Anaphylaxis is thr clinical syndrome of immediate hypersensitivity. It is characterized by cardiovascular collapse, respiratory compromise and cutaneous and GI symptoms ( e.g urticaria, emesis )
1. ABC’s : Establish airway if necessary. Assess breathing. Supply with 100% oxygen with respiratory support as needed. Assess circulation and establish IV access. Place patient on cardiac monitor.
2. Epinephrine: Give epinephrine , 0.01 ml/kg (1:1000) intramuscular, maximum dose 0.5 ml. Repeat every 15 min as needed. The site of choice is lateral aspect of thigh due to its vascularity.
3. Albuterol: Give nebulized albuterol, 0.05 to 0.15 mg/kg in 3 ml normal saline solution ( quick estimate 2.5 mg for < 30kg and 5 mg for > 30kg ) every 15 min as needed.
4. Histamine 1- receptor antagonist: such as diphenhydramine, 1-2 mg/kg through IV.IM or oral route. Also consider a histamine -2 receptor antagonist.
5.Corticosteroids: helps prevent the late phase of allergic response. Administer methlyprednisolone in a 2 mg/kg IV bolus, then 2mg/kg per day IV or IM divided every 6 hrs or prednisone 2 mg/kg PO in a bolus once daily. Observe for 6 to 24 hrs for late phase symptoms depending on clinical condition and stability.
6. Advice on discharge: Patient should be discharged with an epi-pen junior(<30kg) or usual adult epi-pen (>30kg) or any comparable injectable epinephrine product with specific instructions on appropriate use.
Managing Hypotension associated with anaphylaxis
1.Trendelenburg position: Put patient’s head at 30 degree angle below feet.
2. Fluids: Administer 20 ml/kg IV normal saline or lactated ringer’s solution over 5 to 15 min. repeat bolus if necessary.
3. Epinephrine: Give 0.1 ml/kg (1:10,000) IV every 2 to 5 min while an epinephrine or dopamine infusion is being prepared.