A postpartum patient has been receiving a magnesium sulfate infusion for treatment of severe preeclampsia. It has been about 8 hours since her vaginal delivery and upon assessment the nurse finds the following: temperature 98.3°F, pulse rate 88 beats/min, respiratory rate 16 breaths/min, blood pressure (BP) 148/78 mm Hg, 2+ deep tendon reflexes, 100 cc of clear yellow urine over the past hour, heavy rubra lochia, and a boggy fundus. What is the most appropriate action for the nurse to take?