Final answer:
The first action a nurse should take when a client reports severe chest pain is to assess vital signs to ensure stability and to quickly identify any life-threatening conditions.
Step-by-step explanation:
When a client reports severe chest pain, as in the scenario presented, the nurse should prioritize assessment and stabilization of the patient's condition. The first action the nurse should take is D) Assessing vital signs. This is crucial because chest pain can be indicative of life-threatening conditions such as myocardial infarction (heart attack) or other serious cardiac events. It is essential to promptly assess the patient's vital signs, including blood pressure, heart rate, respiratory rate, and oxygen saturation, to determine the stability of the patient and identify any immediate needs for intervention. Notifying the healthcare provider and obtaining a detailed pain history are important subsequent steps, but they come after initial assessment. Administering pain medication may be warranted, but only after careful evaluation and under the direction of a healthcare provider.