Anaphylaxis - Education

Summary

Anaphylaxis is a severe allergic reaction resulting from mast cell and basophil degranulation upon antigen exposure. It can manifest with life-threatening symptoms in respiratory, cardiovascular, and integumentary systems, varying in onset and severity. Common triggers during anesthesia include neuromuscular blockers and antibiotics. Immediate treatment involves calling for help, administering epinephrine, securing an airway, and providing fluids, with histamine blockers and steroids as adjunctive therapies.

Takeaways

• 🚨 Anaphylaxis is a severe allergic reaction resulting from the degranulation of sensitized mast cells and basophils upon antigen exposure.
• 🔬 Mast cells are found in the perivascular spaces of the skin and intestine, while basophils are in the blood.
• 🌟 Immunoglobulin E (IgE) is produced on initial exposure to an antigen and binds to the effector cells' surface, triggering a response on subsequent exposures.
• 💊 Physiologically active mediators like histamine, tryptase, and platelet-activating factor are released during anaphylaxis.
• 🌡 Histamine is a key inflammatory mediator stored in mast cells and basophils, causing vasodilation, increased vascular permeability, and other symptoms.
• 🚑 Symptoms of anaphylaxis can be life-threatening, affecting the respiratory, cardiovascular, and integumentary systems.
• 💉 An anaphylactic reaction can occur on first exposure to certain drugs, such as anaesthetics, due to cross-reactivity.
• 🕒 The onset and severity of anaphylactic symptoms can vary, complicating diagnosis, and may be masked by general anesthesia or surgical drapes.
• 📊 Neuromuscular blocking agents are the most common triggers for an anaphylactic reaction during anesthesia, accounting for over 50% of incidents.
• 🏥 Immediate treatment for anaphylaxis is critical and includes calling for help, administering epinephrine, securing an airway, and providing fluids.
• 🛡 Epinephrine is crucial in anaphylaxis treatment due to its hemodynamic effects and ability to stabilize mast cells, reducing mediator release.

Q & A

What is anaphylaxis?

Anaphylaxis is a severe hypersensitivity reaction caused by the degranulation of sensitized mast cells and basophils after exposure to an antigen.

Where are mast cells and basophils typically located in the body?

Mast cells are located in the perivascular spaces of the skin, long intestine, and other tissues, while basophils are found in the blood.

What is the role of immunoglobulin E (IgE) in anaphylaxis?

IgE is produced upon initial exposure to an antigen and binds to the surface of effector cells, such as mast cells and basophils. Upon subsequent exposure, the antigen binds to the IgE, triggering the release of physiologically active mediators.

What are some of the physiologically active mediators released during an anaphylactic reaction?

During an anaphylactic reaction, mediators such as histamine, tryptase, chemotactic factors, platelet-activating factor, prostaglandins, leukotrienes, and cytokines are synthesized and released.

How does histamine contribute to the clinical signs and symptoms of anaphylaxis?

Histamine, stored in granules within mast cells and basophils, is a primary inflammatory mediator that works on receptors to cause vasodilation, increased vascular permeability, contraction of most smooth muscles, cardiac stimulation, and gastric secretions, leading to various symptoms of anaphylaxis.

Which systems of the body are most notably affected by an anaphylactic reaction?

The respiratory, cardiovascular, and integumentary systems are most notably affected by an anaphylactic reaction.

Can an anaphylactic reaction occur on first exposure to certain substances?

Yes, an anaphylactic reaction can occur on first exposure to certain substances, such as anaesthetic medications, due to cross-reactivity among many drugs and commercial household products.

What are some common triggering agents for an anaphylactic reaction during anesthesia?

Neuromuscular blocking agents are the most common triggering agents, accounting for more than fifty percent of incidents. Other causative agents include latex, antibiotics, colloids, hypnotics, contrast media, protamine, and opioids.

What are the signs and symptoms of an anaphylactic reaction?

Signs and symptoms include angioedema, laryngeal edema, hypotension, tachycardia, dysrhythmias, wheezing, bronchospasm, and a shock-like state secondary to severe hypotension.

What is the role of tryptase in an anaphylactic reaction?

Tryptase is an enzyme released from mast cells along with histamine and serves as a positive indicator for an immunologically mediated event when levels are greater than 25 micrograms per liter.

What is the immediate treatment for an anaphylactic reaction?

Immediate treatment includes calling for help, removing potential causative agents, increasing FIO2 to 100%, administering epinephrine, establishing a secure airway, ensuring adequate IV access, and providing a fluid bolus. An epinephrine infusion may be considered if there is no response to initial interventions.

Why is epinephrine a crucial part of anaphylaxis treatment?

Epinephrine is crucial due to its positive hemodynamic effects and its ability to stabilize mast cells and reduce the amount of inflammatory mediator release.

What are some other treatment options for anaphylaxis besides epinephrine?

Other treatment options include vasopressors, beta-2 agonists, histamine blockers, and steroids to counteract the effects of histamine and assist in reversing hypotension refractory to epinephrine and intravascular fluid replacement.

Outlines

00:00

🚨 Anaphylaxis: Causes and Symptoms

Anaphylaxis is a severe allergic reaction triggered by antigen exposure to sensitized mast cells and basophils. These cells release inflammatory mediators like histamine, tryptase, and leukotrienes upon antigen binding to IgE antibodies. This leads to various symptoms, notably affecting the respiratory, cardiovascular, and integumentary systems. Symptoms can range from angioedema to hypotension and bronchospasm, and it can be life-threatening. The reaction can occur with the first exposure to certain drugs, including anesthetics, and diagnosis can be complicated by variable onset times and masked symptoms under general anesthesia. Common triggers during anesthesia are neuromuscular blocking agents, latex, antibiotics, and others, accounting for over 50% of incidents.

05:01

💡 Anaphylaxis Treatment and Management

Immediate treatment for anaphylaxis is crucial and involves calling for help, removing the causative agent, administering 100% oxygen, and giving epinephrine. Establishing a secure airway and ensuring IV access are also critical. If there's no response, an epinephrine infusion may be necessary. Additional treatments may include vasopressors, beta-2 agonists, histamine blockers, and steroids. Tryptase levels can indicate an immunologically mediated event and are useful for diagnosis, but normal levels do not rule out anaphylaxis. Glucocorticoids may help prevent recurring or prolonged reactions, and H1 and H2 receptor antagonists can counteract histamine effects, aiding in the management of symptoms like urticaria and angioedema.

Keywords

💡Anaphylaxis

Anaphylaxis is a severe, life-threatening allergic reaction that occurs rapidly after exposure to an allergen. It is characterized by the degranulation of sensitized mast cells and basophils, which release a variety of inflammatory mediators. The video script discusses anaphylaxis in the context of its occurrence during anesthesia and the importance of prompt recognition and treatment. The term is central to the video's theme, illustrating the potential dangers of allergic reactions and their management.

💡Mast Cells

Mast cells are immune cells that play a key role in anaphylaxis. They are found in various tissues, including the skin and intestine, and contain granules filled with inflammatory mediators. Upon exposure to an antigen, mast cells degranulate, releasing these mediators. In the script, mast cells are mentioned as the primary cells involved in the initial response to an antigen, leading to anaphylactic symptoms.

💡Basophils

Basophils are a type of white blood cell found in the blood. Similar to mast cells, they are involved in anaphylactic reactions by releasing histamine and other mediators upon exposure to an antigen. The script notes that basophils, along with mast cells, are responsible for the release of physiologically active mediators that cause the symptoms of anaphylaxis.

💡Immunoglobulin E (IgE)

Immunoglobulin E, or IgE, is an antibody that the body produces in response to allergens. It binds to the surface of effector cells like mast cells and basophils. The script explains that upon initial exposure to an antigen, IgE is produced, which upon subsequent exposure, leads to the release of mediators causing anaphylaxis. IgE is a crucial component in the pathophysiology of anaphylactic reactions.

💡Histamine

Histamine is a primary inflammatory mediator stored in granules within mast cells and basophils. It plays a significant role in the clinical signs and symptoms of anaphylaxis by causing vasodilation, increased vascular permeability, and smooth muscle contraction. The script describes histamine as a key player in the manifestation of anaphylactic symptoms, such as respiratory distress and cardiovascular issues.

💡Tryptase

Tryptase is an enzyme released from mast cells along with histamine during an anaphylactic reaction. It has a longer half-life and can be a positive indicator of an immunologically mediated event when present at levels greater than 25 micrograms per liter. The script mentions tryptase as a diagnostic tool for anaphylaxis, despite the fact that normal levels do not rule out the condition.

💡Neuromuscular Blocking Agents

Neuromuscular blocking agents are medications used during anesthesia to induce muscle paralysis. The script identifies these agents as the most common triggering agents for an anaphylactic reaction during anesthesia, accounting for more than fifty percent of the incidents. This highlights the particular risk associated with these drugs in the context of anesthetic procedures.

💡Epinephrine

Epinephrine, also known as adrenaline, is a hormone and medication that is critical in the treatment of anaphylaxis. It has positive hemodynamic effects and helps stabilize mast cells, reducing the release of inflammatory mediators. The script emphasizes the importance of administering epinephrine promptly in the case of an anaphylactic reaction, as it can be life-saving.

💡Vasopressors

Vasopressors are medications that constrict blood vessels and increase blood pressure. In the context of anaphylaxis, they may be used if there is no response to initial treatments like epinephrine. The script suggests considering vasopressors as part of the treatment options for severe anaphylactic shock.

💡Beta-2 Agonists

Beta-2 agonists are a class of medications that relax the smooth muscles of the lungs, increasing airflow. They may be used in the treatment of anaphylaxis to counteract symptoms like wheezing and bronchospasm. The script mentions beta-2 agonists as a treatment option to consider, particularly for respiratory symptoms of an anaphylactic reaction.

💡Glucocorticoids

Glucocorticoids, or steroids, are a class of medications with potent anti-inflammatory effects. They may be used in the treatment of anaphylaxis to reduce the risk of recurring or prolonged symptoms. The script notes that glucocorticoids can be administered to help manage the inflammatory response during an anaphylactic reaction.

Highlights

Anaphylaxis is a severe hypersensitivity reaction caused by degranulation of sensitized mast cells and basophils after exposure to an antigen.

Mast cells are located in the perivascular spaces of the skin, long intestine, while basophils are in the blood.

Immunoglobulin E (IgE) is produced upon initial exposure to an antigen and binds to the surface of effector cells.

Subsequent exposure to the antigen leads to the release of physiologically active mediators, including histamine.

Histamine is a primary inflammatory mediator stored in granules within mast cells and basophils.

Histamine causes vasodilation, increased vascular permeability, and smooth muscle contraction, leading to anaphylactic symptoms.

Anaphylactic reactions can occur in the respiratory, cardiovascular, and integumentary systems.

An anaphylactic reaction can occur on first exposure to certain medications due to cross-reactivity.

The onset and degree of clinical manifestations can vary greatly, complicating diagnosis.

Neuromuscular blocking agents are the most common triggering agents for an anaphylactic reaction during anesthesia.

Signs and symptoms of an anaphylactic reaction include angioedema, laryngeal edema, hypotension, and tachycardia.

A shock-like state can develop due to severe hypotension caused by vasodilation and fluid extravasation.

Tryptase is an enzyme released from mast cells and can be a positive indicator for an immunologically mediated event.

Anaphylactic reactions are life-threatening and require prompt identification and immediate treatment.

Treatment for anaphylaxis includes calling for help, removing causative agents, and administering epinephrine.

Epinephrine has positive hemodynamic effects and stabilizes mast cells, reducing inflammatory mediator release.

H1 and H2 receptor antagonists are used to counteract the effects of histamine and may assist in reversing hypotension.

Glucocorticoids may reduce the risk of recurring or prolonged anaphylaxis.

Transcripts

anaphylaxis is a severe hypersensitivity

reaction caused by the degranulation of

sensitized mast cells and basophils

after exposure to an antigen mast cells

are located in the perivascular spaces

of the skin long and intestine while

basophils are located in the blood upon

initial exposure to an antigen

immunoglobulin E is produced and binds

to the surface of the effector cell with

subsequent exposure the antigen binds to

the IgE antibodies releasing

physiologically active mediators that

include histamine tryptase chemotactic

factors and platelet-activating factor

furthermore metabolites such as

prostaglandins kinase leukotrienes and

cytokines are synthesized and released

histamine is a primary inflammatory

mediator which is stored in granules

within the mast cells and basophils

histamine has an important role in the

clinical signs and symptoms manifested

in anaphylaxis and works on receptors to

cause vasodilation increased vascular

permeability contraction of most smooth

muscle other than blood vessels cardiac

stimulation and stimulation of gastric

secretions this results in a series of

potentially life-threatening symptoms

occurring most notably in the

respiratory cardiovascular and

integumentary systems it is possible for

an anaphylactic reaction to occur on

first exposure to anaesthetic

medications due to cross reactivity

among many drugs and commercial

household products the time of onset and

the degree of clinical manifestations

can vary greatly making diagnosis

complicated in addition many symptoms

may be masked by general anesthesia and

the use of surgical drapes which conceal

the cutaneous signs the most common

triggering agents for an anaphylactic

reaction during anesthesia are

neuromuscular blocking agents they

account for more than fifty percent of

the total incidents other causative

agents include latex antibiotics

colloids hypnotics contrast media

protamine and opioids there are also

several other medications medication

classes and substances that have the

potential to trigger anaphylaxis the

signs and symptoms of an anaphylactic

reaction are the consequence of the

antigen-antibody reaction and the body's

massive immune response that includes

the release of histamine as a result /

itís or tocaria angioedema especially

laryngeal edema hypotension tachycardia

dysrhythmias wheezing and bronchospasm

may occur a shock like state can develop

that is secondary to severe hypotension

caused by vasodilation and the

extravasated of protein and fluids out

of the vascular compartment the clinical

appearance of anaphylaxis may present in

various combinations and usually occurs

within minutes of exposure to the

offending antigen however in some cases

the onset of signs and symptoms may be

delayed for an hour or longer trip taste

is an enzyme released from mast cells

along with histamine and has a half-life

of several hours it has been shown to be

a positive indicator for an

immunologically mediated event at levels

greater than 25 micrograms per liter

however the presence of normal trip

taste levels should not rule out an

anaphylactic reaction since normal

levels have been found in up to

one-third of anaphylactic cases

anaphylactic reactions are

life-threatening and require prompt

identification and immediate treatment

treatment includes calling for help

removing potential causative agents

increasing fio2 to 100% administering

epinephrine establishing a secure airway

and ensuring adequate IV access

providing a fluid bolus if there's no

response to these interventions an

epinephrine infusion should be

considered other treatment options to

consider include vasopressors

beta-2 agonists histamine blockers and

steroids airway patency must be

accomplished by means of intubation and

maintained since a demon the airway is a

common complication of anaphylaxis

epinephrine should not be delayed due to

its positive hemodynamic effects as well

as its ability to stabilize mast cells

and reduce the amount of inflammatory

mediator release epinephrine can be

administered intravenously or

subcutaneously and the dose should be

titrated according to the severity of

symptoms and histamines may be useful

particularly for symptoms of ERDA keria

and angioedema h1 and h2 receptor

antagonists are frequently administered

to counteract the effects of histamine

and may assist in reversing hypotension

refractory to epinephrine and

intravascular fluid replacement

glucocorticoids may reduce the risk of

recurring or prolonged anaphylaxis