Final answer:
The nurse should immediately stop the antibiotic infusion to halt exposure to the allergen and then administer epinephrine to treat the anaphylactic reaction. Monitoring vital signs and seeking further medical assistance are crucial following steps.
Step-by-step explanation:
The nurse's first action upon identifying a patient in anaphylactic shock from an intravenous antibiotic is to stop the antibiotic infusion immediately to prevent further exposure to the allergen. When a patient is having an anaphylactic reaction, it constitutes a medical emergency that requires prompt and decisive action. The signs and symptoms of anaphylaxis might include severe hypotension, tachycardia, difficulty in breathing, and swelling of the tongue and throat, which could quickly lead to suffocation. Immediate cessation of the IV antibiotic halts the introduction of more allergens into the patient's system.
The next urgent step would be to administer epinephrine, as it is the primary treatment for anaphylaxis, aiming to constrict blood vessels, increase blood pressure, relax bronchial smooth muscles, and reduce swelling. After addressing these life-threatening symptoms, the nurse should call for emergency medical assistance and continue to monitor vital signs and provide the necessary supportive care as per the hospital's protocol.