What laboratory value should a nurse prioritize assessing for a client taking oral prednisone and furosemide?

When a client is taking oral prednisone, a corticosteroid, and furosemide, a loop diuretic, it is essential to prioritize the assessment of potassium levels. Prednisone can lead to increased sodium retention and may cause potassium depletion, while furosemide can exacerbate this effect by increasing the excretion of potassium through the kidneys. Therefore, individuals on these medications are at risk for hypokalemia, a condition characterized by low levels of potassium in the blood.

Monitoring potassium levels helps ensure that the client does not develop complications associated with hypokalemia, such as muscle weakness, arrhythmias, and other cardiovascular issues. This makes potassium the most critical lab value to assess in these clients, as maintaining potassium balance is vital for overall health and can significantly impact muscular and cardiac function.