The nurse is preparing to administer digoxin (Lanoxin) to a client experiencing atrial fibrillation. Which of the following electrolyte imbalances would the nurse assess to reduce the incidence of toxicity with digoxin?

Choice A reason: Hypocalcemia, or low calcium levels, can affect heart rhythm and function, but it does not have a direct impact on digoxin toxicity. Digoxin toxicity is more closely related to potassium levels in the blood. While maintaining balanced calcium levels is important for overall cardiac health, hypocalcemia is not the primary concern in the context of digoxin toxicity. Choice B reason: Hypokalemia, or low potassium levels, significantly increases the risk of digoxin toxicity. Potassium and digoxin compete for binding at the same sites in the heart, and low potassium levels enhance digoxin's effects, potentially leading to toxicity. Symptoms of digoxin toxicity can include nausea, vomiting, dizziness, confusion, and cardiac arrhythmias. It is crucial for the nurse to monitor and correct potassium levels to prevent these serious side effects. Choice C reason: Hypophosphatemia, or low phosphate levels, does not have a direct impact on digoxin toxicity. Phosphate levels are important for general cellular function and energy metabolism, but they do not play a critical role in the interaction between digoxin and cardiac cells. Therefore, monitoring phosphate levels is not relevant for managing digoxin toxicity. Choice D reason: Hypernatremia, or high sodium levels, can have various effects on the body, including fluid balance and blood pressure, but it is not directly related to digoxin toxicity. Sodium levels do not affect how digoxin binds to cardiac cells or its overall pharmacodynamics. Therefore, sodium levels are not the primary concern when assessing for digoxin toxicity.