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Chapter 20 Allergies
Case History You have arrived at the scene of an adult male having difficulty breathing. You find a 50-year-old male complaining of shortness of breath and tightness in his throat. He tells you that this began about 10 minutes ago after he was stung by a bee while mowing the lawn. You notice that he begins to wheeze as he tells you that his chest and hands feel itchy.
Allergic Reactions and Anaphylaxis • Allergic reaction • Antibody-antigen reaction • Results in release of substances (e.g., histamine) • Affects the respiratory, circulatory, GI systems, and skin • Anaphylaxis • Antibody-antigen reaction gone haywire • Detrimental rather than protective
Allergic Reaction • Possible causes • Insect bites/stings (bees, wasps, etc.) • Food (nuts, crustaceans, peanuts, etc.) • Plants • Medications • Others
Assessment Findings • Skin • Warm, tingling feeling • Face, mouth, chest, feet, and hands • Itching • Hives
Respiratory System • Tightness in throat/chest • Cough • Rapid breathing • Labored breathing • Retractions • Use of accessory muscles
Respiratory System • Swelling of the airway • Noisy breathing • Inability to speak or cough • Hoarseness • Stridor • Wheezing (audible without stethoscope)
Respiratory System • Respiratory failure • Respiratory arrest
Cardiovascular System • Increased heart rate • Decreased blood pressure • Decreased perfusion (shock) due to vasodilation
Generalized Findings • Itchy, watery eyes • Headache • Sense of impending doom • Runny nose
Other Signs and Symptoms • Decreasing mental status • Signs of shock (hypoperfusion) • Respiratory distress
Emergency Medical Care –Allergic Reaction • Initial assessment • Focused history and physical examination • Vital signs • Treatment
Emergency Medical Care -Focused History/Physical Examination • History of allergies? • What was patient exposed to? • How was he or she exposed? • What effects? • Progression? • Interventions?
Emergency Medical Care • Vital signs • SAMPLE history • Oxygen administration
Emergency Medical Care • Patient has prescribed epinephrine? • Facilitate administration of preloaded epinephrine. • Reassess every 2 minutes. • Record reassessment findings. • No auto-injector • Transport
Patient Without Respiratory Distress or Shock • Continue with focused assessment. • Patient should not receive epinephrine.
Relationship to Airway Management • Airway/respiratory compromise may develop over time. • Ensure a patent airway. • Provide ventilation.
Indications • Patient exhibits the assessment findings of an allergic reaction. • Medication is prescribed for this patient by a physician. • Medical direction authorizes use for this patient.
Form of Medication and Contraindications • Medication form • Liquid • Automatic needle and syringe system • No contraindications, when used in a life-threatening situation
Dosage • Adult: one adult auto-injector (0.3 mg) • Infant and child: one infant/child auto-injector (0.15 mg)
Actions • Dilates bronchioles • Constricts blood vessels • Blocks histamine effects
Increased heart rate Pallor Dizziness Chest pain Headache Nausea Vomiting Excitability, anxiety Side Effects
Reassessment Strategies • Transport. • Continue focused assessment. • Airway • Breathing • Circulatory status
Reassessment Strategies – Patient Condition Worsens • Signs/symptoms • Decreasing mental status • Increasing breathing difficulty • Decreasing blood pressure • Actions • Obtain medical direction. • Give additional dose of epinephrine. • Treat for shock (hypoperfusion). • Administer CPR and AED, as needed.
Reassessment Strategies –Patient Condition Improves • Provide supportive care. • Oxygen • Treatment for shock (hypoperfusion)
Summary • Management of severe allergic reactions requires • Rapid identification of signs and symptoms • Administration of epinephrine • Management of airway and ventilation • Key signs and symptoms • Hives, itching, coughing, sneezing, etc. • Signs of respiratory distress, airway obstruction, or shock