A nurse is caring for an adolescent who states, "I joined the track and field team, so I won't argue with my brothers anymore." The nurse should identify that the client is using which of the following defense mechanisms?

A. Give a dose of alendronate is incorrect. Alendronate is a medication used to treat osteoporosis, and it does not address low potassium levels. In this case, the focus should be on correcting the potassium imbalance.

B. Administer furosemide is incorrect. Furosemide is a diuretic that can cause further loss of potassium. In a client with low potassium levels (hypokalemia., administering furosemide could worsen the condition and lead to life-threatening complications.

C. Apply a cardiac monitor is correct. Hypokalemia (potassium level of 2.9 mEq/L) can cause significant cardiac arrhythmias, including ventricular tachycardia or fibrillation. Applying a cardiac monitor is essential for monitoring the client’s heart rhythm and detecting any abnormalities related to the low potassium level.

D. Monitor for Chvostek's sign is incorrect. Chvostek's sign is indicative of hypocalcemia, not hypokalemia. While both hypocalcemia and hypokalemia can cause neuromuscular excitability, monitoring for Chvostek’s sign is not a priority in the management of hypokalemia.

A. The client should use a hair dryer on a warm setting to relieve itching inside the cast is incorrect. Using a hair dryer could cause skin burns or damage the cast. Additionally, the client should avoid introducing moisture into the cast, which could lead to skin irritation or infection.

B. The client's extremity should be elevated after the cast is applied is correct. Elevating the extremity helps reduce swelling and inflammation during the initial phase after cast application. It is important to elevate the limb above the level of the heart to promote venous return and reduce swelling.

C. The client can shower with the cast after 24 hr is incorrect. The plaster cast should not get wet. The nurse should instruct the client to keep the cast dry at all times. A plastic cover or cast protector should be used when showering to prevent moisture from seeping into the cast.

D. The client should keep the cast covered until it is dry is incorrect. It is true that the cast should be kept dry, but keeping it covered is not enough. The primary concern is preventing moisture and ensuring the plaster cast is allowed to air dry in a well-ventilated area without getting wet.