Correct Answer: A

Rationale: Hypertension is the correct answer. Hypertension, also known as high blood pressure, is a major risk factor for stroke because it puts increased pressure on blood vessels in the brain, making them more prone to damage and increasing the likelihood of a stroke. While diabetes, obesity, and smoking are also risk factors for stroke, hypertension is the most commonly associated condition with a high risk of stroke due to its direct impact on the blood vessels.

Correct Answer: C

Rationale: The correct answer is to instruct the client on how to take deep breaths. Deep breathing exercises are essential in preventing postoperative respiratory complications like atelectasis by promoting lung expansion. Using incentive spirometry is a more specific and advanced method of promoting deep breathing and lung expansion, making it a better choice than just turning in bed. While turning in bed may help with overall comfort and positioning, it is not as directly related to respiratory complications as deep breathing exercises. Coughing, although important for clearing secretions, is not as effective in preventing atelectasis as deep breathing exercises.

Correct Answer: A

Rationale: The correct answer is A: Cardiac arrhythmias. Reperfusion of cardiac tissue following t-PA administration can lead to cardiac arrhythmias, necessitating resuscitation equipment. Hypertension (choice B) is a common side effect of t-PA but is not directly related to reperfusion. Seizures (choice C) and hypothermia (choice D) are not typically associated with reperfusion from t-PA administration.

Correct Answer: C

Rationale: The correct answer is C: Hyperkalemia. Sodium polystyrene sulfonate (Kayexalate) is used to treat high potassium levels (hyperkalemia) by exchanging sodium ions for potassium ions in the large intestine, which is then eliminated through the feces. Therefore, the nurse should monitor the client for changes in potassium levels to ensure the effectiveness of the treatment. Choices A, B, and D are incorrect because sodium polystyrene sulfonate (Kayexalate) is not associated with causing hyponatremia, hypokalemia, or hypocalcemia.

Correct Answer: A

Rationale: A serum potassium level of 2.5 mEq/L is critically low, indicating severe hypokalemia. The immediate action the nurse should take is to inform the healthcare provider of the need for potassium replacement. Option B, preparing to administer glucose-insulin-potassium replacement, is not the first-line intervention; it may be considered in specific situations but requires a healthcare provider's prescription. Option C, changing the plan of care to include hourly urinary output measurement, is not the priority when managing critically low potassium levels. Option D, instructing the client to increase daily intake of potassium-rich foods, is not appropriate in this acute situation where immediate intervention is needed to address the dangerously low potassium level.