What is the treatment for anaphylactic shock?

Treatment of Anaphylactic Shock

Epinephrine should be administered immediately as the first-line treatment for anaphylactic shock, preferably by intramuscular injection in the mid-outer thigh at a dose of 0.2 to 0.5 mg (1:1000) for adults, to be repeated every 5 to 15 minutes as needed. 1

Primary Treatment Algorithm

1. Immediate Epinephrine Administration

   • Route: Intramuscular (IM) injection in the lateral thigh (vastus lateralis muscle)
   • Adult dosing: 0.2-0.5 mg (1:1000 concentration) 1
   • Pediatric dosing: 0.01 mg/kg up to 0.3 mg for prepubertal children 1
   • Timing: Repeat every 5-15 minutes if symptoms persist 1

2. Airway Management

   • Immediate referral to a healthcare professional with advanced airway expertise if signs of oropharyngeal or laryngeal edema 1
   • Emergency cricothyroidotomy or tracheostomy may be required in cases of severe airway obstruction 1

3. Hemodynamic Support

   • Close hemodynamic monitoring is essential 1
   • Intravenous (IV) fluid resuscitation for hypotension
   • Position patient supine with legs elevated unless respiratory distress is present 1

4. Alternative Epinephrine Routes

   • IV epinephrine (when IV access is available): 0.05-0.1 mg (1:10,000 concentration) 1
   • Continuous IV infusion (for persistent shock): 5-15 μg/min, titrated to response 1

Special Considerations

Refractory Anaphylaxis

• For bronchospasm resistant to epinephrine: Consider inhaled β-agonists (e.g., nebulized albuterol) 1
• For hypotension refractory to epinephrine and fluids: Consider vasopressor infusions (e.g., dopamine) 1
• For patients on β-blockers: Consider glucagon (1-5 mg IV over 5 minutes, followed by infusion) 1

Second-Line Medications

• H1 antihistamines (e.g., diphenhydramine 25-50 mg IV/IM) - Note: These should never be used alone for anaphylaxis treatment 1
• H2 blockers (e.g., ranitidine 50 mg IV for adults) - May be used in combination with H1 blockers 1
• Corticosteroids may help prevent protracted or biphasic reactions but are not effective for acute management 1

Common Pitfalls to Avoid

1. Delayed epinephrine administration - This is the most common and potentially fatal error in managing anaphylaxis 2

2. Using antihistamines as first-line treatment - Antihistamines cannot reverse the life-threatening cardiovascular and respiratory effects of anaphylaxis 3

3. Failure to monitor after initial improvement - Biphasic reactions can occur, requiring continued observation 4

4. Improper patient positioning - Avoid standing or sitting positions in patients with hypotension 1

5. Inadequate airway assessment - Rapid development of airway edema can be fatal if not recognized early 1

Follow-up Care

• Transport to emergency department for further monitoring, even if symptoms improve after epinephrine 1
• Additional treatment including supplemental oxygen, IV fluids, and other interventions may be needed 1
• Identify trigger if possible to prevent future episodes 5

Anaphylactic shock is a true medical emergency requiring immediate recognition and treatment. The single most important intervention is prompt administration of epinephrine, which should never be delayed or substituted with other medications. Failure to administer epinephrine promptly is associated with increased mortality, particularly in patients with asthma or adolescents 1.