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:

Sodium is not likely to be elevated in a client who has chronic kidney disease because the kidneys tend to lose sodium along with water. Sodium levels may be low (hyponatremia) or normal in these clients, depending on their fluid status and dietary intake.

Choice B reason:

Potassium is likely to be elevated in a client who has chronic kidney disease because the kidneys are unable to excrete excess potassium. Potassium levels may be high (hyperkalemia) or normal in these clients, depending on their medication use and dietary intake.

Choice C reason:

Calcium is not likely to be elevated in a client who has chronic kidney disease because the kidneys are unable to activate vitamin D, which is needed for calcium absorption. Calcium levels may be low (hypocalcemia) or normal in these clients, depending on their parathyroid hormone levels and supplementation.

Choice D reason:

Phosphorus is likely to be elevated in a client who has chronic kidney disease because the kidneys are unable to excrete excess phosphorus. Phosphorus levels may be high (hyperphosphatemia) or normal in these clients, depending on their dietary intake and phosphate binders.

Choice E reason:

Magnesium is likely to be elevated in a client who has chronic kidney disease because the kidneys are unable to excrete excess magnesium. Magnesium levels may be high (hypermagnesemia) or normal in these clients, depending on their dietary intake and antacid use.

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.

Choice A reason:

A positive Chvostek's sign is a facial twitch that occurs when the facial nerve is tapped. This is a sign of hypocalcemia, which causes increased neuromuscular excitability. According to index 2, a nurse can assess for Chvostek's sign by tapping the cheek just below the temple. If the facial muscles contract, the sign is positive.

Choice B reason:

Decreased deep tendon reflexes are not a sign of hypocalcemia, but rather of hypercalcemia, which causes decreased neuromuscular excitability. According to index 5, symptoms of hypercalcemia include muscle weakness, fatigue, constipation, nausea, vomiting, and confusion.

Choice C reason:

Muscle weakness is also not a sign of hypocalcemia, but rather of hyperkalemia, which causes impaired muscle contraction. According to index 1, a nurse can assess for muscle weakness by testing the client's grip strength and ability to lift the legs against resistance. If the client has difficulty performing these tasks, they may have hyperkalemia.

Choice D reason:

Hypoactive bowel sounds are not a sign of hypocalcemia, but rather of ileus, which is a paralysis of the intestinal muscles that causes obstruction. Ileus can be caused by various factors, such as surgery, infection, medication, or electrolyte imbalance. According to index 6, symptoms of ileus include abdominal pain, distension, nausea, vomiting, and constipation.

Choice A reason:

Tachycardia is not a sign of magnesium toxicity. Magnesium sulfate can cause bradycardia or slow heart rate as a side effect.

Choice B reason:

Diarrhea is not a sign of magnesium toxicity. Magnesium sulfate can cause constipation or decreased bowel movements as a side effect.

Choice C reason:

Respiratory depression is a sign of magnesium toxicity. Magnesium sulfate can cause decreased respiratory rate or difficulty breathing as a side effect. This is a serious complication that requires immediate intervention by the nurse, such as discontinuing the infusion and administering calcium gluconate as an antidote.

Choice D reason:

Hyperthermia is not a sign of magnesium toxicity. Magnesium sulfate can cause hypothermia or low body temperature as a side effect.