Anaphylactic Shock | Shock (Part 6)

Summary

In this sixth lesson of the shock series, Eddie Watson delves into distributive shock, focusing on anaphylactic shock. He explains that it occurs when the immune system overreacts to an allergen, leading to a massive histamine release. The process involves sensitization after the first exposure and a severe reaction upon re-exposure. Symptoms include hypotension, swelling, increased heart rate, and bronchoconstriction. Treatment involves addressing airway, breathing, and circulation, administering epinephrine for its sympathetic effects, and considering IV fluids, antihistamines, corticosteroids, and albuterol to manage symptoms and prevent rebound reactions.

Takeaways

• 📚 The lesson is part of a series on shock, specifically focusing on distributive shock types.
• 👨‍🏫 Eddie Watson is the presenter for the series of lessons on shock.
• 🔔 Viewers are encouraged to subscribe and hit the Bell icon for updates on new lessons.
• 🔍 Distributive shock encompasses anaphylactic shock, neurogenic shock, and septic shock, each with unique causes but similar underlying mechanisms.
• 🌟 Excessive vasodilation and leaky blood vessels are common contributors to the shock state in distributive shock types.
• 🌱 Anaphylactic shock is initiated by an immune system response to allergens, which can be ingested, injected, or absorbed through the skin.
• 🛡️ Immunological reactions involve initial sensitization to an allergen, leading to the production of IgE antibodies that attach to mast cells.
• 🚨 Non-immunological reactions, like anaphylactic reactions, occur without prior sensitization and trigger a direct response from mast cells.
• 💊 The primary treatment for anaphylactic shock includes epinephrine to increase systemic vascular resistance and bronchodilation.
• 🩺 Additional treatments may involve IV fluids to replace leaked intravascular fluid, antihistamines, corticosteroids, and albuterol for respiratory support.
• 📈 The script provides a detailed explanation of anaphylactic shock, its causes, symptoms, and treatment modalities.

Q & A

What is the main topic of the sixth lesson in the series on shock?

The main topic of the sixth lesson is distributive shock, which includes anaphylactic shock, neurogenic shock, and septic shock.

What are the common underlying causes of distributive shock?

The common underlying causes of distributive shock are excessive vasodilation and leaky blood vessels.

What does the term 'anaphylactic shock' mean in the context of this lesson?

Anaphylactic shock refers to a shock state that results from the immune system's response to an allergen, which paradoxically works against the body's own processes.

How does an allergen typically trigger an anaphylactic shock?

An allergen can enter the bloodstream through injection, ingestion, or absorption through the skin, triggering a cascade of events that lead to a shock state.

What are the two types of anaphylactic shock causes mentioned in the script?

The two types of anaphylactic shock causes are immunological, which requires sensitization, and non-immune mediated, which does not require sensitization.

What happens during the sensitization process in an immunological anaphylactic reaction?

During sensitization, the allergen interacts with a B-cell, which produces antibodies (IgE) that attach to mast cells, preparing the body for a potential anaphylactic reaction upon future exposure to the allergen.

What is the role of histamine in an anaphylactic reaction?

Histamine is massively released following an allergen's interaction with antibodies on mast cells, leading to systemic effects such as vasodilation, increased capillary permeability, bronchoconstriction, and decreased AV node conduction.

What are the typical signs and symptoms of anaphylactic shock?

The typical signs and symptoms of anaphylactic shock include decreased blood pressure, swelling, increased heart rate, bronchoconstriction, flushing of the skin, itchiness, and rhinorrhea.

What is the first-line treatment for a patient with anaphylactic shock?

The first-line treatment for a patient with anaphylactic shock is the administration of epinephrine, which helps to increase systemic vascular resistance and promote bronchodilation.

What other treatments are commonly considered for anaphylactic shock besides epinephrine?

Other treatments for anaphylactic shock include IV fluids to replace leaked intravascular fluid, antihistamines (like Benadryl) targeting H1 receptors, H2 receptor antagonists (like Zantac), corticosteroids, and albuterol for bronchial smooth muscle relaxation.

Why might corticosteroids be administered in the treatment of anaphylactic shock?

Corticosteroids are administered not for immediate reaction management but with the thought of preventing rebound anaphylaxis, although evidence supporting this is limited.

Outlines

00:00

📚 Introduction to Distributive Shock

The video begins with a welcome from presenter Eddie Watson, introducing the sixth lesson in a series on shock. The focus of this lesson is distributive shock, which encompasses anaphylactic, neurogenic, and septic shock. These conditions share similar underlying causes, leading to excessive vasodilation and leaky blood vessels. The video promises to delve into each type, starting with anaphylactic shock, and encourages viewers to subscribe and enable notifications for updates on the series.

05:00

🌟 Understanding Anaphylactic Shock

This paragraph delves into anaphylactic shock, a condition triggered by an immune system response to allergens. The term 'anaphylactic' is broken down into its root words, 'ana' meaning against and 'phylaxis' meaning protection, suggesting a protective response gone awry. The body's reaction to allergens, which can be ingested, injected, or absorbed, leads to a massive release of histamine. The causes are divided into immunological and non-immune mechanisms, with the former being more common. The immunological response involves an initial exposure that sensitizes the body by producing IgE antibodies, which then bind to mast cells. A subsequent exposure triggers a cascade of events, including cytokine release and histamine production, leading to systemic effects such as vasodilation, increased capillary permeability, bronchoconstriction, and decreased AV node conduction, culminating in shock.

10:01

🚑 Signs, Symptoms, and Treatment of Anaphylactic Shock

The paragraph discusses the signs and symptoms of anaphylactic shock, which include decreased blood pressure, systemic swelling, increased heart rate, bronchoconstriction, flushing, itching, and rhinorrhea. As shock progresses, additional symptoms typical of shock states may appear. The treatment approach for anaphylactic shock is outlined, emphasizing the importance of addressing airway, breathing, and circulation (ABCs), which may involve intubation and ventilation. Epinephrine is highlighted as the first-line treatment to stimulate a sympathetic response, increasing systemic vascular resistance (SVR) and promoting bronchodilation. Intravenous fluids are used to replace leaked intravascular fluid, and antihistamines like Benadryl target H1 histamine receptors. H2 receptor antagonists like Zantac may also be used, along with corticosteroids to potentially prevent rebound anaphylaxis, and albuterol for refractory wheezing. The paragraph concludes by underscoring the importance of recognizing and treating anaphylactic shock promptly.

15:01

👋 Conclusion and Future Lessons

In conclusion, the video provides a comprehensive overview of anaphylactic shock, its causes, symptoms, and treatment. The presenter thanks viewers for watching and encourages them to like the video and share their thoughts in the comments. They also invite viewers to watch the next lesson on neurogenic shock or explore other educational series on hemodynamics. The video aims to enhance understanding and provide valuable insights into managing anaphylactic shock.

Keywords

💡Distributive Shock

Distributive shock refers to a category of shock states characterized by the body's inability to adequately distribute blood flow to meet the metabolic demands of tissues. In the video, it is the overarching theme, with three specific types being discussed: anaphylactic shock, neurogenic shock, and septic shock. The script explains that distributive shock involves excessive vasodilation and leaky blood vessels, leading to a drop in blood pressure and potentially shock.

💡Anaphylactic Shock

Anaphylactic shock is a severe, potentially life-threatening allergic reaction that can occur rapidly after exposure to an allergen. The script defines it through its root words 'ana' meaning against and 'phylaxis' meaning protection, indicating the body's protective immune response turning against itself. The video details the process by which an allergen triggers a massive release of histamine, leading to vasodilation, increased capillary permeability, and ultimately, shock.

💡Histamine

Histamine is a chemical released by the body in response to an allergen during an immune response. In the context of the video, histamine is a key player in anaphylactic shock, causing vasodilation and increased capillary permeability. The script describes how histamine binding to H1 and H2 receptors leads to various physiological responses, such as bronchoconstriction and decreased blood pressure, which contribute to the shock state.

💡Immunological Response

The immunological response in anaphylactic shock involves the immune system's reaction to an allergen. The video explains that after the first exposure to an allergen, B-cells produce antibodies (IgE) that attach to mast cells, sensitizing the body. Upon subsequent exposure, the allergen binds to these antibodies, triggering a cascade that releases histamine and leads to shock. This process is a central mechanism in the video's explanation of anaphylactic shock.

💡Non-Immunological Response

A non-immunological response, as mentioned in the script, is a type of anaphylactic reaction that does not require prior sensitization to an allergen. Unlike the immunological response, the allergen interacts directly with mast cells, bypassing the antibody production step. This direct interaction still leads to the release of histamine and can result in shock, highlighting the video's point that not all anaphylactic reactions require previous exposure to an allergen.

💡Cytokines

Cytokines are small proteins that play a role in cell signaling, particularly in the immune response. In the video, cytokines are released during an anaphylactic reaction as part of the cascade of events following allergen exposure. Their purpose is to recruit white blood cells to the site of the reaction, which then leads to the release of histamine and the subsequent physiological changes associated with shock.

💡Epinephrine

Epinephrine, also known as adrenaline, is a hormone and medication that is used in the treatment of anaphylactic shock. The script highlights epinephrine as the first-line treatment, aiming to counteract the effects of histamine by causing vasoconstriction to increase systemic vascular resistance (SVR) and bronchodilation to open the airways. This medication is crucial in managing the shock state and supporting the patient's blood pressure and airway.

💡Intravenous (IV) Fluids

IV fluids are used in the medical treatment of conditions where there is a loss of fluid from the vascular compartment, such as in anaphylactic shock. The video script discusses the importance of administering IV fluids to replace the fluid that has leaked out of the blood vessels due to increased capillary permeability, helping to restore blood volume and blood pressure.

💡Antihistamines

Antihistamines are medications that counteract the effects of histamine, particularly useful in allergic reactions. The script mentions antihistamines, specifically H1 receptor antagonists like Benadryl, as part of the treatment for anaphylactic shock. They help to reduce symptoms such as itching, hives, and swelling by blocking the histamine receptors, thus mitigating the allergic response.

💡Corticosteroids

Corticosteroids are a class of drugs that have anti-inflammatory and immunosuppressive properties. In the context of the video, corticosteroids are mentioned as part of the treatment for anaphylactic shock, not for their immediate effect on the ongoing reaction, but possibly for the prevention of rebound anaphylaxis. They are often used in conjunction with other treatments to manage the inflammatory aspects of the shock.

💡Albuterol

Albuterol is a medication that is used to treat bronchoconstriction, a condition where the airways narrow, making it difficult to breathe. The script notes that albuterol may provide relief for patients with anaphylactic shock who are experiencing wheezing and difficulty breathing, even though it does not directly address the cause of the bronchial smooth muscle contraction during an anaphylactic reaction.

Highlights

Introduction to distributive shock and its three types: anaphylactic, neurogenic, and septic shock.

Explanation of the underlying cause of distributive shock involving excessive vasodilation and leaky blood vessels.

Definition and breakdown of anaphylactic shock with its root words 'ana' meaning against and 'phylaxis' meaning protection.

Description of anaphylactic shock as a result of the immune system working against the body's own processes.

Mechanism of anaphylactic shock involving allergens, histamine release, and the immune response.

Differentiation between two causes of anaphylactic shock: immunological and non-immune mediated.

Process of sensitization following the first exposure to an allergen and the subsequent anaphylactic reaction.

Role of mast cells and antibodies (IgE) in the development of anaphylactic shock.

Effects of histamine binding to H1 and H2 receptors, leading to vasodilation, increased capillary permeability, bronchoconstriction, and decreased AV node conduction.

Signs and symptoms of anaphylactic shock, including hypotension, swelling, increased heart rate, and bronchoconstriction.

Importance of focusing on patient's ABCs (airway, breathing, circulation) in the treatment of anaphylactic shock.

First-line treatment for anaphylactic shock with epinephrine to increase SVR and promote bronchodilation.

Administration of IV fluids to replace fluid lost due to leaky vessels in anaphylactic shock.

Use of antihistamines like Benadryl targeting H1 histamine receptor sites in the treatment of anaphylactic shock.

Consideration of medications like Zantac and corticosteroids in the management of anaphylactic shock.

Discussion on the potential use of albuterol for relief in refractory wheezing during anaphylactic shock.

Summary of anaphylactic shock, its causes, symptoms, and treatment strategies.

Transcripts

you

[Music]

all right welcome everybody I want to

welcome you to our six lesson in the

series of lessons on shock and in this

lesson we're going to begin our dive

into the category of shock types that we

refer to as distributive shock and my

name is Eddie Watson and I am gonna be

your presenter for this series of

lessons and so as always in order to

stay up to date on our lessons as they

become available make sure and subscribe

to our channel below and also don't

forget to hit that Bell icon in order to

be notified when those new lessons

become available okay so when we talk

about distributive shock we're really

talking about three different types of

shock States we can divide that up into

anaphylactic shock neurogenic shock and

septic shock now each of these types of

shock has their own causes and unique

pathophysiology but essentially the

underlying cause for the shock state

it's going to be very similar and so

what's going to end up happening in

distributive shock is you're going to

end up with excessive vasodilation as

well as you're gonna have leaky blood

vessels and so again for the three types

of distributive shock that we're going

to talk about they all are going to

achieve this as well as other things

through different processes but these

two things that excessive vasodilation

and the leaky blood vessels are what's

going to contribute to that shock state

all right and so with that said let's go

ahead and move on to the first type of

distributive shock that we are going to

talk about and that is going to be

anaphylactic shock and so like with all

the rest of these that we've done we are

going to break this down into its root

words which we can break down into Anna

and flexus Anna essentially means

against and flexes is protection

and so really you can think about

anaphylactic shock as being a shock

that's a result of our immune system so

our body's protection system but at this

point it's now working against our own

body and our own processes and so really

to sum up what's happening in

anaphylaxis is you end up with some sort

of allergen and when the body sees this

and responds to this you end up with a

massive release of what we call

histamine and so this allergen can

really come in many forms it can be

either something that's injected it can

be ingested or it can even be absorbed

through the skin but essentially the end

result is that that allergen will enter

into the bloodstream and trigger a

cascade of events that will ultimately

lead to a shock state and these

allergens can come in many forms it can

be food allergies such as peanuts or

shellfish it can be from bee stings or

even medications that we give and so now

if we look at the causes for

anaphylactic shock there's essentially

two types which we are going to break

down further here in just a minute the

first and most common one is going to be

the immune illogic and this is going to

be what we refer to as anaphylaxis and

the second one is going to be our

non-immune illogic and this is what

you're going to hear referred to as

anaphylactic

anaphylaxis or the immunological

response is going to be the most common

all right so at this point let's go

ahead and talk about what's actually

happening inside of our body with these

reactions so here we're going to go

ahead and draw out a blood vessel and so

the first one we're going to talk about

is our immune illogic reaction or the

anaphylaxis

so essentially you end up

this allergen that has now entered into

the bloodstream and so the first time

that your body sees this what's going to

happen is it's going to interact with a

b-cell and the whole purpose of this

b-cell is to recognize this allergen and

to create these proteins that we call

antibodies and they're essentially these

why look and proteins and they're also

referred to as IgE and these antibodies

main purpose is to be able to interact

with the allergen and so what happens

after this first exposure in the

creation of these antibodies is these

antibodies will go and they'll attach to

our mast cells and these mast cells are

really what's known as our immune system

mediators and so when this happens in

this process goes through its course

this is what we call being sensitized

and so in order for this reaction to

progress to an anaphylaxis reaction or

anaphylactic shock as we're actually

going to have to have another exposure

to this same allergen and so once again

the allergen will enter into the blood

system and now what will happen is that

allergen will actually go and because of

these antibodies that were produced and

what will happen as the allergen will go

ahead and bind to one of the antibodies

on one of the mast cells and this is

really where the cascade of events

begins to take place and so the first

thing that happens is it's going to

release these cytokines and the whole

point of these cytokines is to recruit

our white blood cells and so when these

white blood cells and mast cells come

together what you're gonna get is a

massive release of histamine and so it's

going to happen as this histamine is

going to bind with a couple histamine

receptors we have our our h1 and our h2

receptors and so when the histamine

binds with these receptor sites each

one's going to have their own unique

response and so when we talk about the

h1 receptor site the first of these that

we're going to see

is an increase in our capillary dilation

and so really if we go back to our blood

vessel here if we think about that we're

talking about an increase in the size of

this capillary and so this is going to

cause these vessels to dilate out which

is going to increase their size and

again you've got to think that this is

happening systemically throughout the

entire body and so this is going to

ultimately lead to a massive drop in our

systemic vascular resistance which

essentially means we are going to have a

massive drop in our blood pressure so

the next thing that we're going to see

is an increase in our capillary

permeability and so what's happening is

these cells in the endothelial lining

the spacing in between them is going to

start to open up and this is going to

cause fluid from our intravascular space

to leak out of our blood vessels and

when this fluid leaks out and collects

up out here this is going to cause

swelling and once again this is

happening throughout the entire body so

you're going to have swelling throughout

the entire body the next thing that

we're going to see specifically with the

h1 receptors is we're going to see an

increase in the bronchial smooth muscle

cell contraction and so in the lungs

what you're gonna see is

bronchoconstriction and so when you take

this combined with the swelling that

you're also going to see as a result of

those leaky blood vessels around the

airway this is where you're going to

begin to really get concerned for your

patients ability to support their own

airway and finally the fourth and last

thing that we will see as a result of

the h1 activation is you're going to see

a decrease in the conduction of the AV

node so now with our h2 receptor site

active the first you're gonna see an

increase in our gastric acid product

production and so you're gonna have a

buildup of the gastric acid in your

patient this could also lead to nausea

and vomiting for them and ultimately an

aspiration risk but the other thing that

you could also see as a result of this

is our vascular smooth muscle

relaxation and so again this smooth

muscle relaxation is going to lead to a

further decrease in our SVR and

ultimately a further decrease in our

patient's blood pressure and so that

essentially is what's going on with the

immunological response and what is

ultimately leading to our shock state

now for the second cause this is our non

amino logic or what we call the

anaphylactic response the important

distinction to note with the

anaphylactic

is unlike the anaphylaxis reaction this

doesn't require an initial sensitization

so essentially what happens is again we

have some sort of allergen that enters

into the bloodstream but what happens in

this case is this allergen is gonna

interact directly with a receptor on the

mast cell and this is again gonna

trigger that same cascade of events of

releasing cytokines and recruiting white

blood cells ultimately leading to the

massive release of histamine and

ultimately the same concerns and

conditions that would lead to the state

of shock that we just discussed again

very important to note though that the

anaphylactic reaction can happen on the

first time a person is exposed to this

particular allergen as opposed to with

the anaphylaxis reaction they're going

to have to have that initial exposure in

order to be sensitized and then have a

second exposure in order to trigger this

cascade of events and so now let's go

ahead and talk about some of the signs

or symptoms that your patient might

exhibit and so just like with every

other type of shock you're gonna have a

decreased blood pressure or hypotension

the other important sign that you're

going to see massively and systemically

with your patient is that swelling as

the body attempts to compensate for this

hypotension you're going to see an

increased heart rate and again as a

result of the histamine release you're

going to have the bronco construction

they may also have flushing of the skin

itchy Ness and rhinorrhea

which is a runny nose and again as the

shock state progresses and continues you

will see all the typical signs that you

would see in a patient who is exhibiting

shock which we did cover in the first

lesson and so finally now let's go ahead

and move on to our treatment and so for

our treatment there's going to be

several things that we're going to be

looking for or trying to do and so the

first of these and probably the the most

important is as you can remember with

this type of shock one of the things

that you're most notably going to see is

is that swelling throughout the entire

body and particularly that combined with

our bronchoconstriction that we're

really going to be concerned for our

patients airway so we're going to make

sure we're focusing on our patients ABCs

so airway breathing circulation and this

ultimately could mean intubation and

ventilation

now for really our first line treatment

for a patient with anaphylactic shock

is going to be the initiation of

epinephrine and so here what we're

really looking for is that sympathetic

response and so here we're going to be

looking for that constriction of blood

vessels to increase our SVR as well as

we're going to be looking for the

response of the bronchodilation and

these two things are going to work to

open our patient's airway as well as

supporting their blood pressure and when

we talk about the administration of

epinephrine the first line is to go with

the intramuscular injection and then if

we find ourselves in a state of

cardiovascular collapse that hasn't been

responsive to the I M injection then

that's when we might consider IV form of

the medication as well so next we're

going to want to look at giving our

patients IV fluids and so think back to

those leaky vessels the fluid has

shifted out of the intravascular space

and so we want to look to replace that

and we also might look at giving them a

medication in the class of an

antihistamine and our primary medication

is going to be directed at the h1

histamine receptor sites so this is

going to be our benadryl and other

things of that sort but you may also

find times we're giving a medication

that has an impact on the h2 receptor

sites and this would be something like a

zantac which is normally going to be

used to reduce the gastric acid

production but in the cases of

anaphylaxis it can also be used in

conjunction with our h1 antihistamines

and finally a couple other things you

might see is the application of

medication such as our corticosteroids

the important thing to know is steroids

aren't going to have any impact on the

reaction that's currently going on there

is some thought around the prevention of

rebound anaphylaxis but there really

hasn't been a whole lot of evidence to

support this but this is often a common

course of treatment especially

considering that as many as 20% of

patients can have a rebound and

Laxus reaction and so finally one of the

more common medication Jame also see is

going to be our albuterol

now while this medication in the midst

of the anaphylaxis reaction is not going

to relieve that bronchial smooth muscle

contraction in a patient who's having

refractory wheezing and having

difficulty breathing it may provide them

some relief alright so that sums up our

discussion on our anaphylactic shock and

again we talked about how this is a

result of an interaction with an

allergen leading to a massive release of

histamine which ultimately leads to our

shock state we talked about the two

different causes immunological

non-immune illogic as well as the signs

and symptoms that you would look to see

if you had a patient who was in

anaphylactic shock and finally we talked

about some of the treatment modalities

that you would be looking to do for your

patient I do hope that this explanation

has helped to make this a little bit

more understandable for you and as

always I do want to thank you for

watching this video and I hope you found

this lesson useful for you now please if

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feel free to ask any questions that you

may have finally make sure and check out

the next lesson in our series which is

going to be on neurogenic shock or you

can 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