Maternity Nursing: Antepartum Q 14
A pregnant client is receiving magnesium sulfate for the management of preeclampsia. A nurse determines the client is experiencing toxicity from the medication if which of the following is noted on assessment?
A. Presence of deep tendon reflexes.
B. Serum magnesium level of 6 mEq/L.
C. Proteinuria of +3.
D. Respirations of 10 per minute.
Correct Answer: D. Respirations of 10 per minute.
Magnesium toxicity can occur from magnesium sulfate therapy. Signs of toxicity relate to the central nervous system depressant effects of the medication and include respiratory depression, loss of deep tendon reflexes, and a sudden drop in the fetal heart rate and maternal heart rate and blood pressure.
Option A: Although deep tendon reflexes are more useful in assessing magnesium toxicity, the presence of clonus may indicate an increased risk of convulsions.
Option B: Therapeutic levels of magnesium are 4-7 mEq/L. Magnesium sulfate is the first-line treatment for the prevention of primary and recurrent eclamptic seizures. For eclamptic seizures that are refractory to magnesium sulfate, lorazepam and phenytoin may be used as second-line agents.
Option C: Proteinuria of +3 would be noted in a client with preeclampsia. Proteinuria is defined as the presence of at least 300 mg of protein in a 24-hour urine collection, a protein (mg/dL)/creatinine (mg/dL) ratio greater than or equal to 0.3, or a urine dipstick protein of 1+ (if a quantitative measurement is unavailable). Serial confirmations 6 hours apart increase the predictive value. Although more convenient, a urine dipstick value of 1+ or more (30 mg/dL) is not reliable in the diagnosis of proteinuria.