Editing Medical-Surgical Nursing – RN Practice Questions (section)

==Question 13==
A patient taking digoxin and furosemide reports nausea, anorexia, and seeing yellow-green halos around lights. The apical pulse is 52 beats per minute and irregular. Which laboratory value most likely contributed to this presentation?
# Serum sodium of 138 mEq/L.
# Serum potassium of 2.8 mEq/L.
# Serum calcium of 9.2 mg/dL.
# Serum magnesium of 2.0 mEq/L.

'''Answer:''' Option 2, serum potassium of 2.8 mEq/L.

''Rationale:'' The patient shows classic digoxin toxicity with gastrointestinal symptoms, yellow-green visual halos, and bradycardia with a new irregular rhythm. Hypokalemia, commonly caused by loop diuretics such as furosemide, markedly potentiates digoxin binding and toxicity even when the digoxin level is within range. The nurse holds the dose, notifies the provider, and obtains a digoxin level. Options 1, 3, and 4 are all within normal limits and do not explain the findings.