Neurogenic Shock | Shock (Part 7)
Summary
TLDRThis educational video, presented by Eddie Watson, delves into neurogenic shock, a type of distributive shock resulting from CNS injury, typically at T6 or higher spinal cord levels. It explains the lack of sympathetic response leading to decreased blood pressure, heart rate, and cardiac output. The video outlines key signs like hypotension, bradycardia, and hypothermia with warm extremities, emphasizing the importance of ruling out other shock causes. Treatment involves protecting the spine, IV fluids, vasopressors, inotropes, and possibly pacing to increase heart rate. It also stresses maintaining a higher mean arterial pressure for spinal cord perfusion and protecting the airway due to potential respiratory failure, offering a comprehensive guide for medical professionals.
Takeaways
- 🧠 Neurogenic shock is a type of distributive shock resulting from CNS injury, typically involving the cervical or high thoracic spinal cord (T6 level or higher).
- 🚫 The injury leads to an impact on sympathetic nerve outflow, causing a lack of sympathetic response while the parasympathetic response remains active.
- 🌡️ In neurogenic shock, there's a decrease in systemic vascular resistance and blood pressure due to the absence of catecholamines that normally cause vasoconstriction.
- 💓 The sympathetic nervous system's absence also affects the heart, leading to decreased cardiac contraction and preload, contributing to reduced cardiac output.
- 🐦 A characteristic sign of neurogenic shock is a low heart rate due to the lack of sympathetic innervation of the SA node.
- 🌡️ Hypothermia can occur in neurogenic shock, but it is central, meaning the patient's core temperature drops due to hypothalamic dysregulation, not peripheral vasoconstriction.
- 📋 Diagnosing neurogenic shock requires ruling out all other possible causes of shock to ensure accuracy.
- 🩺 Key signs of neurogenic shock include decreased blood pressure, bradycardia, decreased cardiac output, and warm, dry extremities despite hypothermia.
- 🛑 Initial treatment involves protecting the spine to prevent further damage, using measures like a flat bed, c-collar, and log rolling.
- 💧 The first line of treatment for neurogenic shock is IV fluids to replace intravascular volume and counteract the effects of decreased vascular tone.
- 💊 If hypotension persists, vasopressors and inotropes may be used to induce vasoconstriction and improve cardiac contractility, respectively.
- 🔁 For significant bradycardia, medications like dopamine and atropine, or pacing, may be considered to increase heart rate and counteract the parasympathetic response.
Q & A
What is the main focus of the seventh lesson in the series?
-The seventh lesson focuses on neurogenic shock, a type of distributive shock, and its various aspects including its causes, effects, diagnosis, and treatment.
What does the term 'neurogenic shock' refer to?
-Neurogenic shock refers to a state of shock that results from an injury to the central nervous system (CNS), particularly involving the brain and spinal cord.
What is the role of the sympathetic nervous system in neurogenic shock?
-In neurogenic shock, there is an impact on the sympathetic nerve outflow, leading to a lack of sympathetic response while the parasympathetic response remains preserved.
How does neurogenic shock affect coronary blood vessels?
-In neurogenic shock, the lack of sympathetic response means there is no dilation of the coronary blood flow that normally occurs during the fight-or-flight response.
What is the impact of neurogenic shock on systemic vascular resistance?
-Neurogenic shock leads to a decrease in systemic vascular resistance, which contributes to a decrease in blood pressure due to the lack of sympathetic activation.
Why does neurogenic shock result in decreased cardiac contraction?
-The sympathetic nervous system normally has a positive inotropic effect on the heart. In neurogenic shock, the absence of this sympathetic activation results in decreased cardiac contraction.
What is the significance of the SA node in neurogenic shock?
-The SA node, or the sinoatrial node, is responsible for controlling the heart rate. In neurogenic shock, the lack of sympathetic innervation to the SA node results in a low heart rate.
Why is hypothermia a potential symptom in neurogenic shock?
-Hypothermia can occur in neurogenic shock due to dysregulation within the hypothalamus, which is responsible for body temperature regulation. The lack of sympathetic response also prevents the typical vasoconstriction that leads to cool, clammy skin.
What is the primary treatment for neurogenic shock?
-The primary treatment for neurogenic shock includes protecting the spine, administering IV fluids to replace intravascular volume, and using vasopressors and inotropes if necessary.
How does treatment for neurogenic shock differ from other types of shock?
-Treatment for neurogenic shock focuses on maintaining a higher mean arterial pressure to ensure adequate spinal cord perfusion, protecting the airway, and managing bradycardia, which are specific considerations due to the CNS injury.
What is the importance of ruling out other causes of shock before diagnosing neurogenic shock?
-It is crucial to rule out other causes of shock to ensure an accurate diagnosis and appropriate treatment. Neurogenic shock has specific treatments and considerations that differ from other shock states.
Outlines
🧠 Understanding Neurogenic Shock
This paragraph introduces the concept of neurogenic shock, a type of distributive shock resulting from central nervous system (CNS) injury, typically involving the brain or spinal cord above the T6 level. The presenter, Eddie Watson, explains how such injuries can disrupt sympathetic nerve outflow, leading to a lack of sympathetic response but a preserved parasympathetic one. This disruption impacts coronary vessels, decreases systemic vascular resistance, and affects cardiac function, resulting in low blood pressure. The absence of sympathetic innervation to the heart leads to decreased contractility and heart rate, contributing to the shock state. Additionally, neurogenic shock can cause hypothermia due to dysregulation in the hypothalamus, but unlike other shock states, the patient's extremities are warm and dry. The importance of ruling out other shock causes before diagnosing neurogenic shock is emphasized.
🚑 Signs and Treatment of Neurogenic Shock
The second paragraph delves into the clinical signs of neurogenic shock, which include decreased blood pressure due to reduced systemic vascular resistance, and a distinctive lack of compensatory sympathetic response, leading to bradycardia. Other signs include decreased cardiac output, reduced central venous pressure (CVP), and hypothermia with warm, dry extremities. The treatment approach for neurogenic shock is discussed, starting with spinal protection to prevent further damage. Initial treatment involves IV fluids to restore intravascular volume, followed by vasopressors if hypotension persists. Inotropes may be used to improve cardiac contractility, and medications like dopamine or atropine can be considered to increase heart rate. Pacing may also be necessary. The goal is to maintain a higher mean arterial pressure to ensure adequate spinal cord perfusion, given the injury and associated swelling. Lastly, airway protection is crucial, as the shock state and the level of spinal injury can affect respiratory function, potentially necessitating intubation and mechanical ventilation.
📚 Conclusion and Further Learning
In the concluding paragraph, the presenter thanks the viewers for watching and summarizes the key points covered in the lesson. The unique aspects of neurogenic shock, its clinical signs, and the specific treatment modalities are reiterated. The importance of understanding the differences between neurogenic shock and other types of shock is highlighted. The presenter encourages viewers to like the video and share their thoughts or questions in the comments. Additionally, they promote the next lesson in the series on septic shock and invite viewers to explore other educational content on hemodynamics. The aim is to ensure that viewers have gained valuable knowledge from the lesson and are motivated to continue their learning journey.
Mindmap
Keywords
💡Neurogenic Shock
💡Sympathetic Nerve Outflow
💡Systemic Vascular Resistance
💡Catecholamines
💡Cardiac Contraction
💡Preload
💡Heart Rate
💡Hypothermia
💡Protect the Spine
💡Vasopressors
💡Inotropes
💡Bradycardia
💡Mean Arterial Pressure (MAP)
💡Respiratory Failure
Highlights
Introduction to the seventh lesson on shock, focusing on neurogenic shock.
Definition of neurogenic shock as a distributive shock resulting from CNS injury.
Explanation of the impact of CNS injury on sympathetic nerve outflow leading to shock.
Absence of sympathetic response in neurogenic shock while parasympathetic response is preserved.
Effects on coronary vessels and systemic vascular resistance due to lack of sympathetic activation.
Decreased blood pressure due to reduced vascular tone in neurogenic shock.
Impact of sympathetic nerve on cardiac function and the resulting decrease in cardiac contraction.
Decreased preload and afterload leading to low cardiac output.
Signs of neurogenic shock include low heart rate and lack of sympathetic innervation of the SA node.
Hypothermia in neurogenic shock due to dysregulation within the hypothalamus.
Importance of ruling out other causes of shock before diagnosing neurogenic shock.
Signs of neurogenic shock include hypotension, bradycardia, and decreased cardiac output.
Treatment of neurogenic shock starts with protecting the spine to prevent further damage.
Use of IV fluids to replace intravascular volume in the treatment of neurogenic shock.
Utilization of vasopressors and inotropes to compensate for lack of sympathetic response.
Medications like dopamine and atropine to increase heart rate in neurogenic shock.
Pacing as a treatment option for hemodynamically significant bradycardia.
Maintaining a higher mean arterial pressure for adequate spinal cord perfusion.
Protecting the airway and potential need for intubation and mechanical ventilation.
Summary of neurogenic shock's unique characteristics and treatment approaches.
Transcripts
you
[Music]
alright and welcome everybody to this
seventh lesson in our series of lessons
on shock in this lesson we're going to
continue our discussion of the various
types of distributive shock specifically
covering neurogenic shock and my name is
Eddie Watson I will be your presenter
for this series of lessons and make sure
and subscribe to our channel below in
order to stay up to date on when our
latest lessons are released and don't
forget to hit the bell icon in order to
get those notifications as those lessons
become available all right so for this
lesson we're gonna take a look at our
neurogenic shock again another type of
shock that is classified as a
distributive shock so like with all the
rest of them we're going to go ahead and
break down our word into its root words
so we have neuro and genic neuro having
to do with the brain and spinal cord and
genic meaning originating from and so in
our case here our shock state is going
to be the result of some sort of CNS
injury and so the CNS injury is going to
be the result of some sort of cervical
or high thoracic and so this is going to
be t6 and above so some sort of injury
to the spinal cord at at least the t6
level or higher and so what happens when
we have a spinal cord injury at this
level or higher is if there is some sort
of impact on the sympathetic nerve
outflow that this is going to have an
impact on things in our body that can
lead to a state of shock
so essentially they'll find themselves
in a state with with no sympathetic
respond but still a preserved
parasympathetic response or activity
and so what does this really mean for
our patients well this is gonna impact
our coronary vessels so again if we
think about that sympathetic response
that fight-or-flight normally we get
that dilation of the coronary blood flow
but in the case of neurogenic shock
we're not going to see that now also
since we're not going to have our
sympathetic activation we're also going
to see a decrease in our systemic
vascular resistance or essentially our
after load and again if you think back
to our first lesson in this series we
have the release of the catecholamines
from the adrenal gland which ultimately
bind with receptor sites in our blood
vessels and work to cause
vasoconstriction
but again in neurogenic shock we're not
going to have this cascade of events
ultimately leading to decreased vascular
tone and since our systemic vascular
resistance plays an important role in
our blood pressure we are going to see
that decreased blood pressure now we
also see this sympathetic nerve
innervate
the heart itself and one of the things
that it does there is it has that
positive inotropic effect and so since
we don't again have that we're going to
see a decrease in our cardiac
contraction now in addition to our
decreased systemic vascular resistance
this means where we're not going to be
getting blood back to the heart as well
as we should so this is going to lead to
a decrease in our preload and finally
one of the most telltale signs of
neurogenic shock is we no longer are
innervating the SA node of the heart and
we're no longer getting that positive
Crona tropic effect of the sympathetic
response and so what happens is you'll
will see a low heart rate in your
patient and so really if we think about
all the factors that go into our cardiac
output we're having an impact on all of
those or decreasing our preload
decreasing our afterload decreasing our
contractility and also decreasing our
heart rate and so this combination of
all of these impacted areas and our lack
of sympathetic response is going to lead
to a low blood pressure
another thing that we also could see in
our patients with neurogenic shock is
hypothermia but one important thing to
note about this is this is going to be
in the patient's core and this is due to
a disc regulation within the
hypothalamus but again if you think
about our lack of sympathetic response
we are not getting that vasoconstriction
that often leads to the cool clammy skin
and so we'll talk about that here in a
minute but our patient will be
exhibiting this this hypothermia within
the body and so one thing that's really
important to note when we're looking at
possibly diagnosing a patient with
neurogenic shock is it's really
important that we rule out all others so
it's really important that we rule out
all other possible causes of shock
before we make the determination that
this is a result of a neurogenic shock
state all right so let's go ahead and
move on to talk about some of the signs
that we would see if we had a patient at
neurogenic shock so as always we're
going to see that decreased blood
pressure or hypotension and this is
going to be a result of that decreased
systemic vascular resistance now one of
the tell-tale signs for neurogenic shock
is that normally our body would attempt
to compensate for this blood pressure by
activating the sympathetic response and
increasing our heart rate and our
vasoconstriction but in this case we no
longer have that ability so you're gonna
find your patient with a decreased heart
rate or bradycardia and along with that
you're often going to see a decreased
cardiac output as well as a decrease in
our CVP or our pulmonary capillary wedge
pressure and again this is a result of
that lack of preload
of the blood not making its way back and
finally like we just talked about you
may also see hypothermia but unlike in
other shock states with this hypothermia
you're actually going to have warm dry
extremities
all right so now let's go ahead and move
on to our treatment and so when we look
at our treatment modalities for a
patient in neurogenic shock probably the
first and most important thing that we
need to make sure we do is we need to
protect the spine and this is very
important because while oftentimes the
damage to the spine may not be
reversible or fixable sometimes it may
be or they may be able to partially
recover some function and so it's
imperative that we do not cause even
more damage and this is where we're
gonna use things like keeping their bed
flat using a c-collar and also log
rolling your patient and so now with
neurogenic shock our first line of
treatment is actually going to be IV
fluids and we're going to look to
replace that intravascular volume and so
essentially we want to be able to
provide more volume of blood in order to
fill all the extra space that now exists
within the vasculature now if the
patient's symptoms persist and they
remain persistently hypotensive then the
next thing we're going to be looking at
doing is using our vasopressors and this
is going to provide the body with that
vasoconstriction that our patient is
just not able to produce themselves but
we might also look at medications like
our inotropes and for these we're
looking to make up for that lack of
contractility again that we're not
receiving as a result of this lack of
sympathetic response now if your patient
remains with a hemodynamically
significant bradycardia then we may also
want to look at ways of increasing our
heart rate so we may try medications
like dopamine which can have a dual
effect on both increasing our heart rate
as well as providing that
vasoconstriction we also often will look
at a medication called atropine and this
medication works to increase our heart
rate by actually blocking the
parasympathetic response which in the
case of neurogenic shock is the
overriding response that our body has
right now and finally may also look at
options such as pacing your patient
and this can be both externally or
internally and so with these
interventions like the fluids and the
pressors and the inotropes and working
to increase their heart rate we're going
to really want to make sure that we're
maintaining a higher mean arterial
pressure than we normally would look in
normal patients and the reason for this
is we're gonna want to be ensuring that
we're providing adequate spinal cord
perfusion and due to the result of the
injury and the swelling that's going on
in the spinal cord we're gonna have to
have a higher map in order to overcome
the increased pressure and increase
swelling in order to profuse that spinal
cord and finally the last thing that we
may need to look at doing for our
patients is we are going to want to be
looking at protecting their airway and
now this may come about as a result of
being in a shock state but also
oftentimes depending on how high the
level of the spinal cord injury that
this could have an impact on respiratory
accessory muscles as well as the direct
innervation of the diaphragm itself
possibly leading to respiratory failure
for your patient requiring intubation
and mechanical ventilation alright so
that just about covers our discussion of
neurogenic shock as you can see the
shock is quite a bit different than some
of the other ones that we've talked to
up to this point and so it really kind
of talked about what's going on and
what's really causing those differences
and how those differences are leading to
that shock state in addition we talked
about some of the signs that you'd see
in your patient and finally covered some
of the courses of treatment that we had
in place specifically for patients with
neurogenic shock and so on that note I
do want to thank you for watching this
lesson I really do hope that you found
this useful for you if you did like the
video and you found it informative
make sure and hit that like button down
below as it really helps to spread the
word about our channel also in the
comments below tell us your favorite
part of this video or feel free to ask
any questions that you might have
finally make sure and check out the next
lesson in this series on septic shock or
also check out another one of our great
series of lessons on hemodynamics thank
you so much for watching and we'll see
you in the next lesson
5.0 / 5 (0 votes)