CCRN Mechanical Ventilation Management 3 — Questions and Answers
Question 1: A patient on SIMV is fighting the ventilator with rapid shallow breaths. Arterial blood gas shows respiratory alkalosis. What is the most appropriate first action?
- Assess for pain, anxiety, and ventilator dyssynchrony (Correct answer)
- Immediately paralyze the patient
- Increase the set respiratory rate
- Disconnect and bag the patient indefinitely
Correct answer: Assess for pain, anxiety, and ventilator dyssynchrony
Patient distress and dyssynchrony should be evaluated for treatable causes like pain or anxiety before escalating sedation or paralysis.
Question 2: What is the primary physiologic benefit of applying PEEP?
- Recruiting collapsed alveoli to improve oxygenation (Correct answer)
- Lowering arterial CO2
- Decreasing airway resistance
- Increasing cardiac output
Correct answer: Recruiting collapsed alveoli to improve oxygenation
PEEP keeps alveoli open at end-expiration, increasing functional residual capacity and improving oxygenation.
Question 3: During a spontaneous breathing trial, which finding suggests the patient is failing and should be returned to full support?
- Rapid shallow breathing index (RSBI) above 105 (Correct answer)
- RSBI below 80
- Stable blood pressure
- SpO2 of 97%
Correct answer: Rapid shallow breathing index (RSBI) above 105
An RSBI (respiratory rate divided by tidal volume in liters) above 105 predicts weaning failure.
Question 4: A pressure-support ventilation mode requires which patient capability?
- An intact spontaneous respiratory drive (Correct answer)
- Complete neuromuscular paralysis
- Absent diaphragmatic function
- A set mandatory rate with no patient effort
Correct answer: An intact spontaneous respiratory drive
Pressure support augments each spontaneous breath, so the patient must be triggering breaths.
Question 5: A ventilated patient's high-pressure alarm sounds repeatedly. After ruling out kinks, what should the nurse assess next?
- Need for suctioning due to secretions (Correct answer)
- Disconnection of the circuit
- A cuff leak
- Hyperventilation
Correct answer: Need for suctioning due to secretions
Secretions are a common cause of high-pressure alarms; suctioning may relieve the obstruction.
Question 6: Which arterial blood gas pattern is most consistent with acute respiratory acidosis from hypoventilation?
- pH 7.28, PaCO2 58, HCO3 24 (Correct answer)
- pH 7.50, PaCO2 30, HCO3 24
- pH 7.32, PaCO2 30, HCO3 16
- pH 7.48, PaCO2 48, HCO3 34
Correct answer: pH 7.28, PaCO2 58, HCO3 24
Low pH with elevated PaCO2 and normal bicarbonate indicates acute (uncompensated) respiratory acidosis.
Question 7: A low-pressure or low-exhaled-volume alarm on the ventilator most commonly indicates what?
- A disconnection or leak in the circuit (Correct answer)
- Mucus plugging
- Bronchospasm
- Decreased compliance
Correct answer: A disconnection or leak in the circuit
Low-pressure and low-volume alarms typically signal a leak or disconnection in the circuit or around the cuff.
CCRN Mechanical Ventilation Management 3
A patient on SIMV is fighting the ventilator with rapid shallow breaths.
Arterial blood gas shows respiratory alkalosis.
What is the most appropriate first action?