A client receives 20 mEq of potassium chloride added to 1000 mL of 0.9% saline. What should the nurse assess first?

In this scenario, the focus on assessing urine output as the priority is based on the critical role potassium plays in renal function. Potassium chloride is often administered to correct hypokalemia or to provide potassium during fluid replacement therapy. It is essential to ensure that the kidneys can excrete potassium to prevent hyperkalemia, which can have severe cardiac implications.

Monitoring urine output provides direct insight into kidney function, which is vital in the context of potassium administration. Adequate urine output indicates that the kidneys are functioning properly and are able to excrete excess potassium, thereby avoiding potential complications related to elevated serum potassium levels.

Observing other vital signs such as blood pressure, heart rate, and respiratory rate is important, but these parameters do not reflect kidney function specifically. If the kidneys are not functioning well, even if other vital signs appear stable, this could lead to dangerous levels of potassium in the bloodstream. Therefore, assessing urine output directly addresses the risk associated with administering potassium chloride.