Final answer:
The nurse should prioritize preparing to assist with a head-up tilt-test in the patient's subsequent diagnostic workup for syncope.
Step-by-step explanation:
The nursing action that the nurse should prioritize in the patient's subsequent diagnostic workup is preparing to assist with a head-up tilt-test. Syncope, which refers to a sudden loss of consciousness, can often be caused by various factors such as orthostatic hypotension. A head-up tilt-test helps identify whether orthostatic hypotension is the underlying cause of syncope.
During a head-up tilt test, the patient is positioned on a table that can be tilted to an upright position. The nurse will closely monitor the patient's blood pressure, heart rate, and symptoms while the table is tilted. This test helps determine if the patient experiences a drop in blood pressure and heart rate when changing positions, which can lead to syncope.
By assisting with the head-up tilt-test, the nurse can gather crucial information to establish a diagnosis and guide further treatment for the patient.