What is the most common reason for late postpartum hemorrhage (PPH)?

A. An increase in lochia suggests continued uterine bleeding and possible uterine atony. Methylergonovine is administered to reduce postpartum hemorrhage by promoting uterine contraction; therefore, increased lochia indicates the medication is not effective.
B. Absence of breast pain is unrelated to methylergonovine’s mechanism of action. This medication acts specifically on uterine smooth muscle and does not relieve breast engorgement or nipple discomfort.
C. An increase in blood pressure is a known adverse effect of methylergonovine because it causes vasoconstriction. For this reason, the drug is contraindicated in clients with hypertension or preeclampsia. An elevated blood pressure indicates a side effect, not therapeutic success.
D. A fundus that is firm to palpation indicates effective uterine contraction. Methylergonovine stimulates sustained uterine contractions, which compress uterine blood vessels and reduce bleeding. A firm, well-contracted uterus is the primary desired outcome and confirms the medication’s effectiveness.

A. While assessing temperature is important for evaluating maternal infection or overall condition, it is not the primary concern when administering magnesium sulfate. Fever does not typically indicate magnesium toxicity, so it is not the priority assessment in this situation.

B. This is the priority assessment because magnesium sulfate can cause respiratory depression if serum levels exceed the therapeutic range. Magnesium acts as a central nervous system depressant and smooth muscle relaxant, which helps inhibit uterine contractions in preterm labor but also poses a risk to respiratory function. The nurse should assess the client’s respiratory rate before initiating the infusion and monitor continuously throughout therapy. A respiratory rate below 12 breaths per minute may indicate early magnesium toxicity, necessitating immediate cessation of the infusion, administration of calcium gluconate as an antidote, and supportive respiratory care.

C. Monitoring blood pressure is important, especially in clients with preeclampsia, because magnesium sulfate can have mild hypotensive effects. However, the most immediate risk of toxicity is respiratory depression, not blood pressure changes. Therefore, while BP is monitored, it is secondary to respiratory assessment in this context.

D. Bowel sounds are part of a routine assessment but are not affected by magnesium sulfate and do not relate to the medication’s most dangerous complications.