A nurse is preparing to administer 4,000 units of heparin subcutaneously to a client who has deep-vein thrombosis. Available in heparin 10,000 units/mL. How many mL of heparin should the nurse administer?
(Round the answer to the nearest tenth. Use a leading zero if it applies. Do not use a trailing zero.)

A. Taking an HMG CoA reductase inhibitor (commonly known as statins) is not directly associated with digoxin toxicity. Statins are used to lower cholesterol levels.
B. Having a 10-year history of COPD (chronic obstructive pulmonary disease) is not directly linked to an increased risk of digoxin toxicity.
C. Having a prolapsed mitral valve is a valvular disorder and is not a primary factor that contributes to digoxin toxicity.
D. Taking a high-ceiling diuretic
The factor that predisposes the client to develop digoxin toxicity is taking a high-ceiling diuretic.
Digoxin toxicity can be influenced by several factors. One important factor is the levels of potassium in the blood. High-ceiling diuretics, also known as loop diuretics (e.g., furosemide), can lead to potassium loss through increased urinary excretion. Low levels of potassium (hypokalemia) can increase the risk of digoxin toxicity, as digoxin has a greater effect on the heart when potassium levels are low.

A. Hypomagnesemia:
Correct Answer: This electrolyte imbalance is the one the nurse should assess the client for.
Explanation: Lithium is primarily excreted by the kidneys, and its excretion can be influenced by factors that affect renal function, including electrolyte imbalances. Hypomagnesemia (low magnesium levels) can potentially reduce the excretion of lithium, leading to increased lithium levels in the blood. This can increase the risk of lithium toxicity, which can be dangerous. Therefore, monitoring magnesium levels is important in clients taking lithium.
B. Hyponatremia:
Incorrect Explanation: While hyponatremia (low sodium levels) is a potential concern, it is not as directly linked to lithium interaction as hypomagnesemia.
Explanation: Lithium can cause diabetes insipidus, which leads to excessive urination and subsequent loss of water and electrolytes, including sodium. However, hyponatremia is not the immediate electrolyte imbalance that arises due to the interaction with lithium.
C. Hypocalcemia:
Incorrect Explanation: Hypocalcemia (low calcium levels) is not a primary concern in the context of lithium use.
Explanation: Lithium does not have a direct interaction with calcium levels. Hypocalcemia is typically not a result of lithium use or its interaction with other factors.
D. Hypokalemia:
Incorrect Explanation: While electrolyte imbalances like hypokalemia (low potassium levels) can have health implications, it is not the primary electrolyte imbalance to be concerned about with lithium use.
Explanation: Hypokalemia is not a direct consequence of lithium interaction. Monitoring potassium levels is important for overall health, but it's not the primary electrolyte imbalance associated with lithium use and its potential interactions.