What is the treatment for severe angioedema in the Emergency Room (ER)?

Emergency Treatment of Severe Angioedema

The treatment of severe angioedema in the emergency room should prioritize airway management and administration of HAE-specific medications such as plasma-derived C1 inhibitor concentrates, icatibant, or ecallantide as first-line treatments. 1, 2

Initial Assessment and Airway Management

• Airway evaluation is the first priority
  • Monitor for signs of impending airway closure: change in voice, difficulty swallowing, difficulty breathing 1
  • Avoid direct visualization of the airway when possible as this may worsen angioedema 1
  • If signs of airway compromise develop, consider early elective intubation 1
  • Have immediate backup tracheostomy available if intubation is needed, as airway anatomy may be severely distorted 1
  • All patients with oropharyngeal or laryngeal angioedema should be observed in a facility capable of performing emergency intubation or tracheostomy 1

Medication Management Based on Angioedema Type

For Hereditary Angioedema (HAE) and Bradykinin-Mediated Angioedema:

1. First-line treatments (in order of preference):

   • Plasma-derived C1 inhibitor concentrates
   • Icatibant (bradykinin B2 receptor antagonist) - 30mg subcutaneously
   • Ecallantide (plasma kallikrein inhibitor) 1, 2

2. If first-line treatments unavailable:

   • Fresh frozen plasma may be considered, though controversial due to potential worsening of symptoms in some cases 1

3. Important note: Standard treatments for allergic reactions (antihistamines, corticosteroids, epinephrine) are NOT effective for HAE or bradykinin-mediated angioedema 1, 3

For Histamine-Mediated (Allergic) Angioedema:

1. Standard therapy is effective:
   • Epinephrine
   • Corticosteroids
   • Antihistamines 3

Supportive Care for Specific Attack Locations

For Abdominal Attacks:

• Pain control with narcotic medications as needed
• Antiemetics for nausea and vomiting
• Aggressive hydration (third-space sequestration is common) 1
• Avoid long-term outpatient use of potent narcotics (risk of addiction) 1

For Genitourinary Attacks:

• Pain medication if discomfort is severe
• Catheterization if urination is impaired 1

For Extremity Attacks:

• Primarily symptomatic treatment 1

Common Pitfalls to Avoid

1. Misdiagnosis: Mistaking bradykinin-mediated angioedema for allergic reactions, leading to ineffective treatment 2

2. Delayed treatment: Particularly dangerous for laryngeal attacks which can be rapidly life-threatening 2

3. Inappropriate medication use: Using antihistamines and corticosteroids for bradykinin-mediated angioedema 3

4. Failure to identify ACE inhibitor-induced angioedema: For patients on ACE inhibitors with angioedema, discontinue the medication immediately 3

5. Direct airway visualization: This can worsen angioedema; avoid unless absolutely necessary 1

By following this algorithm and understanding the pathophysiology of the specific type of angioedema, emergency physicians can provide prompt, effective treatment that reduces morbidity and mortality in these potentially life-threatening conditions.