Final answer:
The nurse should include the information to 'Weigh yourself daily and report sudden weight gain.' Monitoring weight is important for a client with heart failure and taking a potassium-sparing diuretic because it helps to assess fluid balance.
Step-by-step explanation:
The nurse should include the information to "Weigh yourself daily and report sudden weight gain."
Monitoring weight is important for a client with heart failure and taking a potassium-sparing diuretic because it helps to assess fluid balance. Sudden weight gain may indicate fluid retention, which can worsen heart failure symptoms. Prompt reporting of weight gain to the healthcare provider is essential to prevent worsening of the client's condition.