A nurse is caring for a 34-year-old woman who presents to the emergency department with sudden onset shortness of breath, urticaria across her chest and neck, and audible stridor approximately 10 minutes after receiving her first dose of amoxicillin-clavulanate at an urgent care clinic. Her blood pressure is 82/50 mmHg, heart rate is 118 beats/min, respiratory rate is 26 breaths/min, and oxygen saturation is 89% on room air. The client is anxious and states she feels like her throat is 'closing up.' Which action should the nurse take first?
- Administer diphenhydramine 50 mg IV and apply supplemental oxygen via non-rebreather mask.
- Establish IV access and begin a 0.9% normal saline bolus at 500 mL over 30 minutes.
- Obtain a stat arterial blood gas and notify the respiratory therapist for possible intubation.
- Administer epinephrine 0.3 mg intramuscularly into the anterolateral thigh.