RRT RRT Mechanical Ventilation 1 β Questions and Answers
Question 1: What is the primary goal of lung-protective ventilation in ARDS?
- Maximize tidal volume to clear CO2
- Limit tidal volume to 6 mL/kg IBW to prevent volutrauma (Correct answer)
- Use the highest PEEP possible
- Achieve normocapnia at all times
Correct answer: Limit tidal volume to 6 mL/kg IBW to prevent volutrauma
The ARDSNet protocol recommends tidal volumes of 4β6 mL/kg IBW to prevent ventilator-induced lung injury from overdistension.
Question 2: Which ventilator mode delivers a guaranteed tidal volume regardless of lung compliance changes?
- Pressure Support Ventilation (PSV)
- Volume-Controlled Ventilation (VCV) (Correct answer)
- Airway Pressure Release Ventilation (APRV)
- Continuous Positive Airway Pressure (CPAP)
Correct answer: Volume-Controlled Ventilation (VCV)
Volume-controlled ventilation delivers a set tidal volume with each breath by adjusting pressure, ensuring consistent minute ventilation regardless of compliance.
Question 3: What does PEEP stand for and what is its primary purpose in mechanical ventilation?
- Positive End-Expiratory Pressure; prevents alveolar collapse at end-expiration (Correct answer)
- Peak Expiratory Effort Pressure; measures respiratory muscle strength
- Positive Expiratory End Pressure; increases tidal volume
- Peak End-Expiratory Pressure; reduces work of breathing
Correct answer: Positive End-Expiratory Pressure; prevents alveolar collapse at end-expiration
PEEP maintains a baseline positive pressure at end-expiration to recruit collapsed alveoli and improve oxygenation.
Question 4: A patient on volume control ventilation has a plateau pressure of 32 cmH2O. What is the appropriate action?
- Increase PEEP to improve oxygenation
- Increase tidal volume to improve ventilation
- Decrease tidal volume to reduce lung injury risk (Correct answer)
- Switch to pressure control mode
Correct answer: Decrease tidal volume to reduce lung injury risk
Plateau pressures above 30 cmH2O indicate overdistension risk; reducing tidal volume lowers plateau pressure and prevents barotrauma.
Question 5: Which ventilator waveform indicates auto-PEEP (intrinsic PEEP)?
- Flow not returning to zero before the next breath begins (Correct answer)
- A square pressure waveform
- Increasing peak airway pressure over time
- Declining tidal volumes on pressure control
Correct answer: Flow not returning to zero before the next breath begins
Auto-PEEP occurs when expiratory flow does not reach zero before the next breath, indicating air trapping and incomplete exhalation.
Question 6: What is the normal range for static lung compliance in a mechanically ventilated adult?
- 10β20 mL/cmH2O
- 60β100 mL/cmH2O (Correct answer)
- 150β200 mL/cmH2O
- 5β10 mL/cmH2O
Correct answer: 60β100 mL/cmH2O
Normal static compliance in a mechanically ventilated patient is approximately 60β100 mL/cmH2O, reflecting lung-chest wall elasticity.
RRT RRT Mechanical Ventilation 1
What is the primary goal of lung-protective ventilation in ARDS?