bledsoe et al., paramedic care: principles & practice, volume 3: medical emergencies, 3rd ed. ©...
TRANSCRIPT
Bledsoe et al., Paramedic Care: Principles & Practice, Volume 3: Medical Emergencies, 3rd Ed.© 2009 by Pearson Education, Inc. Upper Saddle River, NJ
Paramedic Care:Principles & Practice
Volume 3Medical Emergencies
Bledsoe et al., Paramedic Care: Principles & Practice, Volume 3: Medical Emergencies, 3rd Ed.© 2009 by Pearson Education, Inc. Upper Saddle River, NJ
Chapter 5 Allergies and Anaphylaxis
Bledsoe et al., Paramedic Care: Principles & Practice, Volume 3: Medical Emergencies, 3rd Ed.© 2009 by Pearson Education, Inc. Upper Saddle River, NJ
Topics
Pathophysiology
Assessment Findings in Anaphylaxis
Management of Anaphylaxis
Management of Allergic Reactions
Patient Education
Bledsoe et al., Paramedic Care: Principles & Practice, Volume 3: Medical Emergencies, 3rd Ed.© 2009 by Pearson Education, Inc. Upper Saddle River, NJ
Introduction
Allergic Reaction– An exaggerated
response by the immune system to a foreign substance
Bledsoe et al., Paramedic Care: Principles & Practice, Volume 3: Medical Emergencies, 3rd Ed.© 2009 by Pearson Education, Inc. Upper Saddle River, NJ
Introduction
Anaphylaxis– An unusual or exaggerated allergic reaction– A life-threatening emergency
Injected penicillin and bee and wasp (Hymenoptera) stings are the two most common causes of fatal anaphylaxis
Bledsoe et al., Paramedic Care: Principles & Practice, Volume 3: Medical Emergencies, 3rd Ed.© 2009 by Pearson Education, Inc. Upper Saddle River, NJ
Pathophysiology
Bledsoe et al., Paramedic Care: Principles & Practice, Volume 3: Medical Emergencies, 3rd Ed.© 2009 by Pearson Education, Inc. Upper Saddle River, NJ
Pathophysiology
The Immune System– The goal of the immune response is destruction
or inactivation of:PathogensAbnormal cellsForeign molecules
– Cellular Immunity– Humoral Immunity
Antibodies (Immunoglobulins)IgA, IgD, IgE, IgG, IgM
Bledsoe et al., Paramedic Care: Principles & Practice, Volume 3: Medical Emergencies, 3rd Ed.© 2009 by Pearson Education, Inc. Upper Saddle River, NJ
Pathophysiology
Immune Response– Exposure to antigen produces primary
response. with general antibodiesImmune system develops antigen-specific antibodies and memory
– Future exposures generate a faster secondary response
Natural and Acquired Immunity
Induced Active Immunity
Active and Passive Immunity
Bledsoe et al., Paramedic Care: Principles & Practice, Volume 3: Medical Emergencies, 3rd Ed.© 2009 by Pearson Education, Inc. Upper Saddle River, NJ
Allergies
Sensitization– Initial exposure of an individual to an antigen
Hypersensitivity– Delayed
Results from cellular immunity and does not involve antibodies
Commonly results in skin rash
Results from exposure to certain drugs or chemicals
– ImmediateExposure quickly results in secondary response
More severe than delayed hypersensitivity
Bledsoe et al., Paramedic Care: Principles & Practice, Volume 3: Medical Emergencies, 3rd Ed.© 2009 by Pearson Education, Inc. Upper Saddle River, NJ
Allergies
Allergen– Exposure generates secondary response
Large quantities of IgE are released
Allergen binds to IgE, causing chemical releaseRelease is “allergic reaction”
Includes histamines, heparin, and other substances that are designed to minimize the body’s exposure to an antigen
Histamine causes bronchoconstriction, vasodilation, increased gastric motility, and increased vascular permeability
Angioneurotic edema
Bledsoe et al., Paramedic Care: Principles & Practice, Volume 3: Medical Emergencies, 3rd Ed.© 2009 by Pearson Education, Inc. Upper Saddle River, NJ
Allergic Response
Bledsoe et al., Paramedic Care: Principles & Practice, Volume 3: Medical Emergencies, 3rd Ed.© 2009 by Pearson Education, Inc. Upper Saddle River, NJ
Anaphylaxis
Causes– Antigen that causes release of the IgE
antibodies is referred to as an allergen
Bledsoe et al., Paramedic Care: Principles & Practice, Volume 3: Medical Emergencies, 3rd Ed.© 2009 by Pearson Education, Inc. Upper Saddle River, NJ
Anaphylaxis
Causes– Injections
Most anaphylaxis results from injected allergenAllergen rapidly distributed throughout the body, resulting in massive histamine release
Parenteral penicillin injections and insect stingsAffects cardiovascular, respiratory, gastrointestinal, and integumentary systemsSignificant plasma loss through increased vascular permeabilitySlow-reacting substance of anaphylaxis
Bledsoe et al., Paramedic Care: Principles & Practice, Volume 3: Medical Emergencies, 3rd Ed.© 2009 by Pearson Education, Inc. Upper Saddle River, NJ
Assessment Findings in Anaphylaxis
Bledsoe et al., Paramedic Care: Principles & Practice, Volume 3: Medical Emergencies, 3rd Ed.© 2009 by Pearson Education, Inc. Upper Saddle River, NJ
Assessment Findings in Anaphylaxis
Focused History and Physical Exam– Focused History
SAMPLE and OPQRST HistoryRapid onset, usually 30–60 seconds following exposureSpeed of reaction is indicative of severityPrevious allergies and reactions
– Physical ExamPresence of severe respiratory difficulty is key to differentiating anaphylaxis from allergic reaction
Bledsoe et al., Paramedic Care: Principles & Practice, Volume 3: Medical Emergencies, 3rd Ed.© 2009 by Pearson Education, Inc. Upper Saddle River, NJ
Physical Exam– Facial or laryngeal
edema– Abnormal breath
sounds– Hives and urticaria– Hyperactive bowel
sounds– Vital sign deterioration
as the reaction progresses
Assessment Findings in Anaphylaxis
Bledsoe et al., Paramedic Care: Principles & Practice, Volume 3: Medical Emergencies, 3rd Ed.© 2009 by Pearson Education, Inc. Upper Saddle River, NJ
Pathophysiology of Anaphylaxis
Bledsoe et al., Paramedic Care: Principles & Practice, Volume 3: Medical Emergencies, 3rd Ed.© 2009 by Pearson Education, Inc. Upper Saddle River, NJ
Management of Anaphylaxis
Bledsoe et al., Paramedic Care: Principles & Practice, Volume 3: Medical Emergencies, 3rd Ed.© 2009 by Pearson Education, Inc. Upper Saddle River, NJ
Management of Anaphylaxis
Scene Safety:– Consider the possibility of trauma
Protect the airway– Use airway adjuncts with care– Intubate early in severe cases to prevent total
occlusion of the airway– Be prepared to place a surgical airway
Bledsoe et al., Paramedic Care: Principles & Practice, Volume 3: Medical Emergencies, 3rd Ed.© 2009 by Pearson Education, Inc. Upper Saddle River, NJ
Management of Anaphylaxis
Support breathing– High-flow, high-concentration oxygen or assisted
ventilation if indicated
Establish IV access– Patient may be volume-depleted due to “third
spacing” of fluidAdminister crystalloid solution at appropriate rate
Place a second IV line if indicated
Bledsoe et al., Paramedic Care: Principles & Practice, Volume 3: Medical Emergencies, 3rd Ed.© 2009 by Pearson Education, Inc. Upper Saddle River, NJ
Management of Anaphylaxis
Administer medications:– Oxygen– Epinephrine– Antihistamines– Corticosteroids– Vasopressors– Beta-agonists– Other agents
Psychological support
Bledsoe et al., Paramedic Care: Principles & Practice, Volume 3: Medical Emergencies, 3rd Ed.© 2009 by Pearson Education, Inc. Upper Saddle River, NJ
Management of Allergic Reactions
Bledsoe et al., Paramedic Care: Principles & Practice, Volume 3: Medical Emergencies, 3rd Ed.© 2009 by Pearson Education, Inc. Upper Saddle River, NJ
Scene safetyProtect the airwaySupport breathingEstablish IV accessAdminister medications:– Antihistamines– Epinephrine
Management of Allergic Reactions
© Craig Jackson/In the Dark Photography
Bledsoe et al., Paramedic Care: Principles & Practice, Volume 3: Medical Emergencies, 3rd Ed.© 2009 by Pearson Education, Inc. Upper Saddle River, NJ
Management ofAnaphylaxis and Allergic Reactions
Click here to view the management of Anaphylaxis and Allergic Reactions.
Bledsoe et al., Paramedic Care: Principles & Practice, Volume 3: Medical Emergencies, 3rd Ed.© 2009 by Pearson Education, Inc. Upper Saddle River, NJ
Patient Education
Bledsoe et al., Paramedic Care: Principles & Practice, Volume 3: Medical Emergencies, 3rd Ed.© 2009 by Pearson Education, Inc. Upper Saddle River, NJ
Patient Education
Prevention of Reactions
Recognition of Signs/Symptoms– Patient-initiated treatment
Epinephrine auto-injectors
Desensitization