An older client recently transferred to a rehabilitation facility after aortic valve replacement surgery is experiencing anxiety and difficulty adjusting to the transition. The healthcare provider prescribes an antidepressant and a mild sedative for sleep. Which intervention is most important for the nurse to include in the client's plan of care?

A. Obtain a blood pressure reading before the client gets out of beD This intervention is important because the client is prescribed medications that may affect blood pressure, such as antidepressants and sedatives. Monitoring blood pressure before changes in position can help prevent orthostatic hypotension and related complications. B. Measure and record the client's urinary output every day: While monitoring urinary output is important for overall assessment, it may not be the most immediate concern given the client's recent surgery and medication regimen. C. Provide the client with teaching regarding a cardiac diet: While education on a cardiac diet is important for cardiovascular health, addressing immediate concerns related to medication effects and post-surgical recovery takes priority. D. Obtain the client's vital signs every 4 hours when awake: While vital sign monitoring is essential, the timing of every 4 hours may not be necessary during sleep, and obtaining blood pressure readings before changes in position is more critical to prevent adverse events.