Video Library
Fluid Pressures/Movements (Starling's Law)
Fluid Pressures/Movements (Starling's Law) ( 5 Questions)
A nurse is reviewing the laboratory results of a client who has dehydration. Which of the following findings indicates an increase in osmolality?
Serum sodium 140 mEq/L is a normal value and does not indicate an increase in osmolality. Osmolality is the concentration of dissolved particles in a fluid. Sodium is one of the main electrolytes that affect osmolality, but a normal sodium level does not necessarily mean a normal osmolality.
Serum potassium 4.0 mEq/L is also a normal value and does not indicate an increase in osmolality. Potassium is another electrolyte that affects osmolality, but it has a smaller effect than sodium. A normal potassium level does not necessarily mean a normal osmolality.
Serum glucose 90 mg/dL is also a normal value and does not indicate an increase in osmolality. Glucose is another substance that affects osmolality, but it has a smaller effect than electrolytes. A normal glucose level does not necessarily mean a normal osmolality.
Serum urea nitrogen 25 mg/dL is an elevated value and indicates an increase in osmolality. Urea nitrogen is a waste product of protein metabolism that is excreted by the kidneys. Urea nitrogen is one of the main substances that affect osmolality, along with sodium and glucose. An elevated urea nitrogen level means that the blood is more concentrated and has less water. This can be caused by dehydration, which is a common condition in clients who have dehydration. Dehydration leads to an increase in serum osmolality and activation of antidiuretic hormone (ADH), which results in urinary concentration. Therefore, choice D is the correct answer.
Choice A reason: Serum sodium 140 mEq/L is a normal value and does not indicate an increase in osmolality. Osmolality is the concentration of dissolved particles in a fluid. Sodium is one of the main electrolytes that affect osmolality, but a normal sodium level does not necessarily mean a normal osmolality.
Choice B reason:
Serum potassium 4.0 mEq/L is also a normal value and does not indicate an increase in osmolality. Potassium is another electrolyte that affects osmolality, but it has a smaller effect than sodium. A normal potassium level does not necessarily mean a normal osmolality.
Choice C reason:
Serum glucose 90 mg/dL is also a normal value and does not indicate an increase in osmolality. Glucose is another substance that affects osmolality, but it has a smaller effect than electrolytes. A normal glucose level does not necessarily mean a normal osmolality.
Choice D reason:
Serum urea nitrogen 25 mg/dL is an elevated value and indicates an increase in osmolality. Urea nitrogen is a waste product of protein metabolism that is excreted by the kidneys. Urea nitrogen is one of the main substances that affect osmolality, along with sodium and glucose. An elevated urea nitrogen level means that the blood is more concentrated and has less water. This can be caused by dehydration, which is a common condition in clients who have dehydration. Dehydration leads to an increase in serum osmolality and activation of antidiuretic hormone (ADH), which results in urinary concentration. Therefore, choice D is the correct answer.