Factors affecting the effect of the beta-adrenergic blocking agent:
(1) selectivity of the beta-adrenergic blocking agent
(2) amount of beta-adrenergic blockade in effect at the time of anaphylaxis
(3) severity of anaphylaxis
Effects of nonspecific beta-blockade in a person with anaphylaxis:
(1) prolonged hypotension with bradycardia and intravascular volume depletion
(2) increased airway resistance
(3) decreased response to administered epinephrine, resulting in a muted response to the initial doses and the need for higher doses with an increased risk of epinephrine-related toxicity
Ellis and Day recommend the administration of glucagon IV at a dose of 5 to 15 micrograms per minute. Glucagon exerts an inotropic, chronotropic and vasoactive effect that does not require the blocker beta-adrenergic receptors.
The intravascular volume depletion may respond to fluid resuscitation.
