MSNCB Fluid & Electrolyte Balance 2

Question 1

A patient's ABG shows pH 7.28, PaCO2 38 mmHg, HCO3 16 mEq/L. Which acid-base disturbance does this indicate?

Accepted Answer

Metabolic acidosis

Answer

A pH below 7.35 with low bicarbonate (<22 mEq/L) and normal PaCO2 indicates uncompensated metabolic acidosis.

Question 2

Which clinical finding is most associated with hypocalcemia?

Accepted Answer

Trousseau's sign

Answer

Trousseau's sign — carpopedal spasm triggered by BP cuff inflation — is a classic manifestation of hypocalcemia due to increased neuromuscular excitability.

Question 3

A patient receiving prolonged total parenteral nutrition (TPN) is at risk for which electrolyte imbalance that can cause respiratory muscle weakness?

Accepted Answer

Hypophosphatemia

Answer

Refeeding syndrome with aggressive TPN can cause hypophosphatemia, which impairs ATP production and can result in severe respiratory muscle weakness or failure.

Question 4

Which symptom is characteristic of hypermagnesemia?

Accepted Answer

Loss of deep tendon reflexes

Answer

Hypermagnesemia suppresses neuromuscular transmission, and loss of deep tendon reflexes is an early, clinically significant sign of magnesium toxicity.

Question 5

A patient has a serum potassium of 6.2 mEq/L. Which ECG change would the nurse most likely observe?

Accepted Answer

Peaked (tall, narrow) T waves

Answer

Hyperkalemia classically produces tall, peaked, narrow T waves on ECG, representing one of the earliest electrocardiographic signs of elevated potassium.

(MSNCB) Medical-Surgical Nursing Certification Board Practice Test

(MSNCB) Medical-Surgical Nursing Certification Board Practice Test

MSNCB Fluid & Electrolyte Balance 2