What is the recommended treatment for anaphylaxis?

Anaphylaxis Treatment Protocol

Epinephrine is the first-line and most critical treatment for anaphylaxis and should be administered immediately upon recognition of symptoms. 1, 2

First-Line Treatment

• Epinephrine dosing:

  • Adults and children ≥30 kg: 0.3-0.5 mg (0.3-0.5 mL of 1:1000 concentration)
  • Children <30 kg: 0.01 mg/kg up to maximum 0.3 mg (0.01 mL/kg of 1:1000 concentration)
  • Route: Intramuscular injection into the anterolateral thigh 1

• Epinephrine should be given immediately without delay, as delayed administration is associated with increased mortality 3

Adjunctive Therapies

After administering epinephrine, the following adjunctive treatments should be considered:

1. H1 antihistamines (e.g., diphenhydramine 25-50 mg) for cutaneous symptoms 1
2. H2 blockers (e.g., famotidine 20 mg IV) for urticaria 1
3. Albuterol 2.5-5 mg via nebulizer for persistent bronchospasm 1
4. Systemic glucocorticosteroids (e.g., methylprednisolone 1-2 mg/kg IV every 6 hours or prednisone 0.5 mg/kg orally) to prevent protracted or biphasic reactions 1

Supportive Care

• Positioning: Place patients with hypotension in supine position with legs elevated or Trendelenburg position for severe hypotension 1
• Fluid resuscitation: Administer 1-2 liters of normal saline at 5-10 mL/kg in the first 5 minutes for hypotensive patients 1
• Oxygen: Provide supplemental oxygen for patients with respiratory symptoms or those receiving multiple doses of epinephrine 1
• Monitoring: Continuous monitoring of vital signs including blood pressure, heart rate, and oxygen saturation 1

Monitoring and Observation

• Observe patients for at least 4-6 hours after initial symptoms resolve 1
• High-risk patients (severe initial reaction, required >1 dose of epinephrine, wide pulse pressure, unknown trigger) should have extended observation up to 6 hours or longer, including possible hospital admission 1
• Low-risk patients may be discharged after 1-hour asymptomatic observation 1
• Be prepared to administer a second dose of epinephrine if symptoms persist or recur (6-19% of pediatric patients require a second dose) 1

Patient Education and Follow-up

• Educate patients on recognizing anaphylaxis symptoms and proper use of epinephrine auto-injectors 1
• Prescribe epinephrine auto-injectors to patients with history of anaphylaxis 1, 4
• Refer patients to an allergist/immunologist for identification of triggers and long-term management 1
• Emphasize the importance of activating emergency services (calling 911) during anaphylactic episodes 1

Common Pitfalls to Avoid

1. Delayed epinephrine administration - This is the most critical error and can be fatal 5
2. Relying solely on antihistamines - These are adjunctive treatments only and do not replace epinephrine 3
3. Inadequate observation period - Biphasic reactions can occur hours after initial symptoms resolve 1
4. Improper route of administration - Intramuscular route in the anterolateral thigh is preferred over subcutaneous for faster absorption 1, 4
5. Insufficient patient education - Patients must understand when and how to use epinephrine auto-injectors 1

Remember that anaphylaxis is a clinical diagnosis based on symptoms and does not require laboratory confirmation before initiating treatment 6. Early recognition and prompt epinephrine administration are the cornerstones of effective management.