NCLEX Fluid and Electrolyte Balance

Question 1

A patient has a serum sodium level of 125 mEq/L. Which condition does this value indicate?

Accepted Answer

Hyponatremia

Answer

A serum sodium below 135 mEq/L indicates hyponatremia; normal range is 135–145 mEq/L.

Question 2

Which electrolyte is the primary regulator of extracellular fluid osmolarity?

Accepted Answer

Sodium

Answer

Sodium is the dominant cation in extracellular fluid and the main determinant of extracellular osmolarity.

Question 3

A patient receiving furosemide (Lasix) is at greatest risk for which electrolyte imbalance?

Accepted Answer

Hypokalemia

Answer

Loop diuretics such as furosemide cause significant potassium wasting through the renal tubules.

Question 4

What is the normal serum potassium range?

Accepted Answer

3.5–5.0 mEq/L

Answer

Normal serum potassium is 3.5–5.0 mEq/L; values outside this range cause cardiac and neuromuscular complications.

Question 5

Which clinical finding is most characteristic of fluid volume deficit (dehydration)?

Accepted Answer

Poor skin turgor

Answer

Poor skin turgor (tenting) is a classic sign of dehydration caused by loss of interstitial fluid.

NCLEX Practice Test