Final answer:
The nurse should reduce the magnesium sulfate infusion rate or discontinue the medication if the client is showing signs of magnesium toxicity. Monitoring for adverse effects is important.
Step-by-step explanation:
The client's assessment reveals low urine output, hyporeflexia, and stable blood pressure and heart rate. These symptoms indicate that the client may be experiencing magnesium toxicity, which can occur with prolonged or excessive magnesium sulfate administration. The nurse should reduce the magnesium sulfate infusion rate or discontinue the medication, as it may lead to adverse effects such as respiratory depression or cardiac arrest. Monitoring for adverse effects is also important.