A nurse is providing discharge teaching to a client who has a new arteriovenous fistula in the right forearm. Which of the following manifestations should the nurse include in the teaching as a possible indication of venous insufficiency?

Choice A Reason: This is incorrect because shortening of P-wave duration is not a sign of hyperkalemia or its reversal.

P-wave duration reflects the time it takes for the atria to depolarize and contract.

Choice B Reason: This is incorrect because restoration of QRS complex amplitude is not a sign of hyperkalemia or its reversal. QRS complex amplitude reflects the voltage or strength of the ventricular depolarization and contraction.

Choice C Reason: This is correct because the reduction of T-wave amplitude is a sign of hyperkalemia reversal. T-wave amplitude reflects the repolarization or recovery of the ventricles after contraction. Polystyrene sulfonate is a medication that lowers the serum potassium level by binding to it in the gastrointestinal tract and excreting it in the stool. High serum potassium level, or hyperkalemia, can cause cardiac arrhythmias and ECG changes, such as peaked T waves, prolonged PR interval, flatened P waves, widened QRS complex, and ventricular fibrillation. By lowering the serum potassium level, polystyrene sulfonate can reverse these ECG changes and normalize the cardiac rhythm.

Choice D Reason: This is incorrect because the widening of the QRS complex is a sign of hyperkalemia, not its reversal. Widening of the QRS complex reflects the delay or impairment of ventricular depolarization and contraction.

Choice a) is incorrect because morphine sulfate is an appropriate prescription for a client who has acute heart failure following MI. Morphine sulfate is an opioid analgesic that can relieve pain, anxiety, and dyspnea. Morphine sulfate can also reduce the preload and afterload of the heart, which can improve the cardiac output and oxygenation.

Choice b) is incorrect because laboratory testing of serum potassium is an appropriate prescription for a client who has acute heart failure following MI. Serum potassium is an electrolyte that is important for the normal function of the cardiac cells and muscles. Serum potassium can be altered by various factors, such as renal function, acid-base balance, medications, or dietary intake. Serum potassium can affect the cardiac rhythm and contractility, which can influence the outcome of the client.

Choice c) is correct because 0.9% normal saline IV at 50 mL/hr continuous is a prescription that requires clarification for a client who has acute heart failure following MI. 0.9% normal saline is an isotonic solution that can maintain the fluid balance and blood pressure in the body. However, 0.9% normal saline can also cause fluid overload and worsen the heart failure symptoms, such as edema, crackles, and dyspnea. The nurse should clarify with the provider if this prescription is appropriate for the client's condition and if there are any parameters or limits for the fluid administration.

Choice d) is incorrect because bumetanide 1 mg IV bolus every 12 hr is an appropriate prescription for a client who has acute heart failure following MI. Bumetanide is a loop diuretic that can increase the urine output and reduce the fluid volume and pressure in the body. Bumetanide can also decrease the preload and afterload of the heart, which can improve the cardiac output and oxygenation.