NBRC TMC/CRT/RRT EXAM TESTBANK 3
VERSIONS exam Questions and Correct
Answers (Verified Answers) Plus Rationale
2027 Q&A| Instant Download Pdf
1. A patient with acute respiratory distress has a PaO₂ of 52 mm Hg
while receiving an FiO₂ of 0.50. Which finding best indicates
significant impairment in oxygenation?
A. PaCO₂ of 38 mm Hg
B. pH of 7.42
C. P/F ratio of 104
D. HCO₃⁻ of 24 mEq/L
Rationale: The P/F ratio is calculated by dividing PaO₂ by FiO₂. A ratio
of 104 indicates severe oxygenation impairment and is consistent with
significant intrapulmonary shunting or V/Q mismatch.
, 2. A patient receiving mechanical ventilation has the following ABG
results: pH 7.28, PaCO₂ 58 mm Hg, HCO₃⁻ 25 mEq/L, and PaO₂ 72
mm Hg. How should these results be interpreted?
A. Metabolic acidosis
B. Acute respiratory acidosis with hypoxemia
C. Chronic respiratory alkalosis
D. Metabolic alkalosis
Rationale: The low pH and elevated PaCO₂ indicate respiratory
acidosis. The normal HCO₃⁻ suggests limited renal compensation,
supporting an acute process.
3. A patient with COPD is receiving oxygen therapy. The patient's
PaCO₂ rises from 48 to 68 mm Hg after the FiO₂ is increased
substantially. Which mechanism may contribute to this change?
A. Increased hemoglobin synthesis
B. Decreased physiologic dead space
C. Worsening V/Q mismatch from reversal of hypoxic pulmonary
vasoconstriction
D. Increased alveolar ventilation
Rationale: In some COPD patients, excessive oxygen administration
can worsen V/Q mismatch by reducing hypoxic pulmonary
,vasoconstriction. This may increase PaCO₂ and worsen carbon dioxide
retention.
4. Which ventilator setting directly determines the number of
mandatory breaths delivered by a volume-controlled ventilator?
A. Inspiratory flow
B. Tidal volume
C. Set respiratory rate
D. Inspiratory time
Rationale: In volume-controlled ventilation, the set respiratory rate
determines how many mandatory breaths are delivered each minute.
5. A mechanically ventilated patient suddenly develops a high-
pressure alarm. Peak inspiratory pressure has increased from 25
to 42 cm H₂O, while plateau pressure remains 23 cm H₂O. What is
the most likely cause?
A. Decreased lung compliance
B. Pulmonary edema
C. Pneumothorax
D. Increased airway resistance
, Rationale: A high peak pressure with a normal plateau pressure
indicates increased resistive pressure. Causes include secretions,
bronchospasm, biting the tube, or a kinked circuit.
6. A patient with severe asthma is mechanically ventilated. Which
strategy is most appropriate to reduce the risk of dynamic
hyperinflation?
A. Increase respiratory rate
B. Increase tidal volume
C. Decrease respiratory rate and allow a longer expiratory time
D. Eliminate PEEP completely
Rationale: Asthma produces expiratory flow limitation. Lowering the
respiratory rate and providing more time for exhalation reduces air
trapping and auto-PEEP.
7. Which measurement is most useful for assessing static
respiratory-system compliance during mechanical ventilation?
A. Peak inspiratory pressure
B. Plateau pressure
C. Peak expiratory flow
D. Mean airway pressure
VERSIONS exam Questions and Correct
Answers (Verified Answers) Plus Rationale
2027 Q&A| Instant Download Pdf
1. A patient with acute respiratory distress has a PaO₂ of 52 mm Hg
while receiving an FiO₂ of 0.50. Which finding best indicates
significant impairment in oxygenation?
A. PaCO₂ of 38 mm Hg
B. pH of 7.42
C. P/F ratio of 104
D. HCO₃⁻ of 24 mEq/L
Rationale: The P/F ratio is calculated by dividing PaO₂ by FiO₂. A ratio
of 104 indicates severe oxygenation impairment and is consistent with
significant intrapulmonary shunting or V/Q mismatch.
, 2. A patient receiving mechanical ventilation has the following ABG
results: pH 7.28, PaCO₂ 58 mm Hg, HCO₃⁻ 25 mEq/L, and PaO₂ 72
mm Hg. How should these results be interpreted?
A. Metabolic acidosis
B. Acute respiratory acidosis with hypoxemia
C. Chronic respiratory alkalosis
D. Metabolic alkalosis
Rationale: The low pH and elevated PaCO₂ indicate respiratory
acidosis. The normal HCO₃⁻ suggests limited renal compensation,
supporting an acute process.
3. A patient with COPD is receiving oxygen therapy. The patient's
PaCO₂ rises from 48 to 68 mm Hg after the FiO₂ is increased
substantially. Which mechanism may contribute to this change?
A. Increased hemoglobin synthesis
B. Decreased physiologic dead space
C. Worsening V/Q mismatch from reversal of hypoxic pulmonary
vasoconstriction
D. Increased alveolar ventilation
Rationale: In some COPD patients, excessive oxygen administration
can worsen V/Q mismatch by reducing hypoxic pulmonary
,vasoconstriction. This may increase PaCO₂ and worsen carbon dioxide
retention.
4. Which ventilator setting directly determines the number of
mandatory breaths delivered by a volume-controlled ventilator?
A. Inspiratory flow
B. Tidal volume
C. Set respiratory rate
D. Inspiratory time
Rationale: In volume-controlled ventilation, the set respiratory rate
determines how many mandatory breaths are delivered each minute.
5. A mechanically ventilated patient suddenly develops a high-
pressure alarm. Peak inspiratory pressure has increased from 25
to 42 cm H₂O, while plateau pressure remains 23 cm H₂O. What is
the most likely cause?
A. Decreased lung compliance
B. Pulmonary edema
C. Pneumothorax
D. Increased airway resistance
, Rationale: A high peak pressure with a normal plateau pressure
indicates increased resistive pressure. Causes include secretions,
bronchospasm, biting the tube, or a kinked circuit.
6. A patient with severe asthma is mechanically ventilated. Which
strategy is most appropriate to reduce the risk of dynamic
hyperinflation?
A. Increase respiratory rate
B. Increase tidal volume
C. Decrease respiratory rate and allow a longer expiratory time
D. Eliminate PEEP completely
Rationale: Asthma produces expiratory flow limitation. Lowering the
respiratory rate and providing more time for exhalation reduces air
trapping and auto-PEEP.
7. Which measurement is most useful for assessing static
respiratory-system compliance during mechanical ventilation?
A. Peak inspiratory pressure
B. Plateau pressure
C. Peak expiratory flow
D. Mean airway pressure
