When administering furosemide (Lasix), which parameter should the nurse closely monitor?

Monitoring the patient's potassium level is crucial when administering furosemide (Lasix) because this medication is a loop diuretic that can lead to significant electrolyte imbalances. Furosemide promotes the excretion of sodium and water, but it also increases the excretion of potassium in the urine. This can result in hypokalemia, a condition characterized by low potassium levels, which can have serious consequences, including muscle weakness, cardiac arrhythmias, and other metabolic disturbances.

Given the potential for furosemide to cause potassium depletion, it is essential for the nurse to regularly assess the patient's serum potassium levels, especially if the patient is on long-term therapy or has other risk factors for electrolyte imbalances, such as renal impairment or concurrent use of other medications that affect potassium levels. Monitoring potassium helps ensure patient safety and allows for timely intervention if levels drop too low.

In contrast, while monitoring oxygen saturation, red blood cell counts, or level of consciousness may also be relevant in certain clinical situations, they do not directly reflect the specific risks associated with furosemide use. Potassium levels are particularly pertinent due to the mechanism of action of the medication and the potential complications that can arise from hypokalemia.