A pregnant woman has been receiving a magnesium sulfate infu…

A pregnant woman has been receiving a magnesium sulfate infusion for the treatment of severe preeclampsia for 24 hours. On assessment, the nurse finds the following vital signs: temperature 37.3° C, pulse rate 88 beats per minute, respiratory rate 10 breaths per minute, BP 148/90 mm Hg, absent deep tendon reflexes (DTRs), and no ankle clonus. The woman is sleepy and difficult to wake up.  What is the nurse’s first action?