A nurse is teaching a client who has heart failure about the renin-angiotensin-aldosterone system. Which of the following statements by the client indicates an understanding of the teaching?

Choice A reason:

Hyponatremia is a condition of low sodium level in the blood, which can result from excessive vomiting. Sodium is an important electrolyte that helps regulate fluid balance, nerve and muscle function, and blood pressure. When a person vomits, they lose sodium and water from the stomach, which can lead to dehydration and hyponatremia. Symptoms of hyponatremia include confusion, headache, weakness, nausea, muscle cramps, and seizures.

Choice B reason:

Hyperkalemia is a condition of high potassium level in the blood, which can result from kidney failure, certain medications, or excessive intake of potassium-rich foods. Potassium is an important electrolyte that helps regulate heart rhythm, muscle contraction, and nerve impulses. When a person has hyperkalemia, they may experience irregular heartbeat, chest pain, muscle weakness, numbness, or paralysis. Vomiting does not usually cause hyperkalemia unless the person has other risk factors.

Choice C reason:

Hypercalcemia is a condition of high calcium level in the blood, which can result from hyperparathyroidism, certain cancers, or excessive intake of calcium or vitamin D supplements. Calcium is an important electrolyte that helps regulate bone health, blood clotting, muscle contraction, and nerve function. When a person has hypercalcemia, they may experience nausea, vomiting, constipation, abdominal pain, confusion, lethargy, kidney stones, or cardiac arrhythmias. Vomiting does not usually cause hypercalcemia unless the person has other risk factors.

Choice D reason:

Hypomagnesemia is a condition of low magnesium level in the blood, which can result from malnutrition, alcoholism, diarrhea, diuretics, or certain medications. Magnesium is an important electrolyte that helps regulate muscle and nerve function, blood pressure, blood sugar, and protein synthesis. When a person has hypomagnesemia, they may experience muscle twitching, cramps, tremors, seizures, irregular heartbeat, or changes in mental status. Vomiting does not usually cause hypomagnesemia unless the person has other risk factors.

Choice A reason:

This system helps to increase my blood pressure when it is too low. This is correct because the renin-angiotensin-aldosterone system (RAAS) is a mechanism that regulates arterial blood pressure by increasing sodium and water retention, vasoconstriction, and cardiac output.

Choice B reason:

This system helps to decrease my blood volume when it is too high. This is incorrect because the RAAS does the opposite of this. It increases blood volume by stimulating the secretion of aldosterone, which causes the kidneys to reabsorb sodium and water.

Choice C reason:

This system helps to regulate my blood pH when it is too acidic. This is incorrect because the RAAS does not directly affect blood pH. Blood pH is regulated by the respiratory and renal systems, which adjust the levels of carbon dioxide and bicarbonate in the blood.

Choice D reason:

This system helps to lower my potassium level when it is too high. This is incorrect because the RAAS does not directly lower potassium levels. Potassium levels are regulated by the kidneys, which excrete excess potassium in the urine. However, aldosterone, which is part of the RAAS, can indirectly affect potassium levels by increasing sodium reabsorption and potassium secretion in the distal tubules of the kidneys.