Final answer:
The nurse should perform blood pressure measurement as a priority assessment to monitor for adverse effects when administering IV fluids to an older adult.
Step-by-step explanation:
The priority assessment a nurse should perform when administering IV fluid to an older adult client to monitor for adverse effects is Option 1: Blood pressure measurement. Monitoring blood pressure is vital, as it can help in detecting both hypertension and hypotension, which are critical in assessing a patient's response to intravenous fluids. The pressure exerted by circulating blood upon the walls of blood vessels, especially arteries, is a critical indicator of cardiovascular health. When administering IV fluids, there is a risk of fluid overload, which can lead to increased blood pressure, or in some cases, if the administration is not correct, it can lead to decreased blood pressure. Hence, keeping a close eye on blood pressure changes is essential in elder care to prevent complications like heart failure or vascular collapse.