A nurse is assessing a client who has a magnesium level of 4.4 mEq/L. Which of the following findings should the nurse expect?
A.
Hypotension
B.
Tachycardia
C.
Muscle cramps
D.
Hyperreflexia
The Correct Answer and Explanation is:
The correct answer is A. Hypotension.
Explanation:
Magnesium is an essential electrolyte in the body that plays a critical role in numerous physiological processes, including muscle and nerve function, blood pressure regulation, and bone health. The normal range for serum magnesium levels is typically between 1.5 and 2.5 mEq/L (or 0.75 to 1.25 mmol/L). Therefore, a magnesium level of 4.4 mEq/L is elevated, indicating hypermagnesemia.
Hypermagnesemia can result from excessive magnesium intake, such as from overuse of magnesium-containing supplements or medications (like antacids or laxatives) or from conditions that impair magnesium excretion, such as renal failure. Elevated magnesium levels affect various body systems and can lead to several clinical manifestations:
- Hypotension: Elevated magnesium levels can lead to vasodilation, resulting in low blood pressure. Magnesium acts as a natural calcium antagonist, and its high levels can interfere with the normal contraction of smooth muscle in blood vessels, causing them to dilate and leading to hypotension.
- Bradycardia: While tachycardia (rapid heart rate) is generally associated with hypomagnesemia (low magnesium levels), hypermagnesemia can cause bradycardia (slow heart rate) due to its depressant effect on the cardiac conduction system. This is because high magnesium levels can interfere with the electrical conduction through the heart.
- Muscle Weakness and Reflexes: Hypermagnesemia can lead to muscle weakness, reduced deep tendon reflexes, and decreased neuromuscular excitability rather than muscle cramps or hyperreflexia (overactive reflexes). Muscle cramps and hyperreflexia are more commonly associated with hypomagnesemia.
- Nausea and Vomiting: Elevated magnesium levels can also cause gastrointestinal symptoms such as nausea and vomiting.
Given the elevated magnesium level of 4.4 mEq/L, hypotension is the expected finding. The other options, such as tachycardia, muscle cramps, and hyperreflexia, are not typically associated with hypermagnesemia but rather with hypomagnesemia.