A nurse is collecting data from a client who is receiving magnesium sulfate via continuous IV infusion to treat preeclampsia. Which of the following findings indicates that the medication is having a therapeutic effect?

A. Positive clonus is a sign of hyperreflexia and can indicate worsening preeclampsia or severe central nervous system irritability. It is not a therapeutic effect of magnesium sulfate. B. Urinary output 20 mL/hr is below the minimum expected urine output (which is generally 30 mL/hr). This finding suggests oliguria and may be a sign of worsening renal function, which is not a therapeutic effect of magnesium sulfate. C. Respiratory rate 10/min is too low. Magnesium sulfate can cause respiratory depression, and a respiratory rate of 10/min may indicate toxicity. This is not a therapeutic effect. D. Deep tendon reflexes 2+ is the correct answer. Magnesium sulfate is used to prevent seizures in preeclampsia by acting as a CNS depressant. A normal response of 2+ for deep tendon reflexes indicates that magnesium sulfate is having a therapeutic effect and the client is not experiencing magnesium toxicity (which would typically cause a decreased reflex response..