RRT RRT Clinical Concepts 5 — Questions and Answers
Question 1: Which maneuver is used to assess intrinsic PEEP (auto-PEEP) in a mechanically ventilated patient?
- End-inspiratory hold
- End-expiratory hold (Correct answer)
- Inspiratory pause maneuver
- Maximum inspiratory pressure measurement
Correct answer: End-expiratory hold
An end-expiratory hold occludes the expiratory valve at end-exhalation, allowing trapped pressure to equilibrate and be measured as auto-PEEP.
Question 2: A patient on CPAP for OSA is mouth breathing and complaining of dry mouth. The MOST appropriate intervention is:
- Increase CPAP pressure
- Add a heated humidifier to the circuit
- Switch to BiPAP
- Apply a chin strap and add a humidifier (Correct answer)
Correct answer: Apply a chin strap and add a humidifier
A chin strap reduces mouth opening while a heated humidifier adds moisture to prevent mucosal drying from mouth breathing on CPAP.
Question 3: Which radiographic finding is most characteristic of pulmonary embolism on a plain chest X-ray?
- Bilateral fluffy infiltrates
- Westermark sign (oligemia) (Correct answer)
- Kerley B lines
- Tracheal deviation
Correct answer: Westermark sign (oligemia)
The Westermark sign is a focal area of oligemia (decreased vascular markings) distal to a pulmonary embolus, though it is an uncommon finding.
Question 4: A spontaneously breathing patient with neuromuscular disease has MIP of -18 cmH2O. This indicates:
- Adequate inspiratory muscle strength
- Severely weakened inspiratory muscles (Correct answer)
- Normal respiratory reserve
- Need for bronchodilator therapy
Correct answer: Severely weakened inspiratory muscles
Normal MIP is more negative than -80 cmH2O; an MIP of only -18 cmH2O indicates severely compromised inspiratory muscle strength.
Question 5: Which statement about nitric oxide (NO) therapy in neonatal hypoxic respiratory failure is correct?
- It is a systemic vasodilator
- It selectively dilates pulmonary vasculature in ventilated lung units (Correct answer)
- It is delivered via high-flow nasal cannula only
- It permanently improves pulmonary vascular remodeling
Correct answer: It selectively dilates pulmonary vasculature in ventilated lung units
Inhaled NO selectively reaches ventilated alveoli, dilating adjacent pulmonary vessels and improving V/Q matching without systemic vasodilation.
Question 6: In prone positioning for ARDS, the primary mechanism of improved oxygenation is:
- Increased FRC
- Redistribution of perfusion to better-ventilated dorsal lung units (Correct answer)
- Increased tidal volume delivery
- Reduced pulmonary edema
Correct answer: Redistribution of perfusion to better-ventilated dorsal lung units
Proning redistributes pulmonary blood flow to the dorsal (now dependent) lung regions, which are better ventilated, improving V/Q matching.
Question 7: A patient with a tracheostomy tube is being weaned from ventilator support. Which device allows vocalization while maintaining airway access?
- Passy-Muir speaking valve (Correct answer)
- Capped tracheostomy tube
- Metal inner cannula
- Fenestrated tracheostomy tube alone
Correct answer: Passy-Muir speaking valve
A Passy-Muir valve is a one-way valve placed on the tracheostomy hub that directs exhaled air upward through the vocal cords to allow speech.
Which maneuver is used to assess intrinsic PEEP (auto-PEEP) in a mechanically ventilated patient?