The nurse is assessing the laboratory values for a patient with chronic heart failure before administering furosemide. Which of the following values would cause the nurse to withhold this drug and notify the primary care provider?

Correct Answer: A

Rationale: The correct answer is A: Potassium level of 3.5 mEq/L. In patients with chronic heart failure, furosemide can cause potassium loss leading to hypokalemia, which can worsen cardiac function and lead to arrhythmias. Therefore, a low potassium level warrants withholding furosemide and notifying the primary care provider for appropriate management. Incorrect choices: B: Digoxin level of 0.7 ng/mL - Although digoxin levels should be monitored, a level of 0.7 ng/mL is within the therapeutic range. C: Calcium level of 5 mg/dL - Low calcium levels do not directly contraindicate furosemide use. D: Magnesium level of 1 mg/dL - While magnesium levels should also be monitored, a level of 1 mg/dL is not significantly low to withhold furosemide.

Correct Answer: B

Rationale: The correct answer is B: Tachycardia can be a side effect of digoxin. Digoxin is a cardiac glycoside that can lead to tachycardia as a side effect due to its effects on the heart. Anorexia (A), constipation (C), and urinary retention (D) are not commonly associated with digoxin use and are not typical side effects. Tachycardia is a known adverse effect of digoxin due to its ability to increase heart contractility, leading to a faster heart rate. This is why option B is the most appropriate response to the client's question about digoxin side effects.

Correct Answer: B

Rationale: The correct answer is B: It decreases heart rate and the work of the heart. Beta blockers work by blocking the action of adrenaline on beta receptors in the heart, leading to a reduction in heart rate and contractility. This helps the heart by decreasing its workload and oxygen demand, making it more efficient. A: Incorrect. Beta blockers actually decrease preload by reducing the force of cardiac contraction. C: Incorrect. Beta blockers typically lower blood pressure by reducing heart rate and contractility. D: Incorrect. While beta blockers can be used for certain arrhythmias, such as atrial fibrillation, they are not typically used for ventricular tachycardia.

Correct Answer: C

Rationale: The correct answer is C: Procainamide. Class IA anti-arrhythmic agents, like Procainamide, work by blocking sodium channels, prolonging action potential duration. Metoprolol (A) is a beta-blocker, not a class IA agent. Disopyramide (B) is a class IA agent, but it acts primarily by blocking potassium channels. Morcizine (D) is a class IC anti-arrhythmic agent, not a class IA agent. Therefore, Procainamide is the most likely choice among the options provided.

Correct Answer: C

Rationale: The correct answer is C: Hypertension. ACE inhibitors are commonly prescribed to treat hypertension by blocking the conversion of angiotensin I to angiotensin II, resulting in vasodilation and decreased blood pressure. Explanation for other choices: A: Frequent PVCs - ACE inhibitors are not typically used to treat PVCs as they are more related to cardiac arrhythmias. B: Atrial flutter - ACE inhibitors are not the first-line treatment for atrial flutter, which is usually managed with antiarrhythmic medications or cardioversion. D: Diabetic nephropathy - While ACE inhibitors can be used to treat diabetic nephropathy by reducing intraglomerular pressure, it is not the primary indication for their use in this scenario.