What is the treatment protocol for pediatric patients experiencing anaphylaxis?

Treatment Protocol for Pediatric Anaphylaxis

Administer intramuscular epinephrine immediately into the anterolateral thigh at 0.01 mg/kg (maximum 0.3 mg in children, 0.5 mg in adolescents) as soon as anaphylaxis is recognized—this is the only first-line treatment that reduces morbidity, mortality, and hospitalizations. 1

Immediate Recognition and First-Line Treatment

Epinephrine Administration

• Inject epinephrine 0.01 mg/kg of 1:1000 solution intramuscularly into the mid-outer thigh immediately upon recognition of anaphylaxis 1, 2, 3
• Maximum single dose: 0.3 mg for children <30 kg (66 lbs), 0.5 mg for children ≥30 kg and adolescents 3, 4
• Repeat every 5-15 minutes as needed if symptoms persist or recur 2, 5, 3
• The intramuscular route in the lateral thigh provides superior pharmacokinetics compared to subcutaneous administration 1, 2

Weight-Based Autoinjector Dosing

• 0.1 mg autoinjector for infants where available 2
• 0.15 mg autoinjector for children 10-25 kg (or >7.5 kg when 0.1 mg unavailable) 2
• 0.3 mg autoinjector for individuals ≥25 kg 2

Critical caveat: The lowest available autoinjector dose (0.15 mg) may be excessive for infants <7.5 kg, but this should never deter treatment—there are no absolute contraindications to epinephrine in anaphylaxis 1, 2

Supportive Measures

Positioning and Monitoring

• Place patient supine with lower limbs elevated immediately after epinephrine administration 4
• Never place in upright position—this can precipitate cardiovascular collapse 4
• Establish IV access, provide supplemental oxygen, and continuously monitor vital signs 5

Volume Resuscitation

• Administer crystalloid fluid bolus: 500 mL for moderate reactions, 1 L for severe reactions, escalating to 20-30 mL/kg for refractory cases 5

Management of Refractory Anaphylaxis

Escalation Protocol

• If inadequate response after 10 minutes, double the epinephrine bolus dose 5
• Consider IV epinephrine for severe reactions: 20 μg for Grade II, 50-100 μg for Grade III, 1 mg for Grade IV (cardiac arrest) 2, 5
• Start epinephrine infusion (0.05-0.1 μg/kg/min) when more than three boluses have been administered 2, 5

Additional Vasopressor Support

• For persistent hypotension despite epinephrine, add norepinephrine infusion (0.05-0.5 μg/kg/min) 5
• Consider vasopressin 1-2 IU bolus with or without infusion (2 units/h) for refractory hypotension 5
• For patients on beta-blockers with refractory symptoms, administer IV glucagon 1-2 mg 5

Second-Line Adjunctive Therapies

Antihistamines (NOT First-Line)

• H1 antihistamines (diphenhydramine 25-50 mg IV or chlorphenamine) are adjunctive only for cutaneous symptoms—never administer before or instead of epinephrine 2, 5
• H1 antihistamines have slow onset (≥1 hour) and do not relieve respiratory symptoms or shock 1
• Consider H2 antihistamines (ranitidine 50 mg IV in adults, 1 mg/kg in children) after adequate epinephrine and fluid resuscitation 2, 5

Bronchodilators

• Inhaled albuterol may provide adjunctive therapy for wheezing in patients with preexisting asthma but does not replace epinephrine 1
• Albuterol does not relieve upper airway edema or shock 1

Corticosteroids

• Consider systemic glucocorticosteroids for patients with history of idiopathic anaphylaxis, asthma, or severe/prolonged reactions to potentially prevent biphasic reactions 5
• Corticosteroids have no role in acute treatment due to delayed onset of action 6

Post-Anaphylaxis Management

Observation Period

• Observe in a monitored area for minimum 6 hours or until stable and symptoms are regressing 2, 5
• This observation period is critical to detect biphasic reactions 7

Diagnostic Testing

• Obtain mast cell tryptase samples: first at 1 hour after reaction onset, second at 2-4 hours, and baseline at least 24 hours post-reaction 2, 5

Discharge Planning

• Prescribe epinephrine autoinjector before discharge 1, 7
• Provide written personalized anaphylaxis emergency action plan 1
• Train patient/family on autoinjector use and anaphylaxis recognition 1
• Prescribe Medic-Alert identification 1, 7
• Arrange allergist referral for trigger identification and consideration of allergen immunotherapy (e.g., venom immunotherapy) 1, 5

Critical Pitfalls to Avoid

Common Errors

• Delayed epinephrine administration is associated with fatalities—administer immediately when anaphylaxis is suspected 1, 4
• Never substitute antihistamines or corticosteroids for epinephrine as first-line treatment 2, 5
• Do not administer IV epinephrine in non-arrest situations without appropriate monitoring 5
• Avoid premature discharge without adequate observation for biphasic reactions 5

High-Risk Populations

• Patients with preexisting severe uncontrolled asthma are at higher risk for fatal anaphylaxis 1, 6
• Adolescents have particularly high risk for fatal anaphylaxis 1
• Patients on beta-blockers may have refractory symptoms requiring glucagon 5, 6
• Elderly patients and those with cardiovascular disease may be more sensitive to epinephrine effects but still require treatment 3

The more rapidly anaphylaxis develops, the more likely it is to be severe and life-threatening—when in doubt, administer epinephrine immediately. 1, 2