Presentation on theme: "TRANSITION SERIES Topics for the Advanced EMT CHAPTER Immunology: Anaphylactic and Anaphylactoid Reactions 19."— Presentation transcript:
TRANSITION SERIES Topics for the Advanced EMT CHAPTER Immunology: Anaphylactic and Anaphylactoid Reactions 19
Objectives Review the frequency with which immunologic emergencies occur. Understand the pathology of immunologic emergencies. Illustrate the relationship between pathology and symptomatology. Discuss treatment strategies.
Introduction Allergic reactions may present from mild to severe. Manifestations can be related to the body system failing due to the reaction. Although an allergic reaction is designed to be beneficial to the body, when the response is severe it can be fatal.
Epidemiology Anaphylaxis is not a reportable disease. An estimated 20,000 to 50,000 persons suffer an anaphylactic reaction each year.
Epidemiology (cont’d) Certain drugs, medical dye, and food are the most common triggers. –Food is the most common trigger in children through young adults. –Insect venom and idiopathic causes are most common in middle age.
Pathophysiology Anaphylactic reaction –Patient must be sensitized –Chemical mediators released with subsequent exposure –Effects of mediators causes organ and system failure –Characteristic presentation
Common Causes of Anaphylactic Reactions.
Pathophysiology (cont’d) Anaphylactoid reaction –Not the typical immunologic antigen- antibody reaction –Anaphylactoid trigger “directly” causes the breakdown of mast cells and basophils –Chemical mediators released –Characteristic presentation similar to anaphylactic reaction
Common Causes of Anaphylactoid Reactions
Pathophysiology (cont’d) Effects of chemical mediator release –Increased capillary permeability –Decreased vascular smooth muscle tone –Increased bronchial smooth muscle tone –Increased mucus secretions in the tracheobronchial tract
Life-threatening responses in anaphylactic reaction: bronchoconstriction, capillary permeability, vasodilation, and an increase in mucus production.
Pathophysiology (cont’d) General considerations –Fatal episodes related to airway occlusion, respiratory failure, severe hypoxia, and circulatory collapse
Common Signs and Symptoms of Anaphylactic Reactions
Assessment Findings Other notable assessment characteristics –Parenteral injections produce the severest reactions. –The faster the onset, the worse the reaction. –Signs and symptoms peak in minutes.
Assessment Findings (cont’d) Other notable assessment characteristics –Skin and respiratory reactions are the earliest to present. –Mild reactions could suddenly turn severe. –Most fatalities occur within 30 minutes. –The patient may have a biphasic or multiphasic reaction following treatment.
Differentiating Between a Mild and a Moderate to Severe Reaction.
Assessment Findings (cont’d) Epinephrine as drug of choice –Stimulation of alpha receptor sites –Stimulation of beta receptor sites –Ability to be given IM (by EMTs) or intravenously (by paramedics) –Preferred site: IM anterior thigh
Emergency Medical Care Keep airway patent. Suction secretions. Administer high-flow oxygen. –Ventilate the patient if needed. Administer epinephrine by auto-injector if indicated. Initiate rapid transport.
Emergency Medical Care (cont’d) If an extremity is involved consider application of a loose tourniquet. Some systems allow Advanced EMTs to administer diphenhydramine (Benadryl). Treat wheezing with beta-2 agonist. Treat hypotension with IV fluid bolus. Treat hypotension secondary to beta blockers with glucagon.
Case Study You are alerted for an emergency involving a possible allergic reaction. When you arrive at the residence address, you see an adult male on the porch being propped up in a sitting position by family members on each side. His head is limply flexed forward on his chest. As you approach, you see his head bobbing with each breath, and hives covering his body.
Case Study (cont’d) Scene Size-Up –Standard precautions taken. –Scene is safe, no entry or egress problems. –One patient, adult male, appears unresponsive, mid-30s.
Case Study (cont’d) Scene Size-Up –NOI is suspected allergic reaction/dyspnea. –Given the grave scene size-up, your partner radios for the ALS supervisor to also respond.
Case Study (cont’d) What are some concerns you have, based on the scene size-up? What are possible conditions you suspect at this time?
Case Study (cont’d) Primary Assessment Findings –Patient responds to noxious stimuli with nonpurposeful motion. –With each inhalation, you hear sonorous sounds and slight stridor. –Breathing depth is minimal due to airway blockage, peripheral pulses are absent.
Case Study (cont’d) Primary Assessment Findings (continued) –Skin is cool, pale, and diaphoretic; hives cover face, neck, chest, and arms. –No indication of significant trauma.
Case Study (cont’d) Is this patient a high or low priority? Why? What are the life threats to this patient? Based on the primary survey, what emergency care would be warranted at this time?
Case Study (cont’d) Medical History –Per family, he is allergic to bee stings, but never this bad. Medications –Patient has an auto-eject epi pen; no other medications. Allergies –None per the patient's family.
Case Study (cont’d) Pertinent Secondary Assessment Findings –Patient reportedly was outside when he walked onto the porch and said he was “stung” and then passed out. –Sonorous airway sounds now absent with positioning, faint inspiratory stridor still present. –Bilateral wheezing with auscultation, also poor alveolar sounds.
Case Study (cont’d) Pertinent Secondary Assessment Findings (continued) –Peripheral pulses absent, carotid rapid and weak. –Hives noted to body, skin cool and diaphoretic. –Poor muscle tone bilaterally.
Case Study (cont’d) Pertinent Secondary Assessment Findings (continued) –B/P 72/palp, heart rate 126, resps 34 and shallow. –No other findings contributory to presentation.
Case Study (cont’d) With this information, has your field impression changed at all? What would be the next steps in management you would provide to the patient? Should the Advanced EMT still use the epi pen?
Case Study (cont’d) Care provided: –Supine positioning, legs elevated. –PPV with high-flow oxygen, NPA inserted. –All tight or constrictive clothing and jewelry removed. –Epi auto-eject pen administered x1 (0.3 mg). –Intravenous access and administration of IV fluid.
Case Study (cont’d) In a patient with this field impression, discuss the benefits of the following interventions: –Providing high-flow oxygen –Positioning the patient supine –Loosening tight clothing –Administering epinephrine –Intravenous therapy
Summary An allergic reaction may range from mild to severe. Anaphylactic and anaphylactoid reactions can rapidly cause death to the patient. The Advanced EMT's goal is to recognize the acute allergic reaction and provide appropriate care based on findings.