Final answer:
A client stating "I feel like I can't breathe" after a penicillin dose may indicate anaphylaxis, a severe allergic reaction requiring immediate epinephrine treatment.
Step-by-step explanation:
The statement by the client "I feel like I can't breathe" should indicate to the nurse that the client might be experiencing a severe allergic reaction, potentially anaphylaxis. Anaphylaxis is a life-threatening allergic reaction that can include symptoms such as shortness of breath, swelling of the tongue and throat, a drop in blood pressure, and changes in heart rate.
Treatment for anaphylaxis typically involves an emergency injection of epinephrine, which can help to control the immune reaction by constricting blood vessels, relaxing lung muscles, modulating the heart rate, and reducing airway swelling. Individuals at risk for severe allergic reactions often carry an epinephrine autoinjector, like an EpiPen®, for immediate use in such emergencies.