A nurse is admitting a client who has a diagnosis of preterm labor. The nurse anticipates an order by the provider for which of the following medications?

Choice A reason: Hypocalcemia is not the priority focus of care, as it is a low level of calcium in the blood that can cause muscle twitching, seizures, or cardiac arrhythmias. Hypocalcemia can affect newborns who have mothers with diabetes mellitus, but it is less common and less severe than hypoglycemia.

Choice B reason: Hyperbilirubinemia is not the priority focus of care, as it is a high level of bilirubin in the blood that can cause jaundice, a yellowish discoloration of the skin and eyes. Hyperbilirubinemia can affect newborns who have macrosomia, but it is usually a benign and self-limiting condition that resolves within a few days.

Choice C reason: Hypomagnesemia is not the priority focus of care, as it is a low level of magnesium in the blood that can cause tremors, tetany, or seizures. Hypomagnesemia can affect newborns who have mothers with diabetes mellitus, but it is rare and usually asymptomatic.

Choice D reason: Hypoglycemia is the priority focus of care, as it is a low level of glucose in the blood that can cause diaphoresis, jitteriness, lethargy, or apnea. Hypoglycemia can affect newborns who have macrosomia and mothers with diabetes mellitus, as they have increased insulin production and decreased glucose supply after birth. Hypoglycemia can lead to brain damage or death if not treated promptly.

Choice A reason: To call for an immediate magnesium sulfate level is not the immediate action that the nurse should take, as it is a diagnostic test that requires a blood sample and a laboratory analysis, which can take time and delay the treatment. The nurse should first stop the infusion and notify the provider, as the client is showing signs of magnesium sulfate toxicity, which is a life-threatening condition that can cause respiratory depression, cardiac arrest, or coma.

Choice B reason: To prepare to administer hydralazine is not the immediate action that the nurse should take, as it is a pharmacological intervention that requires a prescription and an assessment of the blood pressure and the fetal status. Hydralazine is an antihypertensive drug that lowers the blood pressure and prevents the complications of severe preeclampsia, such as eclampsia, stroke, or organ damage. However, the client's blood pressure is not very high and is not the main problem at the moment.

Choice C reason: To discontinue the magnesium sulfate infusion is the immediate action that the nurse should take, as it is the first and most important intervention that can reverse the effects of magnesium sulfate and restore the neuromuscular function and the respiratory rate. Magnesium sulfate is a drug that prevents seizures and lowers the blood pressure in clients with severe preeclampsia, but it can also cause toxicity if the dose is too high or the infusion is too fast.

Choice D reason: To administer oxygen is not the immediate action that the nurse should take, as it is a supportive intervention that improves the oxygen delivery to the tissues and organs, but does not address the underlying cause of the respiratory depression, which is the magnesium sulfate toxicity. The nurse should administer oxygen only after stopping the infusion and assessing the oxygen saturation and the respiratory status.