,Q1 INTERPRET AND INTEGRATE ABG, HEMODYNAMIC, AND VENTILATOR WAVEFORM
DATA TO GUIDE THERAPY
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 CORRECT
C. Decrease the set tidal volume by 100 mL
D. Increase PEEP to recruit collapsed alveoli
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.
Q2 INTERPRET AND INTEGRATE ABG, HEMODYNAMIC, AND VENTILATOR WAVEFORM
DATA TO GUIDE THERAPY
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 CORRECT
B. Compensated metabolic alkalosis with mild hypoxemia
C. Chronic respiratory alkalosis with normal oxygenation
D. Mixed metabolic and respiratory acidosis
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.
Page 2
,Q3 INTERPRET AND INTEGRATE ABG, HEMODYNAMIC, AND VENTILATOR WAVEFORM
DATA TO GUIDE THERAPY
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 CORRECT
D. Increase inspiratory flow to shorten inspiratory time
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.
Q4 INTERPRET AND INTEGRATE ABG, HEMODYNAMIC, AND VENTILATOR WAVEFORM
DATA TO GUIDE THERAPY
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 CORRECT
C. Increased hemoglobin concentration
D. Decreased alveolar dead space
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.
Page 3
, Q5 INTERPRET AND INTEGRATE ABG, HEMODYNAMIC, AND VENTILATOR WAVEFORM
DATA TO GUIDE THERAPY
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 CORRECT
C. Prophylactic broad-spectrum antibiotics
D. Chest physiotherapy with postural drainage
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.
Q6 INTERPRET AND INTEGRATE ABG, HEMODYNAMIC, AND VENTILATOR WAVEFORM
DATA TO GUIDE THERAPY
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 CORRECT
C. It has no effect on mean airway pressure
D. It decreases intrinsic PEEP and improves venous return
RATIONALE: Prolonging inspiratory time raises mean airway pressure, which can recruit alveoli
and improve oxygenation, though it may also cause auto-PEEP. The other options misstate the
relationship between inspiratory time and mean airway pressure.
Page 4
DATA TO GUIDE THERAPY
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 CORRECT
C. Decrease the set tidal volume by 100 mL
D. Increase PEEP to recruit collapsed alveoli
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.
Q2 INTERPRET AND INTEGRATE ABG, HEMODYNAMIC, AND VENTILATOR WAVEFORM
DATA TO GUIDE THERAPY
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 CORRECT
B. Compensated metabolic alkalosis with mild hypoxemia
C. Chronic respiratory alkalosis with normal oxygenation
D. Mixed metabolic and respiratory acidosis
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.
Page 2
,Q3 INTERPRET AND INTEGRATE ABG, HEMODYNAMIC, AND VENTILATOR WAVEFORM
DATA TO GUIDE THERAPY
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 CORRECT
D. Increase inspiratory flow to shorten inspiratory time
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.
Q4 INTERPRET AND INTEGRATE ABG, HEMODYNAMIC, AND VENTILATOR WAVEFORM
DATA TO GUIDE THERAPY
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 CORRECT
C. Increased hemoglobin concentration
D. Decreased alveolar dead space
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.
Page 3
, Q5 INTERPRET AND INTEGRATE ABG, HEMODYNAMIC, AND VENTILATOR WAVEFORM
DATA TO GUIDE THERAPY
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 CORRECT
C. Prophylactic broad-spectrum antibiotics
D. Chest physiotherapy with postural drainage
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.
Q6 INTERPRET AND INTEGRATE ABG, HEMODYNAMIC, AND VENTILATOR WAVEFORM
DATA TO GUIDE THERAPY
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 CORRECT
C. It has no effect on mean airway pressure
D. It decreases intrinsic PEEP and improves venous return
RATIONALE: Prolonging inspiratory time raises mean airway pressure, which can recruit alveoli
and improve oxygenation, though it may also cause auto-PEEP. The other options misstate the
relationship between inspiratory time and mean airway pressure.
Page 4
