What is the management of anaphylactic shock?

Management of Anaphylactic Shock

Immediate administration of intramuscular epinephrine is the cornerstone of anaphylactic shock management, followed by oxygen, fluid resuscitation, and additional supportive measures based on clinical response. 1, 2, 3

Initial Management

• Administer epinephrine intramuscularly at a dose of 0.3-0.5 mg (1:1000) for adults or 0.01 mg/kg for children into the anterolateral thigh, which can be repeated every 5-15 minutes as needed 2, 3
• Position the patient supine with legs elevated unless respiratory distress is present 2
• Administer supplemental oxygen to all patients experiencing anaphylaxis, especially those with hypoxia or respiratory distress 1, 2
• Establish intravenous access for fluid resuscitation 2
• Administer large-volume fluid resuscitation with normal saline (500-1000 ml for adults or 20 ml/kg for children) 1, 2
• Monitor vital signs closely (blood pressure, heart rate, respiratory rate, oxygen saturation) 2

Advanced Management for Refractory Anaphylactic Shock

For Persistent Hypotension Despite IM Epinephrine

• If IV access is established and hypotension persists, administer IV epinephrine at 0.05-0.1 mg (1:10,000) slowly 1, 2
• Consider continuous IV epinephrine infusion (5-15 μg/min) for persistent shock 1, 2
• For patients on beta-blockers with refractory hypotension, administer glucagon 1-5 mg IV (adults) or 20-30 μg/kg (children, max 1 mg) over 5 minutes, followed by infusion of 5-15 μg/min 1, 2
• Consider additional vasopressors if shock is refractory to epinephrine 1, 4

For Airway Management

• For obstructive airway edema unresponsive to initial treatment, rapid advanced airway management is critical 1
• Consider early referral to a specialist with expertise in advanced airway placement, including surgical airway management if needed 1
• In severe cases, emergency cricothyroidotomy or tracheostomy may be required 1

Additional Supportive Measures

• For persistent bronchospasm, administer beta-agonist inhalation (albuterol nebulization) 2
• Consider H1 antihistamines (diphenhydramine 25-50 mg IV/IM) for symptom relief, not as primary treatment 2
• Consider H2 antihistamines (ranitidine 50 mg IV for adults) as adjunctive therapy 2
• Consider corticosteroids (methylprednisolone 1-2 mg/kg IV) to potentially prevent biphasic reactions, though evidence for this is limited 2

Management of Cardiac Arrest from Anaphylaxis

• Standard resuscitative measures and immediate administration of epinephrine should take priority 1
• For post-arrest shock in anaphylaxis patients, IV infusion of epinephrine (5-15 μg/min) is recommended 1

Special Considerations

• There are no absolute contraindications to epinephrine use in anaphylaxis, as the risk of death from untreated anaphylaxis outweighs potential adverse effects 1
• Use caution but do not withhold epinephrine in patients with cardiovascular disease, those taking monoamine oxidase inhibitors or tricyclic antidepressants, those on stimulant medications, or those with conditions like recent intracranial surgery, aortic aneurysm, or uncontrolled hypertension 1
• For patients on beta-blockers who are unresponsive to epinephrine, glucagon is essential as it has inotropic and chronotropic effects not mediated through beta-receptors 1, 2

Post-Acute Management

• Observe patients for at least 6 hours after initial symptoms resolve, as biphasic reactions may occur 2
• Provide prescription for epinephrine auto-injector and education on its use before discharge 2, 5
• Consider referral to an allergist for identification of triggers and long-term management 1

Common Pitfalls to Avoid

• Delaying epinephrine administration - this is the most common and potentially fatal error in anaphylaxis management 3, 4
• Administering epinephrine intravenously as first-line (increased risk of cardiovascular complications) - IM is the preferred initial route 1, 2
• Inadequate fluid resuscitation - up to 35% of intravascular volume can shift to extravascular space within minutes 1
• Failure to prepare for airway compromise - early recognition and management of airway obstruction is critical 1
• Discharging patients too early - observe for potential biphasic reactions 2, 4