Final answer:
The nurse should immediately notify the provider if the client being treated with magnesium sulfate for preterm labor has a respiratory rate of 10/min, as it may indicate magnesium sulfate toxicity.
Step-by-step explanation:
The nurse should notify the provider if the client has a respiratory rate of 10/min. This could indicate magnesium sulfate toxicity, which is a serious and potentially life-threatening condition. Normal respiratory rates for adults are generally between 12 to 16 breaths per minute, so a rate of 10 could be concerning. While nausea and feeling flushed can be side effects of magnesium sulfate, and a urinary output of 40 mL/hr is on the low end of normal, it is the significantly reduced respiratory rate that is most alarming and warrants immediate attention.