A client with severe preeclampsia is receiving magnesium sulfate therapy. What is the priority nursing assessment as the nurse monitors this client's response to therapy?

In the context of a client receiving magnesium sulfate therapy for severe preeclampsia, monitoring the respiratory rate is particularly critical. Magnesium sulfate acts as a central nervous system depressant and can lead to respiratory depression if serum magnesium levels become elevated. The risk of respiratory depression increases as magnesium sulfate levels rise, making it essential to assess respiratory function closely.

Moreover, respiratory assessments are crucial because inadequate respiratory function can indicate impending complications, such as respiratory failure, which may require immediate intervention. While blood pressure and urine output are also important in managing preeclampsia, they do not pose the same immediate threat as changes in respiratory status when the patient is on magnesium therapy. Heart rate monitoring is useful but is secondary to respiratory rate in this specific scenario focusing on magnesium sulfate's effects.