CCRN Practice Test

CCRN Respiratory Practice Questions

Respiratory makes up 6 of every 50 questions on a Tigertest CCRN practice test. Here are 10 of the 24 questions on it, each with the answer and the reason.

Updated 2026-11-14 by the Tigertest team. Based on the AACN Adult CCRN test plan. Original questions; 50 per test, weighted like the real exam. Not affiliated with AACN or AACN Certification Corporation.

1. 1. A ventilated patient has a PaO2 of 75 mm Hg on an FiO2 of 0.50. What is the PaO2/FiO2 ratio?

   • A.37.5
   • B.150
   • C.75
   • D.300

   Answer: B. Divide PaO2 by FiO2 as a decimal: 75 / 0.50 = 150. A ratio from 100 to 200 on PEEP of at least 5 is moderate ARDS by the Berlin definition; 300 would come from dividing by 0.25.

2. 2. Which tidal volume is recommended for a patient with ARDS?

   • A.10 mL/kg actual body weight
   • B.12 mL/kg predicted body weight
   • C.6 mL/kg actual body weight
   • D.6 mL/kg predicted body weight

   Answer: D. The Surviving Sepsis Campaign 2021 guideline strongly recommends low tidal volume, about 6 mL/kg of predicted body weight, in sepsis-induced ARDS. Predicted weight comes from height and sex; actual weight overestimates lung size in larger patients.

3. 3. For a patient with ARDS on the ventilator, what upper limit is set for plateau pressure?

   • A.Below 30 cm H2O
   • B.Below 50 cm H2O
   • C.Below 20 cm H2O
   • D.Below 40 cm H2O

   Answer: A. Keeping plateau pressure under 30 cm H2O limits alveolar overdistension; it is a strong recommendation in the 2021 sepsis guideline. Peak pressure includes airway resistance and is not the measure used for this limit.

4. 4. How long should a patient with moderate to severe ARDS stay prone each day?

   • A.Thirty minutes each shift
   • B.Only while asleep at night
   • C.More than 12 hours a day
   • D.Two hours, twice a day

   Answer: C. Prone ventilation for more than 12 hours a day is strongly recommended for moderate to severe ARDS. Short sessions do not give the improvement in ventilation and perfusion matching that lowers mortality.

5. 5. A ventilated patient's peak inspiratory pressure has risen from 28 to 42 cm H2O while the plateau pressure is unchanged at 22. What is the most likely cause?

   • A.Lower lung compliance
   • B.A tension pneumothorax
   • C.Higher airway resistance
   • D.A leak in the ventilator circuit

   Answer: C. A wider gap between peak and plateau pressure means resistance in the airways or tube: secretions, bronchospasm, kinking or biting. Lower compliance, as with pneumothorax or worsening ARDS, raises the plateau pressure too.

6. 6. The low-pressure alarm sounds on a patient's ventilator. What is the most common cause?

   • A.Circuit disconnection
   • B.The patient biting the tube
   • C.A mucus plug in the tube
   • D.The patient coughing hard

   Answer: A. Low pressure means the ventilator cannot build pressure: a disconnection, a leak or a deflated cuff. Mucus, biting and coughing raise airway pressure and set off the high-pressure alarm.

7. 7. A ventilated trauma patient suddenly has SpO2 78%, BP 70/40, tracheal shift to the right and absent breath sounds on the left. What is the priority?

   • A.Bedside bronchoscopy
   • B.Raise the PEEP setting
   • C.Suction the airway
   • D.Needle decompression

   Answer: D. Hypoxemia, hypotension, tracheal deviation away from the silent side and absent breath sounds mean tension pneumothorax, which needs immediate decompression followed by a chest tube. Raising PEEP makes it worse.

8. 8. A chest drain shows continuous bubbling in the water seal chamber. What does this indicate?

   • A.A clamped chest tube
   • B.An air leak
   • C.The lung has re-expanded
   • D.Normal suction function

   Answer: B. Continuous bubbling in the water seal chamber means air is entering the system, from the pleural space or a loose connection. Gentle bubbling belongs in the suction control chamber of a wet suction system, not the water seal.

9. 9. A chest tube becomes disconnected from its drainage system. What should the nurse do first?

   • A.Wait for the provider to arrive
   • B.Submerge the end in sterile water
   • C.Pull the chest tube out of the chest
   • D.Clamp the tube for a full hour

   Answer: B. Submerging the tube end 2 to 3 cm in sterile water makes a temporary water seal while a new system is set up. Clamping for long periods can cause a tension pneumothorax if air is still leaking.

10. 10. A patient with a confirmed massive pulmonary embolism has a BP of 76/40 despite fluids. Which treatment should the nurse expect?

    • A.A vena cava filter alone
    • B.Oral warfarin loading
    • C.IV furosemide infusion
    • D.Systemic thrombolysis

    Answer: D. Massive PE with sustained hypotension is an indication for systemic thrombolytics, or surgical or catheter clot removal when lysis is contraindicated. A filter prevents new emboli but does nothing for the clot already in the lungs.