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, 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)

Level of consciousness.

This is because magnesium sulfate, which is given to prevent seizures in severe preeclampsia, can cause respiratory depression and coma if the dose is too high.Therefore, the nurse should monitor the client’s level of consciousness and respiratory rate closely and report any signs of toxicity to the provider.

Choice A is wrong because hourly intake and output is not the most important assessment for this client.However, the nurse should monitor the urinary output as a sign of renal function and fluid balance and report any output less than 30 ml per hour.

Choice B is wrong because deep tendon reflexes are not the most important assessment for this client.However, the nurse should check the reflexes as a sign of neuromuscular irritability and report any hyperreflexia or clonus.

Choice C is wrong because lung sounds are not the most important assessment for this client.However, the nurse should auscultate the lungs as a sign of pulmonary edema and report any crackles or wheezes.