What is the immediate management for a case of angioedema?

Immediate Management of Angioedema

For immediate management of angioedema, first determine if it's histamine-mediated (with urticaria) or bradykinin-mediated (without urticaria), then secure the airway if compromised, and administer appropriate medications based on the type. 1

Initial Assessment and Airway Management

• Airway assessment is the first priority

  • Do NOT directly visualize oropharyngeal or laryngeal angioedema as trauma can worsen swelling 1
  • Consider early elective intubation if signs of airway compromise develop 1
  • Have emergency tracheostomy equipment immediately available 1
  • Monitor oxygen saturation (maintain >92%) 1

• High-risk features requiring immediate intervention:

  • Edema involving larynx, palate, floor of mouth, or oropharynx
  • Rapid progression (within 30 minutes) 1
  • Respiratory distress or stridor

Treatment Based on Angioedema Type

Histamine-Mediated Angioedema (with urticaria)

1. Epinephrine 0.3-0.5 mg IM (first-line treatment) 1, 2

   • Acts on both alpha and beta-adrenergic receptors
   • Reduces vascular permeability and vasodilation
   • Relieves bronchospasm, pruritus, urticaria and angioedema 2

2. H1 antihistamines (e.g., diphenhydramine 50 mg IV) 1

3. Corticosteroids (e.g., methylprednisolone 125 mg IV) 1

Bradykinin-Mediated Angioedema (without urticaria)

1. For Hereditary Angioedema (HAE):

   • Plasma-derived C1 esterase inhibitor (20 IU/kg) 1
   • Icatibant 30 mg subcutaneously (may repeat at 6-hour intervals, max 3 injections/24 hours) 1
   • Note: Epinephrine, antihistamines, and corticosteroids have limited effectiveness 1, 3

2. For ACE inhibitor-induced angioedema:

   • Immediately discontinue the ACE inhibitor 1
   • Consider C1 esterase inhibitor if symptoms are progressing despite conventional therapy 4
   • Fresh frozen plasma (10-15 ml/kg) can be considered as alternative therapy in resource-limited settings 1

Important Clinical Considerations

• Avoid potentially harmful interventions:

  • Fresh frozen plasma might acutely exacerbate some attacks 1
  • Corticosteroids and antihistamines have no beneficial effect on HAE attacks 1
  • Anabolic androgens and antifibrinolytic drugs are not effective for acute attacks 1

• Supportive care:

  • Aggressive hydration for abdominal attacks (third-space sequestration is common) 1
  • Consider narcotic medications for pain control and antiemetics for nausea/vomiting 1

• Special populations at higher risk:

  • African Americans (for ACE inhibitor-induced angioedema) 1
  • People over 65, women, and those with history of smoking 1

Common Pitfalls to Avoid

• Misdiagnosis: Failing to distinguish between histamine and bradykinin-mediated angioedema leads to ineffective treatment 3
• Delayed intervention: Waiting for complete assessment before securing the airway in rapidly progressing cases 1
• Inappropriate medication: Using only antihistamines and steroids for bradykinin-mediated angioedema 3
• Continued ACE inhibitor use: Failing to recognize ACE inhibitor-induced angioedema, which can occur even after years of use 5

All patients with oropharyngeal or laryngeal angioedema should be observed in a facility capable of emergency airway management, regardless of initial response to treatment 1.