A nurse is assessing a client with severe pre-eclampsia who is receiving magnesium sulfate infusion.

Which finding should alert the nurse to suspect magnesium toxicity?

The correct answer is choice A and E. The nurse should check the client’s blood pressure and magnesium level before giving hydralazine to a client with severe pre-eclampsia who is receiving magnesium sulfate intravenously.

• Choice A is correct because hydralazine is an antihypertensive drug that lowers blood pressure by relaxing blood vessels.The nurse should monitor the client’s blood pressure before and after giving hydralazine to ensure that it is within the target range and to avoid hypotension or rebound hypertension.

• Choice B is wrong because pulse oximetry is not directly related to hydralazine administration or pre-eclampsia.Pulse oximetry measures the oxygen saturation of hemoglobin in the blood and can be affected by factors such as anemia, hypothermia, nail polish, or movement.

The nurse should monitor the client’s pulse oximetry as part of routine care, but it is not a priority before giving hydralazine.

• Choice C is wrong because checking the client’s reflexes is not directly related to hydralazine administration or pre-eclampsia.Reflexes are assessed to monitor for signs of magnesium toxicity, which can cause muscle weakness, respiratory depression, and cardiac arrest.

The nurse should check the client’s reflexes as part of routine care, but it is not a priority before giving hydralazine.

• Choice D is wrong because checking the client’s urine specific gravity is not directly related to hydralazine administration or pre-eclampsia.Urine specific gravity measures the concentration of solutes in the urine and can be affected by factors such as hydration status, renal function, or diuretic use.

The nurse should monitor the client’s urine specific gravity as part of routine care, but it is not a priority before giving hydralazine.

• Choice E is correct because magnesium sulfate is a drug that prevents and treats seizures in women with severe pre-eclampsia or eclampsia.The nurse should monitor the client’s magnesium level before and after giving magnesium sulfate to ensure that it is within the therapeutic range and to avoid magnesium toxicity.

The correct answer is choice A, B, C and E.The nurse should monitor for magnesium toxicity by assessing the deep tendon reflexes, respiratory rate, urine output and serum magnesium level of the client who has severe preeclampsia and is receiving magnesium sulfate IV.Magnesium toxicity can cause life-threatening complications such as hypotension, areflexia (loss of DTRs), respiratory depression, respiratory arrest, oliguria, shortness of breath, chest pains, slurred speech and cardiac arrest.The nurse should also have calcium chloride ready as an antidote for magnesium toxicity.

Choice D is wrong because fetal heart rate is not a direct indicator of magnesium toxicity.However, the nurse should still monitor the fetal heart rate and uterine activity per the Electronic Fetal Monitoring (EFM) Guideline.

Normal ranges for the assessments are:

• Deep tendon reflexes: 1+ to 4+ (normal to hyperactive)

• Respiratory rate: 12 to 20 breaths per minute

• Urine output: at least 30 mL per hour

• Serum magnesium level: 4 to 7 mg/dL (therapeutic range for preeclampsia)