A nurse is preparing to administer intravenous magnesium sulfate to a client who has preeclampsia. The nurse should monitor the client for which of the following adverse effects of magnesium toxicity?

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:

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.