Final answer:
When a nurse observes a critically low blood pressure in a client with cardiogenic shock on dopamine infusion, the next action is to report the findings to the healthcare provider.
Step-by-step explanation:
When caring for a client in cardiogenic shock on a prescribed dopamine infusion and observing a blood pressure of 75/40 mmHg, the next step the nurse should perform is to report the findings to the healthcare provider. It is crucial to collaborate with the healthcare provider to determine the appropriate adjustments to the infusion rate. An immediate recheck of the blood pressure may be warranted to confirm the readings, but the priority is communication with the healthcare provider to address the critically low blood pressure and adjust the treatment plan, which may include titrating the medication up or down as clinically indicated.