What is the management protocol for anaphylaxis?

Management Flow Chart for Anaphylaxis

Prompt administration of intramuscular epinephrine into the mid-outer thigh is the cornerstone of anaphylaxis management and should be given immediately upon recognition of anaphylaxis to reduce hospitalizations, morbidity, and mortality. 1

Initial Recognition and Assessment

• Recognize anaphylaxis using validated clinical criteria:
  • Acute onset of illness with involvement of skin/mucosal tissue PLUS respiratory compromise OR reduced blood pressure
  • Two or more of: skin/mucosal involvement, respiratory compromise, reduced blood pressure, persistent GI symptoms
  • Reduced blood pressure after exposure to known allergen

Immediate Management

1. Administer epinephrine immediately

   • Dose: 0.01 mg/kg of 1:1000 (1 mg/mL) solution, maximum 0.3 mg in children and 0.5 mg in adults 1, 2
   • Route: Intramuscular injection into the anterolateral thigh (vastus lateralis) 3
   • Frequency: Can repeat every 5-15 minutes if symptoms persist 2
   • Warning: Do NOT inject into buttocks, digits, hands, or feet due to risk of tissue necrosis 3

2. Position patient appropriately

   • Place in recumbent position with elevated lower extremities 1
   • If breathing difficulty, allow to sit upright

3. Establish and maintain airway

   • Consider endotracheal intubation or cricothyrotomy if necessary 1

4. Administer oxygen

   • Give at 6-8 L/min 1

5. Establish IV access

   • Insert large-bore IV catheter

Secondary Interventions

1. Fluid resuscitation

   • Normal saline: 1-2 L for adults, 20 mL/kg bolus for children 1, 2
   • Repeat as needed based on response

2. Adjunctive medications (after epinephrine)

   • H1 antihistamines: Diphenhydramine 1-2 mg/kg (max 50 mg) IV/IM 2
   • H2 antihistamines: Ranitidine 1 mg/kg IV (if available) 2
   • Corticosteroids: Prednisone 0.5-1 mg/kg orally or hydrocortisone 200 mg IV 1, 2
   • For bronchospasm: Nebulized albuterol 2.5-5 mg in 3 mL saline 2

3. For refractory hypotension

   • Vasopressors: Dopamine 2-20 μg/kg/min, titrated to maintain systolic BP >90 mmHg 1
   • For patients on beta-blockers: Consider glucagon 1-5 mg IV over 5 minutes, followed by infusion of 5-15 μg/min 1

Management of Cardiopulmonary Arrest

1. Begin CPR and ACLS protocols
2. High-dose IV epinephrine
   • Adults: 1-3 mg (1:10,000) slowly IV over 3 minutes, then 4-10 μg/min infusion 1
   • Children: 0.01 mg/kg (0.1 mL/kg of 1:10,000 solution) every 3-5 minutes 1
3. Aggressive volume expansion
4. Consider atropine and transcutaneous pacing for asystole/PEA
5. Continue prolonged resuscitation (more likely to be successful in anaphylaxis) 1

Observation and Discharge Planning

1. Monitor for biphasic reactions

   • Observe for at least 4-6 hours after symptom resolution 2
   • Longer observation for severe reactions or those requiring multiple epinephrine doses

2. Discharge planning

   • Prescribe epinephrine autoinjector (2 devices) 1, 2
   • Provide training on proper use
   • Create personalized anaphylaxis emergency action plan 2
   • Arrange follow-up with allergist-immunologist 1

Common Pitfalls to Avoid

• Delayed epinephrine administration - Don't wait for complete symptom development
• Incorrect injection site - The anterolateral thigh is the only appropriate site 3
• Using antihistamines or steroids as first-line treatment - These are adjunctive only and do not replace epinephrine 2, 4
• Insufficient monitoring - Biphasic reactions can occur hours after initial resolution
• Failure to prescribe autoinjector - All patients with anaphylaxis should receive prescription and training
• Insufficient dosing for obese patients - Standard autoinjectors may not reach muscle in very obese patients 4

Special Considerations

• Pregnant patients: Administer epinephrine as in non-pregnant patients; benefits outweigh risks 2
• Elderly or cardiac patients: Use epinephrine with caution but do not withhold; benefits outweigh risks 3
• Beta-blocker use: May require glucagon for refractory hypotension 1
• Infants <15 kg: Current lowest autoinjector dose (0.15 mg) may be high; careful dosing required 1

Remember that prompt recognition and immediate epinephrine administration are the most critical factors in preventing anaphylaxis-related mortality.