, Question 1
A patient receiving volume-control ventilation has a sudden rise in peak
inspiratory pressure with an unchanged plateau pressure and a sawtooth
expiratory flow pattern. Which action is most appropriate?
A. Obtain an arterial blood gas and increase the inspiratory time
B. Perform endotracheal suctioning and reassess airway resistance
C. Decrease the set tidal volume by 100 mL
D. Increase PEEP to recruit collapsed alveoli
Correct Answer: B - Perform endotracheal suctioning and
reassess airway resistance
RATIONALE
A rising peak pressure with unchanged plateau indicates increased
airway resistance, and the sawtooth flow pattern confirms retained
secretions. Suctioning addresses the resistive cause; the other options
do not correct airway resistance and may worsen the problem.
Question 2
An ABG shows pH 7.28, PaCO2 58 mm Hg, HCO3- 26 mEq/L, and PaO2 62
mm Hg on room air. Which interpretation is most accurate?
A. Acute respiratory acidosis with moderate hypoxemia
B. Compensated metabolic alkalosis with mild hypoxemia
C. Chronic respiratory alkalosis with normal oxygenation
D. Mixed metabolic and respiratory acidosis
Correct Answer: A - Acute respiratory acidosis with moderate
hypoxemia
Page 2
, RATIONALE
Low pH with elevated PaCO2 and normal HCO3- indicates acute
respiratory acidosis. The PaO2 of 62 mm Hg on room air reflects
moderate hypoxemia; the absence of HCO3- elevation excludes
chronic compensation.
Question 3
A patient with ARDS is ventilated at 6 mL/kg predicted body weight with
PEEP 14 cm H2O. Plateau pressure is 32 cm H2O. Which change best aligns
with lung-protective ventilation?
A. Increase tidal volume to 8 mL/kg to improve ventilation
B. Reduce PEEP to 8 cm H2O to lower plateau pressure
C. Maintain current settings and monitor driving pressure
D. Increase inspiratory flow to shorten inspiratory time
Correct Answer: C - Maintain current settings and monitor
driving pressure
RATIONALE
Plateau pressure 30 cm H2O is preferred, but 32 with a driving
pressure (Pplat-PEEP) of 18 cm H2O is acceptable if oxygenation and
hemodynamics are stable. Increasing tidal volume or lowering PEEP
may worsen injury or derecruitment; monitoring driving pressure is
the evidence-based approach.
Question 4
A patient with COPD has a DLCOSB of 45% predicted and a reduced DL/VA.
Which factor most likely explains the disproportionate reduction in DL/VA?
A. Increased alveolar surface area
B. Loss of pulmonary capillary blood volume
C. Increased hemoglobin concentration
D. Decreased alveolar dead space
Page 3
, Correct Answer: B - Loss of pulmonary capillary blood volume
RATIONALE
A reduced DL/VA suggests a loss of effective alveolar-capillary
membrane or capillary blood volume, typical of emphysema.
Increased surface area or hemoglobin would raise DLCO, and
decreased dead space does not explain the ratio.
Question 5
A patient with status asthmaticus is unresponsive to continuous albuterol and
IV corticosteroids. Which adjunct is best supported by current evidence?
A. Heliox 80:20 via nonrebreather mask
B. IV magnesium sulfate
C. Prophylactic broad-spectrum antibiotics
D. Chest physiotherapy with postural drainage
Correct Answer: B - IV magnesium sulfate
RATIONALE
IV magnesium sulfate is recommended for severe asthma not
responding to standard therapy. Heliox has limited evidence in status
asthmaticus, antibiotics are not indicated without infection, and chest
physiotherapy may worsen distress.
Question 6
Which statement best describes the effect of increasing inspiratory time on
oxygenation during pressure-control ventilation?
A. It decreases mean airway pressure and worsens oxygenation
B. It increases mean airway pressure and may improve oxygenation
C. It has no effect on mean airway pressure
D. It decreases intrinsic PEEP and improves venous return
Correct Answer: B - It increases mean airway pressure and may
improve oxygenation
Page 4
A patient receiving volume-control ventilation has a sudden rise in peak
inspiratory pressure with an unchanged plateau pressure and a sawtooth
expiratory flow pattern. Which action is most appropriate?
A. Obtain an arterial blood gas and increase the inspiratory time
B. Perform endotracheal suctioning and reassess airway resistance
C. Decrease the set tidal volume by 100 mL
D. Increase PEEP to recruit collapsed alveoli
Correct Answer: B - Perform endotracheal suctioning and
reassess airway resistance
RATIONALE
A rising peak pressure with unchanged plateau indicates increased
airway resistance, and the sawtooth flow pattern confirms retained
secretions. Suctioning addresses the resistive cause; the other options
do not correct airway resistance and may worsen the problem.
Question 2
An ABG shows pH 7.28, PaCO2 58 mm Hg, HCO3- 26 mEq/L, and PaO2 62
mm Hg on room air. Which interpretation is most accurate?
A. Acute respiratory acidosis with moderate hypoxemia
B. Compensated metabolic alkalosis with mild hypoxemia
C. Chronic respiratory alkalosis with normal oxygenation
D. Mixed metabolic and respiratory acidosis
Correct Answer: A - Acute respiratory acidosis with moderate
hypoxemia
Page 2
, RATIONALE
Low pH with elevated PaCO2 and normal HCO3- indicates acute
respiratory acidosis. The PaO2 of 62 mm Hg on room air reflects
moderate hypoxemia; the absence of HCO3- elevation excludes
chronic compensation.
Question 3
A patient with ARDS is ventilated at 6 mL/kg predicted body weight with
PEEP 14 cm H2O. Plateau pressure is 32 cm H2O. Which change best aligns
with lung-protective ventilation?
A. Increase tidal volume to 8 mL/kg to improve ventilation
B. Reduce PEEP to 8 cm H2O to lower plateau pressure
C. Maintain current settings and monitor driving pressure
D. Increase inspiratory flow to shorten inspiratory time
Correct Answer: C - Maintain current settings and monitor
driving pressure
RATIONALE
Plateau pressure 30 cm H2O is preferred, but 32 with a driving
pressure (Pplat-PEEP) of 18 cm H2O is acceptable if oxygenation and
hemodynamics are stable. Increasing tidal volume or lowering PEEP
may worsen injury or derecruitment; monitoring driving pressure is
the evidence-based approach.
Question 4
A patient with COPD has a DLCOSB of 45% predicted and a reduced DL/VA.
Which factor most likely explains the disproportionate reduction in DL/VA?
A. Increased alveolar surface area
B. Loss of pulmonary capillary blood volume
C. Increased hemoglobin concentration
D. Decreased alveolar dead space
Page 3
, Correct Answer: B - Loss of pulmonary capillary blood volume
RATIONALE
A reduced DL/VA suggests a loss of effective alveolar-capillary
membrane or capillary blood volume, typical of emphysema.
Increased surface area or hemoglobin would raise DLCO, and
decreased dead space does not explain the ratio.
Question 5
A patient with status asthmaticus is unresponsive to continuous albuterol and
IV corticosteroids. Which adjunct is best supported by current evidence?
A. Heliox 80:20 via nonrebreather mask
B. IV magnesium sulfate
C. Prophylactic broad-spectrum antibiotics
D. Chest physiotherapy with postural drainage
Correct Answer: B - IV magnesium sulfate
RATIONALE
IV magnesium sulfate is recommended for severe asthma not
responding to standard therapy. Heliox has limited evidence in status
asthmaticus, antibiotics are not indicated without infection, and chest
physiotherapy may worsen distress.
Question 6
Which statement best describes the effect of increasing inspiratory time on
oxygenation during pressure-control ventilation?
A. It decreases mean airway pressure and worsens oxygenation
B. It increases mean airway pressure and may improve oxygenation
C. It has no effect on mean airway pressure
D. It decreases intrinsic PEEP and improves venous return
Correct Answer: B - It increases mean airway pressure and may
improve oxygenation
Page 4
