Septic Shock: Diagnosis and Treatment

>> To understand the
labs of septic shock,

let's first go ahead and
recall what septic shock is.

So really briefly, remember,

septic shock is infected
material that you see

in blood vessels, and white
blood cells mount a response

to this septic material,
and in mounting a response,

they release all these
different immune molecules

that can cause damage
to blood vessels

and increase blood vessel
diameter, and the permeability

of blood vessels, and
so on and so forth.

So what's the first thing you
think you would want to do

in a patient who
might have shock?

Well, first of all, we
want to diagnose it, right?

So what can we do
to diagnose shock?

Well, we have a couple of
lab tests that we can use.

So the first thing you
want to do is check,

you know, what's going on?

A patient comes in who
has fevers, chills,

they're sweating, they're
very flushed, and you notice

that their blood
pressure is dropping.

So you're thinking,
maybe septic shock.

So the first thing
you want to do,

aside from checking
your temperature

and checking their vital signs
is you want to check, you know,

maybe they have an
infection in their blood.

Maybe there's infective
material in their blood.

So you can do that now by
getting blood cultures.

Because you want to grow out
whatever is in the blood,

and see if it's a fungus
or a bacteria or a virus.

So blood cultures will
allow you to figure

out what organism is
in the bloodstream.

Next, you should probably figure
out how severe the shock is,

and if in fact it is shock.

You know, are the organs
damaged, or what's going on?

So you'll get values such as
lactic acid or serum lactate,

and serum lactate is important

because it shows you
tissue perfusion.

When cells of the body are
no longer getting oxygen,

so these little orange
boxes are cells,

when these guys are no
longer getting oxygen,

they have to resort to
another way to produce energy,

and that other way is
anaerobic metabolism.

Metabolism without oxygen.

And a byproduct of that
is lactate or lactic acid.

So measuring the levels of serum
lactate will tell you just how

oxygen starved these cells are.

Next, you could also get an
ABG, or arterial blood gas.

That will tell you how much
oxygen is in the blood,

and it will also tell you
things like the carbon dioxide,

different blood gases.

And then you'll get
some other lab tests

that are maybe organ specific.

So for example, you might want
to get a BUN or a creatinine.

And these are specific
tests for the kidney.

So I'm only going to write down
these tests for the kidney,

but you might want to get
tests for other organs as well.

Now, the lab values for the
kidney are especially important

because if the kidneys
are deprived of oxygen

for just a little while,
they cab actually be damaged.

So they're more readily
injured by lack of oxygen.

So these are good labs to get.

Now, once all these
labs are in the works,

the next logical step is to
immediately treat this patient.

And treatment is
associated with mortality.

The sooner the patient is
treated, the more likely it is

that they will survive.

So they will have
decreased mortality

if they're treated more quickly.

And the treatment usually starts

with just very broad
spectrum antibiotics.

Broad spectrum antibiotics.

Now, why broad spectrum?

Well, when you first
treat sepsis,

you will have drawn
a blood culture,

but you won't have the results
back yet, so you have to start

with an antibiotic that can
treat many different types

of infections-- gram
positive, gram negative,

many different types
of bacteria.

And if the patient does
not really get better

with broad-spectrum antibiotics,

use of anti-fungals
may also be indicated,

because there may be
a fungal infection.

But usually you start here,
broad-spectrum antibiotics,

and then you'll check the
blood cultures afterwards,

and once those cultures return,
the patient can e switched

to a more tailored antibiotic
therapy to provide an antibiotic

or anti-microbial that the
organisms is susceptible to.

Now, remember, not only is
there an infection going on,

but as a byproduct
of this infection,

the patient has a drop
in blood pressure,

so treatment will
also include IV fluids

to restore blood
pressure as well

as a medication called
"pressors."

And what pressors do is they
help squeeze down blood vessels

to allow an increase in
systemic vascular resistance,

or resistance of blood vessels,

which helps restore the
blood pressure as well.

So both of these will
increase blood pressure.

So treatment will likely
take days to weeks,

and in the meantime, while
the patient is recovering,

what do you think the
next logical step is?

You know, the patient has been
diagnosed with septic shock,

they're being treated for it.

So the next step is really
to see how the progress

of the patient is, what's the
progress of the infection?

To check the progress, you
know, you might continue

to get lactate, ABG,
BUN and creatinine

to monitor the patient, but
you can also get other labs,

such as a CRP or an ESR.

Now CRP stands for C-reactive
protein, and ESR stands

for erythrocyte sedimentation
rate.

Really, the names of these
are somewhat inconsequential.

The main idea here is you
can track inflammation.

So these allow you to
track inflammation,

and when a patient is first
diagnosed with septic shock,

these values are going
to be very elevated,

possibly up around
100, each of these.

And just to give you an idea the
normal values, the normal value

of CRP should be less
than 1 mg per deciliter,

and the normal ESR
really depends on age,

but it will be probably below 20

or maybe 25 millimeters
per hour.

That's the units of ESR,
erythrocyte sedimentation rate.

And so CRP and ESR,
as I was saying,

may be drastically elevated.

So resolution of septic shock
will show these values starting

to go back down to normal.

Searching for a down-trend
of these elevated lab values.

So really, that's it
with septic shock.

And it all makes sense based
off of what is going on.

Infective material
in the bloodstream.

Let me make a couple
final points.

You always want to start

with blood cultures before
you do antibiotic therapy.

This is very important,
so that the organism

in the patient's
bloodstream can be discovered.

If broad-spectrum antibiotics
are started before blood

cultures are obtained,

there will be antibiotics
in the blood.

So when a lab technician
goes to culture it,

those antibiotics might
interfere with the growth

of the blood cultures.

So always-- blood cultures
first, and then antibiotics.

But also another great thing

to know is these
should not be delayed.

Because remember delay
in treatment can lead

to increased mortality.

And last of all, many hospitals,

we might hear the term
two large-bore IV lines

for IV fluid treatment.

Essentially that's establishing
two lines in either arm,

in which fluids can
get to the patient,

and they'll be called large-bore
because they'll be very large

in diameter, these tubes will
have a very large diameter,

and this allows for
fluid, IV fluid,

to get to the patient quicker.

So that blood pressure can
be increased very quickly.

So remember the steps--
diagnosis, treatment,

and then tracking
progression of septic shock.