Shock and Sepsis Explained Clearly (Remastered) Symptoms, Causes, Diagnosis, Pathophysiology
15
September

By Adem Lewis / in , , , , , , , , , , , , , , , , , , , , , , , , , , , /


okay well welcome to another MedCram
lecture we could talk today about shock there’s different types of shock we’re
gonna talk about all three one is called hypovolemic shock then you’ve got
cardiogenic shock and you’ve got septic shock we’re gonna go through these three
different types of shock how they’re different and why you need to know them
well what I want to do is kind of diagram out what it is I’m talking about
okay so the first thing I want to do is draw some compartments because that’s
gonna be very important the first thing I want to draw is the vascular
compartment and this is where basically the blood is stored okay then it goes
into the vasculature which is then goes into the heart once you understand these
things I think it’s gonna be a lot easier to understand and then there’s a
decision that’s made a choice where it can either go to the vital organs or the
non vital organs okay so we got vital organs here and
then we’ve got the non vital organs what is a non vital organ well something like
skin would fit into that category it’s kind of vital but not absolutely central
to body’s got to make a decision at some point about where blood is gonna go if
there’s not enough of it to go around and then of course everything goes right
back to where it’s being held okay so we’ve got the vasculature and this is
sort of the storehouse of blood it’s primarily in the venous system and so
this is where you can have problems and so we’ll call this a okay next is B
which is the heart and then finally last is C which is the vasculature and so
these are the three areas that really contribute to shock so let’s figure out
what’s happening in the normal system got blood blood goes to the heart the
heart then pumps blood to the non-vital and the vital organs and why does this
happen this happens because you need oxygen
oxygen needs to get to these organs otherwise these organs will go into
shock so what is shock shock is a situation where the vital organs are not
getting oxygen if vital organs don’t get oxygen your
body will go into shock because these organs will shut down and if they shut
down more than three of these organs shut
down there’s a very high mortality associated with this and so not only are
we going to talk about the different types of shock but we’re going to talk
about the different ways of fixing shock in these specific organ systems but it’s
important for you to get a kind of a sense about what’s going on
you’ve got blood blood goes to the heart the heart then pumps that blood and
important because that blood the hemoglobin molecule specifically is
binding to oxygen and taking an oxygen molecule to the target tissues now why
do those target tissues need oxygen you may recall from biochemistry that oxygen
is needed as the final electron acceptor so that the electron transport chain can
continue to function and fadh2 NADH gets transported across and you get protons
pumped into the intermembrane space which then come back into the matrix of
the mitochondria to make ATP if you don’t make ATP you’re dead okay
basically so your target tissues need oxygen so there are three places where
that can break down a if you don’t have enough blood that can cause a problem
and you’ll eventually get into shock because there’s not enough oxygen
reaching the organs B if your heart is just not strong enough to pump that
blood to your organs and finally see kind of a septic shock or distributive
shock if there’s a problem here in the way the body regulates how much blood
goes to the vital and non vital organs so in
other words if it starts messing up and things start going this way and less
going this way that can be a problem and that can cause less oxygen to go to your
vital organs so three different possibilities okay now I want to break
this down so you can see the differences first of all I’m gonna make a column
here and we’re going to have three different columns and we’re gonna have
eight different rows and we’ll see if we can get all of this in here so you can
understand okay so there are three different types of
shock the first type of shock is what we call hypovolemic shock I’m gonna make
that red cuz that has to do with blood hypo Foley Mick you can follow along
hair on your piece of paper now hypovolemic has to do with letter A
that’s where there’s a problem at a there’s not enough blood it’s just not
enough blood and so let’s go ahead before we go through all of these and
quickly label what I want to talk about here we’re going to talk about some
issues Co is the cardiac output HR is the heart rate SVR is systemic vascular
resistance it’s kind of the resistance right here s the R what is the
resistance to flow in these blood vessels that’s what SVR basically is EF
is the ejection fraction it’s how much blood does the heart pump out it’s a
surrogate for basically how strong is the heart beating then we have something
called the post capillary wedge pressure this is this is measured by something
called the right heart catheter it’s where you float a balloon into the
pulmonary artery and there’s a little tip distal to that balloon that can
measure but the pressure is in the pulmonary
artery when there’s no more pulsation coming from the right ventricle this is
a surrogate for the pressure and the pulmonary capillary which is a surrogate
for the pressure in the pulmonary vein which is a surrogate for basically the
pressure in the left atrium so when you see pulmonary capillary
wedge pressure I really want you to think left atrium because that’s really
what it’s measuring next one is jvp that’s the jugular venous pulse when you
see that I want you to think right atrium then we’ve got blood pressure and
then finally skin the temperature okay let’s go through these then and I think
this will be very instructive to figure out what happens in hypovolemic shock
so in hypovolemic shock you’ve got a lot of bleeding you’ve bled out from an
accident from a GI bleed something’s going on and so what’s the first thing
that you’re gonna see well the first thing you’ll see is yet your jugular
venous pressure is low and that makes sense
jugular venous pressure is measured right here you don’t have a lot of blood
obviously the pressure is going to be low if your pressure going into your
heart is low just from the starlings forces if your preload is low your
cardiac output is going to be low as a result your heart’s gonna try to
compensate so your heart rate is gonna go up then what’s gonna happen because
it’ll compensate at some point it’s not going to compensate anymore it’s gonna
get worse and worse and your blood pressure is gonna start to go down as a
result of that your ejection fraction may go up to compensate but as the blood
pressure goes down your systemic vascular resistance is going to go up
now this is important if the cardiac output slowed right here okay the and
your blood pressure is low then these arteries are going to try to squeeze
together to bring the blood pressure up so there’s enough pressure to reach the
non-vital and the vital organs that’s why the SVR
the systemic vascular resistance goes up now you can imagine if there’s not
enough volume circulating both your right atrial pressure and your left
atrial pressure are going to be low now here’s the important thing because the
pressure is low and systemic vascular resistance is increasing which one do
you think is going to increase more this is going to increase more the blood
going to the vital organs or more going to the non vital well you’re right it’s
gonna actually shunt a lot of the blood towards the vital organs and it’s gonna
close off the non vital like the skin and so therefore your skin temperature
is gonna be cool it’s gonna be low so that’s what happens
in hypovolemic shock okay let’s talk about cardiogenic shock will make that
green cardio genic shock that’s B that’s where we are here at B okay so what’s
the primary problem with cardiogenic shock primary problem is it’s the
harshest not working and your cardiac output is gonna be low so that’s where
it’s starting notice we’re starting in a different place here the problem is not
not enough volume the problem is there’s not enough cardiac output as a result of
that the heart rate may speed up unless of course the thing that’s causing your
cardiogenic shock is something like beta blockers and therefore your heart rate
would be good low so just depends on what’s causing your cardiogenic shock
and that’s gonna be the thing that causes it to have problems so when that
happens what do you think is gonna happen to the pressure of fluid behind
the heart well if the heart’s not pumping everything’s gonna back up and
so both your left atrial pressure and your right atrial pressure are both
going to go up because you’re in cardiogenic shock however your blood
pressure is going to go down now what do you think is going to happen to your
systemic vascular resistance well again because your heart is having a problem
pumping blood your blood vessels are going to do the same thing your blood
vessels don’t know the difference between whether it’s the heart not
pumping or just not having enough blood they’re going to do the same thing and
so systemic vascular resistance is going to go up your ejection fraction
obviously because you’re in cardiogenic shock is good to be low and what’s going
to be your skin temperature once again since you’re having constriction here
and you’re getting a shunting of blood from the non vital to the vital organs
your skin temperature is gonna be cold okay so let’s take a moment to notice
what the difference is between hypovolemic and cardiogenic shock
everything else is the same really except for the fact that these indices
go up vs. go down so if you can measure the jvp that would be a great way of
determining if someone is in hypovolemic or cardiogenic shock okay let’s talk
about septic shock now septic shock is a lot different
septic shock is caused by an infection and when you have an infection you’ve
got an immune response against that well something funny happens when you
get that immune response that immune response or these antibodies or cells
will have them down here as cells they release cytokines and chemokines and all
of these sorts of things and what do they do they cause dysregulation of
vasoconstriction here that where we’ve been talking about at the arterioles
both going to the non vital and vital organs and basically what happens is
because there’s dysregulation and specifically vasodilation okay so
opening up widening there is this shunting of blood if you will to non
vital organs away from the vital organs so where’s the problem the problem
starts off here at the systemic vascular resistance systemic vascular resistance
plummets it drops and that’s a big problem and as a result of that you have
compensation so in other words if this thing opens up and the pressure just
drops which you’ll see blood pressure drops and septic shock that causes a
compensatory increase in heart rate and an increase in cardiac output at least
early on in pick shocked the ejection fraction
because of the infection actually is stunned and drops somewhat okay and as a
result of the increased cardiac output the post capillary wedge pressure
actually drops and so does your jugular venous pulse it also drops now because
there’s this regulation here and blood is going to the skin believe it or not
your skin temperature is actually up and if these patients actually feel very
warm so notice here that whereas in cardiogenic shock your post capillary
wedge pressure and jugular venous pulse was high in septic shock it’s low so
what I would recommend is studying these looking them over and over so you can
see quickly the differences skin temperature is very important sometimes
you can just walk into a room and touch the patient and look up on the monitor
and see that they’ve got a fast heart rate and see that their blood pressure
is low and just by simply touching the skin and a feeling if it’s very warm you
can tell if this patients in septic shock although it’s not a hundred
percent of course and there’s other things that you should look at but the
key here is is that there are certain readings that you’ll see depending on
the type of shock that you’re in and knowing where everything starts off
you’ll be able to fill in the rest of the blanks so there’s another lecture
coming up talking about how we treat septic shock and using something called
early goal-directed therapy early goal-directed therapy and that’s very
important it’s been shown to save lives we’ll talk about why it’s important to
to use early goal-directed therapy all right thanks for joining me


19 thoughts on “Shock and Sepsis Explained Clearly (Remastered) Symptoms, Causes, Diagnosis, Pathophysiology

  1. I love watching these videos even though some are far over my head. Thanks for the education. Know anyone that does these for politics? In an unbiased way?

  2. Thanks for the nice video…. But I need to know why there is an increase in PCWP,JVP and decrease in BP in cardiogenic shock..??

  3. Can someone please explain why in septic shock PCWP and RVP are decreased with an increase in CO. Thank you!

  4. Wow! Iโ€™ve got to say, I really love how you explain everything clearly! I love your videos! They are awesome! Keep up the great work! I love learning all about different types of diseases, and what our liver does! I learn a lot from your videos. I wish that I could be in the medical field, but I cannot be a doctor because I am blind. Keep on teaching me more about shock, asthma, and all about our vital organs! You are a really great teacher, sir! ๐Ÿ˜‚

  5. You explained how the skin is warm with septic shock, due to massive vasodilation, but in septic shock the patient often also has a fever, which would also make the skin very warm. Love your lectures, listened to many of them. Will listen to all of them. Pertains to my work as an RN on a chronically critically ill unit (LTACH).

Leave a Reply

Your email address will not be published. Required fields are marked *