Acute Care Nurse Practitioner Mechanical Ventilation and Respiratory Support 2 — Questions and Answers
Question 1: Prone positioning in ARDS is recommended when PaOâ‚‚/FiOâ‚‚ ratio is below which threshold?
- 300 mmHg
- 200 mmHg
- 150 mmHg (Correct answer)
- 100 mmHg
Correct answer: 150 mmHg
Prone positioning is recommended for moderate-to-severe ARDS when PaOâ‚‚/FiOâ‚‚ <150 mmHg despite optimal ventilator settings.
Question 2: Which ventilator setting should be adjusted to correct hypercapnia in a patient on volume control ventilation?
- Increase FiOâ‚‚
- Increase PEEP
- Increase respiratory rate or tidal volume (Correct answer)
- Switch to pressure support
Correct answer: Increase respiratory rate or tidal volume
COâ‚‚ elimination depends on minute ventilation; increasing respiratory rate or tidal volume will increase minute ventilation and lower PaCOâ‚‚.
Question 3: A spontaneous breathing trial (SBT) should be attempted when which criteria are met?
- FiO₂ ≤0.40, PEEP ≤5, hemodynamically stable, able to follow commands (Correct answer)
- FiO₂ ≤0.60, PEEP ≤8, spontaneous respiratory rate >30
- MAP >65 on 2 vasopressors, FiO₂ ≤0.50
- GCS >10, PEEP ≤10, FiO₂ ≤0.70
Correct answer: FiO₂ ≤0.40, PEEP ≤5, hemodynamically stable, able to follow commands
Standard SBT readiness criteria include FiO₂ ≤40%, PEEP ≤5 cmH₂O, hemodynamic stability, and ability to follow simple commands.
Question 4: Which parameter is MOST predictive of successful extubation?
- PaOâ‚‚/FiOâ‚‚ >200
- Rapid shallow breathing index (RSBI) <105 (Correct answer)
- Minute ventilation <10 L/min
- Negative inspiratory force (NIF) < −30 cmH₂O
Correct answer: Rapid shallow breathing index (RSBI) <105
RSBI (f/Vt) <105 breaths/min/L is the best validated predictor of successful extubation from mechanical ventilation.
Question 5: An ACNP manages a patient with severe bronchospasm on mechanical ventilation. Which strategy minimizes air trapping?
- Increase respiratory rate to 20/min
- Increase inspiratory time
- Decrease respiratory rate and increase expiratory time (Correct answer)
- Add PEEP to 15 cmHâ‚‚O
Correct answer: Decrease respiratory rate and increase expiratory time
In obstructive disease, decreasing RR and prolonging expiratory time (I:E ratio 1:4 or greater) prevents breath stacking and auto-PEEP.
Question 6: High-flow nasal cannula (HFNC) is MOST appropriate as a first-line intervention in which condition?
- Hypercapnic COPD exacerbation requiring ventilatory support
- Acute hypoxemic respiratory failure with PaOâ‚‚/FiOâ‚‚ <300 (Correct answer)
- Post-extubation stridor from laryngeal edema
- Apneic patient requiring immediate airway
Correct answer: Acute hypoxemic respiratory failure with PaOâ‚‚/FiOâ‚‚ <300
HFNC is most effective for acute hypoxemic respiratory failure, reducing intubation rates compared to conventional oxygen.
Acute Care Nurse Practitioner Mechanical Ventilation and Respiratory Support 2
Prone positioning in ARDS is recommended when PaOâ‚‚/FiOâ‚‚ ratio is below which threshold?