A nurse is assessing a client who has heart failure and is taking digoxin. Which of the following findings should the nurse identify as an early indication of medication toxicity?

Choice A Reason:
Extravasation is incorrect. This occurs when the intravenous fluid leaks into the surrounding tissue rather than remaining within the vein. It may cause swelling, pain, and potential tissue damage due to the infused solution's irritant effects.
Choice B Reason:
Phlebitis is correct. Phlebitis refers to the inflammation of a vein often characterized by redness, warmth, swelling, and tenderness along the course of the vein. It can occur due to various reasons, including irritation from the IV catheter, chemical irritation from the infused solution, or infection.
Choice C Reason:
Infiltration is incorrect. Infiltration refers to the inadvertent leakage of the infused fluid into the surrounding tissues. It may cause swelling and discomfort but doesn't typically present with redness and inflammation along the vein.
Choice D Reason:
Venous spasm is incorrect. Venous spasm involves the involuntary contraction of the vein, which can occur in response to irritation or trauma. It may cause temporary difficulty in IV access but does not usually present with redness and inflammation along the vein as the primary signs.

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.