A patient with atrial fibrillation has been prescribed digoxin (Lanoxin). The nurse should monitor which laboratory value to evaluate therapeutic effectiveness?

The client has a blood pressure of 120/78 mm Hg. This indicates that the medication is effective because it lowers the blood pressure below the hypertensive levels.In adults 60 years of age or older, this is typically defined as a systolic pressure below 150 mm Hg and a diastolic pressure below 90 mm Hg.

Choice A is wrong because the client has no edema in the lower extremities. This is not a specific outcome of lisinopril, an angiotensin II receptor blocker (ARB). Edema can be caused by many factors, such as heart failure, kidney disease, or venous insufficiency. Lisinopril does not directly affect fluid retention or edema.

Choice B is wrong because the client has a urine output of 30 mL/hr. This is a low urine output that may indicate dehydration, kidney impairment, or urinary obstruction. Lisinopril is expected to increase urine output by reducing the blood pressure and improving the renal blood flow.

Choice D is wrong because the client has a serum creatinine level of 1.2 mg/dL. This is a high serum creatinine level that may indicate kidney damage or reduced kidney function. Lisinopril is expected to lower the serum creatinine level by preventing the progression of kidney disease and protecting the kidney from further injury.

Normal ranges of urine output, blood pressure, and serum creatinine are:

• Urine output: 800 to 2000 mL/day or 40 to 80 mL/hr

• Blood pressure: less than 120/80 mm Hg for adults

• Serum creatinine: 0.6 to 1.2 mg/dL for males and 0.5 to 1.1 mg/dL for females

Digoxin (Lanoxin) is a cardiac glycoside that is used to treat atrial fibrillation and heart failure.

It works by increasing the force of cardiac contraction and slowing down the heart rate.

However, digoxin can also cause toxicity, which can lead to life-threatening arrhythmias.

One of the risk factors for digoxin toxicity is hypokalemia, or low serum potassium level.

Potassium is an electrolyte that is essential for normal cardiac function and conduction.When the serum potassium level is low, digoxin binds more strongly to the cardiac cells and increases its effects, which can result in bradycardia, heart block, or ventricular tachycardia.

Therefore, the nurse should monitor the serum potassium level to evaluate the therapeutic effectiveness and safety of digoxin therapy.

Choice B) Serum sodium level is wrong because sodium is not directly related to digoxin action or toxicity.

Sodium is another electrolyte that is important for fluid balance and blood pressure regulation.However, sodium does not affect the binding of digoxin to the cardiac cells or its effects on the heart rate and contractility.

Therefore, the nurse does not need to monitor the serum sodium level to evaluate digoxin therapy.

Choice C) Serum magnesium level is wrong because magnesium is not directly related to digoxin action or toxicity.

Magnesium is another electrolyte that is involved in many enzymatic reactions and neuromuscular function.However, magnesium does not affect the binding of digoxin to the cardiac cells or its effects on the heart rate and contractility.

Therefore, the nurse does not need to monitor the serum magnesium level to evaluate digoxin therapy.

Choice D) Serum calcium level is wrong because calcium is not directly related to digoxin action or toxicity.

Calcium is another electrolyte that is essential for bone health and muscle contraction.However, calcium does not affect the binding of digoxin to the cardiac cells or its effects on the heart rate and contractility.

Therefore, the nurse does not need to monitor the serum calcium level to evaluate digoxin therapy.

The normal range for serum potassium level is 3.5-5.0 mEq