RRT RRT Clinical Concepts 4 — Questions and Answers
Question 1: A patient with Guillain-Barré syndrome has FVC declining toward 15 mL/kg. The appropriate action is:
- Administer bronchodilators
- Initiate non-invasive positive pressure ventilation
- Begin prophylactic intubation (Correct answer)
- Obtain a pulmonary function test
Correct answer: Begin prophylactic intubation
The '20-30-40 rule' (FVC <20 mL/kg, MIP >-30 cmH2O, MEP <40 cmH2O) triggers prophylactic intubation before respiratory failure occurs.
Question 2: Which type of pulmonary edema is caused by increased hydrostatic pressure rather than increased permeability?
- ARDS
- Aspiration pneumonia
- Cardiogenic pulmonary edema (Correct answer)
- High-altitude pulmonary edema
Correct answer: Cardiogenic pulmonary edema
Cardiogenic pulmonary edema results from elevated pulmonary capillary hydrostatic pressure due to left heart failure forcing fluid into alveoli.
Question 3: A mechanically ventilated patient's plateau pressure rises from 22 to 35 cmH2O with no change in peak pressure. This suggests:
- Increased airway resistance
- Decreased lung compliance (Correct answer)
- Mucus plugging
- Bronchospasm
Correct answer: Decreased lung compliance
A rise in plateau pressure without a change in the peak-to-plateau difference indicates a compliance problem, not a resistance problem.
Question 4: Which arterial blood gas pattern is expected during the initial compensatory response to metabolic acidosis?
- Elevated PaCO2
- Decreased PaCO2 (Correct answer)
- Elevated bicarbonate
- Decreased pH with normal PaCO2
Correct answer: Decreased PaCO2
The respiratory system compensates for metabolic acidosis by increasing ventilation to blow off CO2, lowering PaCO2.
Question 5: During cardiac arrest, which ventilation strategy is recommended by current AHA guidelines?
- Hyperventilation at 20-24 breaths/min
- 1 breath every 6 seconds asynchronous to compressions (Correct answer)
- Bag-mask at a ratio of 30:2
- 100% oxygen at 15 L/min without positive pressure
Correct answer: 1 breath every 6 seconds asynchronous to compressions
After advanced airway placement, AHA recommends asynchronous ventilation at 10 breaths/min (one every 6 seconds) without interrupting compressions.
Question 6: A patient's flow-volume loop shows a fixed plateau on both inspiration and expiration. This pattern is most consistent with:
- Emphysema
- Asthma
- Fixed upper airway obstruction (Correct answer)
- Variable extrathoracic obstruction
Correct answer: Fixed upper airway obstruction
A fixed upper airway obstruction truncates both the inspiratory and expiratory limbs equally, producing a box-shaped flow-volume loop.
Question 7: Which finding on a capnography waveform suggests esophageal intubation?
- Shark fin appearance
- Prolonged plateau phase
- Absent CO2 waveform (near zero reading) (Correct answer)
- Elevated baseline
Correct answer: Absent CO2 waveform (near zero reading)
Esophageal intubation produces no sustained CO2 waveform since there is no alveolar CO2 being exhaled through the tube.
RRT RRT Clinical Concepts 4
A patient with Guillain-Barré syndrome has FVC declining toward 15 mL/kg.
The appropriate action is: