Okay, this is going to be a really important clinical question and it's complex so let's jump right in.
A 51-year-old male presents to the urgent care center with a blood pressure of 201/111.
He has a severe headache and chest pain. Ischemic changes are noted on his ECG.
What is the most appropriate treatment for this patient's blood pressure?
Answer choice A: Oral clonidine, gradually lower blood pressure over the next 24 to 48 hours.
Answer choice B: Oral beta-blocker, lower mean arterial pressure no more than 25% over the first hour.
Answer choice C: IV labetalol, gradually lower blood pressure over the next 24 to 48 hours.
Answer choice D: IV labetalol, lower mean arterial pressure no more than 50% over the next hour.
Answer choice E: IV labetalol, lower mean arterial pressure no more than 25% over the first hour.
Now, take a moment to come to an answer choice by yourself before we go over it together.
Okay. This is a super, super, super important question for both USMLE step 2 and also for when you're on the wards.
Now, let's kinda go through the question characteristics before we actually tackle the answer choices themselves.
Now, this is an internal medicine cardiovascular question.
If someone's coming getting with elevated blood pressure, they're having a headache,
they're having chest pain, EKG showing ischemic changes,
classic bread and butter internal medicine and classic cardiovascular consult.
Now, this is a two-step question. First thing you need to do for this question is to be able to determine the diagnosis.
What's going on? What does this patient's blood pressure mean? How high is it?
What are the organs are involved? You know, figuring out what's going on.
And then the next step is being able to figure out how do you manage it.
And that's bread and butter for USMLE step 2.
They don't just ask you for the diagnosis.
They always take it one step further to tell you, "Hey you know what? We may give you the diagnosis sometimes
but what is the next step in clinical management?" Which is what this question's asking.
And of course the stem is absolutely required.
We need to know the blood pressure numbers, the organ involvement,
the patient's complaints, any objective EKG data in this case so absolutely required.
Now, let's walk through this question together.
Like I said, the first thing we need to do is be able to determine the diagnosis.
Now, when looking at the question's stem, we have a 51 year old male coming in
and he's got a high blood pressure, 201/111. That's elevated.
Now, in addition to having high blood pressure, it says he has a severe headache and chest pain.
Now, an important buzzword when people talk about this is end organ damage.
So this person has elevated blood pressure with end organ damage.
Because symptomatically, they're clinically endorsing chest pain and headache which can be brain and heart involvement.
And they even go one step further in this case to show you an EKG
and tell you, "Hey, there's ischemic changes noted on the EKG.
Here's some objective data for end organ damage of the heart. In this case
and they wanna know what do you do next.
Now, it's really, really important that you understand the numbers to look for
for systolic and diastolic to be able to diagnose two different entities.
One of them is called hypertensive emergency and the other one is called hypertensive urgency.
Now, for both of these, you're gonna be looking for a blood pressure in which the systolic is greater than 180
and a diastolic is greater than 120.
So patient comes in, blood pressure is greater than 180/120, okay.
Next to thing you need to look for is, is there end organ damage?
Now, that can get a bit confusing when trying to explain but it's very simple.
End organ damage can be objective in which you have EKGs, laboratory findings,
or it can be subjective in a patient's complaint.
Now, if it's subjective, patients can endorse a headache which can be evidence of increased intracranial pressure.
They can have chest pain which can be evidence of mismatch of the heart-oxygen supply and demand,
or they can have even kidney failure in which they can tell you,
"Hey, I see bladder filming in my urine, or maybe you check the labs and you saw an elevated BUN and creatinine,
or maybe you check the troponin and saw it was elevated, or you checked an EKG
and saw that was showing ischemic changes or maybe you look in the patient's eyes
and get an ophthalmoscopy exam and saw papilledema."
All of these are both a mixture of clinical, subjective forms of end organ damage
or objective forms with laboratory imaging or EKG findings.
Now, the two of those are gonna help you diagnose and differentiate the entity
between hypertensive emergency and hypertensive urgency.
Now, I told you that the number to look for is 180/120.
Now, how do you memorize that?
The way I do it is, we knew the textbook definition of a good blood pressure is 120/80.
All I do is I flip those numbers around. I put the 120 on bottom and I put the 80 on top,
and I just put a one in front of the 80.
Now, it's 180 over 120 and that's the actual threshold for how we can diagnose hypertensive emergency or urgency.
So if it's greater than 180 over 120, ahah!
Now, I'm in the range of hypertensive emergency or urgency.
Now, how do you differentiate hypertensive emergency from hypertensive urgency?
It's simple, end organ damage.
So if someone's coming in with a high blood pressure, now in this question stem,
the blood pressure of 201/111, you go, aha!
Created the 180/120, I'm in the world of hypertensive emergency or urgency.
Now, I need to look back at the question stem and say, "Do I see any evidence of end organ damage?"
Well, we have a severe headache, brain involvement.
We have chest pain, heart involvement. Oh! Even more.
I have an EKG's showing me ischemic changes.
Now that's objective evidence of heart involvement.
So the diagnosis here is hypertensive emergency because of blood pressure is greater than 180/120
and also we have evidence of end organ damage.
Now, pay attention to that term, hypertensive emergency.
It's an emergency which means we have to do something.
Now, let's look down our answer choices.
The big thing we'll notice is, answer choices A and B are oral forms of medication.
While answer choices C, D and E are IV forms.
Now, since this is hypertensive emergency and even say you don't even know what this is yet.
If it's an emergency, what do you think I'm going to do?
Give an oral agent, put it in someone's mouth, let them sip some water and walk away
and come back a couple of hours later?
Or am I gonna throw in an IV, and jam in some medications and try to help an emergency?
That's the mnemonic. It's an emergency. Let's get moving fast.
So, looking at our questions, we set the two step question.
Step one: Determine the diagnosis. We already know, it's hypertensive emergency.
Step two: Let's come to the right treatment. Well, we already know.
Hypertensive emergency needs to be managed emergently.
So it cannot be answer choices A or B. We don't treat hypertensive emergency with oral agents.
We use IV. But before we completely delete those, let me throw in a few comments to help you along.
Oral clonidine, clonidine is an outrageously strong blood pressure medication
that you will use for patients who have persistent multi-medication high blood pressure.
It is not a first agent. You don't throw it on casually in an acute setting.
You usually put it on to someone who has very difficult and hard to control blood pressure.
So that's when clonidine’s appropriate. Not in this acute setting.
So you can eliminate answer choice A based on two different things.
One, we're not gonna use oral agents for hypertensive emergency, and two, clonidine's not an acute agent.
If I give it to someone, it'll lower the blood pressure aggressively but not right away.
So, we can erase that. And answer choice 2, B, oral beta-blocker.
We can get rid of that as well.
Though, you know, we do use beta blockers to control hypertensive emergency.
We don't use oral forms. We use the IV.
So we can delete that.
Now we're left with three answer choices.
Look at that, our odds went from one out of five to one out of three.
We're making moves. Now, IV labetalol.
Okay. Answer choices C, D and E all have IV labetalol in it.
Now, it's the second part of the question that's going to be the key.
Now let's look at answer choice C.
It says, okay, gradually lower blood pressure over the next 24 to 48 hours.
Answer choice D, lower the MAP (Mean Arterial Pressure) no more than 50% over the first hour.
And answer choice E, lower the MAP no more than 25%.
Now, this is the definition, you just need to know it.
But let me explain to you how to think about it so it becomes easier as I give you the answer.
Now, the treatment obviously here is to lower blood pressure
and we've concluded that in an emergent situation of hypertensive emergency, we're gonna use IV, not oral forms.
Now, the question becomes, how do you lower it?
Do you wanna go like answer choice C says, lower over the next 24 to 48 hours?
Do you wanna go in the next hour? Do you wanna lower 50% like answer choice D?
Do you wanna lower 25% by answer choice E?
Well, here's what we need to do. We need to lower the blood pressure with an IV agent.
We've already concluded that, but we need to smoothly lower the blood pressure.
We don't want to cause a hyper acute lowering in blood pressure
which will lead to end organ hypoperfusion and ischemia infarction.
You don't wanna cause a stroke to the brain or a heart attack or any other hypoperfusion
to an organ by lowering someone's blood pressure too fast.
And the rationale behind that is imagine this, let's think about the brain.
It's come -- this person's coming into an urgent care center.
Their body right now is running at a systolic of 201 and diastolic of 111.
All the organs in the body are a kind of adjusting to this right now.
They are living with it. They're used to it.
It probably didn't happen suddenly.
Now, if you come in and give a lot of medication to lower the blood pressure too much,
now those organs were gonna say woh, woh, woh, we weren't ready for that.
Now I don't have enough blood because I was already in set up for dealing with too high of blood pressure.
Now if you lower the blood pressure too fast, I can't change that quickly.
You're gonna make me infarct these organs.
So that's like the way to think about it.
You want to lower blood pressure but smoothly and gradually, not suddenly and aggressively.
So, we obviously wanna use IV labetalol,
and the answer is you wanna lower the mean arterial pressure no more than 25% over the first hour.
Answer choice E. That's the right answer but you need to memorize that.
For hypertensive emergency, we use IV agents, not oral.
And the goal is we wanna lower the MAP by no more than 25%, a quarter, in the first hour.
You will be asked that question on USMLE step two.
You will be asked that question while on the wards.
You will even be asked that question in managing it as a resident and intern.
It's that important. Memorize it.
Now, let me tell you how you actually could have eliminated answer choice C and even narrowed your chances better.
So answer choice C says, gradually lower blood pressure over the next 24 to 48 hours.
Now, if you look at answer choices D and E,
now let's just say maybe you've heard of this hypertensive emergency
and now you listen to this audio once and it's kind of in your head.
Well, looking at all the answer choices, you may to say, "Hey, I remember something about hypertensive emergency.
Lowering it by like 25%," something like that. Answer choice C is vague.
It's not as focused like answer choices D and E.
Gradually lower blood pressure by the next 24 to 48 hours.
What does that even mean? That doesn't mean anything.
Yeah, we wanna lower blood pressure but gradually is not doctorial. It's not scientific.
It's not specific. It doesn't mean anything. So you can eliminate it based on that.
It's too vague. We have guidelines and that's what the USMLE is testing.
Are you even aware of this basic guidelines?
So you could've diminished and deleted answer choice C right there,
and then you're down to a 50-50 split which is where you really wanna end up on USMLE questions,
and that's where the best test takers end up, on this 50-50 split between answer choices D and E in which you're saying,
"Okay. I'm definitely giving IV labetalol. I know I look at the MAP as my objective data point.
The question becomes, do I lower it by 50% or 25% in the first hour?"
And if you think about that model I gave you about the body and all the organs being used to a high blood pressure,
they're not gonna tolerate a 50% drop in the first hour.
You're gonna stroke him and infarct him.
So the answer is 25% and that's what guideline show.
And I'm just giving you this way to think about it, to memorize it easier.
So the answer is answer choice E, IV labetalol, lower mean arterial blood pressure by no more than 25% over the first hour.
Outrageously important. Memorize it.
If you're having a tough time, tattoo it on your arm. It's that important.
Now let's review some high-yield facts, we talked about them throughout this explanation
but I wanna reinforce these points even more.
Now, hypertensive emergency, we talked about this. How do we diagnose it?
Blood pressure systolic greater than 180, diastolic greater than 120.
And I gave you the mnemonic of how to do that. Perfect blood pressure is 120/80.
Flip those numbers. Throw a number one in front of the 80, 180/120.
That's how you memorize this number threshold.
And to diagnose hypertensive emergency, you have to have end organ damage.
It can be clinical symptoms such as headache, chest pain,
patient's saying he's urinating blood or is urinating auto foam, or it could be objective data.
You look at the patient's eye, see papilledema for increase intracranial pressure.
You get an EKG or measured shrope, show heart damage.
Measure BUN and creatinine, see acute kidney damage, etc., end organ damage.
So having end organ damage with this elevated blood pressure,
we just diagnosed hypertensive emergency.
Now this is a potentially life threatening condition.
Having blood pressure that high can cause a heart attack or stroke among other problems.
Now, what can cause hypertensive emergency, and the differential here is very wide.
It can be drug use. Patient can just use cocaine, amphetamine,
something, it's getting their body going, elevating their blood pressure.
Maybe they were on multiple blood pressure agents and they stop taking their anti-hypertensive
and now they're having rebound.
Maybe it's a pregnant patient coming in with eclampsia. The list goes on and on.
Almost anything that can elevate your blood pressure and can cause hypertensive emergency.
Now, the incidence of these in the US is greater than 500,000 annually.
It's half a million people. Very dangerous.
Now the treatment objective is to lower the blood pressure
and we use IV and high hypertensive because it's an emergency.
And by definition, our treatment guideline goal is to lower the mean arterial pressure
by no more than 25% in the first hour.
Now, this is different from another diagnosis called hypertensive urgency
in which you have the same elevated blood pressure above our threshold of 180/120
but no evidence of end organ damage. The patient just comes in.
We see the high blood pressure. They're not endorsing a headache.
They're not endorsing chest pain. They're endorsing any urinary complaints.
We look in their eyes, there's no papilledema.
Trope is negative. EKG is normal. BUN creatinine's within normal limits for the patient.
Hypertensive urgency is our diagnosis.
Now, this is less serious than hypertensive emergency.
And we actually treat hypertensive urgency with oral agents because it's just urgent.
It's not emergent.
Now, the different medications you can use to lower blood pressure are all the blood pressure medications
you learn in pharmacology -- diuretics, calcium channel blocker, ARBs, ACs, etcetera.
The list goes on and on. But we want to use IV forms
and our goal is to lower it by a maximum MAP of 25% within the first hour.
Anything more risks hypoperfusion and infarction.
So now we know for this question we understand hypertensive emergency,
its management, and again the answer is answer choice E.