ATI Fluid and Electrolytes

Correct Answer: D

Rationale: Specific gravity is a test used to determine the concentration of solutes in the urine, reflecting the kidney's ability to concentrate urine. Changes in specific gravity can indicate fluid volume status, such as dehydration (fluid volume deficit) or overhydration (fluid volume excess). Options A, B, and C are incorrect as specific gravity does not directly detect nutritional deficits, hyperkalemia, or hypercalcemia.

Correct Answer: D

Rationale: Newborns have a higher percentage of body water compared to adults due to their higher body fluid content. Factors such as the higher ratio of body surface area to body volume and lower body fat content contribute to this. This is why a newborn would have the greatest percentage of body water. Choices A, B, and C are incorrect because obesity and gender do not determine the percentage of body water in individuals. Therefore, the correct answer is a newborn.

Correct Answer: A

Rationale: Corrected Rationale: To assess a patient's magnesium status, the nurse should check deep tendon reflexes. Diminished deep tendon reflexes may indicate high serum magnesium levels, as hypermagnesemia can lead to neuromuscular effects. Tachycardia, cool clammy skin, and acute flank pain are not typically associated with high magnesium levels and are not priority assessments in this situation.

Correct Answer: B

Rationale: The correct answer is Potassium (K+). Potassium is the predominant cation found within cells, making it the most prevalent positive ion in intracellular fluid. Calcium, sodium, and magnesium are also essential ions in the body, but they are not as abundant in intracellular fluid. Calcium is vital for bone health and muscle function, sodium helps in maintaining fluid balance and nerve function, and magnesium is involved in numerous biochemical reactions.

Correct Answer: C

Rationale: In dehydration, the body first draws fluid from the interstitial space to maintain blood volume, leading to a decrease in interstitial fluid volume. This is why choice C is correct. Choice A is incorrect because intracellular fluid is not the first to be affected. Choice B is also incorrect as plasma volume reduction typically occurs after interstitial fluid loss. Choice D is incorrect as dehydration impacts both interstitial and intracellular fluid volumes.