Anatomy and Physiology Review
- Early intervention is important. In the presence of anaphylaxis or signs indicating that anaphylaxis will develop, administer epinephrine.
- A patient may have a reaction even if he or she hasn’t been exposed to an allergen previously (anaphylactoid reaction).
- Differentiation between allergic reaction and anaphylaxis is crucial and is based on multisystem, life-threatening conditions or the potential for those conditions.
- Gastrointestinal signs are often ignored as a significant systemic reaction of anaphylaxis.
- Bring additional epi autoinjectors with you to the hospital in case the reaction outlasts the first dose of epi.
Allergen/antibody reaction causes the release of chemical mediators (e.g., histamine) that cause:
- vasodilation: hypotension and shock
- bronchoconstriction: narrowing of smaller to medium airways, resulting in wheezing and reduced tidal volume
- increased capillary permeability: hives, and/or swelling, especially in the face, throat and mouth
- increased gastric motility: abdominal pain, diarrhea, vomiting
Signs and Symptoms
- Respiratory distress and wheezing
- Hives and swelling of tissues
- Rapid pulse and respirations
- Gastrointestinal symptoms (diarrhea, vomiting, abdominal pain)
- Allergy symptoms (runny nose, watery eyes)
- Administer epinephrine (autoinjector or kit)
- Adult: 0.3 mg epinephrine
- Child: 0.15 mg epinephrine
- Administer oxygen
- Treat for shock (position, keep warm)
- Ventilate and resuscitate as necessary
- Transport promptly