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 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 Itching Hives 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

Side Effects Increased heart rate Pallor Dizziness Chest pain Headache Nausea Vomiting Excitability, anxiety

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