A client is admitted to the intensive care unit (ICU) after surgical repair of an aortic abdominal aneurysm (AAA). Sodium nitroprusside is infusing for severe postoperative hypertension. Normal saline is also infusing at 50 mL/hr. When the client suddenly reports back pain, the nurse measures the client's vital signs to be a heart rate of 38 beats/minute and a blood pressure of 80/60 mm Hg. Which intervention should the nurse implement first?

A. Notifying the rapid response team is essential in cases of sudden hemodynamic instability, but immediate actions to stop potential causes of hypotension must be taken first. Delaying this step could worsen shock or compromise perfusion. B. Discontinuing the nitroprusside infusion is the first priority because the client is experiencing hypotension, which may be exacerbated by ongoing vasodilation from the medication. Rapid intervention to stop the source of hypotension is critical to prevent further cardiovascular collapse and maintain organ perfusion. C. Increasing the saline infusion rate may help restore intravascular volume, but it does not address the immediate cause of hypotension from the vasodilator. Volume expansion alone may be insufficient if nitroprusside continues to lower blood pressure. D. Placing the client with head flat and feet elevated can temporarily improve venous return and perfusion, but this is a supportive measure and does not treat the underlying cause of sudden hypotension. Immediate discontinuation of the vasodilator takes precedence.