Question

The nurse caring for a client receiving magnesium sulfate must closely observe for side effects associated with drug therapy. An expected side effect of magnesium sulfate is: A. Decreased urinary output B. Hypersomnolence C. Absence of knee jerk reflex D. Decreased respiratory rate

Short answer

Answer: Absence of knee-jerk reflex

Step-by-step solution

Understanding magnesium sulfate and its effects

Magnesium sulfate is a medication commonly used to treat various health issues. It can be used as a laxative, antacid, and to treat magnesium deficiency. One of its primary uses is to prevent seizures in pregnant women with preeclampsia. It acts as a CNS (central nervous system) depressant, which means it can slow down or suppress the activity of the brain and nerves.

Evaluating the possible side effects

We have four possible expected side effects of magnesium sulfate: A. Decreased urinary output B. Hypersomnolence C. Absence of knee jerk reflex D. Decreased respiratory rate Let's analyze each option.

Evaluating Option A

Decreased urinary output might be related to kidney issues. However, magnesium sulfate is not directly associated with reduced urinary output as an expected side effect. So, we can eliminate this option.

Evaluating Option B

Hypersomnolence refers to excessive sleepiness. As magnesium sulfate acts as a CNS depressant, it may cause drowsiness or sedation. However, hypersomnolence is an extreme case and is not considered an expected side effect. So, we can eliminate this option too.

Evaluating Option C

Absence of knee jerk reflex: The knee jerk reflex is a neurological response that can be altered by a CNS depressant like magnesium sulfate. When the levels of magnesium sulfate in the body are high or toxic, a decrease or absence of knee jerk reflex is expected as the central nervous system is being depressed. Therefore, this option seems plausible.

Evaluating Option D

Decreased respiratory rate: Magnesium sulfate can cause a decrease in the respiratory rate due to its effect as a CNS depressant. However, a significant decrease in respiratory rate is considered a clinical sign of magnesium sulfate toxicity, not a regular side effect. So, we can eliminate this option as well.

Choose the correct answer

Based on our evaluation of each option, we can conclude that the expected side effect of magnesium sulfate is: C. Absence of knee-jerk reflex