Week 9 Anaphylaxis Past Paper PDF

EHS 202 Pharmacology for EMS Week 9 - Anaphylaxis 10/13/2022 1 ANAPHYLAXIS Learning Objectives By the end of this lesson you will be able to: List the symptoms of anaphylactic shock; Discuss th...

EHS 202 Pharmacology for EMS Week 9 - Anaphylaxis 10/13/2022 1 ANAPHYLAXIS Learning Objectives By the end of this lesson you will be able to: List the symptoms of anaphylactic shock; Discuss the role of the immune system in fighting antigens; Define an allergic reaction; Describe the body’s response to a foreign substance; Identify the most common cause of death from anaphylaxis; Discuss medications used to treat anaphylaxis Demonstrate the proper procedure for using an epinephrine autoinjector. 10/13/2022 ANAPHYLAXIS 2 Introduction Anaphylaxis: exaggerated hypersensitivity reaction to a previously encountered antigen Potentially life-threatening series of events that affects multiple body systems Anaphylactic shock: a serious and rapid allergic reaction that can result in death Symptoms: shortness of breath, syncope, itching, swelling of throat, sudden drop in blood pressure 10/13/2022 ANAPHYLAXIS 3 Immune System A system designed to mitigate the effects of harmful substances that enter the body and compromise essential body functions. Identifies and targets antigens (foreign molecules that are capable of generating a specific response). 10/13/2022 ANAPHYLAXIS 4 Immune Response Its role against antigens Once affected by antigens, immune system forms proteins, called antibodies or immunoglobulins, that are intended to bind with that specific antigen. Antibodies have a variety of mechanisms to either destroy the antigen or facilitate its removal from the body. In patients with an autoimmune disorder, the immune system uses this same process to attack specific and otherwise healthy body cells and tissues, causing a vast array of harmful effects. 10/13/2022 ANAPHYLAXIS 5 https://patients.eaaci.org/what-is-allergy/ Allergic Response Hypersensitivity to a particular antigen out of proportion to its hazard to the body The allergic response, not the antigen, is the real threat. Common causes of allergic reaction include food, medicines, insect stings and airborne allergens such as animal fur and dust mites. Allergens— substance or antigen that produce an exaggerated allergic reaction 10/13/2022 6 https://patients.eaaci.org/what-is-allergy/  Anaphylactic Shock Most often stimulated by drugs such as penicillin or insect bites and stings Involves skin rashes, hives (urticaria), itching, redness, and edema Shortness of breath, syncope, itching, swelling of the throat, and a sudden drop in blood pressure The patient can feel warm and flushed, exhibit edema of the lips and eyelids, and have watery eyes. 10/13/2022 ANAPHYLAXIS 7  Anaphylaxis Pathophysiology In response to allergens, cells within the body release the chemical mediators. The chief chemical among these is histamine, whose release produces: Vasodilation - results in a drop in the systemic blood pressure and a decrease in peripheral tissue perfusion and oxygen delivery. Increased capillary permeability - results in oedema of the airway. Spasm of smooth muscle that produces diarrhoea, vomiting, and laryngospasm. The magnitude of this response determines whether the patient has an allergic reaction or anaphylaxis. Allergic responses can be minor or severe. 10/13/2022 8  Anaphylaxis Pathophysiology Most patients begin to show symptoms within minutes to an hour after exposure. The faster the onset of symptoms, the more serious the threat to life. As the condition progresses, laryngoedema, swelling of the vocal cords, can cause varying degrees of airway obstruction along with tightness in the chest, shortness of breath, and light- headedness. http://pennstatehershey.adam.com/cont ent.aspx?productid=112&pid=28&gid=00 0005 The patient’s history often confirms the diagnosis of allergic response and 9 anaphylaxis. Anaphylaxis Management The most deaths caused by allergy are the result of airway obstruction. So a rapid and thorough assessment of the airway and breathing is of utmost importance. Patients with airway or ventilatory deficits should be assisted as their history is obtained. 10/13/2022 ANAPHYLAXIS 10 http://anaesthesiatoday.blogspot.com/2010/03/anaphylaxi s-extreme-hypersensitivity.html  Epinephrine First-line treatment Epinephrine given intramuscularly (IM) Epinephrine is a catecholamine that: o Increases the rate and force of heart contractions, increasing cardiac https://coreem.net/core/anaphylaxis/ output o Relaxes bronchial smooth muscle. Also causes peripheral vasoconstriction, which raises the arterial blood pressure. Should be administered as quickly as possible. 10/13/2022 ANAPHYLAXIS 11 Epinephrine The IM administration Maintaining circulatory integrity – If blood pressure drops - Infuse crystalloids, normal saline, or Ringer’s lactate solution to maintain sufficient volume in the vascular space to promote adequate perfusion. 10/13/2022 ANAPHYLAXIS 12 Oxygen Establish airway Administer high levels of supplementary oxygen. Administer using a non-rebreather mask at 15 litres / minute 10/13/2022 ANAPHYLAXIS 13 Second-Line Medications JRCALC 2019 Include antihistamines, corticosteroids, and bronchodilators. Salbutamol (Albuterol): Stimulate beta2 receptors – results in broncho-dilation Hydrocortisone: Has anti-inflammatory properties, prevent some of the later complications of laryngoedema and urticaria These medications are helpful, but they do not replace epinephrine. Epinephrine should not be delayed while these other medications are prepared or administered. 10/13/2022 ANAPHYLAXIS 14 Second-Line Medications Steroids—not helpful in the acute treatment of anaphylaxis, but they do prevent some of the later reactions of an allergic response – Hydrocortisone. Anti-histamines with anticholinergic properties to block histamines effects – Chlorphenamine. Also used in allergic reactions. For continuing respiratory distress, nebulizer treatments of bronchodilators such as salbutamol (Albuterol) frequently are used. 10/13/2022 ANAPHYLAXIS 15 Resuscitation Council U.K In May 2021 the Resuscitation Council U.K updated their guidelines on the management of anaphylaxis. The recognition of anaphylaxis remains the focus and correction of life-threatening problems relating to; airway, breathing and circulation. Early administration of adrenaline with repeat doses every 5 minutes IV fluids for refractory anaphylaxis and to treat hypotension or developing shock Antihistamines are considered as third-line treatment Corticosteroids are no longer advised FOLLOW YOUR LOCAL GUIDELINES 10/13/2022 ANAPHYLAXIS 16 Now it’s time to do some research What drugs and doses do we give (and in what order) for Allergic reaction & Anaphylaxis? Use JRCALC to prepare your list Return to class to discuss 10/13/2022 ANAPHYLAXIS 17 10/13/2022 18 ANAPHYLAXIS Summary Immune response Signs & symptoms of anaphylaxis Anaphylaxis management 10/13/2022 ANAPHYLAXIS 19 Medications to Review Epinephrine autoinjector Salbutamol Chlorphenamine Hydrocortisone 10/13/2022 ANAPHYLAXIS 20 References Andrew Pollak (2018). Nancy Caroline’s Emergency Care in the Streets, Eighth Edition. Jones & Bartlett Learning. Guy J (2020). Pharmacology for the Prehospital Professional, Second Edition. Jones & Bartlett Learning. Jones & Bartlett Learning (2020). Pharmacology for the Prehospital Professional, Second Edition Instructor's Toolkit. Jones & Bartlett Learning. 10/13/2022 ANAPHYLAXIS 21