CCRN General Review 3 — Questions and Answers
Question 1: A patient with diabetic ketoacidosis has a serum potassium of 5.8 mEq/L. Why must potassium be monitored closely during insulin therapy?
- Insulin drives potassium into cells, causing rapid hypokalemia (Correct answer)
- Insulin raises serum potassium
- Potassium does not change with insulin
- Insulin causes potassium retention by the kidneys
Correct answer: Insulin drives potassium into cells, causing rapid hypokalemia
Insulin shifts potassium intracellularly, so serum levels can fall quickly during DKA treatment.
Question 2: Which ECG change is the earliest sign of hyperkalemia?
- Peaked T waves (Correct answer)
- ST elevation
- Prolonged QT interval
- U waves
Correct answer: Peaked T waves
Tall, peaked T waves are the earliest ECG manifestation of hyperkalemia.
Question 3: A patient with increased intracranial pressure shows Cushing's triad. Which set of vital signs reflects this?
- Hypertension, bradycardia, irregular respirations (Correct answer)
- Hypotension, tachycardia, rapid respirations
- Hypertension, tachycardia, apnea
- Hypotension, bradycardia, deep respirations
Correct answer: Hypertension, bradycardia, irregular respirations
Cushing's triad is hypertension with widened pulse pressure, bradycardia, and irregular respirations.
Question 4: What is the primary goal when managing a patient with acute respiratory distress syndrome on the ventilator?
- Low tidal volume lung-protective ventilation (Correct answer)
- High tidal volumes to maximize oxygenation
- Minimizing PEEP
- Permissive hyperoxia
Correct answer: Low tidal volume lung-protective ventilation
Low tidal volume (6 mL/kg) ventilation reduces ventilator-induced lung injury in ARDS.
Question 5: A post-operative patient has a sudden drop in blood pressure, tachycardia, and cool clammy skin. Which type of shock is most likely?
- Hypovolemic shock (Correct answer)
- Neurogenic shock
- Anaphylactic shock
- Cardiogenic shock from tamponade
Correct answer: Hypovolemic shock
Hemorrhage causing hypovolemia presents with hypotension, tachycardia, and cool clammy skin.
Question 6: Which lab value is most specific for myocardial cell injury?
- Troponin I (Correct answer)
- Myoglobin
- CK total
- LDH
Correct answer: Troponin I
Troponin I is the most cardiac-specific and sensitive marker of myocardial injury.
Question 7: A patient with severe sepsis has a lactate of 4.5 mmol/L. What does this elevated lactate indicate?
- Tissue hypoperfusion and anaerobic metabolism (Correct answer)
- Adequate oxygen delivery
- Metabolic alkalosis
- Improving organ perfusion
Correct answer: Tissue hypoperfusion and anaerobic metabolism
Elevated lactate reflects anaerobic metabolism from tissue hypoperfusion in sepsis.
CCRN General Review 3
A patient with diabetic ketoacidosis has a serum potassium of 5.8 mEq/L.
Why must potassium be monitored closely during insulin therapy?