Anaphylaxis%20(pediatric) Treatment

Prompt assessment and treatment are critical as death can ensue rapidly

• Rapid assessment of airway, breathing, circulation and level of consciousness
  • Remove triggering allergens if possible (eg induce vomiting if food-induced, stop drug intake/infusion, etc)
• Place the patient in the supine position with the lower extremities elevated if tolerated (left lateral position for vomiting patients or in a comfortable position for patients with dyspnea)

• Infants and young children should be held flat or horizontally in the carer’s arms and not upright over the shoulder 
• Until fully stabilized, do not let patient sit up suddenly once supine as doing so can cause hypotension and death

• Administer Epinephrine 1:1000 dilution (0.01 mg/kg) at a dose of 0.01 mL/kg (max dose: 0.3-0.5 mL or 0.3-0.5 mg) every 5-15 minutes, until condition stabilizes
  • Dose is equivalent to 10 mcg/kg
  • Intramuscular (IM) injection into the lateral side of the mid thigh is the best route and site to give epinephrine to treat an anaphylactic reaction
  • IM injection in the thigh produces more rapid absorption and higher plasma epinephrine concentration than IM injection in the arm
• Inhaled Epinephrine via metered dose inhalers or nebulizers may be beneficial to treat laryngeal edema or persistent bronchospasm in cases where intravenous (IV) route cannot be obtained or despite a previous IM Epinephrine dose
• Repeated doses of Epinephrine are administered until clinical improvement is achieved
  • If no improvement after 3-4 doses, patient should be transported to an emergency medical facility

Epinephrine Intravenous (IV) Infusion

• Indicated during cardiac arrest or in profoundly hypotensive patients who have failed to respond to several inj doses of Epinephrine and IV fluid replacement
• May be prepared by adding 1 mg (1 mL) of 1:1000 dilution of Epinephrine to 250 mL of D5W to yield 4 mcg/mL
  • Infused at a rate of 1-4 mcg/minute; max of 10 mcg/minute for adolescents
• An alternative is the “rule of 6”: 0.6 x body weight (kg) = number of mg diluted in 100 mL of saline, then 1 mL/hour delivers 0.1 mcg/kg/minutes
• Continuous cardiac monitoring is recommended due to potential for lethal arrhythmias and to minimize the risk of overtreatment and Epinephrine toxicity
  • Consider possible Epinephrine toxicity instead of worsening anaphylaxis in a patient with normal or elevated SBP who is nauseous, vomiting, shaky or tachycardic

Adjunctive Therapy
Antihistamines (H1- and H2-receptor Antagonists)

• Used in the treatment of urticaria-angioedema or pruritus related to allergic reaction
  • There is no evidence of their efficacy in anaphylaxis treatment
• H1 antihistamines are considered second-line agents to Epinephrine but are not replacements for Epinephrine in anaphylaxis treatment 
• Combination of H1- and H2-receptor antagonists has been reported to be more effective in anaphylaxis than H1-receptor antagonist alone
  • Combination or alone, both H1 and H2 antagonists are second line only to Epinephrine
  • Lacks high quality evidence that supports their use in emergency treatment for anaphylaxis

Inhaled Bronchodilators

• Eg Salbutamol
• Additional treatment for persistent bronchospasm not responsive to Epinephrine
  • Not to be used as replacement for Epinephrine as first-line agent 
• Given intermittently or continuously, depending on the patient’s symptoms and the availability of cardiac monitoring

Corticosteroids

• Eg Hydrocortisone, Methylprednisolone, Prednisone, Prednisolone 
• Used to prevent recurrence of symptoms of protracted anaphylaxis and biphasic reactions
• May be given in patients with a history of idiopathic anaphylaxis and asthma, and in patients who experience severe or prolonged anaphylaxis
  • Recommended IV/PO dose of Methylprednisolone or equivalent formulation is 1-2 mg/kg up to 125 mg per dose
  • Should be discontinued once full recovery is achieved
• Steroids should not be used as replacement for Epinephrine as first-line agent
• Not to be given for acute anaphylaxis management 
• For mild-moderate attacks, oral administration of Prednisone is recommended
• For severe anaphylaxis, Methylprednisolone IV is recommended to modulate the late-phase response

Vasopressors

• Eg Dopamine, Norepinephrine, Vasopressin
• Given if Epinephrine and fluid resuscitation have failed to alleviate hypotension

Absolute Indications for Prescribing Self-injectable Epinephrine

• History of cardiovascular or respiratory reaction to an allergen (eg food, latex, insect sting)
• Food-induced anaphylaxis associated with exercise
  • At least 2 auto-injections should be prescribed and carried at all times by patients at risk for food-induced anaphylaxis

• Patients with food allergy and co-existent persistent asthma
• Idiopathic anaphylaxis
• Children with severe skin involvement (>50% body surface), increased basal serum tryptase levels and with blistering in the 1st 3 years of life

Relative Indications for Prescribing Self-injectable Epinephrine

• Previous reaction to small amounts of food
• History of only a previous mild reaction to a tree nut or peanut
• Severe food allergic reaction in an adolescent
• Remote location without rapid access to medical facility