What is a critical sign of magnesium toxicity in a client receiving magnesium sulfate?

Identifying a critical sign of magnesium toxicity is essential for effective clinical management, especially in patients receiving magnesium sulfate. A respiratory rate below 12 breaths per minute is significant because magnesium toxicity can lead to respiratory depression. As magnesium levels rise, they can interfere with neuromuscular function and compromise the respiratory system, resulting in decreased respiratory drive. This is a crucial sign that indicates a need for immediate intervention, as impaired respiration can lead to severe complications, including respiratory failure.

The other choices do present concerning symptoms, but they are not as directly indicative of magnesium toxicity as a low respiratory rate. For instance, while hypotension can occur with magnesium toxicity, a blood pressure below normal is a more generalized sign that may not directly arise from magnesium specifically. Similarly, a high fever might suggest infection or other systemic issues rather than specifically indicating magnesium toxicity. An increased heart rate can be attributed to many factors and is less specific to magnesium overload, potentially signaling other physiological responses at play.

In essence, monitoring respiratory rate in the context of magnesium sulfate administration is particularly vital and serves as a critical indicator of potential toxicity.