Anaphylaxis

Definition

Anaphylaxis is a rapid-onset, IgE-mediated systemic allergic reaction that can progress to shock, respiratory failure, and death within minutes of exposure. It represents the most severe form of type I hypersensitivity.

Common Triggers

• Medications (penicillin, NSAIDs, contrast dye)
• Foods (peanuts, tree nuts, shellfish, eggs)
• Insect stings (bees, wasps, fire ants)
• Latex exposure
• Blood products

Signs and Symptoms

Urticaria, angioedema, wheezing, stridor, hypotension, tachycardia, nausea, vomiting, abdominal cramping, and altered mental status. A sense of impending doom is a classic early cue.

Nursing Interventions

Administer intramuscular epinephrine 0.3 to 0.5 mg (1:1000) into the mid-anterolateral thigh. Repeat every 5 to 15 minutes as needed. Maintain airway, administer supplemental oxygen, and establish large-bore IV access with rapid crystalloid infusion for hypotension, such as adjuncts include diphenhydramine, corticosteroids, and nebulized albuterol. Remove the trigger if possible (stop infusion, remove stinger).

NCLEX Relevance

A top 'stop and act' emergency topic. Epinephrine IM is always the first action. Antihistamines and steroids are secondary.