(Sensitivity 97%, Specificity 82%, positive predictive value (PPV) 69%, negative predictive value (NPV) 98%)
1. Illness with acute onset involving skin/mucosa AND one of the following: Respiratory compromise or Hypotension
2. Two of the following after exposure to suspected antigen: Skin involvement, Respiratory compromise, Hypotension, GI complaints
3. Hypotension after exposure to known allergen.
Immediate intramuscular (IM) adrenaline administration in the anterior thigh.
Adult: 0.3-0.5 mg 1:1000 adrenaline IM q5 min
Children: 0.01 mg/kg q5 min 1:1000 adrenaline IM q5 min
In refractory cases when patients do not respond to two IM doses, proceed to intravenous adrenaline.
Adult: 1 mg in 250 mL D5W, 0.25-1 mL/min (1-4 ug/min) up to 2.5 mL/min (10ug/min)
Children: 0.1 ug/kg/min with max of 1.5 ug/kg/min (0.6 x body weight (kg) of epinephrine diluted in 100 mL normal saline (NS) yields 0.1 ug/kg/min if run at 1 mL/hr)
- IM Piriton 10mg (H1 antagonist)
- IV Ranitidine 50mg (H2 antagonist)
- Dopamine/Dobutamine for refractory shock: 5-20 ug/kg/min- if adrenaline infusion didn’t stabilize the BP.
- Glucagon (for those on beta-blockers): 1-5 mg IV over 5 minutes, then 5-15 ug/min (20-30 ug/kg up to 1 mg in children)
Hemodynamic instability is secondary to intravascular volume shifts. Volume resuscitation of 2-7 liters should be used in those with persistent hypotension, with NS preferred over Ringer’s Lactate.