A nurse is assessing a client who has heart failure and is taking furosemide. Which of the following findings should indicate to the nurse that the client is experiencing fluid volume deficit?

Choice A Reason:
Hypomagnesemia is incorrect. Lithium therapy itself is not a direct cause of hypomagnesemia. While exercise can affect magnesium levels to some extent, it's not a primary electrolyte imbalance that is typically associated with lithium use or considered a significant concern specifically due to lithium.
Choice B Reason:
Hypocalcemia is incorrect. Similarly, lithium therapy is not a direct cause of hypocalcemia. Exercise can affect calcium metabolism, but it's not a primary electrolyte imbalance typically associated with lithium use or considered a significant concern specifically due to lithium.
When a client taking lithium begins a new exercise program, the nurse should primarily assess for the risk of:
Choice C Reason:
Hyponatremia is correct. Lithium can affect the body's regulation of sodium, and excessive sweating due to increased exercise can lead to sodium loss. This combination can potentially contribute to the development of hyponatremia (low sodium levels). Therefore, when a client on lithium starts a new exercise regimen that may induce sweating, monitoring for signs of hyponatremia becomes crucial. Symptoms of hyponatremia can include confusion, headaches, nausea, and in severe cases, seizures or coma.
Choice D Reason:
Hypokalemia is incorrect. Lithium itself does not commonly cause hypokalemia. Exercise can lead to potassium loss through sweating, but hypokalemia is not the primary electrolyte imbalance typically associated with lithium use or considered a significant concern specifically due to lithium.

Choice A Reason:
Using the applicator paper is appropriate for measuring the dosage accurately, but simply measuring the dosage is not the only step; the medication needs to be spread over the specified area of the skin.
Choice B Reason:
Spread the medication over a 12.7 cm (5 in) area of the client's skin. Nitroglycerin ointment is typically measured using a specific paper or measuring tape provided with the medication to ensure accurate dosing. The ointment is spread thinly and evenly over a specific measured area of the skin, usually about 12.7 cm (5 inches) in length, to maintain consistent dosing.
Choice C Reason:
Covering the medication with a sterile gauze pad is not typically done with nitroglycerin ointment. The ointment is meant to be absorbed through the skin, and covering it may interfere with its absorption.
Choice D Reason:
Nitroglycerin ointment is often applied to different sites to prevent skin irritation and tolerance from developing at one site. It's usually rotated to different clean areas of the skin to prevent skin irritation and tolerance buildup. Applying it to the same site for three consecutive days is not standard practice.