A -year-old woman is brought to the emergency department by emergency medical services after being stung by a bee. She has a history of severe bee sting allergy. On arrival, her blood pressure is mm Hg, heart rate is /min, and respiratory rate is /min. She has diffuse urticaria, facial swelling, and prominent expiratory wheezing. Arrange the following pharmacologic interventions in the correct prioritized sequence of administration for the acute management of this patient.
- 1Intramuscular epinephrine
- 2Intravenous crystalloid fluid bolus
- 3Intravenous methylprednisolone and diphenhydramine
Cevap
The correct sequence is: 1) Intramuscular epinephrine, 2) Intravenous crystalloid fluid bolus, 3) Intravenous methylprednisolone and diphenhydramine.
In a patient presenting with anaphylactic shock (characterized by hypotension, bronchospasm, and mucocutaneous signs after an allergen exposure), the absolute first step is the administration of intramuscular epinephrine. Epinephrine's alpha-1 agonism increases systemic vascular resistance, while its beta-2 agonism causes bronchodilation and decreases mast cell degranulation. If hypotension persists, the next step is rapid volume expansion with intravenous crystalloid fluids to counteract the massive fluid shift caused by increased vascular permeability. Only after the patient's airway and hemodynamics are stabilized with epinephrine and fluids should adjunctive medications, such as intravenous corticosteroids (e.g., methylprednisolone) and antihistamines (e.g., diphenhydramine), be administered. These adjuncts help relieve cutaneous symptoms and may reduce the risk of a biphasic anaphylactic reaction, but they have no immediate life-saving role.
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Anahtar Kavram
In the management of anaphylactic shock, intramuscular epinephrine is the absolute first priority, followed by fluid resuscitation for persistent hypotension, and finally adjunctive medications like antihistamines and corticosteroids.