Allergic Reaction- General

Most intraoperative allergic reactions are caused by IV medications and usually occur within 3 min of the drug administration. For a list of medications known to induce allergic reactions see Medications with Potential Allergies.

Symptoms: Flushing, perioral and periorbital edema, urticaria, bronchospasm, laryngeal edema, fulminant pulmonary edema, hypotension, tachycardia, dysrrhythmias, low systemic vascular resistance, pulmonary hypertension, cardiac arrest. Only one or any combination of these signs may be present.

Initial treatment:

	Stop administration of suspected antigen.
	Maintain airway with O2 100%.
	Stop all anesthetic agents.
	Fluid load with crystalloid/colloid to combat hypotension.
	Start epinephrine 5-10 µg IV bolus with hypotension; 0.1-1.0 mg IV with cardiovascular collapse or severe bronchospasm.

Secondary treatment:

	Antihistamines, e.g. diphenhydramine 0.5-1 mg/kg.
	Catecholamines infusions, e.g. epinephrine 0.05-1 µg/kg/min; norepinephrine 0.05-1 µg/kg/min; isoproterenol 0.5-1 µg/min; titrate as needed.
	Aminophylline: 5-6 mg/kg over 20 min or inhaled bronchodilators if bronchospasm persists.
	Corticosteroids: hydrocortisone 0.25-1 g or methylprednisolone 1-2 g.
	Sodium bicarbonate, e.g. 0.5-1 mEq/kg with persistent acidosis.