CCRN Plan

Respiratory: practice questions

3 original questions · 3 editor-approved · every choice explained.

Practice this topic

Blueprint-mapped questions with full rationales for every choice.

Start practice
RespiratoryDifficulty 3/5

A ventilated patient's peak inspiratory pressure rises from 28 to 42 cmH2O while the plateau pressure stays at 22 cmH2O. What does this indicate?

  1. ATension pneumothorax with mediastinal shift and cardiovascular collapse
  2. BVentilator circuit disconnection causing loss of delivered pressure
  3. CReduced lung compliance from developing acute respiratory distress syndrome
  4. DIncreased airway resistance from secretions, bronchospasm or a kinked tube
Show answer and rationale

Correct: D. The difference between peak and plateau reflects airway resistance; an isolated rise in peak with an unchanged plateau points to a resistance problem. A compliance problem such as ARDS or pneumothorax raises the plateau as well.

  • C — Reduced compliance raises the plateau pressure.
  • A — Tension pneumothorax raises both peak and plateau and causes haemodynamic collapse.
  • B — A disconnection produces low pressures and an alarm, not high peak pressures.
RespiratoryDifficulty 3/5

Which ventilator strategy is most consistent with lung-protective ventilation in ARDS?

  1. ATidal volume 6 mL/kg predicted body weight with plateau below 30 cmH2O
  2. BPressure support ventilation with the highest tolerated tidal volume for comfort
  3. CTidal volume titrated to the patient's actual body weight and normal carbon dioxide
  4. DTidal volume 10 mL/kg predicted body weight to guarantee adequate minute ventilation
Show answer and rationale

Correct: A. Lung-protective ventilation uses low tidal volumes based on predicted body weight with plateau pressure limited, accepting permissive hypercapnia. Higher tidal volumes worsen ventilator-induced lung injury.

  • D — 10 mL/kg is the volume associated with ventilator-induced injury.
  • B — Maximising tidal volume for comfort contradicts lung protection.
  • C — Volumes are calculated from predicted, not actual, body weight, and normocapnia is not the goal.
RespiratoryDifficulty 2/5

An arterial blood gas shows pH 7.28, PaCO2 58 mmHg, HCO3 26 mEq/L. How is this best described?

  1. AMixed respiratory and metabolic alkalosis from over-ventilation
  2. BAcute respiratory acidosis, with the kidneys not yet compensating
  3. CChronic respiratory acidosis with full renal compensation and a normal pH
  4. DMetabolic acidosis with appropriate respiratory compensation
Show answer and rationale

Correct: B. The pH is acidic and the PaCO2 is elevated, so the primary problem is respiratory. The bicarbonate is nearly normal, indicating the kidneys have not yet compensated — an acute picture.

  • C — Chronic compensation would show a markedly elevated bicarbonate and a near-normal pH.
  • D — A metabolic acidosis would show a low bicarbonate.
  • A — Alkalosis would raise the pH above normal.

Primary references

  1. CCRN Exam Handbook — Direct Care (July 2026) — AACN Certification Corporation · primary · retrieved 2026-09-22, verified 2026-09-22