Final answer:
The nurse should assess the client's serum potassium level when administering a loop diuretic to a client diagnosed with CAD.
Step-by-step explanation:
When administering a loop diuretic to a client diagnosed with CAD, the nurse should implement the intervention of assessing the client's serum potassium level. Loop diuretics, such as furosemide, can cause potassium loss in the body. By monitoring the client's serum potassium level, the nurse can detect and address any imbalances and prevent complications.