusual for physical exam findings to point you towards different outcomes,
and that's okay. It's rare that a person's,
you know, murmur on cardiac exam read the textbook and is exactly following the rules.
So, sometimes, you will have disordinate physical exam findings
and understanding the likelihood ratio on how to put them together is important.
So, let's say for example, we have a patient who comes in with a history of cirrhosis
and they've got some reports of lower extremity swelling and they say that they feel bloated.
And we want to perform a physical exam.
Can anyone name some findings that would support the presence of ascites on exam?
Shifting dullness. Great. Puddle sign, haven't seen that one in a while.
That's an interesting exam maneuver.
Mostly I'm seeing shifting dullness. A thrill, less useful in this context.
Certainly, the presence of caput medusae or spider vessels, spider angioma.
Jaundice, certainly. Spider naevi. Great.
So, a variety of different findings there.
So, let's say that we had, you know, we performed the full exam and we used -
we looked at bulging flanks or the presence of bulging flanks.
We used shifting dullness, which is actually depicted here.
And I think the term that some folks were alluding to,
maybe it's a different term in some other countries, but we - I would use the term fluid wave,
but fluid thrill, I can see how that's sort of is the same concept.
So, a fluid wave is where you basically give a quick push to one side of the abdomen
and you're feeling on the other side of the abdomen to feel a wave crash into your hand,
and that would be consistent with ascites as well.
So, let's say your pre-test probability of having ascites
before you performed the physical exam is 30% based on this person coming.
Maybe they, you know, drink 6 drinks a day and they're reporting that their abdomen feels full.
If you do bulging flanks, a fluid wave, and shifting dullness,
the pre-test probability by combining those likelihood ratios
can dropped all the way to 2.5% if all those tests are negative.
So, I'd feel comfortable. I don't know about you,
but if my physical exam lowered my pre-test probability down to a post-test probability of 2.5%,
I would not get an ultrasound.
I don't need to. I feel so comfortable with my physical exam
telling me this person does not have ascites that I'm not going to waste the patient's time
or the radiologist's time looking for ascites if my post-test probability is so low.
So, this is the concept of multiplicative likelihood ratios,
combining different exam maneuvers.
I'm showing here the example for the ACL tear again.
If I had a negative likelihood ratio from the Lachman
and a negative anterior drawer sign which had a negative likelihood ratio of 0.5,
you can simply multiply those LRs together.
So, the post-test - the pre-test odds, there's a typo there.
The first - that second bullet there should say pre-test odds.
So, it was 1/4 x 0.2 x 0.5, my post-test odds is now 0.025,
or actually, that's not a typo because post-test odds. Got you.
And now, my post-test probability when I convert that is now 2.4%.
So, my patient who came in with that knee complaint
have now done two physical exam maneuvers
and reduced his likelihood of having an ACL tear to 2.4%.
So, I'm going to tell that patient to walk it off.
You know, I'll recommend NSAIDs, maybe some, you know, we use PRICE,
which is, RICE, anti-inflammatories, immobilization for a day or so,
leg elevation, that kind of stuff, but I would not order an MRI on this patient at this time.
With that, I will close the formal part of this presentation
so that we have a good 20 minutes to answer questions that have arisen in the chat there.
But first, obviously, in this particular presentation,
I'm not really explaining how to do different physical exam maneuvers.
I'm really sort of talking about the importance of the physical exam
and how exciting and fun it can be to develop proficiency in the physical exam.
If you actually want to learn the skills themselves,
I invite you to take a dive into the Lecturio course on physical exam itself
where I go through all these different maneuvers.
I include likelihood ratios about all the maneuvers as we go through the presentation,
and we have real patients here or real standardized patients
who I'm examining throughout the course.
And there's a lot of great images and stuff which are overlaid on the actual videos of the patients,
so it's a pretty good way to learn a lot of this stuff.
And with that, I will turn things back over to Kate.
KATE: So, I know you guys probably have a lot of questions.
We've gotten a few in the chat already, but feel free to add in your questions there.
This course is even more than you got today, but this is your chance to ask the professor.
Ask the expert, so please, you know, leave a few questions in the chat,
and I'll give Dr. Holt a chance to answer some of them.
So, there's one that I already saw that I want to kick us off with.
Let me find it again. So, here we go.
We're going to answer the first question live. Can you see it, Dr. Holt?
HOLT: Unsure if this is related to the talk today, but I'm curious.
I don't know what you see of telemedicine on physical exam.
Is it doable in the future? Yeah. That's a great question.
So, well, this is obviously an evolution,
but I would say there's actually a lot of things that you can glean from just televideo.
And it's actually, in some ways, great that televideo has become an option,
because I think for me, it has reminded me and also my students, my residents and my students,
how much one can observe about a patient without actually laying hands on the patient.
So, a person calls you and says that they're experiencing shortness of breath
and that they're worried about it.
And if you're watching them and you can see that they're saying
that I'm feeling really short of breath
and I'm not sure whether I should go to the emergency room,
my answer is go to the emergency room. I can tell that.
You know, you can tell from just how many words they're speaking
before they have to take a breath.
You can see that they're using accessory muscles of respiration.
All those kinds of things could help to clue you in,
whereas if they're describing in an excruciating detail how short of breath they are,
but they're doing it in full sentences and even paragraphs without taking a breath,
well, I think you've got time to sort things out.
Of course, you can look at jaundice, you can look at things like for a thyroid disease,
you can look at Queen Anne's sign, which is loss of the outer third of the eyebrows.
You can look for - obviously, you can look at the levels of anxiety and agitation.
You can look at pupillary dilation pretty easily if you're worried about certain toxidromes.
You can look in somebody's mouth and as long as the patient has a flashlight,
you can get a decent shot of that.
You can certainly look at a lot of rashes and the field of dermatology
has really embraced this idea of looking - of helping - supporting communities
that have less access to dermatology as by using video
and photography to be able to look at lesions to - that are concerning for malignant skin lesions.
So, I do think there's a lot of role for telemedicine or at least video medicine.
There's less you're going to glean from a phone call,
but you know, that being said, I still obviously prefer to have patients in my office
where I can do a lot more on the physical exam.
KATE: All right. Thank you so much for that one.
I can also fill the questions if you want,
or you can also see them on your right side if you want to pick a couple.
HOLT: Got it, yeah.
KATE: So, I'll let you kind of make that decision.
So, we got a lot of great questions.
And am I supposed to hit the button 'Answer Live' or do I -
KATE: Yeah, just click that one so then it'll pop up here. Yeah. HOLT: Okay
- what I mean. KATE: Yeah.
HOLT: Okay. Okay, I'm just figuring out which ones here are - okay, which -
sir, which books do you recommend for clinical methods?
So, learning physical exam stuff. There's a few that I'm very fond of.
The Evidence-Based Physical Diagnosis by Steve McGee
is probably my favorite physical exam textbook.
And I can write in the text down here just to - put it in the text there.
I actually forget if it's called Evidence-Based Physical Exam or Physical Diagnosis,
but you'll find it if you look for Steve McGee.
He provides likelihood ratios for everything, really great explanatory text
on how different maneuver, you know, basically, what the semiophysiology of disease is,
why do certain things show up in the way that they do.
And another one of my favorite texts is Joseph Sapira's Art and Science of Physical Diagnosis.
I've also put it in the text. It's now on the 4th or 5th edition.
It's not even written by Joseph Sapira anymore, though it's, you know,
derived from the original ones that he wrote,
and it's an outstanding description of a lot of the history of the physical exam
that's relevant still today.
If you go - it's a lot more of a colorful text than the Steve McGee one,
which is fairly wrote and really going through more of the utility of the physical exam.
I find Sapira's to be a little bit more fun to read,
but I think it complements the first text that I mentioned.
The Steve McGee version - that you can put on your phone that has all of the - oop, looks like -
KATE: Can you just repeat that real quick?
HOLT: Yeah, sure.
KATE: What you were saying about the phone? Yeah.
HOLT: Can you hear me now?
HOLT: There we go. Yeah, I got kicked out for a second.
That the - that includes an - a cellphone app that comes with the Steve McGee text
that has access to all the likelihood ratios, other explanations for different exam maneuvers.
It's really a great place to remember that stuff.
Stanford School of Medicine has access to the, what's called the Stanford 25,
which is a listing of a number of physical exam videos, which are useful.
And then, for musculoskeletal exam, I always go to Mark Hutchinson's series.
Mark Hutchinson, these are free videos online.
They're probably 10 or 15 years old.
That's a useful place to get some of this stuff.
And a lot of those sources are what I drew from when we created this series in Lecturio,
which I think I'm impossibly biases, but I think it captures all that stuff in a single place
and includes likelihood ratios for all these maneuvers
and has a benefit of a fantastic production team that was able to get all the right angles,
so you can really see what's going on with all these overlays on top.
So, there's great places to learn this stuff,
but I do think the Lecturio version is pretty topnotch.
All right, let me look for other questions. Let me see this one.
What can you recommend to give a patient confidence
that he or she doesn't feel attacked or violated when examining?
That's such a great question.
There's actually this whole idea of trauma-informed medicine
in the trauma-informed physical exam,
which is this idea that, you know, there are many people in the world
who've experienced trauma from either being in,
you know, experiencing intimate partner violence or you know, sexual assault, etc.,
or military, you know, soldiers who've experienced trauma from being imprisoned
or being attacked or what have you,
and who, you know, you're not going to stand behind that person
and hold their neck while examining the thyroid.
You know, you have to be sensitive to the fact that trauma can
or the physical exam can be triggering for folks,
because when a patient is being examined, they're very vulnerable.
So, to ameliorate that, I talk to my patients if I'm doing any sensitive part of the exam,
very explicit to patients about what I'm going to perform,
especially if we're talking about the genital exam.
These are the specific steps that I'm going to do.
They're all an important part of my ability to help you today
and is there any part of the exam that you don't want me to do?
And I just think communication is key whenever you're examining sensitive areas.
And if I am examining the thyroid,
I tend to stand on the side and I kind of examine like this.
I try to never stand behind a patient for any part of the exam.
I really try and stand to their side because this can be triggering for folks
with any kind of history in that regard.
Okay. How to approach physical exam for pediatrics?
It's not easy to do physical exam with children.
You know, I confess, I'm not a pediatrician.
I do work in an urgent care center
where sometimes, I do have to examine little children with a pediatrician's backup.
there's a reason I didn't go into pediatrics and trying to examine a 3-year-old's ear
or an 18-month-old's ear, that's probably one of the reasons I did not go into pediatrics,
because it is very challenging.
I know that a pediatrician will give you much better insights
about how to find a way to get that, you know, to get that ear exam in
and to look at the back of the throat for looking for tonsillar exudates.
Unless the patient is 5 years or older, I don't have a lot of luck.
I do the best I can, but I agree that the physical exam
in pediatrics is its own discipline, if you will.
And I'm sure there are some excellent sources for how to get that done,
but probably shadowing a pediatrician is your best bet.
Okay, let's see. Let's try this one.
Do we count the likelihood ratio in real-life practice?
So, what I would say to that question is yes and no.
So, over time, as you get more skilled at the physical exam,
you'll start to just know certain likelihood ratios by heart.
If you really go out of your way to learn them,
you'll start to know the ones that have the highest diagnostic value.
Like, you know, I know that egophony
has a positive likelihood ratio of 4 for diagnosing a consolidated pneumonia.
And I know likelihood ratios for a variety of musculoskeletal tests as well.
And I find that, you know, while the number may not stick with me for very long,
knowing that some physical exam maneuvers have value when some don't,
like I know that the Tinel sign for identifying carpal tunnel syndrome, it's really not great.
I can't tell you I remember what the likelihood ratio is,
but it's, you know, for the positive likelihood ratio for a positive Tinel's,
it's probably less than two.
I just can't remember off the top of my head, but I know that it's not good.
Whereas I do know something like the hand elevation test or the CT diagram
or even looking for weakness with thumb ADduction, abduction, ABduction.
I know that that does have a higher positive likelihood ratios.
So, I'm going to rely upon those instead.
So, I don't need to memorize all those numbers.
What's more important is that you take a look at them
at some point when you're examining that patient who has,
you know, some evidence of dullness to percussion on their,
you know, on their right lung field, take a look at,
you know, tactile fremitus and dullness to percussion and bronchophony
and see which ones actually are the most efficacious and prioritize those skills.
Just like looking for pulsus paradoxus in a patient who you think has a muffled heart sound.
You need to know how to do that
because it has such an excellent positive likelihood ratio for finding a pericardial effusion,
which can be a life or death kind of thing.
So, that's what I would say is. I don't have these numbers at my fingertips.
What I do have at my fingertips is I know which tests are great,
which ones are historically kind of interesting and fun like,
you know, water hammer pulse for aortic regurgitation.
It's kind of cool, but I'm not going to hang my head on that
to make a diagnosis for aortic regurgitation.
So, that's my long-winded answer to that question.
Let's look at abdominocentesis by ascites.
Of course, abdominal paracentesis is useful when you think somebody actually has ascites,
but as I said, I wouldn't stick a needle into somebody's belly
if my post-test probability of having ascites is, you know, less than 3%,
So, ultimately, the physical exam helps to guide the next step in treatment.
Helps to tell me whether or not doing a paracentesis
or doing a subacromial steroid injection or getting an echocardiogram
or getting actually radiologic imaging, that next step is informed by my physical exam.
So, that's how that goes.
Let's see this one.
So, you're basically asking about some of the physical exam findings
to diagnose coma or brain death.
Those aren't the same thing, but I'm saying you may -
there are physical exam findings that can help to distinguish between the two.
I don't think that those physical exam findings are obsolete.
It's true that there are some better diagnostic imaging tests nowadays
especially when you're talking about legal ramifications.
You know, you can look for a variety of brain stem findings on physical exam.
Like, you alluded to doll's eyes, and you know, blink to threat in order ones.
But when you're talking about, you know, deciding whether or not
somebody is or is not brain dead, then they're, you know, you can use EEG
and other, and MRI, etc., to further characterize that.
So, it kind of depends on the stakes of the decision,
but the physical exam certainly can be very helpful to identify cortical function
versus just brain stem function.
How can we use the LRs to navigate around false positives and true negatives?
I think the same thing. This is where playing that cord is important.
You don't ever want to rely upon a single physical exam finding to make a high stakes diagnosis.
So, when you combine different physical exam findings,
some of which may have a positive LR and some of which may have a negative LR.
You can multiply a positive and a negative LR together,
and hopefully, that increases your diagnostic precision.
And so, you're just less likely to have false positives
and more likely to just have true positives and true negatives.
Just like you would for any laboratory testing.
It's the same kind of principle putting those things together.
And let's take a look on this one.
How can we make patients who already request a series of lab tests they read about online,
oh, I love that question.
I wish I had seen this one before.
So, yeah, some patients insist upon getting an MRI,
they insist upon getting blood work, and it's hard.
I would say that for me, there's many times patients come to me
and ask me for something that I'm not going to give them.
Maybe it's antibiotics, maybe it's, you know, opioid pain medications,
maybe it's an MRI of their brain because they're concerned about their headache,
and all I can say is that I have found that listening to the patient,
making eye contact with the patient sitting at eye level,
letting them tell their whole story, and then I summarize back to them what they've said.
So, it sounds like, you know, you've told me that you've had your sore throat for the past three days,
your son was recently sick with strep throat,
and you were having some fevers at home, and I sort of summarize that stuff,
and then I say, "Well, on my physical exam, I'm not seeing any tonsillar exudates.
You don't have a fever here in the office.
You invoke consensual criteria. You have a cough.
All these things tell me some good news, which is that you don't have a bacterial infection.
You have a viral upper respiratory infection,
and the good news is that I don't - there's no role for antibiotics in treating you."
And so, I think it really just comes down to making sure the patient knows they've been heard,
making sure that you're summarizing what they've said,
and that you go through with thorough physical exam,
and they're confident in your physical exam that,
because you're going through it as opposed to just quickly,
you know, bring your stethoscope on two points on their lungs.
I have found that I'm more likely to have - to get buy in from the patient
that they're comfortable not getting that x-ray or not getting,
not giving antibiotics and that kind of thing.
But I'm not going to suggest that I'm 100% successful with that.
There are some patients who are just insistent,
and I tell them that I simply cannot, in good conscience, as a clinician, recommend antibiotics.
I can't, in good conscience, send you for a CT scan
because it would violate my code of ethics to do something
that I think is not the right thing to do.
That patient may not come back, and you just have to accept that,
but I don't think you should ever feel pressured to do something
that you don't think is clinically appropriate because there's always a consequence.
You're always going to find something you weren't looking for and go down a dark path that could get you into trouble.
KATE: All right. I'm going to jump in here. May I pick the last two questions?
KATE: Okay. So, there's one more very related to some of the future things
and then there's one about Lecturio. Let's see if I can click it. There you go.
HOLT: Yeah. I mean, I think - obviously, if you live - it's different if you live in the States
versus if you're trying to get to the States to do an observership.
It is challenging. I mean, I know I get emails all the time from folks
all over the world asking to do observerships and research experiences, etc.,
and you know, I frankly am - there's already so many students
and learners that already have that.
We simply don't have room, so I think, you know, sending emails to the people
at big name institutions who are already part of a medical school
and already have lots of, you know, MD students, PA students, nurse practitioner students,
interns, residents, you know, all kinds of folks here,
it's just it's very unlikely that somebody at an institution like Yale
or other sort of, you know, well-known institutions are going to have opportunities for you.
In contrast, if you find affiliate hospitals that maybe may have educators
that are sort of part of a residency, part of an institution like Yale
but actually aren't saturated with learners, you may have more luck.
So, trying to find folks at, you know, I don't want to name any specific institutions
because they'll get bombarded with emails within 30 minutes,
but there are sort of residency programs that are attached to premiere institutions
where they have educators who may be more likely to accommodate folks coming.
But that really is, you have to do this work, this hands-on work.
If you go through the course, I always say upfront that you should make sure
that you are actually practicing the skills on your roommate
or your housemate or your loved one or whoever it is.
Actually practice the physical exam skills because watching videos is not going to do it.
You have to go through the muscle memory.
So, use the videos as a guide, but then you have to practice them,
and if it's not with real patients, if it's hard to get real patients or exposure to real patients,
then just practice them on friends and family to really get this stuff down.
KATE: All right. Awesome.
And that actually answered the last question that I wanted to pull up as well,
which is what is the best way to use the Lecturio physical examination course?
Let me see if it'll pop up here for us. You can go ahead and already start answering that. Yeah.
HOLT: Yeah, sure. Yeah. Yeah, I think, you know, we have a lot of videos
that I use here in my residency program as well,
and I have found that when my residents were students,
actually show up to examine a standardized patient or a real patient.
Knowing the content. You know, having watched all the videos, that's only step one.
If you're not actually laying hands on a patient
and seeing where your hands are supposed to be when you're,
you know, assessing, you know, doing valgus stress on the knee,
the video it's not sufficient.
You actually have to get in there and examine folks in order for it to be fruitful.
So, I think that's the best way to use the content,
is to make sure that you are very vigilant and deliberate about examining real people,
real human beings, in order to consolidate that knowledge.
KATE: All right. Well, thank you so much.
And just again, we've got the slide back up here.
These are some of the many topics covered on our physical exam course.
And you know, I'm sorry we couldn't get to all the questions today.
We have a lot of really good ones.
So, yeah, these are just some of the topics. We just did our Q and A.
For those of you, I know there are some who are new to Lecturio.
We've been mentioning this video course. What is this?
Lecturio is an all-in-one resource to help you with your studies in med school.
Many of you already know what it is,
but for those of you who are still new, we've got video lectures.
We have retention quiz questions that come with the lectures
to make sure you're remembering what you're just learning.
And then, of course, we also have a Q bank.
So, we've got clinical case questions covering a wide range of topics.
Everything you need for, you know, all the USMLE steps.
For example, in many other licensure exams around the world.
For you guys who are here today, first of all, we want to say thank you again for taking the time
and we want to give you guys a chance to watch our whole physical exam course.
So, this is obviously just, you know, a little taste of what we have today,
but if you haven't already joined Lecturio, you can try it.
We set up a one-week free trial for you so that you can check it out,
watch the course, I highly recommend it. It's very, very interesting.
I've learned a lot just even watching the videos in today in the session,
and I hope you all have as well.
Yeah, so I've got this up. There should be a little pop up on your screen.
If you have any questions about Lecturio, of course, you can also contact us.
The link is also here in the chat.
One of my colleagues is going to put that email address in here.
And if you have any specific questions for Dr. Holt, go into our - into Lecturio,
go to the physical exam course, and you can actually leave your questions under the course.
There's a discussion board and that is where he could get back to you with other questions.
HOLT: Oh, man. I'm in trouble now, Kate.
KATE: Sorry. Yeah, I'll help answer. No, you don't want me to help answer.
I don't know the answers.
But you know, go check it out, pay attention in the course
because maybe your questions are actually already answered there.
Yeah, so if you - we have a question in the chat of only for the new ones.
The 7-day trial is just for people who are new to Lecturio,
but if you've been with us for a while, shoot us an email anyway and we'll see what we can do.
So, all right. While we're leaving it at this, just since you guys are here,
if you haven't checked out the course yet, we do have a little sneak preview in here if I can see it. There we go.
Hopefully, this will play.
HOLT: So, let's start off with cranial nerve number one.
This is the olfactory nerve, but historically,
KATE: Just so you have an idea of what it's like.
HOLT: - we haven't paid as much attention to the olfactory never.
I think the COVID-19 pandemic brought to life the fact
that there are certain conditions that do compromise the olfactory system,
and COVID-19 virus had a predilection for causing anosmia.
So, it's useful towards the bedside, quickly assess for olfactory.
A simple test at the bedside is simply to use two or three common sense.
And for me, I'll oftentimes use the following.
All right, so Shaun, what I'd like you to do is to close your eyes and occlude your right nostril.
Great. What do you smell?
SHAUN: Alcohol, for sure.
HOLT: Perfect. Okay, now, occlude your other nostril. What do you smell?
HOLT: Perfect. Simple bedside test of the olfactory system.
KATE: All right, so that was just a super sneak peak, but there's a lot more of that where that came from.
So, make sure you, again, check out Dr. Holt's course on Lecturio.
Thank you, guys, all so much for being here. We hope to see you next time.
We're planning to do more of these with some of our other courses as well.
And if you've got any other questions, always feel free to contact us through Lecturio
So, thank you all so much. And Dr. Holt, thank you so much.
It's been great and we hope to see you all next time.
HOLT: Thanks a lot.
KATE: All right. Bye.