NACE Fluid and Electrolyte Balance 2

Question 1

A nurse taps a patient's facial nerve anterior to the ear and observes facial muscle twitching. This positive Chvostek's sign indicates which electrolyte imbalance?

Accepted Answer

Hypocalcemia

Answer

A positive Chvostek's sign (facial muscle twitching upon tapping the facial nerve) indicates hypocalcemia, which increases neuromuscular excitability by reducing calcium's stabilizing effect on nerve membranes.

Question 2

A patient receiving total parenteral nutrition (TPN) develops tetany and muscle spasms. Which laboratory finding would confirm hypomagnesemia?

Accepted Answer

Serum magnesium 0.8 mEq/L

Answer

The normal serum magnesium level is 1.5–2.5 mEq/L; a level of 0.8 mEq/L confirms hypomagnesemia, which causes neuromuscular irritability and tetany similar to hypocalcemia.

Question 3

A patient's ABG results show: pH 7.30, PaCO2 38 mmHg, HCO3- 18 mEq/L. How should the nurse interpret these results?

Accepted Answer

Metabolic acidosis

Answer

A pH of 7.30 (acidosis), normal PaCO2 (38 mmHg), and low HCO3- (18 mEq/L) indicate metabolic acidosis as the primary disorder, with the respiratory system not yet compensating.

Question 4

A nurse is administering a hypotonic IV solution. Which physiologic effect should be anticipated?

Accepted Answer

Fluid shifts from the vascular space into cells

Answer

Hypotonic solutions have lower osmolality than plasma, causing water to move by osmosis from the vascular space into cells, expanding intracellular volume and potentially causing cellular swelling.

Question 5

Which clinical presentation is most consistent with third-spacing of fluid?

Accepted Answer

Decreased urine output with low intravascular volume despite visible fluid accumulation

Answer

Third-spacing occurs when fluid shifts into non-functional compartments (e.g., ascites, burn edema), reducing intravascular volume and urine output while fluid appears to accumulate in the body.

Nursing Acceleration Challenge Exam (NACE) I PN-RN Practice Test

Nursing Acceleration Challenge Exam (NACE) I PN-RN Practice Test

NACE Fluid and Electrolyte Balance 2